Bio-Medical Materials and Engineering - Volume 19, issue 6

Authors: Kim, Kyung Sook | Kang, Yun Mi | Lee, Ju Young | Kim, E. Sle | Kim, Chun Ho | Min, Byoung Hyun | Lee, Hai Bang | Kim, Jae Ho | Kim, Moon Suk

Article Type: Research Article

Abstract: A number of materials have been considered as sources of grafts to repair bone defects. Here, we examined the possibility of creating in situ-forming gels from sodium carboxymethylcellulose (CMC) and poly(ethyleneimine) (PEI) for use as an in vivo carrier of demineralized bone matrix (DBM). The interaction between anionic CMC and cationic PEI was examined by evaluating phase transition behavior and viscosity of CMC solutions containing 0–30 wt% PEI. CMC solutions containing 10 wt% PEI exhibited a sol-to-gel phase transition at temperatures greater than 35°C. The phase transition is caused by electrostatic crosslinking of the CMC/PEI solution to form a gel …with a three-dimensional network structure. In situ-formed gel implants were successfully fabricated in vivo by simple subcutaneous injection of the CMC/PEI (90/10) solution (with and without DBM) into Fisher rats. The resulting in situ-formed implant maintained its shape for 28 days in vitro and in vivo. Our results show that in situ-forming CMC/PEI gels can serve as a DBM carrier that can be delivered with a minimally invasive procedure. Show more

Keywords: Sodium carboxymethylcellulose, poly(ethyleneimine), demineralized bone matrix, in situ gel

DOI: 10.3233/BME-2009-0603

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 381-390, 2009

Authors: Hashimoto, Yoshiya | Adachi, Seita | Matsuno, Tomonori | Omata, Kazuhiko | Yoshitaka, Yamauchi | Ozeki, Yasuyuki | Umezu, Yoshikazu | Satoh, Tazuko | Nakamura, Masaaki

Article Type: Research Article

Abstract: The objective of this study was to evaluate the effect of β-tricalcium phosphate (β-TCP) bead size on the behavior of KUSA/A1 mouse osteoblasts when the β-TCP beads are used as the solid phase of a scaffold in which alginate was used as the gel phase. KUSA/A1 cells were loaded onto a three-dimensional (3D) scaffold fabricated from β-TCP beads with diameters ranging from 300 to 500 μm (small beads), 500–700 μm (medium beads) and 700–850 μm (large beads); cells were cultured for 3, 7 and 14 days. Scanning electron microscope observations showed that each bead was connected in a network consisting …of the alginate gel and KUSA/A1 cellular matrix that was tightly bonded to form a 3D structure. After 3 days, cells in the 3D scaffold with medium beads had a significantly higher alkaline phosphatase activity (ALP) than cells in the other scaffolds. However, by 7 and 14 days in culture there was no significant difference in DNA levels, ALP activity or osteocalcin expression. At 8 weeks, only the composite containing small beads and KUSA/A1 cells had turned completely into bone in vivo. Thus, bead size may influence the success of bone formation in this context. Show more

Keywords: β-tricalcium phosphate (β-TCP), alginate, injectable scaffold, bone tissue engineering, 3D scaffold

DOI: 10.3233/BME-2009-0604

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 391-400, 2009

Authors: Chu, C.L. | Hu, T. | Yin, L.H. | Pu, Y.P. | Dong, Y.S. | Lin, P.H. | Chung, C.Y. | Yeung, K.W.K. | Chu, P.K.

Article Type: Research Article

Abstract: Microstructural characteristics and biocompatibility of a Type-B carbonated hydroxyapatite (HA) coating prepared on NiTi SMA by biomimetic deposition were characterized using XRD, SEM, XPS, FTIR and in vitro studies including hemolysis test, MTT cytotoxicity test and fibroblasts cytocompatibility test. It is found CO3 2− groups were present as substitution of PO4 3− anions in HA crystal lattice due to Type-B carbonate. The growth of Type-B carbonated HA coating in SBF containing HCO3 − ions is stable during all periods of biomimetic deposition. The carbonated HA coating has better blood compatibility than the chemically-polished NiTi SMA. There was …a good cell adhesion to this HA coating surface and cell proliferation in the vicinity of the coating was better than that for the chemically-polished NiTi SMA. Thus biomimetic deposition of this carbonated HA coating is a promising way to improve the biocompatibility of NiTi SMA for implant applications. Show more

Keywords: Carbonated hydroxyapatite, NiTi shape memory alloy, biomimetic deposition

DOI: 10.3233/BME-2009-0605

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 401-408, 2009

Authors: Elder, Steven H. | Borazjani, Ali

Article Type: Research Article

Abstract: The mechanical properties of engineered cartilage are strongly dependent on collagen content, but the collagen to glycosaminoglycan ratio in engineered cartilage is often much lower than that of the native tissue. Therefore culture medium supplements which increase collagen production by chondrocytes are of interest. It had previously been reported that collagen hydrolysate stimulated type II collagen biosynthesis in short-term, high density monolayer chondrocyte cultures. It was hypothesized that collagen hydrolysate added to the culture medium of three dimensional chondrocyte-agarose constructs would enhance their mechanical properties. Porcine articular chondrocytes were embedded in 2% agarose and cultured for up to 6 weeks …with and without 1 mg/ml collagen hydrolysate. The instantaneous compressive modulus and equilibrium compressive modulus were significantly lower in the collagen hydrolysate-treated constructs, consistent with the finding of lower collagen and GAG content. Contrary to our hypothesis, our results indicate that 1 mg/ml collagen hydrolysate may actually inhibit macromolecule biosynthesis and be detrimental to the mechanical properties of long term chondrocyte-agarose constructs. Show more

Keywords: Cartilage tissue engineering, medium supplement, mechanical properties, glycosaminoglycan

DOI: 10.3233/BME-2009-0606

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 409-414, 2009

Authors: Gisep, Armando | Boger, Andreas

Article Type: Research Article

Abstract: Cement leakage is considered to be one of the major and most severe complications during percutaneous vertebroplasty. The viscosity of the material plays a key role in this context. At high cement viscosity, the risk of leakage is reduced; however, injection forces are highly increased, rendering injection difficult or even impossible. This study investigated the correlation of injection forces of poly-(methylmethacrylate) (PMMA) cement through different injection systems to the viscosity of the setting material. The in vitro simulation proved to give consistent data compared to clinically observed values. The difference of measurements carried out at room or body temperature was …significant. There was an increase in injection force to be overcome after breaks during the injection process. This is caused by the accelerated setting process in that part of the injection needle that was placed in body temperature conditions. Finally, viscosity application limits of the different injection systems were estimated using a required manual force limit of 100 N. In a clinical routine, the use of a viscometer might enhance the safety of the percutaneous vertebroplasty by reducing cement extravasation and avoiding early setting of the material in the injection devices. Show more

Keywords: Vertebroplasty, cement viscosity, extravasation, injection force, safety

DOI: 10.3233/BME-2009-0607

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 415-420, 2009

Authors: Nakashima, Shojiro | Matsuyama, Yukihiro | Takahashi, Katsuya | Satoh, Tomoya | Koie, Hiroshi | Kanayama, Kiichi | Tsuji, Taichi | Maruyama, Koji | Imagama, Shiro | Sakai, Yoshihito | Ishiguro, Naoki

Article Type: Research Article

Abstract: The degeneration of intervertebral disc (IVD) is a major cause of low back pain. However, there is no satisfactory preventive treatment for degenerative disc disease (DDD). In this study, we examined the effects of a novel cross-linked hyaluronate hydrogel and cross-linked chondroitin sulfate (CS) hydrogel on a rabbit model of IVD injury. We injected 300 μl of phosphate buffer saline, 1% sodium hyaluronate, cross-linked hyaluronate hydrogel, or cross-linked CS hydrogel into the injured IVDs. One, three or six months after treatment, the whole spinal columns were dissected and magnetic resonance (MR) images of the IVDs were examined. It was …noted that the IVD, which was injected with cross-linked hyaluronate hydrogel or cross-linked CS hydrogel mostly retained the normal signal intensity of the MR images. These IVDs exhibited a higher degree of staining with safranin-O than the control discs or 1% sodium hyaluronate-injected discs, suggesting that the intradiscal application of cross-linked hyaluronate hydrogel or cross-linked CS hydrogel probably inhibits the degenerative cascade of the DDD. The intradiscal administration of these drugs is safe, easy and costs less. In the near future, these intradiscal injections may become the standard therapy for the treatment of DDD instead of the spine surgeries. Show more

Keywords: Degenerative disc disease, MRI, intervertebral disc, chondroitin sulfate, hyaluronate hydrogel, rabbit

DOI: 10.3233/BME-2009-0608

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 421-429, 2009

Authors: Okubo, Yasushi | Teramura, Satoshi | Niwa, Yasuhito | Ibaraki, Kento | Murata, Koji | Hyon, Suong-Hyu | Pezzotti, Giuseppe | Tomita, Naohide

Article Type: Research Article

Abstract: The effects of vitamin E addition on the strain-induced crystallization and molecular chain orientation of ultrahigh molecular weight polyethylene (UHMWPE) were examined in order to clarify the wear mechanism of vitamin E-blended UHMWPE in knee prostheses. The structure changes of vitamin E-blended UHMWPE before and after tensile strain were analyzed by X-ray diffraction, Raman spectroscopy and image correlation method. The vitamin E-blended UHMWPE exhibited lower strain-induced crystallization than virgin UHMWPE but a higher Ic value in Raman spectroscopic analysis. The vitamin E-blended UHMWPE also exhibited a larger percentage of negative areal dilatation under tensile strain. These results suggest that …the addition of vitamin E to UHMWPE decreases the strain-induced crystallization and increases the strain-induced orientation of the molecular chains present in the amorphous phase. Show more

Keywords: Artificial knee joint, UHMWPE, vitamin E, wear, crystallization, molecular chain orientation

DOI: 10.3233/BME-2009-0609

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 431-439, 2009

Article Type: Other

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 441-448, 2009

Article Type: Other

Citation: Bio-Medical Materials and Engineering, vol. 19, no. 6, pp. 449-451, 2009