Vascularization of poly(hydroxybutyrate-co-hydroxyoctanoate) osteochondral scaffold in vitro / 中国组织工程研究

BACKGROUND:The poly(hydroxybutyrate-co-hydroxyoctanoate) osteochondral scaffold which has been constructed in previous experiments has good biocompatibility and biodegradability and generates non-toxic degradation products. OBJECTIVE:To observe the vascularization of rabbit renal microvascular endothelial cels co-cultured with poly(hydroxybutyrate-co-hydroxyoctanoate) osteochondral scaffold. METHODS:The poly(hydroxybutyrate-co-hydroxyoctanoate) osteochondral scaffold having a three-layer structure (layer of bone/bone and cartilage interface layer/layer of cartilage) was prepared by solvent casting/particle leaching method. The renal microvascular endothelial cels at passage 3 were seeded onto the scaffold of bone layer. The proliferation of the renal microvascular endothelial cels growing on the scaffolds was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, the growth of cels in the scaffold was observed by hematoxylin-eosin staining under electron microscope after 10 days. RESULTS AND CONCLUSION:The integrated osteochondral scaffold had a clear appearance of three-layer structure, which had closed connections between the three layers. Porous bone layer was visible as wel as uniform and interlinked pores, and the porosity was 78%. The renal microvascular endothelial cels seeded onto the scaffold proliferated wel and presented a three-dimensional growth after 10 days of co-culture, but there were no cels on the interface layer. Cels which adhered and grew between the pores of the bone layer were observed through hematoxylin-eosin staining. Cels showed a luminal-like structure growing on the scaffold with the porous structure, but they did not grow into the interface layer of bone and cartilage.

Cell affinity of cartilage tissue engineering scaffolds prepared by poly(hydroxybutyrate-co-hydroxyoctanoate)/collagen composite materials / 中国组织工程研究

BACKGROUND:Many experiments have demonstrated that tissue engineering scaffolds prepared by polymer materials alone or biomaterials cannot meet the requirement of tissue engineering research. OBJECTIVE:To evaluate biological characteristics and cel affinity of poly(hydroxybutyrate-co-hydroxyoctanoate)/col agen composite scaffold. METHODS:Tissue engineering scaffolds were prepared by combination of poly(hydroxybutyrate-co-hydroxyoctanoate) and col agen at different proportions (2%, 4%, 6%, 8%and 10%) using solvent casting/particulate leaching method. Inner structure and apertures were observed by scanning electron microscope, and the porosity was determined by liquid displacement method. Rabbit chondrocytes were co-cultured with poly(hydroxybutyrate-co-hydroxyoctanoate)/col agen composite scaffold and poly(hydroxybutyrate-co-hydroxyoctanoate) scaffold. Growth curve of cel s was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cel adhesion on the scaffolds was observed by scanning electron microscope. RESULTS AND CONCLUSION:The pore size and porosity of the composite scaffold were about 200μm and (85±2)%, respectively. The cel affinity dynamical y increased with the increasing of proportion of col agen. Compared with the poly(hydroxybutyrate-co-hydroxyoctanoate) scaffold, the poly(hydroxybutyrate-co-hydroxyoctanoate)/col agen composite scaffolds are better to improve cel adhesion and proliferation, with favorable cel ular affinity.

Short-term therapeutic effect of neoadjuvant chemotherapy with herceptin and docetaxel in patients with localized advanced breast cancer / 中国综合临床

Objective To investigate the efficacy and adverse effect of herceptin combined with docetaxel in patients with localized advanced breast cancer. Methods 16 patients with localized advanced breast cancer were treated with herceptin (8 mg/kg in the first cycle and 6 mg/kg from 2 to 4 cycles,d1) and docetaxel (75 mg/m2 ,d2) for 4 cycles. Three weeks were taken as a cycle. Following chemotherapy, the patients underwent improved radical operation of breast cancer or radical operation of preserving breast. Results The overall response rate (oRR) was 87.5%. The complete clinical remission rate (cCR) was 56. 3%. The complete pathologic remission rate (pCR) was 25.0%. The mainly adverse effects were bone marrow depression and gastrointestinal toxicity. Conclusion The regimen of herceptin combined with docetaxel is effective and can be well-tolerated by patients with localized advanced breast cancer. It shows promising prospect in clinical application.