• Korean Journal of Materials Research
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• v.34 no.4
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• pp.215-222
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• 2024

Because collagen is inherently piezoelectric, research is being actively conducted to utilize it to harvest energy. In this study, a collagen solution was prepared using edible low-molecular-weight peptide collagen powder, and collagen films were fabricated using a dip coating method. The collagen films prepared by dip coating showed a smooth surface without defects such as pinholes or cracks. Dehydrothermal treatment of the collagen films was performed to induce a stable molecular structure through cross-linking. The collagen film subjected to dehydrothermal treatment at 110 ℃ for 24 h showed a thickness reduction rate of 19 %. Analysis of the collagen films showed that the crystallinity of the collagen film improved by about 7.9 % after dehydrothermal treatment. A collagen film-based piezoelectric nanogenerator showed output characteristics of approximately 13.7 V and 1.4 ㎂ in a pressure test of 120 N. The generator showed a maximum power density of about 2.91 mW/m² and an output voltage of about 8~19 V during various human body movements such as finger tapping. The collagen film-based piezoelectric generator showed improved output performance with improved crystallinity and piezoelectricity after dehydrothermal treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.112-119
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• 2011

Purpose: Collagen membranes are used extensively as bioabsorbable barriers in guided bone regeneration. However, collagen has different effects on tissue restoration depending on the type, structure, degree of cross-linking and chemical treatment. The purpose of this study was to evaluate the inflammatory reaction, bone formation, and degradation of dehydrothermal treated porcine type I atelocollagen (CollaGuide$^{(R)}$) compared to of the non-crosslinked porcine type I, III collagen (BioGide$^{(R)}$) and the glutaldehyde cross-linked bovine type I collagen (BioMend$^{(R)}$) in surgically created bone defects in rat mandible. Methods: Bone defect model was based upon 3 mm sized full-thickness transcortical bone defects in the mandibular ramus of Sprague-Dawley rats. The defects were covered bucolingually with CollaGuide$^{(R)}$, BioMend$^{(R)}$, or BioGide$^{(R)}$ (n=12). For control, the defects were not covered by any membrane. Lymphocyte, multinucleated giant cell infiltration, bone formation over the defect area and membrane absorption were evaluated at 4 weeks postimplantation. For comparison of the membrane effect over the bone augmentation, rats received a bone graft plus different covering of membrane. A $3{\times}4$ mm sized block graft was harvested from the mandibular angle and was laid and stabilized with a microscrew on the naturally existing curvature of mandibular inferior border. After 10 weeks postimplantation, same histologic analysis were done. Results: In the defect model at 4 weeks post-implantation, the amount of new bone formed in defects was similar for all types of membrane. Bio-Gide$^{(R)}$ membranes induced significantly greater inflammatory response and membrane resorption than other two membranes; characterized by lymphocytes and multinucleated giant cells. At 10 weeks postoperatively, all membranes were completely resorbed. Conclusion: Dehydrotheramal treated cross-linked collagen was safe and effective in guiding bone regeneration in alveolar ridge defects and bone augmentation in rats, similar to BioGide$^{(R)}$ and BioMend$^{(R)}$, thus, could be clinically useful.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.413-419
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• 2007

Purpose: In this study, porous type I collagen scaffolds were cross-linked using dehydrothermal(DHT) treatment and/or 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide(EDC), in the presence and absence of chondroitin-6-sulfate(CS) and cultured autologous chondrocytes(Chondro) for cartilage regeneration. Methods: Cartilage defects were created in the proximal part of the ear of New Zealand rabbits. Four prepared types of scaffolds(n=4) were inserted. The groups included Chondro-Collagen-DHT(Group 1), Chondro- Collagen-DHT-EDC(Group 2), Chondro-CS-Collagen- DHT(Group 3), and Chondro-CS-Collagen-DHT-EDC (Group 4). Histomorphometric analysis and cartilage-specific gene expression of the reconstructed tissues were evaluated 4, 8, and 12 weeks after implantation. Results: EDC cross-linked groups 2 and 4 regenerated more cartilage than other groups. However, calcification was observed in the 4th week after implantation. CS did not increase chondrogenesis in all groups. Cartilage-specific type II collagen mRNA expression increased in the course of time in all groups.Conclusion: EDC cross-linking methods maintain the scaffold and promote extracellular matrix production of chondrocytes.

• Archives of Plastic Surgery
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• v.33 no.6
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• pp.723-731
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• 2006

Purpose: Collagen is the principal structural biomolecule in cartilage extracellular matrix, which makes it a logical target for cartilage engineering. In this study, porous type I collagen scaffolds were cross-linked using dehydrothermal(DHT) treatment and/or 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide(EDC), in the presence and absence of chondroitin-6-sulfate(CS) for cartilage regeneration. Methods: Cartilage defects were created in the proximal part of the ear of New Zealand rabbits. Four types of scaffolds(n=4) were inserted. The types included DHT cross-linked(Group 1), DHT and EDC cross- linked(Group 2), CS added DHT cross-linked(Group 3), and CS added DHT and EDC cross-linked(Group 4). Histomorphometric analysis and cartilage-specific gene expression of the reconstructed tissues were evaluated respectively 4, 8, and 12 weeks after implantation. Results: The largest quantity of regenerated cartilage was found in DHT cross-linked groups 1 and 3 in the 8th week and then decreased in the 12th week, while calcification increased. Calcification was observed from the 8th week and the area increased in the 12th week. Group 4 was treated with EDC cross-linking and CS, and the matrix did not degrade in the 12th week. Cartilage-specific type II collagen mRNA expression increased with time in all groups. Conclusion: CS did not increase chondrogenesis in all groups. EDC cross-linking may prevent chondrocyte infiltration from the perichondrium into the collagen scaffold.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.439-443
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• 2006

Biocompatibility and tissue regenerating capacity are essential characteristics in the design of collagenous biomaterials for tissue engineering. Attachment of glycosaminoglycans to collagen may add to these characteristics by creating an appropriate micro-environment. In this study, porous type I collagen matrices were crosslinked using dehydrothermal treatment and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide, in the presence and absence of chondroitin sulfate (CS). The scaffold like discs in 3 mm diameter were inserted into the intralamellar stromal pockets of rabbit cornea. In 8 weeks of follow up, clinical evaluation including corneal neovascularization, opacity and transparency of the graft scaffold was performed, and the inflammatory reaction and migration of corneal fibroblast were evaluated histologically. No inflammation, neovascularization and opacity in any of the implant were observed. CS increased the corneal fibroblast invasion and the transparency. It is concluded that the type I collagen sponge showed a biocompatibility in corneal stromal layer and addition of CS slightly improved the quality of the bioartificial corneal stromal layer. These results could be useful for the development of corneal substitutes.