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Journal of Biomedical Materials Research

Weiyuan John Kao, Yiping Liu
Fibronectin and RGD- and/or PHSRN-containing oligopeptides were preadsorbed onto physicochemically distinct substrata: polyethyleneglycol-based networks or tissue culture polystyrene (TCPS). The role of selected signaling kinases (namely protein tyrosine kinases, protein serine/threonine kinases, PI3-kinase, Src, and MAPK) in the adhesion of human primary blood-derived macrophages and the formation of foreign-body giant cells (FBGC) on these modified substrata was investigated. The involvement of individual intracellular signaling molecules in mediating macrophage adhesion dynamically varied with the culture time, substrate, and ligand...
December 15, 2002: Journal of Biomedical Materials Research
Liping Tang, Weiwu Jiang, Stephen E Welty
Biomaterial-mediated inflammatory responses often compromise the functions of implantable devices. The mechanism(s) involved in the inflammatory responses, which can be arbitrarily divided into phagocyte transmigration, chemotaxis, and adhesion to implant surfaces, are not totally understood. Because adhesion molecules have been shown to involved in phagocyte transmigration, this study was designed to investigate the participation of endothelial adhesion molecules in the pathogenesis of biomaterial-mediated inflammatory responses and fibrotic tissue formation...
December 15, 2002: Journal of Biomedical Materials Research
Chan-Moon Chung, Min-Sung Kim, Joong-Gon Kim, Doo-Ok Jang
1,1,1-Tris[4-(2'-hydroxy-3'-methacryloyloxypropoxy)phenyl]ethane (THMPE) and tris[4-(2'-hydroxy-3'-methacryloyloxypropoxy)phenyl]methane (THMPM) were synthesized and evaluated as base monomers in a dental composite system. The photopolymerization reactivity of the trifunctional methacrylates was similar to that of conventional 2,2-bis[4-(2'-hydroxy-3'-methacryloyloxy-propoxy)phenyl]propane (bis-GMA). Of the three monomers (THMPE, THMPM, and bis-GMA), THMPE has the greatest molecular volume, and its composite showed the lowest photopolymerization shrinkage of the composites derived from the three monomers...
December 15, 2002: Journal of Biomedical Materials Research
J H Kim, S H Kim, H K Kim, T Akaike, S C Kim
Since natural blood vessels are lined with an endothelial cell (EC) monolayer, it is proposed that synthetic biomaterial surfaces be covered or seeded with endothelial cells for ideal nonthrombogenicity under normal conditions. The effects of the surface energy of hydrophilic-hydrophobic IPN on EC adhesion and growth were investigated. The human umbilical vein endothelial cells (HUVECs) were cultured on polyurethane (PU)/polystyrene (PS) IPN prepared by changing only the amphiphilic balance and controlling the microphase separated surface structure...
December 15, 2002: Journal of Biomedical Materials Research
S Koutsopoulos
For the synthesis of hydroxyapatite crystals from aqueous solutions three preparation methods were employed. From the experimental processes and the characterization of the crystals it was concluded that aging and precipitation kinetics are critical for the purity of the product and its crystallographic characteristics. The authentication details are presented along with the results from infrared spectroscopy, X-ray powder diffraction, Raman spectroscopy, transmission and scanning electron photographs, and chemical analysis...
December 15, 2002: Journal of Biomedical Materials Research
Seung-Han Oh, Se-Young Choi, Yong-Keun Lee, Kyoung Nam Kim
We investigated lithium fluoride (LiF) and maleic acid (MA) containing calcium aluminate cement (CAC) for hard tissue repair. The objective of this study is to estimate the addition effects of LiF and MA on setting behavior, compressive strength, and biocompatibility of CAC and to find the most compatible composition of LiF and MA for using CAC as a new bone cement. The CAC was composed mainly of CaO. Al(2)O(3). Samples of LiF and MA containing CAC were formed along with recording of setting time and peak temperature and then set cement was analyzed by X-ray diffraction (XRD)...
December 15, 2002: Journal of Biomedical Materials Research
P Sepulveda, A H Bressiani, J C Bressiani, L Meseguer, B König
Hydroxyapatite (HA) is widely applied as bone graft material due to its osteoconductive potential and well-established biocompatibility. In this work, macroporous hydroxyapatite structures made through foaming of aqueous suspensions and gelcasting were tested for in vivo osteointegration. These foams are composed of a three-dimensional array of spherical pores with diameters of approximately 100-500 microm, interconnected by windows of smaller size in the range of 30-120 microm. The HA foams were implanted in the tibia of albino New Zealand rabbits and removed after a period of 8 weeks...
December 15, 2002: Journal of Biomedical Materials Research
Naoshi Ozawa, Takeshi Yao
Two kinds of methods combining a biomimetic process and transcription of resist pattern were conducted to form an apatite micropattern. For method 1, apatite nuclei were formed on a resist pattern printed substrate by setting it in contact with CaO-SiO(2)-based glass in a simulated body fluid (SBF) with inorganic ion concentrations nearly equal to those of human blood plasma. Next, apatite was grown from the nuclei by soaking the substrate in an aqueous solution with ion concentrations 1.5 times those of SBF (1...
December 15, 2002: Journal of Biomedical Materials Research
F Rupp, D Axmann, C Ziegler, J Geis-Gerstorfer
As a result of inflammatory processes, plaque formation on dental titanium implants often leads to clinically pathogenic situations. This special biofilm formation on (bio)materials in contact with saliva is initiated by ionic and protein interactions. In this interfacial process, albumin becomes a main constituent of dental pellicle. Interfacial reactions change the surface characteristics. They determine the following steps of macromolecular adsorption and bacterial adhesion. This work focuses on the dynamic contact angle analysis (DCA), which is a tool for online measurements of dynamic changes of wettability without disturbing the interface during detection...
December 15, 2002: Journal of Biomedical Materials Research
Kazuhiro Tanahashi, Antonios G Mikos
We synthesized poly(propylene fumarate-co-ethylene glycol) block copolymers [P(PF-co-EG)] that were crosslinked to form hydrogels and investigated the effect of copolymer composition on cell adhesion to the hydrogels. These copolymers were water soluble when the molar ratio of ethylene glycol repeating unit to propylene fumarate repeating unit was higher than 4.4. The water content of swollen hydrogels increased from 29 to 63% and the water contact angle decreased from 38 to 21 degrees as the molar ratio increased from 0...
December 15, 2002: Journal of Biomedical Materials Research
A Nakahira, M Tamai, H Aritani, S Nakamura, K Yamashita
In the present study, the preparation of dense hydroxyapatite (HAp) materials at relative low temperatures using a spark plasma sintering was carried out. The bioactivity of HAp samples prepared by a spark plasma sintering method was investigated by in vitro tests and compared with HAp obtained by a conventional hot-pressing method. No growth of bone-like HAp crystals on surface of HAp sintered by a conventional hot-pressing method at 1200 degrees C was observed after immersion in a simulated body fluid (SBF) for 2 days...
December 15, 2002: Journal of Biomedical Materials Research
Eiichiro Watanabe, Masahiko Suzuki, Kazuya Nagata, Toshiaki Kaneeda, Yoshitada Harada, Masahiro Utsumi, Akiko Mori, Hideshige Moriya
Oxidative degradation of ultra-high molecular weight polyethylene (UHMWPE) attributed to sterilization by gamma-radiation in the presence of air has been cited as one of the major causes of premature wear in total joint arthroplasty. For example, in retrieved UHMWPE tibial bearings, not only adhesive and abrasive wear, but also fatigue wear characterized by delamination and fracture is frequently observed. In this study, we examined the effects of gamma radiation on the microstructural morphology of UHMWPE tibial bearings, and propose a severe fatigue wear mechanism...
December 15, 2002: Journal of Biomedical Materials Research
Huiguang Zhu, Jian Ji, Rongyi Lin, Changyou Gao, Linxian Feng, Jiacong Shen
Chitosan and chitosan-amino acid derivatives were explored to engineer poly(D,L-lactic acid) (PDL-LA) as an extracellular matrix-like surface to promote cell adhesion and growth. Four kinds of chitosan-amino acid derivatives were prepared to mimic the carbohydrate moieties of cell matrix glycoprotein. The chitosan-amino acid derivatives were characterized by using Fourier transform infrared and ultraviolet spectra. The amino acid content on chitosan-amino acid derivatives was determined by using a ninhydrin-ultraviolet method...
December 15, 2002: Journal of Biomedical Materials Research
Anne Meddahi, Françoise Brée, Dulce Papy-Garcia, Jean Gautron, Denis Barritault, Jean-Pierre Caruelle
RGTA is a family of chemically modified polymers that have been engineered to mimic the properties of heparan sulfates towards heparin binding growth factors. In vivo, RGTA stimulated tissue repair and protection when injected at the site of an injury. These properties have been reported in various models, suggesting a potential interest for therapeutic uses as a general tissue repair agent. We have focused our interest on RGTA(11), a dextran derivative that was shown to enhance, after a unique and local administration, muscle regeneration after total crushing...
December 15, 2002: Journal of Biomedical Materials Research
Rebecca A Caldwell, Jennifer E Woodell, Sunita Pullela Ho, Shalaby W Shalaby, Thomas Boland, Eugene M Langan, Martine LaBerge
The use of catheters for vascular applications is often complicated by the development of friction between the catheter material and the vessel wall, which leads to endothelial cell removal and intimal lesions. Phosphonylation, a chemical surface treatment, has been proposed as a means of increasing the hydrophilicity of low-density polyethylene (LDPE), a commonly used catheter material, in efforts to impart lubricity to the material and reduce vascular tissue damage. In an in vitro tribological study, phosphonylated LDPE produced a lower coefficient of friction and allowed greater retention of endothelial cells on vessels as compared to untreated LDPE when the materials were reciprocated against normal porcine aorta...
December 15, 2002: Journal of Biomedical Materials Research
Xiaoping Jiang, Dominic Tessier, Lê H Dao, Ze Zhang
The biostability of a series of polypyrrole (PPy)-coated polyester fabrics was investigated in an in vitro model. PPy-coated sample fabrics were incubated in saline at 37 degrees C for 1 and 2 weeks. After each period of incubation, the surface electrical resistivity of the sample fabrics was measured to monitor the changes caused by the incubation. Redoping was then performed by immersing the sample fabrics in a 1N HCl solution at room temperature for 30 min, which was followed by another measurement of the surface resistivity...
December 15, 2002: Journal of Biomedical Materials Research
Alvaro Mata, Cynthia Boehm, Aaron J Fleischman, George Muschler, Shuvo Roy
Growth of human connective tissue progenitor cells (CTPs) was characterized on smooth and microtextured polydimethylsiloxane (PDMS) surfaces. Human bone-marrow-derived cells were cultured for 9 days under conditions promoting osteoblastic differentiation on smooth PDMS surfaces and on PDMS post microtextures that were 6 microm high and 5, 10, 20, and 40 microm in diameter, respectively. Glass tissue-culture dishes were used as controls. The number of viable cells was determined, and an alkaline phosphatase stain was used as a marker for osteoblastic phenotype...
December 15, 2002: Journal of Biomedical Materials Research
Charles-H Rivard, Souad Rhalmi, Christine Coillard
We are developing a new spinal implant system (SIS) without fusion (bone graft). This SIS is made from two materials, metal and polyetheretherketone (PEEK) polymer. The Food and Drug Administration recommended testing in vivo, in an animal model, whether the PEEK polymer could be used in a SIS without any harm of wear debris to the nervous tissue (spinal cord and nerve roots). The objective was to evaluate the biological response of the spinal cord and nerve roots (dura mater) to PEEK polymer particles. Twenty-four female New Zealand white rabbits were used...
December 15, 2002: Journal of Biomedical Materials Research
Masami Harimoto, Masayuki Yamato, Motohiro Hirose, Chie Takahashi, Yuki Isoi, Akihiko Kikuchi, Teruo Okano
Confluent human aortic endothelial cells (HAECs) cultured on thermo-responsive culture dish grafted with poly (N-isopropylacrylamide) were recovered as a contiguous cell sheet. The double-layered co-culture was achieved by placing the recovered HAEC sheet onto the rat hepatocyte layer directly. The double-layered structure of HAEC and hepatocytes remained in tight contact during culture. Hepatocytes in the layered co-culture system with the HAEC sheet maintained the differentiated cell shape and the albumin expression for over 41 days of culture, whereas the functions disappeared within 10 days of culture in control hepatocytes without the HAEC sheet...
December 5, 2002: Journal of Biomedical Materials Research
Yu Sogo, Tokoha Sakurai, Kazuo Onuma, Atsuo Ito
The (Ca+Zn)/P molar ratio of zinc-containing tricalcium phosphate and hydroxyapatite composite ceramics (ZnTCP/HAP) was investigated in the range from 1.50 to 1.66 to reveal the minimum zinc content possible in ceramics used in the promotion of osteoblastic cell proliferation and bone formation. The release rate of zinc increased with an increase in the (Ca+Zn)/P molar ratio up to 1.64 (ZnTCP/HAP1.64) and then decreased over 1.64 even when the zinc content of ZnTCP/HAP was the same. The zinc release rate of ZnTCP/HAP1...
December 5, 2002: Journal of Biomedical Materials Research
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