Bio-Medical Materials and Engineering - Volume 28, issue 5

Authors: Gołąb, Agnieszka | Kulesa-Mrowiecka, Małgorzata | Gołąb, Marek

Article Type: Research Article

Abstract: Background: Nowadays we observe growing popularity of kinesiotaping as a supportive method in physiotherapy. In documents available on kinesiotaping we can find that mechanical properties of tapes are similar to the ones of a human skin, but usually there is hardly any numerical data characterizing these properties. Objective: Therefore, testing and comparing physical properties of commercially available kinesiotapes seems to be important. Methods: Physical properties of five commercially available kinesiotapes were examined. Strain vs. stress data was collected up to 15 N. Program Origin 9.0 was used for data analysis. Results: The obtained results show …that up to about 2 N the strain vs. stress characteristics of the tested tapes are similar while for greater stress they differ essentially. Conclusions: An alternative, to commonly used, way of defining relative strain is proposed. This definition could be more suitable in those cases when desired tape tensions are higher than 50% i.e. in ligament and tendon techniques. Show more

Keywords: Kinesiotaping, mechanical properties of kinesiotapes, stretch characteristics

DOI: 10.3233/BME-171695

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 457-462, 2017

Authors: Beigzadeh, Borhan | Mirmohammadi, Seyed Alireza | Ayatollahi, Majid Reza

Article Type: Research Article

Abstract: Background: Stenting has been proposed as an effective treatment to restore blood flow in obstructed arteries by plaques. Although several modified designs for stents have been suggested, most designs have the risk of disturbing blood flow. Objective: The main objective is to propose a stent design to attain a uniform lumen section after stent deployment. Methods: Mechanical response of five different designs of J & J Palmaz-Schatz stent with the presence of plaque and artery are investigated; four stents have variable strut thickness of different magnitudes and the rest one is a uniform-strut-thickness stent. Nonlinear finite …element is employed to simulate the expansion procedure of the intended designs using ABAQUS explicit. Results: The stent design whose first cell thickness linearly increases by 35 percent, exhibits the best performance, that is it has the lowest recoiling and stress induced in the intima for a given lumen gain. It also enjoys the minimal discrepancy between the final at the distal and proximal ends. Conclusions: A uniform widened artery can be achieved by using the stent design with 35 percent increase in its first cell, which provides the possibility to prevent from disturbing blood flow and consequently post-operation complications. Show more

Keywords: Stent, effect of geometrical parameters, numerical simulation, FEM

DOI: 10.3233/BME-171691

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 463-476, 2017

Authors: Mallis, Panagiotis | Michalopoulos, Efstathios | Dimitriou, Constantine | Kostomitsopoulos, Nikolaos | Stavropoulos-Giokas, Catherine

Article Type: Research Article

Abstract: Background: Each year, more than 800,000 vascular and cardiac surgeries are performed therefore, there is a great need for suitable material for bioprosthetic operations. Porcine pericardium is a double-walled sac that covers the heart and can be used in vascular and cardiac thoracic surgery. Objective: The aim of the present study was to evaluate the decellularization process and biomechanical properties in porcine pericardial tissue after the decellularization treatment. Methods: A detergent based protocol was used for the decellularization of porcine pericardium. Histological analysis and contact cytotoxicity assay were performed. Additionally, biomechanical testing and in vivo …biocompatibility by implantation into Wistar Rats were performed. Results: The histological analysis showed the preservation of the extracellular matrix, without any observable cellular remnants. No toxic effects were noticed when contact cytotoxicity assay performed. The decellularized tissues, after implantation in Wistar Rats, remained for up to 12 weeks without being rejected. Finally, the biomechanical testing showed no significant differences between native and decellularized tissues. Conclusion: In this study, the decellularization of the porcine pericardium produced a non toxic scaffold, free of any cellular remnants, thus serving as an alternative material for tissue engineering applications including heart valve and vascular patch development. Show more

Keywords: Porcine pericardium, tissue-engineering, regenerative medicine, decellularization, heart valve, vascular graft, patch, extracellular matrix, detergent, implantation

DOI: 10.3233/BME-171689

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 477-488, 2017

Authors: Mahmoodi, Mahboobeh | Zamanifard, Mohammad | Safarzadeh, Mina | Bonakdar, Shahin

Article Type: Research Article

Abstract: Background: Polytetrafluoroethylene (PTFE) is poorly biocompatible due to its low surface energy and hydrophobicity, which cause weak cell attachment and proliferation and complicate its use in implants. Objective: NH3 plasma was used for surface modification and binding of amine groups on the PTFE surface. Collagen was immobilized on the plasma-treated PTFE in order to enable it to support enhanced cell adhesion and growth. Methods: PTFE was exposed to NH3 plasma and collagen was immobilized on the NH3 plasma-treated surface. ATR-IR, SEM, EDXA and contact angle were conducted to determine the composition, microstructure and …wettability of samples. The cytocompatibility of the samples was assessed via the growth HUVEC cells using MTT assay. Results: Plasma treatment resulted in an incorporation of functional groups, containing N2 and O2 that caused the PTFE surface to become hydrophilic with contact angle 68°. Also, a reduction in F/C ratio was observed after collagen immobilization that indicates the presence of collagen. Cells proliferated in greater numbers on the collagen immobilized-PTFE as compared to the plasma-treated one. Conclusions: Plasma treatment incorporates functional polar moieties on the PTFE surface, causing enhanced wettability, collagen immobilization and cell viability. Collagen-immobilized PTFE may offer a valuable solution in biomedical applications such as vessel grafts. Show more

Keywords: Surface biological modifications, collagen immobilization, NH3 plasma, biocompatibility, polytetrafluoroethylene, artificial blood vessel, hydrophilicity

DOI: 10.3233/BME-171692

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 489-501, 2017

Authors: Hsu, Hsueh-Chuan | Wu, Shih-Ching | Hsu, Shih-Kuang | Liao, Yi-Hang | Ho, Wen-Fu

Article Type: Research Article

Abstract: BACKGROUND: As titanium (Ti) alloys are bioinert, various chemically-modified Ti surface has been developed to promote bioactivity and bone ingrowth. OBJECTIVE: In this study, various post treatments (water aging, hydrothermal, and heat treatments) were applied to NaOH-treated Ti–5Si to improve its bioactivity. METHODS: The bioactivity of surface-modified Ti–5Si was access by using the apatite formation ability of Ti–5Si surfaces soaking in a simulated body fluid (SBF). RESULTS: The results showed that the NaOH-treated surface formed a porous network structure composed of sodium titanate hydrogel, which was changed to sodium titanate after subsequent post treatments, …whereas sodium titanate, anatase and rutile phases were found on the Ti–5Si surfaces after heat treatment. After immersion in SBF for 14 days, compact apatite layers were observed on the surfaces of all the Ti–5Si tested. The results of XRD and FTIR indicated that the apatite deposited on the Ti–5Si substrate with various surface modified conditions was carbonate-substituted hydroxyapatite. CONCLUSIONS: The apatite-forming ability of the surface of the Ti–5Si was excellent, even though Ti–5Si was not subjected to surface modifications. As a result, the bioactivity of Ti–5Si alloy was verified by the apatite-forming ability, making it suitable for use in orthopedic and dental implants. Show more

Keywords: Titanium alloy, alkali treatment, post treatment, apatite, simulated body fluid (SBF)

DOI: 10.3233/BME-171693

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 503-514, 2017

Authors: Ko, Chia-Ling | Wu, Hui-Yu | Lin, Yu-Sheng | Yang, Chun-Hui | Chen, Jian-Chih | Chen, Wen-Cheng

Article Type: Research Article

Abstract: Background: A biodegradable porous particle for the controlled biofactor delivery which assembly of pores in scaffolds can improve the permeation and diffusion of drugs or growth factors. Objective: Porous-spheres in millimeter scale were prepared by mixing sodium alginate and gelatin interpenetrating networks with cross-linkers; interconnected open pores were fabricated through solvent casting and particulate leaching. Methods: Morphological characteristics, degradation, and bovine serum albumin (BSA) release rates of the porous-spheres immersed in three different solutions, namely, deionized distilled water, simulated body fluid (SBF), and phosphate-buffered saline (PBS), were detected. Results: Porous-spheres with a large amount …of gelatin exhibited an increase in water absorption rates without affecting scaffold strength and no cytotoxicity was elicited. Highly interconnected pores with a diameter of 100–200 µm were uniformly distributed in scaffolds. The weight loss in PBS was faster than that in other solutions; the highest release rate of BSA in SBF was observed for 2 h. The release rates also exhibited linear patterns from 2 h to 24 h in all of the groups. Conclusions: After 1 d of immersion in solutions, BSA release rates in scaffolds logarithmically decreased for 14 d. The degradation of porous-spheres also showed an inverse pattern. Show more

Keywords: Sodium alginate, gelatin, porous-sphere, solvent casting/particulate leaching, cross-linker

DOI: 10.3233/BME-171690

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 515-529, 2017

Authors: Wang, Fei | Zhang, Jian | Wang, Rong | Gu, Yongquan | Li, Jianxin | Wang, Cong

Article Type: Research Article

Abstract: Background: Morbidity and mortality of cardiovascular diseases are increasing in recent years. To solve these problems, vascular transplantation has become a common approach. Decellularization has been a hot spot of tissue engineering to prepare vessel substitutes for vascular transplantation. However, there is no established canonical protocol for decellularization thus far. Objective: To further understand the decellularization effect of decellularization protocols and the causal relationship between decellularization and mechanical properties. Methods: Three decellularization protocols including two chemical protocols based on SDS and Trypsin respectively and a combination of Triton X-100 with chymotrypsin were adopted to obtain decellularized …porcine carotid arteries in our study. After decellularization, histological analysis, scanning electron microscopy and mechanical tests were performed to evaluate their efficiency on removing of cellular components, retention of extracellular matrix and influence on mechanical properties. Results: All these decellularization protocols used in our study were efficient to remove cellular components. However, SDS and trypsin performed more disruptive effect on ECM structure and mechanical properties of native arteries while Triton X-100 combines with chymotrypsin had no significant disruptive effect. Conclusions: Compared with decellularization protocols based on SDS and trypsin, Triton X-100 combines with chymotrypsin used in our study may be a more promising protocol to prepare decellularized porcine carotid arteries for vascular tissue engineering applications. Show more

Keywords: Decellularization, Triton X-100, chymotrypsin, extracellular matrix, sodium dodecyl sulfate, trypsin

DOI: 10.3233/BME-171694

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 531-543, 2017

Authors: Ota, Tsuyoshi | Itoh, Soichiro | Yamashita, Kimihiro

Article Type: Research Article

Abstract: Background: There are few reports of Low-intensity pulsed ultrasound (LIPUS) treatment for fresh forearm fractures in children. Objectives: LIPUS stimulation was applied after surgery of forearm fractures in children and the efficacy and safety of combination therapy of LIPUS treatment were evaluated. Patients and methods: Children with both radius and ulna fracture, twenty-five diaphysis (mid-R&U) and nineteen metaphysis (dist-R&U) fractures, were treated with intramedullary nailing followed by cast and splint mobilization. Thirteen patients in the mid-R&U fracture group and eight patients in the dist-R&U fracture group were combined with LIPUS stimulation postoperatively. Results: Periosteal …callus appeared significantly earlier after surgery in the LIPUS-treated groups than in the groups without LIPUS treatment. The duration of external fixation was significantly shorter in the dist-R&U fracture group treated with LIPUS stimulation compared with that in the mid-R&U fracture group without LIPUS treatment. Furthermore, the time span needed for bone union in the groups with LIPUS stimulation was significantly shorter than in the groups without LIPUS stimulation. Conclusions: It is suggested that LIPUS stimulation can lead to a reduction of treatment periods of unstable forearm fractures safely after operation even in children. Show more

Keywords: Both radius and ulna fracture, metaphysis, diaphysis, children, low-intensity pulsed ultrasound (LIPUS)

DOI: 10.3233/BME-171697

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 545-553, 2017

Authors: Suzuki, Yuma | Shimizu, Tetsuhide | Yang, Ming

Article Type: Research Article

Abstract: Background: The quantitative evaluation of the biomolecules transport with multi-physics in nano/micro scale is demanded in order to optimize the design of microfluidics device for the biomolecules detection with high detection sensitivity and rapid diagnosis. Objective: This paper aimed to investigate the effectivity of the computational simulation using the numerical model of the biomolecules transport with multi-physics near a microchannel surface on the development of biomolecules-detection devices. Methods: The biomolecules transport with fluid drag force, electric double layer (EDL) force, and van der Waals force was modeled by Newtonian Equation of motion. The model validity was …verified in the influence of ion strength and flow velocity on biomolecules distribution near the surface compared with experimental results of previous studies. The influence of acting forces on its distribution near the surface was investigated by the simulation. Results: The trend of its distribution to ion strength and flow velocity was agreement with the experimental result by the combination of all acting forces. Furthermore, EDL force dominantly influenced its distribution near its surface compared with fluid drag force except for the case of high velocity and low ion strength. Conclusions: The knowledges from the simulation might be useful for the design of biomolecules-detection devices and the simulation can be expected to be applied on its development as the design tool for high detection sensitivity and rapid diagnosis in the future. Show more

Keywords: Biomolecules transport, multiphysics, microfluidics, electric double layer, numerical modeling, computational simulation

DOI: 10.3233/BME-171696

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 555-565, 2017

Authors: Usman, | Huang, Shyh-Chour

Article Type: Research Article

Abstract: The knee joint is one of the more important parts in the human body. Its continuous involvement in the human movement makes it prone to breakage. Due to small contact area, the contact pressure is quite large in this joint. Therefore, the understanding of stresses behavior in knee joint contact is a necessity. In this study, we investigated the stresses behavior in the tibial insert by FEA. A two-dimensional FE model representing the knee joint contact mechanism was created. In the elastic simulation, the contact pressure dropped by 0.2% when the coefficient of friction (CoF) was added. While in the …plastic simulation it rose by 12.06%. The average contact pressure fell by 36.42% of the inclusion of plasticity. The CoF lowered the Tresca stress by 0.16% and 12.37% in the elastic and plastic simulation, respectively. Meanwhile, the inclusion of plasticity decreased the average Tresca stress by 74.25%. The CoF, in the elastic simulation, decreased the compressive and tensile stress by 3.29% and 12.46%, respectively. Conversely, in the plastic simulation the compressive stress and tensile rose by 12.01% and 8.20%, respectively. Meanwhile, the inclusion of plasticity caused the compressive stress to decrease by 70.50% and tensile stress to increase by 72.06%. Show more

Keywords: Total knee replacement, two-dimensional finite element analysis, UHMWPE

DOI: 10.3233/BME-171688

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 5, pp. 567-578, 2017