首页|期刊导航|中华医学杂志（英文版）|Biodegradable chitosan scaffolds containing microspheres as carriers for controlled transforming growth factor-β1 delivery for cartilage tissue engineering
中华医学杂志（英文版）2007，Vol.120Issue(3)：197-203,7.
Biodegradable chitosan scaffolds containing microspheres as carriers for controlled transforming growth factor-β1 delivery for cartilage tissue engineering
Biodegradable chitosan scaffolds containing microspheres as carriers for controlled transforming growth factor-β1 delivery for cartilage tissue engineering
摘要
Abstract
Background Natural articular cartilage has a limited capacity for spontaneous regeneration. Controlled release of transforming growth factor-β1 (TGF-β1) to cartilage defects can enhance chondrogenesis. In this study, we assessed the feasibility of using biodegradable chitosan microspheres as carriers for controlled TGF-β1 delivery and the effect of released TGF-β1 on the chondrogenic potential of chondrocytes.Methods Chitosan scaffolds and chitosan microspheres loaded with TGF-β1 were prepared by the freeze-drying and the emulsion-crosslinking method respectively. In vitro drug release kinetics, as measured by enzyme-linked immunosorbent assay, was monitored for 7 days. Lysozyme degradation was performed for 4 weeks to detect in vitro degradability of the scaffolds and the microspheres. Rabbit chondrocytes were seeded on the scaffolds containing TGF-β1 microspheres and incubated in vitro for 3 weeks. Histological examination and type Ⅱ collagen immunohistochemical staining was performed to evaluate the effects of released TGF-β1 on cell adhesivity, proliferation and synthesis of the extracellular matrix.Results TGF-β1 was encapsulated into chitosan microspheres and the encapsulation efficiency of TGF-β1 was high (90.1%). During 4 weeks of incubation in lysozyme solution for in vitro degradation, the mass of both the scaffolds and the microspheres decreased continuously and significant morphological changes was noticed. From the release experiments, it was found that TGF-β1 could be released from the microspheres in a multiphasic fashion including an initial burst phase, a slow linear release phase and a plateau phase. The release amount of TGF-β1 was 37.4%, 50.7%,61.3%, and 63.5% for 1, 3, 5, and 7 days respectively. At 21 days after cultivation, type Ⅱ collagen immunohistochemical staining was performed. The mean percentage of positive cells for collagen type Ⅱ in control group (32.7%± 10.4%) was significantly lower than that in the controlled TGF-β1 release group (92.4%±4.8%, P＜0.05). Both the proliferation rate and production of collagen type Ⅱ in the transforming growth factor-β1 microsphere incorporated scaffolds were significantly higher than those in the scaffolds without microspheres, indicating that the activity of TGF-β1 was retained during microsphere fabrication and after growth factor release.Conclusion Chitosan microspheres can serve as delivery vehicles for controlled release of TGF-β1, and the released growth factor can augment chondrocytes proliferation and synthesis of extracellular matrix. Chitosan scaffolds incorporated with chitosan microspheres loaded with TGF-β1 possess a promising potential to be applied for controlled cytokine delivery and cartilage tissue engineering.关键词
chitosan/microsphere/transforming growth factor/sustained release/chondrocyteKey words
chitosan/microsphere/transforming growth factor/sustained release/chondrocyte分类
医药卫生引用本文复制引用
CAI Dao-zhang,ZENG Chun,QUAN Da-ping,BU Li-si,WANG Kun,LU Hua-ding,LI Xiao-feng..Biodegradable chitosan scaffolds containing microspheres as carriers for controlled transforming growth factor-β1 delivery for cartilage tissue engineering[J].中华医学杂志（英文版）,2007,120(3):197-203,7.基金项目
This research was supported by grants from the National Natural Science Foundation of China (No.30000056) and the Science and Technology Project Foundation of Guangdong Province (No.2003A302102). （No.30000056）
