BACKGROUND:A preliminary experiment developed a double-chamber stirred bioreactor which can carry out osteogenic and cartilage induction at the same time.
OBJECTIVE:To explore the effects of double-chamber stirred bioreactor on the repair of goat knee cartilage defects with tissue-engineered cartilage.
METHODS:Twelve goats were selected to make bilateral femoral condyle osteochondral defects models and randomized to three groups:experimental group, implanted with the composites ofβ-tricalcium phosphate and bone marrow mesenchymal stem cells that were subjected to 2-week chondrogenic and osteogenic induction simultaneously in the double-chamber stirred bioreactor under mechanical stimulation;control group, implanted with the composites ofβ-tricalcium phosphate and bone marrow mesenchymal stem cells that were subjected to 2-week chondrogenic and osteogenic induction simultaneously in the double-chamber stirred bioreactor;blank control group, without treatment. After 12 and 24 weeks of implantation, general observation, Masson staining, II col agen immunohistochemical staining and histological scoring were performed.
RESULTS AND CONCLUSION:In the experimental and control groups, new cartilage tissue and bone tissue were visible, but the experimental group showed better repair effects than the control group (P<0.05). The blank control group had no cartilage formation. These findings indicate that under the mechanical stimulation by the double-chamber stirred bioreactor in vitro, the repair effect of tissue-engineered osteochondral complex on knee joint cartilage defects can be improved.

Objective To investigate the effect of calcitonin gene-related peptide (CGRP) on angiogenesis of human umbilical vein endothelial cells (HUVECs).Methods The HUVECs were collected from human umbilical core,and the expression of the CGRP receptor-1 was identified though immunofluorescence.After HUVECs were treated with CGRP,the angiogenesis was detected through tube formation experiment.The secretion of vascular endothelial growth factor (VEGF) was detected through ELISA method.The mRNA expression of VEGF,VEGF receptor-1 (FLT1),VEGF receptor-2 (KDR) and CGRP receptor-1 were detected through quantitative PCR (Q-PCR) at 3,7,10 days after culturing.Western blot method was used to detect the protein expression of FLT1 and KDR in HUVECs.Results Immunofluorescence result showed CGRP receptor-1 expressed in HUVECs.CGRP could significantly promote angiogenesis and increase VEGF secretion in direct manner.The Q-PCR results showed that the mRNA expression level of CGRP receptor-1 was significantly higher in CGRP groups than that in control group,especially at 10 days.Compared to the control group,the mRNA and protein expression level of FLT1 and KDR were statistically higher in CGRP groups at different time.Conclusion CGRP can significantly promote angiogenesis of HUVECs in vitro,which may be because it can promote VEGF secretion and expression of FLT1 and KDR in HUVECs.Meanwhile,the increase of CGRP receptor-1 expression also can promote angiogenesis of HUVECs.

BACKGROUND: Though there were many experiments addressing repairing osteochondral defects before, faulty restoration occurred at coupling interfaces. OBJECTIVE: To investigate the feasibility of repairing of osteochondral composite defects in rabbit knees with animal-origin osteochondral scaffold combined with bone marrow mesenchymal stem cells (BMSCs)/chondrocytes.METHODS: New Zealand white rabbits were randomly divided into the experimental, control and blank groups and prepared for unilateral knee joint osteochondral defects. Animal-origin osteochondral scaffold combined with BMSCs/chondrocytes, animal-origin osteochondral scaffold and no material was implanted to repair the defects in the experimental, control and blank groups, respectively. Healing condition was evaluated by gross observation, hematoxylin-eosin staining, and toluidine blue staining at 4, 8, and 12 weeks after operation. RESULTS AND CONCLUSION: At 12 weeks after operation, gross observation showed the defects were repaired completely without local depression and the regenerated tissues were fused with surrounding tissues in the experimental group. Hematoxylin-eosin staining and toluidine blue staining revealed that there were many new hyaline cartilages in the cartilage defects in which columnar cells were lined well and cartilage lacuna was obviously, also, there were many bony tissues in the bone defects. The regeneration cartilage, the underlying subchondral bone and host bone were coupled completely. The toluidine blue positive rate and histologic scores of the experimental group were superior to those of the control and blank groups (P < 0.05). It is demonstrated that animal-origin osteochondral scaffold combined with BMSCs/chondrocytes is an ideal method to repair defects between cartilage and the underlying subchondral bone.