Bio-Medical Materials and Engineering - Volume 24, issue 1

Authors: Fu, Jian | Tan, Renbo

Article Type: Research Article

Abstract: X-ray phase contrast micro computed tomography (micro-CT) can non-destructively provide the internal structure information of soft tissues and low atomic number materials. It has become an invaluable analysis tool for biomedical specimens. Here an in-line phase contrast micro-CT reconstruction technique is reported, which consists of a projection extraction method and the conventional filter back-projection (FBP) reconstruction algorithm. The projection extraction is implemented by applying the Fourier transform to the forward projections of in-line phase contrast micro-CT. This work comprises a numerical study of the method and its experimental verification using a biomedical specimen dataset measured at an X-ray tube source …micro-CT setup. The numerical and experimental results demonstrate that the presented technique can improve the imaging contrast of biomedical specimens. It will be of interest for a wide range of in-line phase contrast micro-CT applications in medicine and biology. Show more

Keywords: X-ray in-line phase contrast imaging, micro computed tomography, reconstruction algorithm, X-ray tube source

DOI: 10.3233/BME-130827

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 431-437, 2014

Authors: Woo, SeongTak | Jung, EuiSung | Lim, HyungGyu | Lee, Jang Woo | Seong, Ki Woong | Won, Chul Ho | Kim, Myoung Nam | Cho, Jin Ho | Lee, Jyung Hyun

Article Type: Research Article

Abstract: Input for fully implantable hearing devices (FIHDs) is provided by an implantable microphone under the skin of the temporal bone. However, the implanted microphone can be affected when the FIHDs user chews. In this paper, a dual implantable microphone was designed that can filter out the noise from mastication. For the in vivo experiment, a fabricated microphone was implanted in a rabbit. Pure-tone sounds of 1 kHz through a standard speaker were applied to the rabbit, which was given food simultaneously. To evaluate noise reduction, the measured signals were processed using a MATLAB program based adaptive filter. To verify the …proposed method, the correlation coefficients and signal to-noise ratio before and after signal processing were calculated. By comparing the results, signal-to-noise ratio and correlation coefficients are enhanced by 6.07dB and 0.529 respectively. Show more

Keywords: Implantable microphone, in vivo experiment, adaptive filter, Mastication, fully implantable hearing devices

DOI: 10.3233/BME-130828

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 439-444, 2014

Authors: Wang, Zhigang | Tai, Lik-Ren | McLean, Donald | Wright, Emma J. | Florence, Gordon J. | Brown, Stuart I. | Andre, Pascal | Cuschieri, Alfred

Article Type: Research Article

Abstract: Safe and effective manipulation of soft tissue during laparoscopic procedures can be achieved by the use of mucoadhesive polymer films. A series of novel adhesive polymer films were formulated in house based on either Carbopol or Chitosan modified systems. The mechanical properties of the polymers and their adherence to bowel were evaluated using ex-vivo pig bowel immersed in 37°C water bath and connected to an Instron tensiometer. Young's modulus was 300 kPa for the Carbopol-polymer and 5 kPa for the Chitosan-polymer. The Chitosan-polymer exhibited much larger shear adhesion than its tensile adhesion: 3.4 N vs. 1.2. Both tensile and shear …adhesions contributed to the large retraction force (2.6 N) obtained during l polymer-bowel retraction testing. Work of adhesion at the polymer/serosa interface, defined as the area under the force curve, was 64 mJ, which is appreciably larger than that reported with existing polymers. In conclusion, adhesive polymers can stick to the serosal side of the bowel with an adhesive force, which is sufficient to lift the bowel, providing a lower retraction stress than that caused by laparoscopic grasping which induces high localized pressures on the tissue. Show more

Keywords: mucoadhesive polymer, mechanical property, adhesive force, laparoscopic surgery, bowel retraction

DOI: 10.3233/BME-130829

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 445-451, 2014

Authors: Yang, Hoe S. | Yoo, Ji W. | Lee, Bo A. | Choi, Chang K. | You, Joshua H.

Article Type: Research Article

Abstract: The present study established inter-tester and intra-tester reliabilities of ultrasound imaging and diagnostically differentiated muscle imbalances in lateral abdominal muscle sizes between normal adolescents and adolescents with idiopathic scoliosis (AIS). Fifteen adolescents with AIS were age- and gender-matched with 15 normal adolescents. There was no significant difference between bilateral abdominal muscles in normal adolescents, but there was a significant difference between bilateral abdominal muscles in adolescents with AIS (P<0.05). Overall, inter-tester and intra-tester reliabilities in normal and AIS adolescents ranged from 0.801–0.984. This novel study shows that using ultrasound imaging to measure lateral abdominal muscle thickness is: (1) highly reliable …between and within the testers; and (2) capable of distinguishing between subjects with and without pathological muscle morphology due to AIS. Show more

Keywords: Muscle thickness, Ultrasound imaging, Adolescent idiopathic scoliosis, Reliability

DOI: 10.3233/BME-130830

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 453-458, 2014

Authors: Wang, Lifang | Zhou, Xiaohua | Shen, Mingxiu | Sun, Yanping | Sun, Guifang

Article Type: Research Article

Abstract: Hemodynamics plays a crucial role in the formation, progression and rupture of intracranial aneurysms. Understanding these mechanisms is important to improve current diagnosis and treatment of intracranial aneurysms. In this study we simulate and analyze the pressure gradients and the blood flow fields in growing intracranial aneurysms. Firstly, the pressure gradients are obtained according to the blood velocity waveform at the axis of the inlet to the artery, which can be acquired by transcranial Doppler technology. Then, blood flow fields are calculated by solving the linearized Navier-Stokes equations and continuity equation using the Fourier series method. Results show that the …higher the aneurysm dilatation degree is, the lower the maximum oscillatory velocity will be. Therefore, the oscillatory velocity may be used to analyze the characteristics of blood flow signals from aneurysm and to forecast the size of aneurysm. This sensitive parameter can be utilized for the detection of vessel diseases, which is promising to provide a useful reference in clinical application. Show more

Keywords: hemodynamics, aneurysms, numerical simulation, oscillatory blood flow, pressure gradients

DOI: 10.3233/BME-130831

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 459-466, 2014

Authors: Lin, Haoming | Wang, Tianfu | Chen, Siping

Article Type: Research Article

Abstract: This paper describes a new method for shear wave velocity estimation that is capable of extruding outliers automatically without preset threshold. The proposed method is an adaptive random sample consensus (ARANDSAC) and the metric used here is finding the certain percentage of inliers according to the closest distance criterion. To evaluate the method, the simulation and phantom experiment results were compared using linear regression with all points (LRWAP) and radon sum transform (RS) method. The assessment reveals that the relative biases of mean estimation are 20.00%, 4.67% and 5.33% for LRWAP, ARANDSAC and RS respectively for simulation, 23.53%, 4.08% and …1.08% for phantom experiment. The results suggested that the proposed ARANDSAC algorithm is accurate in shear wave speed estimation. Show more

Keywords: Shear elasticity, shear wave speed, shear wave displacement, adaptive RANDSAC, radon sum

DOI: 10.3233/BME-130832

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 467-474, 2014

Authors: Wei, Qiang | Xu, Yuan-Qing | Tian, Fang-bao | Gao, Tian-xin | Tang, Xiao-ying | Zu, Wen-Hong

Article Type: Research Article

Abstract: A size-based blood cell sorting model with a micro-fence structure is proposed in the frame of immersed boundary and lattice Boltzmann method (IB-LBM). The fluid dynamics is obtained by solving the discrete lattice Boltzmann equation, and the cells motion and deformation are handled by the immersed boundary method. A micro-fence consists of two parallel slope post rows which are adopted to separate red blood cells (RBCs) from white blood cells (WBCs), in which the cells to be separated are transported one after another by the flow into the passageway between the two post rows. Effected by the cross flow, RBCs …are schemed to get through the pores of the nether post row since they are smaller and more deformable compared with WBCs. WBCs are required to move along the nether post row till they get out the micro-fence. Simulation results indicate that for a fix width of pores, the slope angle of the post row plays an important role in cell sorting. The cells mixture can not be separated properly in a small slope angle, while obvious blockages by WBCs will take place to disturb the continuous cell sorting in a big slope angle. As an optimal result, an adaptive slope angle is found to sort RBCs form WBCs correctly and continuously. Show more

Keywords: Blood cell separation, Lattice Boltzmann method, immersed Boundary, Microfludics, Cross flow

DOI: 10.3233/BME-130833

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 475-481, 2014

Authors: Zhu, Zhiwen | Zhang, Qingxin | Xu, Jia

Article Type: Research Article

Abstract: Nonlinear dynamic characteristics of shape memory alloy (SMA) intravascular stent under radial stochastic loads were studied in this paper. Von de Pol item was improved to interpret the hysteretic phenomena of SMA, and the nonlinear dynamic model of SMA intravascular stent under radial stochastic loads was developed. The conditions of stochastic stability of the system were obtained in singular boundary theory. The steady-state probability density function of the dynamic response of the system was given, and the stochastic Hopf bifurcation characteristics of the system were analyzed. Theoretical analysis and numerical simulation show that the stability of the trivial solution varies …with bifurcation parameters, and stochastic Hopf bifurcation appears in the process, which can cause stent fracture or loss. The results of this paper are helpful to application of SMA intravascular stent in biomedical engineering fields. Show more

Keywords: Shape memory alloy (SMA), intravascular stent, radial stochastic load, stochastic stability, stochastic bifurcation

DOI: 10.3233/BME-130834

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 483-489, 2014

Authors: Zhang, Chi | Wang, Ling | Li, Xiaoyun | Li, Shuyu | Pu, Fang | Fan, Yubo | Li, Deyu

Article Type: Research Article

Abstract: Circle of Willis (CoW) plays a significant role in maintaining the blood supply for the brain. Specifically, when the stenosis occurs in the internal carotid artery (ICA), abnormal structures of CoW would decrease the compensatory capacity, leading to the local insufficiency of cerebral blood supply. The present paper built a series of lumped parameter models for CoW, and simulated the blood redistribution caused by the unilateral ICA stenosis with different severities in cerebral arteries in the normal and abnormal CoW respectively. The results showed that when unilateral ICA stenosis occurred, the collateral circulation was built through the anterior communicating artery …and the ipsilateral posterior communicating artery, maintaining the flow in cerebral arteries. The absence of the two communicating arteries would cause an obvious decrease of flow in local cerebral arteries in the anterior circulation. In conclusion, the two arteries play a significant role in maintaining the balance of cerebral blood supply in the development of ICA stenosis. Show more

Keywords: Circle of Willis, internal carotid artery, stenosis, anatomical variation, lumped parameter model

DOI: 10.3233/BME-130835

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 491-499, 2014

Authors: Wang, Tianmiao | Li, Changsheng | Hu, Lei | Tang, Peifu | Zhang, Lihai | Du, Hailong | Luan, Sheng | Wang, Lifeng | Tan, Yiming | Peng, Cheng

Article Type: Research Article

Abstract: In traditional long bone fracture reduction surgery, there are some drawbacks such as low accuracy, high radiation for surgeons and a risk of infection. To overcome these disadvantages, a removable hybrid robot system is developed, which integrates a removable series-parallel mechanism with a motor-double cylinder (MDC) driven mode. This paper describes the mechanism in detail, analyses the principle and the method of the fracture reduction, presents the surgical procedure, and verifies the reduction accuracy by experiments with bone models. The results are shown as follows. The mean deviations of the axial displacement and lateral displacement are 1.60mm and 1.26mm respectively. …The standard deviations are 0.69mm and 0.30mm. The mean deviations of the side angle and turn inward are 2.06° and 2.22° respectively. The standard deviations are 0.50° and 0.99°. This minimally invasive robot features high accuracy and zero radiation for surgeons, and is able to conduct fracture reduction for long bones. Show more

Keywords: Hybrid robot, fracture reduction, long bone, surgical robot

DOI: 10.3233/BME-130836

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 501-509, 2014

Authors: Luan, Sheng | Sun, Lei | Hu, Lei | Hao, Aimin | Li, Changsheng | Tang, Peifu | Zhang, Lihai | Du, Hailong

Article Type: Research Article

Abstract: This paper presents a compact orthopedic robot designed with modular concept. The layout of the modular configuration is adaptive to various conditions such as surgical workspace and targeting path. A biplanar algorithm is adopted for the mapping from the fluoroscopic image to the robot, while the former affine based method is satisfactory only when the projection rays are basically perpendicular to the reference coordinate planes. This paper introduces the area cross-ratio as a projective invariant to improve the registration accuracy for non-orthogonal orientations, so that the robotic system could be applied to more orthopedic procedures under various C-Arm orientation conditions. …The system configurations for femoral neck screw and sacroiliac screw fixation are presented. The accuracy of the robotic system and its efficacy for the two typical applications are validated by experiments. Show more

Keywords: Medical robotics, projective invariant, modular design

DOI: 10.3233/BME-130837

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 511-518, 2014

Authors: Liu, Hongying | Qiao, Panpan | Wu, Xueli | Wang, Li | Ao, Yilu | Jia, Ziru | Pi, Xitian

Article Type: Research Article

Abstract: Prior research indicated that occult blood screening can be used to detect early gastric cancer. Based on capsule endoscopy and occult blood detection theory, an automatic detection capsule system for gastric occult blood (GOB) was proposed. This paper designed the detecting sensor, image acquisition system and wireless transmitter module respectively based on collaurum immune theory, the image sensor and radio frequency chip. In vitro experiments were conducted to testify the system, and the detecting result image information was acquired by the image acquisition (IMAQ) system and transmitted to the outside of the body through the wireless transmitter module. The receiver …module received and displayed the information on the computer, from which doctors could diagnose whether there was occult blood (OB) or not. Therefore, this paper provides a new idea for the screening of early-stage gastric cancer with reliability and simplicity. Show more

Keywords: smart capsule system, gastric occult blood, imaging sensor, image acquisition, wireless transmission

DOI: 10.3233/BME-130838

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 519-528, 2014

Authors: Deng, Xin | Xu, Jian-Xin

Article Type: Research Article

Abstract: This paper provides an undulatory locomotion model inspired by C. elegans, whose nervous system and muscular structure are well studied. C. elegans is divided into 11 muscle segments according to its anatomical structure, and represented as a multi-joint rigid link model in this work. In each muscle segment, there are four pieces of muscles located in four quadrants. The muscles change their lengths according to the outputs of nervous system. In this work, the dynamic neural networks (DNN) are adopted to represent the nervous system. The DNN are divided into the head DNN and the body DNN. The head DNN …produces the sinusoid waves to generate the forward and backward undulatory movements. The body DNN with 11 segments is responsible for passing the sinusoid wave and creating the phase lag. The 3D locomotion of this system are implemented by using the DNN to control the muscle lengths, and then using the muscle lengths to control the angles between two consecutive links on both horizontal and vertical planes. The test results show good performances of this model in both forward and backward locomotion in 3D, which could serve as a prototype of the micro-robot for clinical use. Show more

Keywords: C. elegans, dynamic neural networks, locomotion, 3D

DOI: 10.3233/BME-130839

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 529-537, 2014

Authors: Chen, Kan | Li, Bin | Tian, Lian-fang | Zhu, Wen-bo | Bao, Ying-han

Article Type: Research Article

Abstract: Pulmonary nodules are potential manifestation of lung cancer. Accurate segmentation of juxta-vascular nodules and ground glass opacity (GGO) nodules is an important and active area of research in medical image processing. At present, the classical active contour models (ACM) for segmentation of pulmonary nodules may cause the problem of boundary leakage. In order to solve the problem, a new fuzzy speed function–based active model for segmentation of pulmonary nodules is proposed in this paper. The fuzzy speed function incorporated into the ACM is calculated by the degree of membership based on intensity feature and local shape index. At the boundary …of pulmonary nodules, the fuzzy speed function approaches zero and the evolution of the contour curve will stop, so the accurate segmentation of pulmonary nodules can be obtained. Experimental results on juxta-vascular nodules and GGO nodules show that the proposed ACM can achieve accurate segmentation. Show more

Keywords: Image segmentation, boundary leakage, active contour models (ACM), fuzzy speed function, fuzzy clustering

DOI: 10.3233/BME-130840

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 539-547, 2014

Authors: Li, Jing | Ji, Zhenyu | Shi, Xuetao | You, Fusheng | Fu, Feng | Liu, Ruigang | Xia, Junying | Wang, Nan | Bai, Jing | Wang, Zhanxi | Qin, Xiansheng | Dong, Xiuzhen

Article Type: Research Article

Abstract: Skeletal muscle exhibiting complex and excellent precision has evolved for millions of years. Skeletal muscle has better performance and simpler structure compared with existing driving modes. Artificial muscle may be designed by analyzing and imitating properties and structure of skeletal muscle based on bionics, which has been focused on by bionic researchers, and a structure mode of linear electromagnetic array artificial muscle has been designed in this paper. Half sarcomere is the minimum unit of artificial muscle and electromagnetic model has been built. The structural parameters of artificial half sarcomere actuator were optimized to achieve better movement performance. Experimental results …show that artificial half sarcomere actuator possesses great motion performance such as high response speed, great acceleration, small weight and size, robustness, etc., which presents a promising application prospect of artificial half sarcomere actuator. Show more

Keywords: Artificial muscle, electromagnetic actuator, series-parallel array, multi-object optimization, finite element

DOI: 10.3233/BME-130841

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 549-555, 2014

Authors: Guo, Qiaohang | Zheng, Huang | Chen, Wenzhe | Chen, Zi

Article Type: Research Article

Abstract: Bistable structures, exemplified by the Venus flytrap and slap bracelets, can transit between different configurations upon certain external stimulation. Here we study, through three-dimensional finite element simulations, the bistable behaviors in elastic plates in the absence of terminate loads, but with pre-strains in one (or both) of the two composite layers. Both the scenarios with and without a given geometric mis-orientation angle are investigated, the results of which are consistent with recent theoretical and experimental studies. This work can open ample venues for programmable designs of plant/shell structures with large deformations, with applications in designing bio-inspired robotics for biomedical research …and morphing/deployable structures in aerospace engineering. Show more

Keywords: Bistability, elasticity theory, finite element analysis, geometric nonlinearity, biomimetic structures

DOI: 10.3233/BME-130842

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 557-562, 2014

Authors: Stasiak, Joanna | Nair, Sukumaran | Moggridge, Geoff D.

Article Type: Research Article

Abstract: The mechanical behavior of three styrenic thermoplastic block copolymer elastomers with applied surgical sutures was studied by uniaxial tensile testing. The materials exhibited oriented cylindrical microstructure. Distinct macroscopic deformation mechanisms have been observed upon stretching of samples with vertical and horizontal orientation. Deformation progressed along the axis of the suture in samples with parallel orientation (P), while it in case of normal orientation (N) the whole sample responded to the applied force. Also the analysis of the stress–strain curves showed a significant difference between samples P and N. Greater stress at break was observed for samples P, while samples N …showed the capability to tolerate higher strain. The influence of morphology on the tear-out shape has been also observed. The thread made a vertical tear out in samples P while for samples N ripping off the bottom was observed. Show more

Keywords: biomaterials, heart valves, sutures, mechanical behavior

DOI: 10.3233/BME-130843

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 563-569, 2014

Authors: Jang, Dong-Jin | Kim, Sung Tae | Oh, Euichaul | Ban, Eunmi

Article Type: Research Article

Abstract: To develop a solid dosage form of dutasteride for improving its oral bioavailability, a novel dry elixir (DE) system was fabricated. DEs incorporating dextrin and/or xanthan gum were prepared using spray-drying and evaluated by morphology, ethanol content, crystallinity, dissolution and oral bioavailability. DEs were spherical with a smooth surface and had an average particle size of 20–25 μm. The ethanol content could be easily varied by controlling the spray-drying temperature. The dissolution profiles of dutasteride from each DE proved to be much faster than that of dutasteride powder due to the amorphous state and a high amount of incorporated ethanol. …In particular, the pharmacokinetic profiles of dutasteride were significantly altered depending on the proportions of dextrin and xanthan gum. Blood concentrations of dutasteride from DE formulations were similar to those of market products and much greater than those of native dutasteride. Interestingly, the dissolution and pharmacokinetic profiles were easily controlled by changing the ratio of dextrin to xanthan gum. The data suggests that a DE using dextrin and/or xanthan gum could provide an applicable solid dosage form to improve the dissolution and bio-availability of dutasteride as well as to modulate its pharmacokinetics. Show more

Keywords: Dutasteride, dry elixir, xanthan gum, dissolution, oral bioavailability

DOI: 10.3233/BME-130844

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 571-579, 2014

Authors: Marin, E. | Offoiach, R. | Lanzutti, A. | Regis, M. | Fusi, S. | Fedrizzi, L.

Article Type: Research Article

Abstract: Titanium alloys are nowadays used for a wide range of biomedical applications thanks to their combination of high mechanical resistance, high corrosion resistance and biocompatibility. Nevertheless, the applicability of titanium alloys is sometimes limited due to their low microhardness and tribological resistance. Thus the titanium alloys cannot be successfully applied to prosthetic joint couplings. A wide range of surface treatments, in particular PVD coatings such as CrN and TiN, have been used in order to improve the tribological behaviour of titanium alloys. However, the low microhardness of the titanium substrate often results in coating failure due to cracks and delamination. …For this reason, hybrid technologies based on diffusive treatments and subsequent PVD coatings may improve the overall coating resistance. In this work, conventional PVD coatings of CrN or TiCN, deposited on Titanium Grade 5, were characterized and then combined with a standard thermal diffusive nitriding treatment in order to improve the tribological resistance of the titanium alloys and avoid coating delamination. The different treatments were studied by means of scanning electron microscopy both on the sample surface and in cross-section. In-depth composition profiles were obtained using glow discharge optical emission spectrometry (GDOES) and localized energy dispersive X-ray diffraction on linear scan-lines. The microhardness and adhesion properties of the different treatments were evaluated using Vickers microhardness tests at different load conditions. The indentations were observed by means of SEM in order to evaluate delaminated areas and the crack's shape and density. The tribological behaviour of the different treatments was tested in dry conditions and in solution, in alternate pin-on-flat configuration, with a frequency of 0.5 Hz. After testing, the surface was investigated by means of stylus profilometry and SEM both on the surface and in cross-section. The standalone PVD coatings show a limited tribological resistance due to the low hardness of the substrate, which results in fractures and delamination. The combination of a diffusive process and a subsequent PVD coating shows a stronger effect in improving the tribological resistance of the substrate. Show more

Keywords: Ti-6Al-4V, PVD, titanium hardening, nitridation, TiN

DOI: 10.3233/BME-130845

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 581-592, 2014

Authors: Noh, Dong K. | Lee, Nam G. | You, Joshua H.

Article Type: Research Article

Abstract: This study highlights a novel spinal kinematic analysis method and the feasibility of X-ray imaging measurements to accurately assess thoracic spine motion. The advanced X-ray Nash-Moe method and analysis were used to compute the segmental range of motion in thoracic vertebra pedicles in vivo. This Nash-Moe X-ray imaging method was compared with a standardized method using the Vicon 3-dimensional motion capture system. Linear regression analysis showed an excellent and significant correlation between the two methods (R2 = 0.99, p < 0.05), suggesting that the analysis of spinal segmental range of motion using X-ray imaging measurements was accurate and comparable …to the conventional 3-dimensional motion analysis system. Clinically, this novel finding is compelling evidence demonstrating that measurements with X-ray imaging are useful to accurately decipher pathological spinal alignment and movement impairments in idiopathic scoliosis (IS). Show more

Keywords: Accuracy, X-ray imaging, spinal kinematics, idiopathic scoliosis

DOI: 10.3233/BME-130846

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 593-598, 2014

Authors: Miao, Feng-qin | An, Yan-li | Yang, Rui | Tang, Qiu-sha | Zhang, Jian-qiong

Article Type: Research Article

Abstract: This paper aimed to investigate the preparation of doxorubicin-loaded bovine serum albumin nanoparticles (DOX/BSANP) and their effect on killing liver cancer cells in vitro and in vivo. DOX/BSANP was prepared using a desolvation-chemical crosslinking method. Their morphology and particle size were observed using transmission electron microscopy (TEM). The envelopment, drug-loading rates and slow-release characteristics were determined spectrophotometrically. Their ability to kill liver cancer cells in vitro was determined using the methyl thiazolyl tetrazolium (MTT) assay and flow cytometry (FCM). The tumor-suppressing effect of the nanoparticles in experimental animals in vivo was also evaluated. Under TEM, DOX/BSANP appeared spherical and was …distributed uniformly, with a diameter of about 120 nm and hydrated particle size of 170 nm determined by dynamic light diffraction. The envelopment rate was 82% and the drug-loading rate was 11.2%. The in vitro drug-release experiment showed that about 50% of the drug in drug-loaded nanoparticles was released continuously and slowly for 7 days. The MTT assay showed that DOX/BSANP significantly inhibited cell proliferation, while FCM showed that it induced tumor cell apoptosis. The in vivo tumor suppression test showed that the therapeutic effect of drug-loaded nanoparticles was superior to that of DOX alone. Show more

Keywords: DOX, albumin nanoparticles, desolvation-chemical crosslinking, liver cancer

DOI: 10.3233/BME-130847

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 599-607, 2014

Authors: Dlugosz, Tomasz

Article Type: Research Article

Abstract: The aim of this paper is to focus attention of experimenters on several sources of error that are not taken into account in the majority of bioelectromagnetics experiments, and which may lead to complete falsification of the results of the experiments.

Keywords: Electromagnetic field measurements, exposure systems, bioelectromagnetics studies, biomedical engineering

DOI: 10.3233/BME-130848

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 609-617, 2014

Authors: Li, Jia | Zheng, Wei | Pan, Ping | Sun, Xiaojun | Zhang, Yanfei

Article Type: Research Article

Abstract: In this paper, citric acid, 1,8-octanediol and 1,2-propanediol were used as reactive monomers to synthesize poly(1,2-propanediol-co-1,8-octanediol-co-citrate) (PPOC) elastomers by melt polycondensation. The PPOC elastomers were characterized by FTIR, 1H-NMR, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), hydrophilic test and mechanical test. The results indicated that citric acid had reacted with 1,8-octanediol and 1,2-propanediol, respectively. The sol content, swelling degree and hydrophilicity of PPOC elastomers increased with the higher content of 1,2-propanediol, while the tensile strength and the thermal degradation temperature decreased. The results indicate the addition of 1,2-propanediol reduces the crosslinking density and the flexibility of PPOC elastomers.

Keywords: Poly(1,2-propanediol-co-1,8-octanediol-co-citrate), 1,2-propanediol, elastomer

DOI: 10.3233/BME-130849

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 619-624, 2014

Authors: Wang, Xian-Kang | Ye, Jin-Duo | Gu, Fu-Shun | Wang, Ai-guo | Zhang, Chun-Qiu | Tian, Qian-Qian | Li, Xue | Dong, Li-Min

Article Type: Research Article

Abstract: In this paper, the single arm external fixation of intertrochanteric fracture healing process after surgery was simulated to obtain a postoperative fracture healing and stress distribution in the external fixator. Firstly CT images of intertrochanteric fracture are reconstructed into the femur solid model. Then based, the external fixator is installed on the model, which lastly formed a finite element model of unilateral external fixation for intertrochanteric fracture. The calculated results show: during the beginning of the fracture healing, there is much higher stress in both screws and femur in the model with solid screws than that in the model with …hollow screw. The stress of the femur in the model with hollow screw is more evenly. During the middle time of Fracture healing, stress in the femoral head significantly decreases. And the stress at fracture site gradually increased with the healing occurrence. According to the results, the authors designed hollow screws to use external fixation surgery. Surgery confirmed that the use of hollow screws in fractures treatment can satisfy the strength requirements, and can effectively reduce operative time, less patient suffering. The research for external fixation can provide a reference, and promote the use of external fixation hollow screws. Show more

Keywords: single arm external fixation, the femoral intertrochanteric fracture, stress distribution, numerical simulation, surgery scheme

DOI: 10.3233/BME-130850

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 625-632, 2014

Authors: Zhao, Peng | Deng, Cuijun | Xu, Hongzhen | Tang, Xing | He, Hailong | Lin, Chao | Su, Jiansheng

Article Type: Research Article

Abstract: Photo-crosslinked chitosan-gelatin scaffolds were fabricated and applied for chondrocyte culture in vitro. Photocurable methacryloyl chitosan was synthesized and characterized by FTIR and 1H NMR, respectively. Microstructure and mechanical properties of the chitosan-gelatin scaffold treated with or without EDC as crosslinking agent were analyzed by scanning electronic microscopy (SEM), compression and viscoelastic measurement. It is demonstrated that EDC-treated chitosan-gelatin scaffold possesses better porous structure and improved mechanical properties. Photo-crosslinked chitosan-gelatin scaffold could be further integrated in sodium alginate hydrogel using calcium chloride to support proliferation of chondrocytes for over 21 days and maintain spherical phenotype, as evaluated by AlamarBlue assay and …SEM, respectively, implying that the chitosan-gelatin-hydrogel system exhibits great cyto-biocompatibility. Results of this study show that photo-crosslinked chitosan-gelatin scaffold in sodium alginate hydrogel is suited as a scaffold candidate for cartilage tissue engineering. Show more

Keywords: chitosan, gelatin, chondrocyte, hydrogel, cartilage tissue engineering

DOI: 10.3233/BME-130851

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 633-641, 2014

Authors: Wang, Min | Ning, Yingyuan | Zou, Haixiao | Chen, Si | Bai, Yi | Wang, Aihua | Xia, Haibin

Article Type: Research Article

Abstract: Ti6Al4V discs with a thickness of 2.5 mm and dimensions of 15 × 15 mm2 were fabricated. The titanium nitride (TiN) surface was formed via Nd:YAG laser-nitriding. A sandblast acid-etched (SA) surface was used as a control. Scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and surface roughness tests were conducted to study the surface and cross-section morphologies as well as the properties of TiN and SA surfaces. MC3T3-E1 osteoblast-like cells were cultured on the TiN and SA surfaces to evaluate the effect of TiN surface on cellular behaviors, including attachment, proliferation and differentiation. Morphological testing results revealed that …the cross-section of TiN exhibited dendritic crystallization without cracking. The proliferation and differentiation of MC3T3-E1 cells on the laser-nitriding TiN surface were significantly increased compared to those cultured on SA surface. These findings suggested that the TiN surface generated from Nd:YAG laser-nitriding were favorable for the proliferation and differentiation of MC3T3-E1 cells, which is significant for implant surface modification. Show more

Keywords: laser-nitriding, TiN surface, MC3T3-E1 cells, adhesion, differentiation

DOI: 10.3233/BME-130852

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 643-649, 2014

Authors: Wang, Haiyan | Lin, Derong | Wang, Di | Hu, Lijiang | Huang, Yudong | Liu, Li | Loy, Douglas A.

Article Type: Research Article

Abstract: Sunscreens that absorb UV light without photodegradation could reduce skin cancer. Polyvinyl silsesquioxanes are known to have greater thermal and photochemical stability than organic compounds, such as those in sunscreens. This paper evaluates the UV transparency of vinyl silsesquioxanes (VS) and its hybrids with SiO2(VSTE) and TiO2(VSTT) experimentally and computationally. Based on films of VS prepared by sol-gel polymerization, using benzoyl peroxide as an initiator, vinyltrimethoxysilane (VMS) formulated oligomer through thermal curing. Similarly, VSTE films were prepared from VMS and 5–25 wt-% tetraethoxysilane (TEOS) and VSTT films were prepared from VMS and 5–25 wt-% titanium tetrabutoxide (TTB). Experimental average transparencies …of the modified films were found to be about 9–14% between 280–320 nm, 67–73% between 320–350nm, and 86–89% between 350–400nm. Computation of the band gap was absorption edges for the hybrids in excellent agreement with experimental data. VS, VSTE and VSTT showed good absorption in UV-C and UV-B range, but absorbed virtually no UV-A. Addition of SiO2 or TiO2 does not improve UV-B absorption, but on the opposite increases transparency of thin films to UV. This increase was validated with molecular simulations. Results show computational design can predict better sunscreens and reduce the effort of creating sunscreens that are capable of absorbing more UV-B and UV-A. Show more

Keywords: Silsesquioxane, silica, titanium dioxide, hybrid films, ultraviolet region, sunscreen, computation of band gap

DOI: 10.3233/BME-130853

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 651-657, 2014

Authors: Wu, Ming-Yue | Li, Quan-Li | Chen, Lian-Zi

Article Type: Research Article

Abstract: In this study, orthophosphoric acid (H3 PO4 ) in the treatment of porous titanium (Ti) is investigated and the ability of rat bone marrow stromal cells (BMSCs) is assessed to proliferate and differentiate on these modified surfaces in vitro. To improve the cytocompatibility of Ti surfaces, pure Ti was activated commercially by simple chemical pretreatment in H3 PO4 with different densities. Next, the phosphorylated specimens were soaked in simulated body fluid (SBF) to study the effect of biomineralization. The3-[4,5-dimethylthiazol-2-y1]-2, 5-diphenytetrazolium bromide (MTT) assay and the measurement of alkaline phosphatase (ALP) activity utilized to assess proliferation and differentiation of BMSCs …on exposure to modified Ti surfaces. Scanning electron microscopic (SEM) images showed that the surfaces of the pre-treated samples were characterized by a complex structure which consisted of a mesh-like morphological matrix and an uniform surface with different morphic crystals of titanium dihydrogen orthophosphate (Ti(H2 PO4 )3 ). These crystals contained hydroxyl with phosphate residues that resulted in biomineralization of cells. Therefore, BMSCs reveales a well-dispersed morphology on these modified and functionalized Ti surfaces. The viability and ALP activity of BMSCs on these altered biomimetic surfaces are found to be greater than those of the controls. It is concluded that the treatment of Ti by acid etching in orthophosphoric acid is a suitable method to enhance the in vitro proliferation and differentiation of BMSCs. Show more

Keywords: titanium implant, phosphorylation, cytocompatibility, stem cells, biomaterials, cellular engineering

DOI: 10.3233/BME-130854

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 659-671, 2014

Authors: Lin, Chao | Song, Yanyan | Lou, Bo | Zhao, Peng

Article Type: Research Article

Abstract: A dextranated, bioreducible cationic polyamide was designed and employed for non-viral gene delivery in vitro and in vivo. Initially, a new bioreducible cationic polyamide with p-nitrophenyl ester terminal group (denoted as SSBAP) was synthesized by polycondensation reaction of an excess amount of bis-(p-nitrophenyl)-3, 3'-dithiodipropanoate and 1, 4-bis(3-aminopropyl)piperazine. The SSBAP was then chemically conjugated with 5kDa amino-terminated dextran to yield dextran-SSBPA-dextran triblock copolymer (denoted as Dex-SSBAP-Dex). This copolymer was capable of binding genes to form nanoscale polyplexes with a near-neutral surface charge. Moreover, a sufficient gene release from the polyplexes in response to an intracellular reducing environment was observed. In vitro …transfection against MCF-7 and SKOV-3 cells showed that Dex-SSBAP-Dex copolymer effectively transfected the cells with comparable efficiency to that of 25kDa branched or linear polyethylenimine as positive controls. Besides, intravenous administration of the copolymer-based polyplexes in nude mice afforded detectable gene expression largely in the lung. Importantly, the copolymer revealed low cytotoxicity in vitro, as determined by AlamarBlue assay, and caused no death of the mice. Dextranated, bioreducible cationic polyamide holds high potential as a non-viral vector for gene delivery. Show more

Keywords: Dextran, disulfide, gene delivery, transfection, in vivo

DOI: 10.3233/BME-130855

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 673-682, 2014

Authors: Qu, Z.W. | Meng, Q.G. | Xiao, X. | Li, B.L. | Zhang, F.M.

Article Type: Research Article

Abstract: A high degree of cell adhesion to a scaffold at the initial stage of cell inoculation is essential to bone tissue engineering. In realising high cell adhesion rate on a scaffold within a few hours, a chitosan/hydroxyapatite (CS/HA) scaffold with a channel/sphere pore was prepared via in situ hybridisation in combination with lyophilisation, in which the HA nanoparticles were dispersed in the CS uniformly. The size of the channel pore and the sphere pore of the CS/HA scaffold was 150 μm to 650 μm and 3 μm to 15 μm, respectively. The compression strength and porosity of the CS/HA scaffold …were 3.54±0.32 MPa and 88.4%, respectively. The nitrogen content increased by 7.5% compared with the CS/HA scaffold without Arg-Gly-Asp (RGD) modification. More than 67% of the RGD in the PBS solution diffused into the CS/HA scaffold spontaneously. The effect of the RGD peptide on bone marrow mesenchymal stem cells (MSCs) on the CS/HA scaffold was investigated through cell adhesion rate, alkaline phosphatase (ALP) activity, and mineralised calcium nodules. The cell adhesion rates of the CS/HA scaffold with different RGD concentrations (50, 100 mg/L) were 71.6% and 80.7%, respectively, after 4 hours of culture; the rates were 30.9% and 47.5% higher than that of the CS/HA group (54.7%), respectively. The expressed ALP content of the CS/HA scaffold with RGD (191±6 U/g protein) was 107.7% higher than that (92±9U/g protein) of CS/HA (p<0.01). Furthermore, a higher amount of mineralised calcium nodules with red brown appeared in the CS/HA scaffold with RGD as opposed to that in the CS/HA group. The RGD peptide in the CS/HA scaffold not only achieved high cell adhesion in a short period of time, but also enhanced cell adhesion ability and promoted the MSCs to differentiate from osteoblasts. Show more

Keywords: RGD peptides, Chitosan, Hydroxyapatite, Bone Marrow Mesenchymal Cells, Tissue engineering

DOI: 10.3233/BME-130856

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 683-693, 2014

Authors: Yu, Deng-Guang | Li, Xiao-Yan | Chian, Wei | Li, Ying | Wang, Xia

Article Type: Research Article

Abstract: The influence of different types of solvents as sheath fluids on the quality of electrospun ethyl cellulose (EC) nanofibers is investigated in this paper by a modified coaxial process. With 24 w/v % EC in ethanol as electrospinning core fluid and pure solvents including methanol, ethanol and N,N-dimethyl formamide (DMF) as sheath fluids, EC nanofibers were generated by the modified processes. Field emission scanning electron microscope observations demonstrate that the modified process is effective in improving the nanofibers' quality in terms of nanofibers' diameters, distributions and structural uniformity. The key of the modified coaxial process is the reasonable selection of …the sheath solvents that is suitable for the drawing process of core EC fluid during the electrpospinning. The EC nanofibers' diameters (D, nm) could be manipulated through the reasonable selection of the type of the sheath solvents based on their boiling point (T, °C) D = 841–3.71T (R=0.9753). This paper provides useful methods for the implementation of the modified coaxial process controllably to obtain polymer nanofibers with high quality. Show more

Keywords: Coaxial electrospinning, sheath solvent, nanofibers, quality, ethyl cellulose

DOI: 10.3233/BME-130857

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 695-701, 2014

Authors: Tang, Wenwei | Xia, Jin | Zeng, Xinping | Wu, Lujun | Ye, Guoqing

Article Type: Research Article

Abstract: A new manganese-oxidizing strain FM-2 was screened out from biological activated carbon (BAC) filter column and was identified as Citrobacter freundii. The results of the systematic study on this species are as follows: At 27°C, the optimum pH for Citrobacter sp. FM-2 to remove manganese was 7.0–8.0.The best removal rate of manganese under 27°C, pH 7.0 by FM-2 was reached at 4 d, being 76.2%; Compared with adsorption, biological oxidation played a dominant role in this removing process. Almost 75.7% of manganese was oxidized into oxides by Citrobacter sp and there were some particular oxides analogs generated on the bacterial …surface; A 296bp DNA fragment amplified from Citrobacter sp. FM-2 revealed that this species has multicopper oxidase genes. Meanwhile, the phylogenetic tree indicated that compared with other related species, Citrobacter sp. FM-2 has its own evolutional independence. Show more

Keywords: manganese-oxidizing strain, Citrobacter freundii, multicopper oxidase, evolutional independence

DOI: 10.3233/BME-130858

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 703-709, 2014

Authors: Tang, Qiusha | Chen, Daozhen

Article Type: Research Article

Abstract: This paper aimed to investigate the treatment efficiency of 188 Re labeled folate targeting albumin nanoparticles with cis-Diamminedichloroplatinum Cisplatin (188 Re-folate-CDDP/HAS MNP) on human ovarian cancer. SKOV3 cells or tumor-bearing mice were divided into different groups and treated as follow: (A) negative control; (B) chemotherapy; (C) radiotherapy; (D) hyperthermia; (E) chemotherapy and radiotherapy; (F) chemotherapy and hyperthermia; (G) radiotherapy and hyperthermia; (H) chemotherapy, radiotherapy and hyperthermia. Treatment of B to H inhibited proliferation of SKOV3 cells, with the greatest inhibition being observed in group H (P<0.05). Obvious apoptotic hypodiploid peak appeared beside G1 phase in groups of B …to H. The apoptotic rates of SKOV3 cells in groups of A to H were 0.08%, 7.56%, 8.64%, 17.14%, 21.64%, 23.77%, 33.94% and 57.16%, respectively. Our findings in vivo study showed that the mass of tumor in each group of B to H was significantly lower than that in the negative control (p <0.05). In addition, compared with each group of B to G, group H showed highest inhibition of tumor growth (p<0.05). In conclusion, the combination of magnetic induced hyperthermia, chemotherapy and targeted radionuclide of radiation exposure can effectively inhibit the growth of ovarian cancer, which indicates a potential applications in ovarian cancer treatment. Show more

Keywords: Cisplatin, folic acid, albumin magnetic nanoparticles, 188Reovarian cancer, combinated therapy

DOI: 10.3233/BME-130859

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 711-722, 2014

Authors: Kang, Can | Huang, Qifeng | Li, Yunxiao

Article Type: Research Article

Abstract: Rotary blood pump (RBP) is a kind of crucial ventricular assist device (VAD) and its advantages have been evidenced and acknowledged in recent years. Among the factors that influence the operation performance and the durability of various rotary blood pumps, medium property and the flow features in pump's flow passages are conceivably significant. The major concern in this paper is the fluid dynamics aspects of such a kind of miniaturized pump. More specifically, the structural features of axial-flow blood pump and corresponding flow features are analyzed in detail. The narrow flow passage between blade tips and pump casing and the …rotor-stator interaction (RSI) zone may exert a negative effect on the shear stress distribution in the blood flow. Numerical techniques are briefly introduced in view of their contribution to facilitating the optimal design of blood pump and the visualization of shear stress distribution and multiphase flow analysis. Additionally, with the development of flow measurement techniques, the high-resolution, effective and non-intrusive flow measurement techniques catering to the measurement of the flows inside rotary blood pumps are highly anticipated. Show more

Keywords: Axial-flow pump, ventricular assist device, flow, rotor-stator interaction, numerical simulation

DOI: 10.3233/BME-130860

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 723-729, 2014

Authors: Yang, Mingying | Shuai, Yajun | Zhou, Guanshan | Mandal, Namita | Zhu, Liangjun

Article Type: Research Article

Abstract: Antheraea pernyi (A. pernyi) silk fibroin, which is spun from a wild silkworm, has increasingly attracted interest in the field of tissue engineering. The aim of this study was to investigate the nucleation of hydroxyapatite (HAp) on A. pernyi fibroin film. Von Kossa staining proved that A. pernyi fibroin had Ca binding activity. The A. pernyi fibroin film was mineralized with HAp crystals by alternative soaking in calcium and phosphate solutions. Spherical crystals were nucleated on the A. pernyi fibroin film according to scanning electron microscopeimaging results. The FT-IR and X-ray diffraction spectra confirmed that these spherical crystals were HAp. …The results of in vitro cell culture using MG-63 cells demonstrated that the mineralized A. pernyi fibroin film showed excellent cytocompatibility and sound improvement of the MG-63 cellviability. Show more

Keywords: Antheraea pernyi fibroin, hydroxyapatite, mineralization, cell culture

DOI: 10.3233/BME-130861

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 731-740, 2014

Authors: Zhu, Deyi | Jin, Liqiang | Wang, Xuemei | Xu, Li | Liu, Tianqi

Article Type: Research Article

Abstract: The objective of this work was to evaluate the effect of decellularization and hyaluronic acid derivative on the improvement of anticalcification of glutaraldehyde fixed bovine pericardium (GFBP) using a rat subcutaneous implantation model A cell extraction process was employed to remove the cells and cellular components from bovine pericardium (BP), leaving a framework of largely insoluble collagen. Then acellular BP was cross-linked by glutaraldehyde solution and treated with hyaluronic acid derivative (HA-ADH) which was obtained by coupling adipic dihydrazide (ADH) on–COOH of hyaluronic acid (HA). The results of in vivo calcification tests showed that the calcium content was decreased dramatically …by decellularization alone (from 28.07±18.87 to 2.44±0.55μg Ca/mg dry tissue after 8 weeks' implantation), and even less concentration was shown by the combination of HA derivative treatment and decellularization (GFaBP-HA group) (0.25±0.08μg Ca/mg dry tissue after 8 weeks' implantation). In addition, GFaBP-HA group not only presented a lower degree of calcification, but also showed lower ratios of Ca/P molar, which corresponded to amorphous calcium phosphates. The obtained results indicated that GFaBP-HA was a potential candidate for the manufacture of anticalcification bioprostheses. Show more

Keywords: Glutaraldehyde fixed bovine pericardium, anticalcification, decellularization, hyaluronic acid derivative

DOI: 10.3233/BME-130862

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 741-749, 2014

Authors: Wu, Gang | Chen, Long | Li, Hong | Wang, Ying-jun

Article Type: Research Article

Abstract: Hyaluronic acid (HA) was used as an internal phase additive to improve the loading efficiency of ofloxacin, a hydrophilic drug encapsulated by hydrophobic polylactic-co-glycolic acid (PLGA) materials, through a double emulsion (water-in-oil-in-water) solvent extraction/evaporation method. Results from laser distribution analysis show that polyelectrolyte additives have low impact on the average particle size and distribution of the microspheres. The negatively charged HA increases the drug loading efficiency as well as the amount of HA in microspheres. Burst release can be observed in the groups with the polyelectrolyte additives. The release rate decreases with the amount of HA inside the microspheres in …all negatively charged polyelectrolyte-added microsphere groups. Show more

Keywords: Drug release, microsphere, ofloxacin, hyaluronic acid

DOI: 10.3233/BME-130863

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 751-756, 2014

Authors: Liu, Hsia-Wei | Huang, Ching-Cheng

Article Type: Research Article

Abstract: New designed combined products and its determination for pain management and cancer treatment were studied. A rapid and sensitive stability indicating HPLC method had been developed and validated for the determination of Indomethacin(IDM) in a transdermal patch. This analytical method was successfully applied to the determination of Indomethacin in a transdermal patch and can be used for routine quality control analysis. Chromatographic separation was achieved isocratically on an Inertsil® C8-3 column utilizing a mobile phase of acetonitrile / 0.01 M monobasic sodium phosphate and 0.01M dibasic sodium phosphate buffer (pH 3) (65:35, v/v) at the flow rate of 1 mL/min …with UV detection at the wavelength of 210 nm. The system suitability was performed, and the result showed that Indomethacin(IDM) and its impurity were separated. The calibration curve of Indomethacin(IDM) was linear in the range of 0.1~15 ppm (r = 0.9989, n = 3). Show more

Keywords: Controlled release, HPLC, Indomethacin, transdermal route, drug delivery

DOI: 10.3233/BME-130864

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 757-762, 2014

Authors: Sun, Lin | Xu, Jiucheng

Article Type: Research Article

Abstract: Feature selection is a key problem in tumor classification and related tasks. This paper presents a tumor classification approach with neighborhood rough set-based feature selection. First, some uncertainty measures such as neighborhood entropy, conditional neighborhood entropy, neighborhood mutual information and neighborhood conditional mutual information, are introduced to evaluate the relevance between genes and related decision in neighborhood rough set. Then some important properties and propositions of these measures are investigated, and the relationships among these measures are established as well. By using improved minimal-Redundancy-Maximal-Relevancy, combined with sequential forward greedy search strategy, a novel feature selection algorithm with low time complexity …is proposed. Finally, several cancer classification tasks are demonstrated using the proposed approach. Experimental results show that the proposed algorithm is efficient and effective. Show more

Keywords: Feature selection, neighborhood rough set, mutual information, tumor classification

DOI: 10.3233/BME-130865

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 763-770, 2014

Authors: Jung, Gu-In | Kim, Ji-Sun | Lee, Tae-Hee | Choi, Ju-Hyeon | Oh, Han-Byeol | Kim, A-Hee | Eom, Gwang-Moon | Lee, Jeong-Hwan | Chung, Soon-Cheol | Park, Jong-Rak | Lee, Young-Jae | Park, Hee-Jung | Jun, Jae-Hoon

Article Type: Research Article

Abstract: For diagnostic and therapeutic purposes, the joint angle measurement of a patient after an accident or a surgical operation is significant for monitoring and evaluating the recovering process. This paper proposed an optical fiber sensor for the measurement of angular displacement. The effect of beveled fiber angle on the detected light signal was investigated to find an appropriate mathematical model. Beveled fiber tips redirected the light over a range of angles away from the fiber axis. Inverse polynomial models were applied to directly obtain and display the joint angle change in real time with the Lab-VIEW program. The actual joint …angle correlated well with the calculated LabVIEW output angle over the test range. The proposed optical sensor is simple, cost effective, small in size, and can evaluate the joint angle in real time. This method is expected to be useful in the field of rehabilitation and sport science. Show more

Keywords: Optical fiber, Angular sensor, Beveled tip, Asymmetric beam profile, Goniometer

DOI: 10.3233/BME-130867

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 771-780, 2014

Authors: Pan, Chang-Jiang | Hou, Yan-Hua | Zhang, Bin-Bin | Zhang, Lin-Cai

Article Type: Research Article

Abstract: This paper presents a simple method to sequentially immobilize poly (ethylene glycol) (PEG) and albumin on titanium surface to enhance the blood compatibility. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis indicated that PEG and albumin were successfully immobilized on the titanium surface. Water contact angle results showed a better hydrophilic surface after the immobilization. The immobilized PEG or albumin can not only obviously prevent platelet adhesion and activation but also prolong activated partial thromboplastin time (APTT), leading to the improved anticoagulation. Moreover, immobilization of albumin on PEG-modified surface can further improve the anticoagulation. The approach in the present …study provides an effective and efficient method to improve the anticoagulation of blood-contact biomedical devices such as coronary stents. Show more

Keywords: Titanium, surface modification, anticoagulation, PEG, albumin

DOI: 10.3233/BME-130868

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 781-787, 2014

Authors: Guan, Guoping | Wang, Lu | Li, Mingzhong | Bai, Lun

Article Type: Research Article

Abstract: Since the bioresorption process has a strong impact not only on the mechanical properties of the biomaterial but also on the extent of tissue regeneration, in vivo biodegradation of absorbable porous biomaterials plays a key role in tissue repair and wound healing. In the present work, porous silk fibroin films (PSFFs) were prepared by a freeze-drying method and then implanted beneath the dorsal skin and the femoral skeletal muscle of the rat. The objective was to study the rate of biodegradation of the PSFFs in different tissues, each with its distinct metabolic rate. In addition we examined the relationship between …the biodegradation rate and tissue-regeneration rate semi-quantitatively by incorporating histology, microscopy and image analysis methods. Furthermore, based on our previous findings, we also explored the relationship between in vitro and in vivo rates of biodegradation. The results suggest that the PSFFs experience a similar biodegradation process regardless of the type of tissue in which they are implanted, in spite of the higher metabolic rate of the skeletal muscle. In addition, the in vitro biodegradation rate of the PSFFs was comparable to that of both skin and skeletal muscle, suggesting that an in vitro biodegradation test could be used to predict in vivo performance. Show more

Keywords: biodegradation, porous biomaterials, silk fibroin, in vivo

DOI: 10.3233/BME-130870

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 789-797, 2014

Authors: Chahal, Sugandha | Fathima, Shahitha Jahir Hussain | Yusoff, Mashitah Binti Mohd

Article Type: Research Article

Abstract: In this study, randomly oriented hydroxyethyl cellulose/polyvinyl alcohol (HEC/PVA) nanofibers were fabricated by electrospinning. The blend solutions of HEC/PVA with different weight ratio of HEC to PVA were prepared using water as solvent to fabricate nanofibers. These nanofibrous scaffolds were coated with bone-like apatite by immersing into 10x simulated body fluid (SBF) for different time periods. The morphology and structure of the nanofibers were characterized by SEM, FTIR and DSC. FESEM-EDS and FTIR analysis were used to confirm the deposition of apatite on the surface of nanofibers. The results of this study suggest that this apatite coated nanofibrous scaffolds could …be a suitable biomaterial for bone tissue engineering. Show more

Keywords: Hydroxyethyl cellulose, electrospinning, bone-like apatite, simulated body fluid, bone tissue engineering

DOI: 10.3233/BME-130871

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 799-806, 2014

Authors: Chen, Na | Chen, Meimei | Liu, Shupeng | Guo, Qiang | Chen, Zhenyi | Wang, Tingyun

Article Type: Research Article

Abstract: This paper presents a long-period fiber-grating (LPG) based Michelson interferometric refractometry to monitor the change in refractive index of porcine muscle during laser-induced interstitial thermotherapy (LITT). As the wavelength of RI interferometer alters with the change in refractive index around the probe, the LPG based refractometry is combined with LITT system to measure the change in refractive index of porcine muscle when irradiated by laser. The experimental results show the denaturation of tissue alters the refractive index significantly and the LPG sensor can be applied to monitor the tissue state during the LITT.

Keywords: Refractive index, laser-induced interstitial thermotherapy, long-period fiber grating, Michelson interferometer

DOI: 10.3233/BME-130872

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 807-813, 2014

Authors: Yang, Mingying | Mandal, Namita | Shuai, Yajun | Zhou, Guanshan | Min, Sijia | Zhu, Liangjun

Article Type: Research Article

Abstract: This study aimed to investigate the mineralization of Antheraea pernyi (A. pernyi) silk sericin. Mineralization of A. pernyi sericin was performed by alternative soaking in calcium and phosphate. The inhibition of precipitation of calcium carbonate and von Kossa staining on A. pernyi sericin were tested, and the corresponding results prove that A. pernyi sericin has Ca binding activity. Scanning electron microscope (SEM) observation shows that spherical crystals could be nucleated on the A. pernyi sericin film. These crystals were confirmed to be hydroxyapatite according to FT-IR and XRD spectra, indicating that A. pernyi sericin is capable of mineralization. In addition, …cell adhesion and growth activity assay demonstrate that A. pernyi sericin shows excellent biocompatibility for the growth of MG-63 cells. Show more

Keywords: Antheraea pernyi (A. pernyi) silk sericin, mineralization, hydroxyapatite, cell adhesion and growth activity assay

DOI: 10.3233/BME-130873

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 815-824, 2014

Authors: Wang, Yanen | Wei, Qinghua | Pan, Feilong | Yang, Mingming | Wei, Shengmin

Article Type: Research Article

Abstract: Molecular dynamics (MD) simulations emerged to be a helpful tool in the field of material science. In rapid prototyping artificial bone scaffolds process, the binder spraying volume and mechanism are very important for bone scaffolds mechanical properties. In this study, we applied MD simulations to investigating the binding energy of α-n-butyl cyanoacrylate (NBCA) on Hydroxyapatite (HA) crystallographic planes (001, 100 and 110), and to calculating and analyzing the mechanical properties and radial distribution function of the HA(110)/NBCA mixed system. The simulation results suggested that HA (110) has the highest binding energy with NBCA owing to the high planar atom density, …and the mechanical properties of HA(110)/NBCA mixed system is stronger than pure HA system. Therefore, the multi-grade strength bone scaffold could be fabricated through spraying various volume NBCA binders during 3D printing process. By calculating the radial distribution function of HA(110)/NBCA, the essence of the interface interaction were successfully elucidated. The forming situation parameters can be referred to calculation results. There exists a strong interaction between HA crystallographic plane (110) and NBCA, it is mainly derived from the hydrogen bonds between O atoms which connect with C atoms of NBCA and H atoms in HA crystal. Furthermore, a strong adsorption effect can be demonstrated between HA and NBCA. Show more

Keywords: Molecular dynamics simulation, hydroxyapatite, poly α-n-butyl cyanoacrylate, binding energy, mechanical properties, radial distribution function

DOI: 10.3233/BME-130874

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 825-833, 2014

Authors: Wang, Juan | Qiao, Pengyan | Dong, Limin | Li, Fangfang | Xu, Tao | Xie, Qiufei

Article Type: Research Article

Abstract: As an injectable scaffold material for bone tissue engineering, calcium phosphate cement (CPC) has good biocompatibility, self-setting, and osteoconduction properties. Alginate-microencapsulated seed cells can pick up the degradation speed and bioactivity of CPC. The aim of this study was to explore the osteogenic ability of a composite of microencapsulated rabbit bone marrow mesenchymal stem cells (rBMMSCs) with β-tricalcium phosphate/calcium phosphate cement (β-TCP/CPC) in vivo. Cavity defects were created in both femoral condylar regions of New Zealand White rabbits. β-TCP/CPC (control group) and alginate microencapsulated rBMMSCs/β-TCP/CPC composite (composite group) were implanted separately into the bone defects of both femurs. Bone substitute …degradation and new bone formation were evaluated by CBCT, and the defects were examined histologically 8, 16, and 24 weeks after implantation. In addition, fluorescent carbocyanine CM-Dil was used to track the rBMMSCs in vivo after implantation. The results showed that far more new bone and bone marrow grew into the bone defects in the composite group. Few CM-Dil labeled positive cells were observed postoperatively. However more native cells were detected in the graft areas of the composite group than those of the control group. The study indicates that a composite of microencapsulated seed cells/β-TCP/CPC might be considered as a promising injectable material for the generation of new bone tissue. Show more

Keywords: Calcium phosphate cement, microencapsulation, injectable, bone marrow mesenchymal stem cell

DOI: 10.3233/BME-130875

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 835-843, 2014

Authors: Ji, Yu-Bin | Ji, Chen-Feng | Yue, Lei

Article Type: Research Article

Abstract: In this study, we investigated the effect of fucosterol on HL-60 and the molecular mechanism. HL-60 Cells were treated with fucosterol, and 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) method was used to study fucosterol anti-tumor activity. Morphology of HL-60 cells was observed. Flow cytometry (FCM) was employed to detect the cell cycle. Laser scanning confocal microscope (LSCM) was used to analyze mitochondrial membrane potential (MMP) and the expressions of Fas, FasL, Fadd and Caspase-8. Western blot was performed to analyze the expressions of Cyt-C, Pro-Caspase-9 and Pro-Caspase-3. Caspase activity kits were used to determine the activity of Caspase-9, Caspase-8 and Caspase-3. …The results showed fucosterol could inhibit the growth of HL-60 cells, and the cell cycle was arrested at G2/M phase. HL-60 cells showed obvious apoptosis morphology. After being treated with fucosterol for 24 h, HL-60 cells decreased MMP, induced Cyt-C release and Caspase-9, Caspase-3 activation. Fucosterol also increased the protein expression of Fas, FasL, Fadd and Caspase-8. Moreover, the activity of Caspase-9, Caspase-8 and Caspase-3 was increased significantly. In conclusion, Fucosterol can induce HL-60 cells apoptosis, suggesting that it may be a potent agent for cancer prevention and treatment. Show more

Keywords: Human promyelocytic leukemia, Fucosterol, apoptosis, mechanism

DOI: 10.3233/BME-130876

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 845-851, 2014

Authors: Bernad, Sandor I. | Bosioc, Alin | Bernad, Elena S. | Craina, Marius L.

Article Type: Research Article

Abstract: The long-term success of arterial bypass surgery is often limited by the progression of intimal hyperplasia at the anastomosis between the graft and the native artery. The experimental models were manufactured from glass tubing with constant internal diameter of 8 mm, fashioned into a straight configuration and helical configuration. The aim of this study was to determine the three-dimensional flow structures that occur at the proximal anastomosis under pulsatile flow conditions, to investigate the changes that resulted from variations in the anastomosis angle and flow division, and to establishing the major differences between the straight and helical graft. In the …anastomosis domain, a strong region of recirculation is observed near the occluded end of the artery, which forces the flow to move into the perfused host coronary artery. The proximal portion of the host tube shows weak counter-rotating vortices on the symmetry plane. The exact locations and strengths of the vortices in this region are only weakly dependent on Re. A detailed comparison of experimentally measured axial velocity patterns for straight and helical grafts confirm the very strong nature of the secondary flows in the helical geometry. The helical configuration promotes the mixing effect of vortex motion such that the flow particles are mixed into the blood stream disal to the anastomotic junction. Show more

Keywords: Bypass graft, helical graft, hemodynamics, anastomosis

DOI: 10.3233/BME-130877

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 853-860, 2014

Authors: Yu, Hao | Chen, Siping

Article Type: Research Article

Abstract: The shear stress exerted on the cell membrane is an important factor in sonoporation. However, almost all previous calculations of shear stress were based on the Rooney's assumption, which is not applicable for the sonoporation experiments. In the article, to construct the microstreaming-shear stress model in sonoporation, it theoretically analyzed the microstreaming-shear stress exerted on the cell membrane generated by oscillating microbubble based on Nyborg's acoustic streaming theory. And the response of the model was compared with that of the sonoporation experiment. Cells were exposed by 1MHz 150kPa ultrasound in the presence of SonoVue® microbubbles. The sonoporated cells were …labeled by fluorescent markers and detected by fluorescence microscopy and flow cytometry. The theoretically analyzed microstreaming-shear stress was in accordance with the cell experimental result. Although some minor factors are ignored when building the model to calculate the microstreaming-shear stress, the model was still reasonable. Show more

Keywords: shear stress, model, ultrasound, microbubble, sonoporation

DOI: 10.3233/BME-130878

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 861-868, 2014