ABSTRACT
BACKGROUND: A silk fibroin/chitosan scaffold has good biocompatibility, osteoinductivity and degradability.OBJECTIVE: To review the structure, performance and application of the silk fibroin/chitosan scaffold in bone,cartilage and soft tissue engineering regeneration.METHODS: PubMed, Wanfang, and CNKI databases were retrieved by computer for articles related to the structure, performance and application of the silk fibroin/chitosan scaffold in orthopedics published from 1998 to 2016. The keywords were chitosan, silk protein, bone tissue engineering in English and Chinese, respectively.RESULTS AND CONCLUSION: The silk fibroin/chitosan scaffold is characterized by good biocompatibility, bone inductivity and biodegradability that make cells grow well on the scaffold. The silk fibroin/chitosan scaffold has been widely used in bone tissue engineering, and has a prominent performance in bone defect repair and cartilage injury treatment. Meanwhile, the silk fibroin/chitosan scaffold exerts a crucial role in wound healing as well as in the treatment of spinal nerve injury and other soft tissue injuries. However, the silk fibroin/chitosan scaffold currently is less reported in the clinical use due to various reasons, and it will be the main research direction of future efforts. As is known to us, silk protein can be used to prepare the cruciate ligament and construct tissue-engineered nuclei; therefore, the silk fibroin/chitosan scaffold can be developed in the treatment of tendon ligament injury and intervertebral disc tissue engineering.
ABSTRACT
BACKGROUND:Previous studies have confirmed that ethanol can promote adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), and up-regulate the expression of PPARγ and aP2 in the tumor necrosis factor α (TNF-α) signaling pathway. As a member of the ZIP protein family, Zrt/Irt-like protein 1 (ZIP1) is closely related to bone metabolism and osteogenic differentiation.OBJECTIVE:To study the effect of BMSCs transfected by ZIP1 on TNF-α signaling pathway in the process of adipogenic differentiation.METHODS:The BMSCs from rabbits were isolated and cultured under different concentrations of alcohol (0.03, 0.09,0.15, 0.21 mol/L), followed by transfection by ZIP1 siRNA and ZIP1 expression vector.RESULTS AND CONCLUSION:After culture in alcohol, the expression levels of aP2 and PPARγ proteins were both significantly increased (P < 0.05), and the level of triglyceride was increased in all alcohol groups except for 0.03 mol/L alcohol group (P < 0.05). After siRNA transfection, the expression levels of aP2 and PPARγ as well as the level of triglyceride were increased significantly in all the alcohol groups (P < 0.05); however, ZIP1 transfection decreased the expression levels of aP2 and PPARγ proteins (P < 0.05). To conclude, ZIP1 siRNA could promote the adipogenic differentiation of BMSCs through the activation of TNF-α signaling pathway.
ABSTRACT
BACKGROUND:Studies have shown that human cartilage glycoprotein-39 has a certain relationship to articular cartilage degeneration and repair, but the mechanism of action is not very clear. OBJECTIVE:To investigate the effect of human cartilage glycoprotein-39 on chondrogenesis of precartilaginous stem cels. METHODS: Precartilaginous stem cels were isolated from the adult articular cartilage. Cels which could express CD105 and CD166 were detected using flow cytometry folowed by isolation and purification. Isolated precartilaginous stem cels werecultured using monolayer method, and then, passage 2 cels were cultured in the medium containing human cartilage glycoprotein-39 and normal chondrogenic medium for 14 days, respectively. Immunohistochemical staining was used to observe expression of type II colagen and gross observation was done for evaluation of cartilage formation. RESULTS AND CONCLUSION:The precartilaginous stem cels isolated from the adult articular cartilage could express CD105 and CD166. After induction, differentiated precartilaginous stem cels gradualy gathered and formed nudes. The induced cels were positive for type II colagen; after induction by human cartilage glycoprotein-39, the nodules became larger and the expression of type II colagen was increased. These findings indicate that precartilaginous stem cels with chondrogenic ability can be isolated from the adult articular cartilage, and can be induced to differentiate into chondrocytes, in which human cartilage glycoprotein-39 plays an important role.