Bio-Medical Materials and Engineering - Volume 24, issue 3

Authors: Kuboki, Yoshinori | Furusawa, Toshitake | Sato, Masaaki | Sun, Yongkun | Unuma, Hidero | Abe, Shigeaki | Fujisawa, Ryuichi | Akasaka, Tsukasa | Watari, Fumio | Takita, Hiroko | Sammons, Rachel

Article Type: Research Article

Abstract: Based on our previous finding that a chromatography with titanium beads selectively binds phosphoproteins, including caseins, phosvitin and dentin phosphoproteins, we investigated whether bone phosphoproteins also bind to titanium. Bovine bone matrix proteins were extracted with 2 M urea/PBS after demineralization. The 2 M urea extract was directly applied to the titanium chromatography column as reported. The chromatogram showed an initial large peak at breakthrough position (non-binding fraction) and a smaller second peak eluted later (titanium-binding fraction). Both peaks were analyzed by SDS polyacrylamide gel electrophoresis. Stains-all staining which preferentially identifies phospho-proteins revealed that the first peak contained no positively …stained band, while the second peak showed 4 or 5 distinctive bands indicative of bone phosphoproteins. To investigate the biological functions of the titanium-binding bone proteins (TiBP), we implanted them into calvaria of rats, combined with titanium web (TW), a highly porous titanium scaffold of thin titanium-fibers. Bone TiBP induced significantly enhanced bone formation, and new bone appeared connected directly to titanium fibers, accompanied by active blood vessel formations. Control TW alone did not induce bone formation within the titanium framework. These results demonstrate that the bone titanium-binding proteins include phosphoproteins which enhance bone formation when implanted into bone with titanium. Show more

Keywords: Bone phosphoprotein, titanium, bone formation, chromatography

DOI: 10.3233/BME-140958

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1539-1548, 2014

Authors: Järvinen, Elina | Muhonen, Virpi | Haaparanta, Anne-Marie | Kellomäki, Minna | Kiviranta, Ilkka

Article Type: Research Article

Abstract: Biomaterial scaffolds have been used in autologous chondrocyte implantation to facilitate the repair of large lesions and to advance the formation of articular cartilage [Exp. Biol. Med. (Maywood) 237(1) (2012), 10–17]. Biomaterial scaffolds are usually three-dimensional (3-D) porous structures consisting of biodegradable materials to support articular cartilage formation. Adequate porosity of the scaffold is necessary for uniform cell distribution and cell attachment, and the density of the cells in the scaffold should be appropriate for cartilage formation [Cartilage 3(2) (2012), 108–117]. There have been only a restricted number of studies on the spatial distribution of cells in scaffolds, and on …the role of this to cartilage formation [J. Biotechnol. 129 (2007), 516–531; Biotechnol. Progr. 14 (1998), 193–202; Biotechnol. Bioeng. 84 (2003), 205–214]. This may be due to the limited availability of appropriate visualization methods. Acquiring 3-D images throughout the scaffold by histology or confocal methods are not applicable to all types of scaffolds, and moreover, they are time consuming, laborious and thus not very feasible for a large scale analysis. To make the visualization of the spatial distribution of the cells easier in biomaterial scaffolds we have applied optical projection tomography (OPT). OPT microscope produces high-resolution 3-D images of both fluorescent and non-fluorescent specimens [Science 296(5567) (2002), 541–545]. Here we demonstrate that the OPT method can be used for the evaluation and visualization of the cell seeding method, spatial distribution and density of cells in biomaterial scaffolds and thus establish the OPT as a valid tool for analysis of cell distribution in cartilage tissue engineering samples. Show more

Keywords: Optical projection tomography, cell seeding, cartilage tissue engineering

DOI: 10.3233/BME-140959

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1549-1553, 2014

Authors: Tadano, Shigeru | Yamada, Satoshi | Kanaoka, Masaru

Article Type: Research Article

Abstract: Orthopedic implants are widely used to repair bones and to replace articulating joint surfaces. It is important to develop an instantaneous technique for the direct bonding of bone and implant materials. The aim of this study was to develop a technique for the laser bonding of bone with an implant material like ceramics. Ceramic specimens (10 mm diameter and 1 mm thickness) were sintered with hydroxyapatite and MgO–Al2 O3 –SiO2 glass powders mixed in 40:60 wt% proportions. A small hole was bored at the center of a ceramic specimen. The ceramic specimen was positioned onto a bovine bone specimen …and a 5 mm diameter area of the ceramic specimen was irradiated using a fiber laser beam (1070–1080 nm wavelength). As a result, the bone and the ceramic specimens bonded strongly under the irradiation conditions of a 400 W laser power and a 1.0 s exposure time. The maximum shear strength was 5.3±2.3 N. A bonding substance that penetrated deeply into the bone specimen was generated around the hole in the ceramic specimen. On using the fiber laser, the ceramic specimen instantaneously bonded to the bone specimen. Further, the irradiation conditions required for the bonding were investigated. Show more

Keywords: Bone, biomechanics, fiber laser, bonding, ceramics, hydroxyapatite

DOI: 10.3233/BME-140960

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1555-1562, 2014

Authors: Chadwick, E.G. | Clarkin, O.M. | Raghavendra, R. | Tanner, D.A.

Article Type: Research Article

Abstract: The properties of porous silicon make it a promising material for a host of applications including drug delivery, molecular and cell-based biosensing, and tissue engineering. Porous silicon has previously shown its potential for the controlled release of pharmacological agents and in assisting bone healing. Hydroxyapatite, the principle constituent of bone, allows osteointegration in vivo, due to its chemical and physical similarities to bone. Synthetic hydroxyapatite is currently applied as a surface coating to medical devices and prosthetics, encouraging bone in-growth at their surface and improving osseointegration. This paper examines the potential for the use of an economically produced porous silicon …particulate–polytetrafluoroethylene sheet for use as a guided bone regeneration device in periodontal and orthopaedic applications. The particulate sheet is comprised of a series of microparticles in a polytetrafluoroethylene matrix and is shown to produce a stable hydroxyapatite on its surface under simulated physiological conditions. The microstructure of the material is examined both before and after simulated body fluid experiments for a period of 1, 7, 14 and 30 days using Scanning Electron Microscopy. The composition is examined using a combination of Energy Dispersive X-ray Spectroscopy, Thin film X-ray diffraction, Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy and the uptake/release of constituents at the fluid–solid interface is explored using Inductively Coupled Plasma–Optical Emission Spectroscopy. Microstructural and compositional analysis reveals progressive growth of crystalline, ‘bone-like’ apatite on the surface of the material, indicating the likelihood of close bony apposition in vivo. Show more

Keywords: Porous silicon (PS), metallurgical grade silicon (MGSi), nanoporous silicon, nanosponge, porous structure, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), hydroxyapatite (HA)

DOI: 10.3233/BME-140961

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1563-1574, 2014

Authors: Hedia, H.S. | Aldousari, S.M. | Abdellatif, A.K. | Fouda, N.

Article Type: Research Article

Abstract: One of the most frequent complications of total hip replacement (THR) is aseptic loosening of femoral component which is primarily due to changes of post-operative stress distribution pattern with respect to intact femur. Stress shielding of the femur is known to be a principal factor in aseptic loosening of hip replacements. Many designers show that a stiff stem shields the surrounding bone from mechanical loading causing stress shielding. Others show that reducing stem stiffness promotes higher proximal interface shear stress which increases the risk of proximal interface failure. Therefore, the task of this investigation is to solve these conflicting problems …appeared in the cemented total hip replacement. The finite element method and optimization technique are used in order to find the optimal stem material which gives the optimal available stress distribution between the proximal medial femoral bone and the cement mantle interfaces. The stem is designed using the concept of functionally graded material (FGM) instead of using the conventional most common used stem material. The results showed that there are four feasible solutions from the optimization runs. The best of these designs is to use a cemented stem graded from titanium at the upper stem layer to collagen at the lower stem layer. This new cemented stem design completely eliminates the stress shielding problem at the proximal medial femoral region. The stress shielding using the cemented functionally graded stem is reduced by 98% compared to titanium stem. Show more

Keywords: Hip replacement, functionally graded material, interface shear stress, stress shielding, finite element, optimization

DOI: 10.3233/BME-140962

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1575-1588, 2014

Authors: Valappil, Sabeel P. | Higham, Susan M.

Article Type: Research Article

Abstract: Gallium and silver incorporated phosphate-based glasses were evaluated for antibacterial effect on the growth of Pseudomonas aeruginosa, which is a leading cause of opportunistic infections. The glasses were produced by conventional melt quenching methods at 1100°C for 1 h. Glass degradation studies were conducted by weight loss method. Disc diffusion assay and cell viability assay displayed statistically significant (p≤0.0005) effect on P. aeruginosa growth which increased with decreasing calcium content in the glasses. The gallium ion release rates (1.83, 0.69 and 0.48 ppm·h−1 ) and silver ion release rates (2.97, 2.84 and 2.47 ppm·h−1 ) were found to account for …this variation. Constant depth film fermentor was used to evaluate the anti-biofilm properties of the glasses. Both gallium and silver in the glass contributed to biofilm growth inhibitory effect on P. aeruginosa (up to 2.68 reduction in log 10 values of the viable counts compared with controls). The glasses were found to deliver gallium and silver in a controlled way and exerted cumulative antibacterial action on planktonic and biofilm growth of P. aeruginosa. The antibacterial, especially anti-biofilm, properties of the gallium and silver incorporated phosphate-based glasses make them a potential candidate to combat infections caused by P. aeruginosa. Show more

Keywords: Phosphate-based glass, gallium, silver, constant depth film fermentor, biofilm, Pseudomonas aeruginosa

DOI: 10.3233/BME-140963

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1589-1594, 2014

Authors: Rekola, J. | Lassila, L.V.J. | Nganga, S. | Ylä-Soininmäki, A. | Fleming, G.J.P. | Grenman, R. | Aho, A.J. | Vallittu, P.K.

Article Type: Research Article

Abstract: BACKGROUND: Wood has been used as a model material for the development of novel fiber-reinforced composite bone substitute biomaterials. In previous studies heat treatment of wood was perceived to significantly increase the osteoconductivity of implanted wood material. AIM: The objective of this study was to examine some of the changing attributes of wood materials that may contribute to improved biological responses gained with heat treatment. METHODS: Untreated and 140°C and 200°C heat-treated downy birch (Betula pubescens Ehrh.) were used as the wood materials. Surface roughness and the effect of pre-measurement grinding were measured with contact and non-contact profilometry. …Liquid interaction was assessed with a dipping test using two manufactured liquids (simulated blood) as well as human blood. SEM was used to visualize possible heat treatment-induced changes in the hierarchical structure of wood. RESULTS: The surface roughness was observed to significantly decrease with heat treatment. Grinding methods had more influence on the surface contour and roughness than heat treatment. The penetration of the human blood in the 200°C heat-treated exceeded that in the untreated and 140°C heat-treated materials. SEM showed no significant change due to heat treatment in the dry-state morphology of the wood. DISCUSSION: The results of the liquid penetration test support previous findings in literature concerning the effects of heat treatment on the biological response to implanted wood. Heat-treatment has only a marginal effect on the surface contour of wood. The highly specialized liquid conveyance system of wood may serve as a biomimetic model for the further development of tailored fiber-composite materials. Show more

Keywords: Natural fiber-composite, heat treatment, roughness, liquid interaction, biomimetic

DOI: 10.3233/BME-140964

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1595-1607, 2014

Authors: Wójtowicz, Joanna | Leszczyńska, Joanna | Chróścicka, Anna | Ślósarczyk, Anna | Paszkiewicz, Zofia | Zima, Aneta | Rożniatowski, Krzysztof | Jeleń, Piotr | Lewandowska-Szumieł, Małgorzata

Article Type: Research Article

Abstract: BACKGROUND: Calcium phosphate ceramics have been widely considered as scaffolds for bone tissue engineering. Selection of the best support for cultured cells, crucial for tissue engineered systems, is still required. OBJECTIVE: We examined three types of calcium phosphate compounds: α-tricalcium phosphate – the most soluble one, carbonate hydroxyapatite – chemically the most similar to the bone mineral and biphasic calcium phosphate – with the best in vivo biocompatibility in order to select the best support for osteoblastic cells for tissue engineered systems. METHODS: Human osteoblasts were tested in direct contact with both dense samples and 3D scaffolds in …either static or dynamic culture. Cell viability, cell spreading, osteogenic cell capacity, and extracellular matrix production were examined. RESULTS: The obtained data indicate that biphasic calcium phosphate is the optimal cell-supporting material. In addition, dynamic culture improved cell distribution in the scaffolds, enhanced production of the extracellular matrix and promoted cells osteogenic capacity. CONCLUSIONS: Biphasic calcium phosphate should be recommended as the most suitable matrix for osteogenic cells expansion and differentiation in tissue engineered systems. Show more

Keywords: Tissue engineering, ceramics, biphasic calcium phosphate, osteoblast, dynamic culture

DOI: 10.3233/BME-140965

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1609-1623, 2014

Authors: Marycz, Krzysztof | Szarek, Dariusz | Grzesiak, Jakub | Wrzeszcz, Karol

Article Type: Research Article

Abstract: BACKGROUND: Great potential of cellular therapies has generated extensive research in the field of cells harvesting and culturing. Transplantation of cell cultures has been used in a variety of therapeutic programs but in many cases it appeared that biomaterial scaffold or sheath would enhance cells regenerative potential. OBJECTIVE: Hydrogels composed of different proportions sodium and calcium alginates, were undertaken to evaluate their influence on mesenchymal stem cells and olfactory bulb-derived glial cells cultures. Additionally, these biomaterials were also enriched with fibrin protein. METHODS: The structure of materials was visualized by means of scanning electron microscopy. After seeding with …cells – hydrogels were observed with inverted and fluorescence microscope. Cell's morphology, behavior and phenotype were analyzed in investigated materials by means of light, fluorescence and scanning electron microscopes. Also, viability assay was performed with Alamar Blue cytotoxic test. RESULTS: Our observations showed that basic alginate hydrogels had significant influence on both cell types. Materials maintained cells alive, which is desired attribute, however none of them kept cells in normal, flat form. Alginates with significant calcium component kept cells alive for longer period of culture. CONCLUSIONS: Addition of fibrin protein resulted in material's biocompatibility properties improvement, by creation of adhesion surface, which helps cells to keep proper morphology and behavior. Our findings suggest that addition of fibrin protein to alginate hydrogels improves them as cell carriers for regenerative medicine applications. Show more

Keywords: Hydrogel, fibrin, glial cells, mesenchymal stem cells

DOI: 10.3233/BME-140966

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1625-1637, 2014

Authors: Vlad, Mihaela | Andronescu, Ecaterina | Grumezescu, Alexandru Mihai | Ficai, Anton | Voicu, Georgeta | Bleotu, Coralia | Chifiriuc, Mariana Carmen

Article Type: Research Article

Abstract: The synthesis of carboxymethyl-cellulose/magnetite (CMC/Fe3 O4 ) was carried out. This magnetic hybrid material was characterized by infrared spectroscopy, scanning electron microscopy and X-ray diffractometry. The adsorption of norfloxacin and cefotaxim antimicrobial substances (ATB) onto the CMC/Fe3 O4 was performed in order to investigate the capacity of the magnetic scaffold to improve the antimicrobial activity of the respective therapeutic agents, assessed by an in vitro quantitative assay. The obtained results proved that CMC/Fe3 O4 /ATBs might be a promising candidate for the development of efficient and cheap antimicrobial drugs carriers under magnetic field.

Keywords: CMC/Fe3O4, magnetic scaffold, drug delivery, antimicrobial activity, biocompatibility

DOI: 10.3233/BME-140967

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 3, pp. 1639-1646, 2014