Bio-Medical Materials and Engineering - Volume 30, issue 4

Authors: Ghazi Zadeh, Leili | Chevrier, Anik | Lamontagne, Martin | Buschmann, Michael D. | Hoemann, Caroline D. | Lavertu, Marc

Article Type: Research Article

Abstract: BACKGROUND: Platelet-rich plasma (PRP) has been used to solubilize freeze-dried chitosan (CS) formulations to form injectable implants for tissue repair. OBJECTIVE: To determine whether the in vitro performance of the formulations depends on the type of PRP preparation used to solubilize CS. METHODS: Formulations containing 1% (w/v) CS with varying degrees of deacetylation (DDA 80.5–84.8%) and number average molar mass (M n 32–55 kDa), 1% (w/v) trehalose and 42.2 mM calcium chloride were freeze-dried. Seven different PRP preparations were used to solubilize the formulations. Controls were recalcified PRP. RESULTS: CS solubilization was achieved …with all PRP preparations. CS-PRP formulations were less runny than their corresponding PRP controls. All CS-PRP formulations had a clotting time below 9 minutes, assessed by thromboelastography, while the leukocyte-rich PRP controls took longer to coagulate (>32 min), and the leukocyte-reduced PRP controls did not coagulate in this dynamic assay. In glass culture tubes, all PRP controls clotted, expressed serum and retracted (43–82% clot mass lost) significantly more than CS-PRP clots (no mass lost). CS dispersion was homogenous within CS-PRP clots. CONCLUSIONS: In vitro performance of the CS-PRP formulations was comparable for all types of PRPs assessed. Show more

Keywords: Chitosan, platelet-rich plasma, injectable implants

DOI: 10.3233/BME-191058

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 349-364, 2019

Authors: Nakamura, Yoshiharu | Yamamoto, Takatsugu | Shigeta, Yuko | Ogawa, Takumi

Article Type: Research Article

Abstract: BACKGROUND: Ceramic crown that fires the layering porcelain on zirconia corping is starting to be used due to aesthetic requirements. However, many ceramics are used, but wear characteristics are often unknown. OBJECTIVE: This study was performed to investigate the wear of human enamel by porcelains, and to determine the influence of porcelain hardness, surface roughness and crystal of porcelain on the enamel wear. METHODS: Enamel specimens were prepared from extracted human molar teeth. Porcelain specimens were prepared from Deguceram Gold, Vita Omega 900, and Cercon Ceram Kiss. Enamel wear volume was calculated and the porcelain wear …depth, surface roughness and Vickers hardness was measured. Moreover, the observation of a crystal by scanning electron microscope and the crystal by X-ray diffraction were identified. RESULTS: Omega 900 showed the smallest enamel wear volume and porcelain wear depth. The Vickers hardnesses of Omega 900 and Cercon Ceram Kiss were almost identical. Leucite was detected from Deguceram Gold and Omega 900, and Silica and Silicon Nitride were detected from Cercon Ceram Kiss. CONCLUSIONS: The enamel wear is influenced not by the hardness of the porcelain but by the surface roughness, the size and shape of the crystal. Show more

Keywords: Wear, human enamel, porcelain, Vickers hardness, surface roughness

DOI: 10.3233/BME-191059

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 365-374, 2019

Authors: Wint, Wit Yee | Horiuchi, Naohiro | Nozaki, Kosuke | Nagai, Akiko | Yamashita, Kimihiro | Miyashin, Michiyo

Article Type: Research Article

Abstract: BACKGROUND: The scaffold for head and neck reconstruction needs mechanical strength to maintain specific forms. Hydroxyapatite (HA) enhances the mechanical strength of hydrogel and is routinely used for cartilage regeneration. However, there is a demand for hydroxyapatite that controls chondrogenic cell behavior. OBJECTIVE: Our aim was to regulate HA morphology through a hydrothermal process using organic acid and enhance chondrocyte proliferation and differentiation using shaped-regulated HA. METHODS: HA was synthesized from dodecanedioic acid (DD:HA) and oleic acid (OA:HA) by a hydrothermal method and then coated onto glass plates. Surface properties of the samples were compared by …various techniques. Surface roughness and contact angles were calculated. Proliferation and differentiation of chondrogenic cells were measured by MTT assays and Alcian Blue staining, respectively, after various incubation periods. RESULTS: The morphological structures of DD:HA and OA:HA were different; however, the crystallinity and chemical structures were similar. Surface roughness and hydrophilic behavior were higher on DD:HA. DD:HA enhanced chondrogenic cell proliferation over time. The differentiation of ATDC5 cells was also increased on the DD:HA surface compared with those in other groups. CONCLUSIONS: DD:HA enhanced cell viability to a greater extent than OA:HA did, indicating its excellent potential as an inorganic material compatible with chondrocyte regeneration. Show more

Keywords: Hydroxyapatite, surface topography, chondrogenic cell, cell proliferation, cell differentiation

DOI: 10.3233/BME-191060

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 375-386, 2019

Authors: Kumar, Rajneesh | Vashishth, Anil K. | Ghangas, Suniti

Article Type: Research Article

Abstract: In this work, a nonlocal dual-phase-lag (NL DPL) model is introduced to accommodate the effects of thermomass and size-dependent thermophysical properties at nanoscale heat transport. Heat transfer at nanoscale is essentially nonlocal and quite different from that at the micro- or macro scale. To illustrate the nonlocal effect, a bi-layered structure is considered during magnetic fluid hyperthermia (MFH) treatment which is used successfully in prostate, liver, and breast tumors and the effect of size-dependent characteristic lengths is discussed in tumor and normal region of tissue. The problem is solved by using the finite difference scheme in space coordinate and Legendre …wavelet Galerkin approach in time coordinate with the Dirichlet, Neumann and Robin boundary conditions. The effect of boundary conditions, characteristic lengths, phase lag parameters and nanomaterial parameters is discussed in tumor and healthy tissue domain and the results are presented graphically. This study is expected to be helpful for modeling of bioheat transfer equation at nano-scale, and may be beneficial to design nano-sized and multi-layered devices for heat transfer. Show more

Keywords: Size effect, bioheat transfer, bi-layer, magnetic-fluid-hyperthermia, dual phase lag, finite element Legendre wavelet Galerkin method

DOI: 10.3233/BME-191061

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 387-402, 2019

Authors: Watanabe, Atsuya | Mainil-Varlet, Pierre | Decambron, Adeline | Aschinger, Caroline | Schiavinato, Antonella

Article Type: Research Article

Abstract: BACKGROUND: Various biomaterials/technologies have been tested for treatment of intervertebral disc (IVD) degeneration (IDD). Only few non-surgical options exist. OBJECTIVE: Assessment of efficacy and safety of the hyaluronic acid derivative hydrogel HYADD® 4-G in IDD using a well-established rabbit annular puncture model. METHODS: Rabbits were punctured at two IVDs to induce IDD. Thirty days after, IVDs were injected with HYADD® 4-G or saline. IVD hydration, height, appearance and tissue organization were assessed by radiographs, MRI and histopathology. Safety of HYADD® 4-G injection was evaluated in non-punctured IVDs. RESULTS: HYADD® 4-G injection restored disc height …to over 75% of the pre-punctured disc, saline injections led to 50% of initial disc height. Compared to saline, HYADD® 4-G treatment resulted in improved water retention as revealed by MRI quantification. 83.3% of HYADD® 4-G injected discs had normal appearance and reached grade I of the Pfirrmann scale. Regarding tissue organization and cellularity, HYADD® 4-G treatment resulted in significantly lower IDD scores than saline (p < 0.01). HYADD® 4-G injected into healthy IVDs did not induce inflammation or foreign body reactions. CONCLUSIONS: Intra-discal HYADD® 4-G injection is safe and has therapeutic benefits: IDD could be limited through restoration of disc height and hydration and maintenance of normal IVD tissue organization. Show more

Keywords: Intervertebral disc degeneration, HYADD®4-G, disc therapy, annulus puncture rabbit model, nucleus pulposus (NP), annulus fibrosus (AF)

DOI: 10.3233/BME-191062

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 403-417, 2019

Authors: Sagsoz, Omer | Polat Sagsoz, Nurdan

Article Type: Research Article

Abstract: BACKGROUND: The chemical properties of the oral environment have an appreciable influence on the in vivo degradation of CAD/CAM materials. OBJECTIVE: The aim of the present study was to investigate the effect of organic acids, heptane and ethanol (the food-simulating liquids) on CAD/CAM restorative materials. METHODS: Four CAD/CAM materials were selected: (1) 3M ESPE LAVA Ultimate, (2) VITA Enamic, (3) IPS e.max CAD, (4) VITA Suprinity. Seven different samples were fabricated in 15 × 4 × 1.2 mm dimensions from each material (n = 7, N = 140). The materials were conditioned for 7 …days at 37 °C as follows: artificial saliva, 75% ethanol, heptane, 0.02 N citric acid, 0.02 N lactic acid in aqueous solution and were tested to obtain flexural strength, surface micro-hardness and wear characteristics. After conditioning, the flexural strength values were assessed using a universal testing machine (1 mm/min crosshead speed) and the fractured samples were used for determination of Vickers hardness values using a digital micro-hardness tester (100 g/10 s) and determination of wear using a chewing simulator. Two factor analysis of variance with interaction model and Tukey’s post hoc test were used for statistical analysis. RESULTS: The highest mechanical property values were found for IPS e.max and VITA Suprinity and the lowest values were found for LAVA Ultimate. Organic acids negatively affected the mechanical properties of e.max CAD and Suprinity. Ethanol and heptane were more effective on LAVA Ultimate and Enamic. There were significant differences among groups (p < 0.05). CONCLUSION: The mechanical properties of CAD/CAM restorative materials are influenced by food-simulating liquids. Show more

Keywords: CAD/CAM, food-simulating liquids, mechanical properties

DOI: 10.3233/BME-191063

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 419-426, 2019

Authors: Jahed, Mahsa | Ghalichi, Farzan | Farhoudi, Mehdi

Article Type: Research Article

Abstract: BACKGROUND: The development of any disturbance in the Circle of Willis (COW) can change the hemodynamics of blood flow and result in damage to the vascular system. Clinical methods such as TCD for diagnosing an aneurysm or growth factors and rupture can measure blood velocity. Several factors influence the accuracy of TCD that can lead to wrong evaluations and affect the treatment planning. OBJECTIVE: In this study, the conformity between CFD and TCD was accomplished for investigating the accuracy of the clinical method (TCD) in different vessels of the Circle of Willis. METHODS: The realistic three-dimensional …models have been produced from angiography images. Considering fluid-structure interaction, a domain of the blood flow and vessel wall has been simulated by the ANSYS.CFX software. The velocity in the cerebral arteries has been calculated and compared with the velocity acquired from TCD. RESULTS: According to the findings, there were significant differences between the results obtained from computational fluid dynamics and Doppler test in different vessels of the Circle of Willis. In some areas, differences close to 80 cm/s were also reported. CONCLUSION: According to the results, there are possibilities of errors in carrying out a Doppler test in some arteries and can lead to wrong estimates and ultimately incorrect decisions. Show more

Keywords: Aneurysm, blood velocity, cerebral arteries, Transcranial Doppler, computational fluid dynamics

DOI: 10.3233/BME-191064

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 427-438, 2019

Authors: Almoammar, Salem | AlShahrani, Ibrahim | Asiry, Moshabab A. | Duarte, Simone | Janal, Malvin | Khoo, Edmund

Article Type: Research Article

Abstract: BACKGROUND: Adhesion strength of orthodontic attachments to enamel should be within optimal range to resist occlusal forces and to allow debonding without enamel damage. OBJECTIVE: The present study compared the effect of non-thermal plasma (NTP) and conventional surface treatment on the adhesion strength of orthodontic bracket to enamel. METHODS: A total of 100 premolar teeth were allocated into 5 groups according to the bonding procedure followed: Group 1 (Etch, prime and composite adhesive); Group 2 (Prime and composite adhesive); Group 3 (Glass ionomer cement); Group 4 (NTP, prime and composite adhesive) and Group 5 (NTP and …glass ionomer cement). Ten specimens in each group were subjected to artificial aging and the remaining ten specimens served as baseline specimens. Adhesion strength values were recorded after debonding and bond failure types were scored. Water contact angles of the NTP treated and untreated enamel surface were measured. RESULTS: Group 1 specimen demonstrated highest bond strength at baseline (21.5 ± 3.01) and thermocycling (15.8 ± 2.87) and the least values were in Group 2 specimens at baseline (3.9 ± 1.01) and thermocycling (1.6 ± 0.7). Among the experimental (NTP) groups, Group 4 specimens exhibited high adhesion strength at baseline (10.2 ± 1.76) and after thermocycling (9.8 ± 2.15) compared to Group 5 specimens at baseline (10.1 ± 1.05) and thermocycling (6.5 ± 2.19). The water contact angle on untreated enamel surface was 53.1° ± 2.1° as compared to 1.4° ± 0.7° in treated surface. CONCLUSION: Non-thermal plasma (NTP) treatment in conjunction with composite adhesives demonstrated clinically acceptable adhesion strength and was well within the optimal range (7–14 MPa) for enamel bonding. Show more

Keywords: Non-thermal plasma, orthodontic bonding, adhesion strength, acid etching

DOI: 10.3233/BME-191065

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 439-448, 2019

Authors: Eltayeb, Engy N. | Salem, Nancy M. | Al-Atabany, Walid

Article Type: Research Article

Abstract: Brain tumors are considered to be a leading cause of cancer death among young people. Early diagnosis is thus essential for treatment. The brain segmentation process is still challenging due to complexity and variation of the tumor structure, intensity similarity between tumor tissues and normal brain tissues. In this paper, a fully automated and reliable brain tumor segmentation system is proposed. This system is able to detect range of slices from a volume that is likely to contain tumor in MRI images. An iterated k-means algorithm is used for the segmentation process in conjunction with a cluster validity index to …select the optimal number of clusters. The proposed approach is evaluated using simulated and real MRI of human brain from multimodal brain tumor image segmentation benchmark (BRATS) organized by MICCAI 2012 challenge. Our results achieved average for Dice overlap and Jaccard index for complete tumor region of 91.96% and 98.31% respectively when testing a set of 77 volumes. This shows the robustness of the new technique for clinical routine use. Show more

Keywords: Brain tumor, MRI, image segmentation, k-means clustering, validity index

DOI: 10.3233/BME-191066

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 449-462, 2019

Authors: Kamangar, Sarfaraz | Salman Ahmed, N.J. | Badruddin, Irfan Anjum | Al-Rawahi, Nabeel | Husain, Afzal | Govindaraju, Kalimuthu | Yunus Khan, T.M.

Article Type: Research Article

Abstract: BACKGROUND: The most common cause of coronary artery disease (CAD) is vascular damage with the cholesterol built-up and other materials on the inner arterial wall, known as atherosclerosis. OBJECTIVE: This paper aims to investigate the effect of stenosis on the hemodynamics in the four suspected coronary artery disease patients. Computer tomography (CT) data was acquired from patients of suspected coronary artery disease to reconstruct left coronary artery. METHODS: The 3D computational simulation was carried out with four patient-specific models with area stenosis >50% located at the left anterior descending (LAD) and left circumflex (LCX) branches. …RESULTS: The pressure, velocity and wall shear stress were calculated during the cardiac cycle. A significant pressure drop across the stenosis and increase in the velocity at the stenosis were observed at LAD and LCX branches. An increase in the wall shear stress in the region of stenosis also observed with the prevalence of the recirculation zone at the post stenosis region which results in the formation of stenosis. CONCLUSIONS: Our analysis provides an insight into the progression of stenosis and wall rupture, thus improving our understanding the flow behavior patient-specific realistic artery models. Show more

Keywords: Coronary artery, non-Newtonian flow, stenosis, CFD, computer tomography

DOI: 10.3233/BME-191067

Citation: Bio-Medical Materials and Engineering, vol. 30, no. 4, pp. 463-473, 2019