Papers by Keyword: Collagen

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Authors: Marcia S. Sader, Elena Mavropoulos, Ana Paula Moreira Duarte, Moema Hausen, Andrea Machado Costa, Jessica Dornelas, Marcelo N. Tanaka, Gloria A. Soares, Alexandre Rossi
Abstract: The influence of surface chemistry, roughness and hidrophilicity on the protein adhesion onto the biomaterial modulates the cell attachment, proliferation and differentiation. β-TCP is a synthetic bone substitute with bioactive, osteoconductive properties. Insulin is a polypeptide hormone that acts as a growth-stimulating factor for some cells types in culture. Few studies have been discussing this hormone role in bone remodeling and cells metabolism in vitro. The aim of this work was to evaluate the cell responses when insulin is adsorbed on β-TCP commercial discs surfaces. FTIR detected the characteristics bands of insulin adsorbed on sintered powder surface. The insulin adsorption on discs surface increase its wettability and favored growth and differentiation of the pre-osteoblastics cells. Although no addition of differentiation factors was present, it was observed deposits of extracellular matrix and collagen at 7 days in culture. The increase on affinity and cellular activity to the adsorbed insulin β-TCP substract was remarkable. It was quite clear that the insulin presents a role on activate and speed up the bone cells response while adhered to β-TCP substract. However, the insulin application on bone grafts for clinical purposes must be considered after detailed studies on animal models, which are required to fully evaluate the safe use of hormone containing grafts in clinical trials.
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Authors: Masanori Kikuchi, Atsushi Irie
Abstract: Osteoclast differentiation of bone marrow cells on hydroxyapatite/collagen self-organized bone-like nanocomposite (HAp/Col) disk in vitro was evaluated by coculture of mouse bone marrow cells with mouse osteoblasts with or without addition of osteoclastic inducers, 1,25-Dihydroxyvitamin D3 and 1 µM prostaglandin E2. Dentine slice and tissue culture polystyrene were used as controls. Good osteoclastic differentiation at day 7 were observed among the bone marrow cells cultured on the HAp /Col disk and controls with osteoclastic inducers. On the contrary, osteoclastic differentiation was observed only for marrow cells cultured on the HAp/Col disk. Nano- and micro- structures as well as chemical and mechanical properties have a potential to control cell differentiation.
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Authors: D.W. Lee, E.J. Lee, Sung Su Chun, Myun Whan Ahn, I.W. Song, I.K. Kang, Suk Young Kim
Abstract: A collagen material was chemically grafted on hydroxyapatite (HA) to enhance bone cell attachment because the collagen is a major constituent of connective tissues and has been regarded as one of the most excellent coating materials for bone bonding. First, HA disks were prepared with 12mm diameter and 1mm thickness. And then collagen (type I) was immobilbized on the HA surface using a 3-APTES coupling agent on HA disk surfaces. MC3T3-E1 osteoblasts were seeded on the collagen-grafted and non-grated HA disks and cultured for 4 hrs to evaluate the cell adhesion on the HA discs. The Attached cell morphology on discs was observed with a fluorescent optical microscopy (FOM) and a scanning electron microscopy (SEM). The osteoblasts on the collagen-grafted sample were more spread than those on the non-grafted sample. It is believed that collagen-grafted HA surface provides suitable sites for cell attaching due to the high biocompatibility of collagen.
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Authors: Larry L. Hench, Julia M. Polak
Abstract: Historically the function of biomaterials has been to replace diseased, damaged and aged tissues. First generation biomaterials, including bio ceramics, were selected to be as inert as possible in order to minimize the thickness of interfacial scar tissue. Bioactive glasses provided an alternative from the 1970’s onward; second generation bioactive bonding of implants with tissues and no interfacial scar tissue. This chapter reviews the discovery that controlled release of biologically active Ca and Si ions from bioactive glasses leads to the up-regulation and activation of seven families of genes in osteoprogenitor cells that give rise to rapid bone regeneration. This finding offers the possibility of creating a new generation of gene activating bioceramics designed specially for tissue engineering and in situ regeneration of tissues.
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Authors: Guo Ping Chen, Takashi Ushida, Tetsuya Tateishi
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Authors: Giulio D. Guerra, Caterina Cristallini, Elisabetta Rosellini, Niccoletta Barbani
Abstract: Composites between hydroxyapatite (HA) and collagen (Col) may be used to make bioresorbable scaffolds for bone reconstruction. A suspension of micro-particles (average diameter ≅ 30 µm) of HA annealed at 1100°C in Col solution (80:20 HA to Col weight ratio) was manufactured in films by casting, and then some films were cross-linked by glutaraldehyde vapours. Cross-linked sponges were obtained by treating the suspension with transglutaminase, and by lyophilizing the so obtained gel. Characterization by scanning electron microscopy, water sorption test, Col release in water, thermogravimetric analysis and differential scanning calorimetry shows that the cross-linking enhances the stability of the composite. Conversely, neither the interactions between HA and Col, detected by spotlight FT-IR, nor the degradation by collagenase, which is a requirement for the bioresorbibility, are affected by the cross-linking.
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Authors: D.P. Li, Xiao Hong Wang, B. Meng, Qing Ling Feng, Fu Zhai Cui
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Authors: Jia Long Chen, Quan Li Li, Jun Ying Chen, Nan Huang
Abstract: This study deals with improving the cytocompatibility of titanium by a coating with heparin(hep), collagen(col) and CD34 antibody. Collagen and heparin molecules were adsorbed onto a titanium surface using a layer-by-layer (LBL) self-assembly technique. The col/hep coating were formed by alternating deposition of negatively charged heparin and positively charged collagen based on electrostatic interactions. Finally the CD34 antibody was absorbed onto the surface of col/hep coating by electrostatic interactions. The chemical composition and surface topography were investigated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The fluorescence microscopy images proved that the CD34 antibody was existed on the surface of the col/hep coating. The SEM results and the MTT test results showed that, compared to the surface of col/hep coating and the surface of titanium, the CD34 surface had better endothelial progenitor cells (EPCs) attachment and proliferation. The EPCs on the CD34 surface displayed the morphology of flat endothelium, and a confluent cell layer after cultured for 2d. This study suggested that this method maybe have good potential for surface modification of cardiovascular devices.
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Authors: Yong Liang Zhuang, Li Ping Sun
Abstract: Collagen was extracted from jellyfish (Stomolophus meleagris) and hydrolyzed to prepare collagen peptides. Three fractions (JCP-1<1kDa, 1kDa3kDa) were collected by ultrafiltration from jellyfish collagen peptides and inhibitory abilities of melanogenesis were evaluated using cultured B16 melanoma cells. The results showed three fractions could inhibit intracellular tyrosinase activity, decrease melanin content and enhance glutathione synthesis. Furthermore, they decreased intracellular cAMP levels and suppressed tyrosinase mRNA expression. JCP-2 showed much higher anti-melanogeneic activities than JCP-1 and JCP-3 because of its amino acids composition and molecular weight distribution. Our results indicated JCP-2 could be used as a natural skin-lightening agent in the medicine and food industries.
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