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

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