Study on effect of PluronicF-127 and vascular endothelial growth factor composite delivery system for improving the survival of grafted fat / 生物医学工程学杂志

To explore the effect of PluronicF-127 and Vascular endthelial growth factor(VEGF) delivery system on the survival of the grafted fat, we divided fat harvest under the same condition into 4 groups. One group served as blank control; the other 3 groups served for experiments with respective to DMEM containing 20 ng/ml VEGF; DMEM containing 30% Pluronic F-127; DMEM containing 20 ng/ml VEGF and 30% Pluronic F-127, and then we transplanted the 4 groups of fat, subcutaneously, on the back of 3 groups of BALB/c nude mice (8 mice per group; injecting 4 points per mouse; 0.2 ml per point). At 3 weeks, 6 weeks and 12 weeks, we dissected the fat grafts, measured their weight retention, and put them in histopathologic examination with the use of HE and CD34 staining. And we compared the weight retention and microvessel density (MVD) of each experiment group versus those of control group. The relation between adipose cell and PluronicF-127 was observed through electron microscope. The results reveal that the MVD and weight of pluronicF-127 and VEGF of the experiment groups are significantly greater than those of other groups. The PluronicF-127 and VEGF composite delivery system can significantly improve the blood circulation for fat transplantation, and increase the survival rate of grafted fat.

Preparation and osteoinduction capacity of collagen/bone morphogenetic protein composites / 生物工程学报

Collagen/bone morphogenetic protein composites were prepared with collagen type I sponge and bone morphogenetic protein-2 (BMP-2). The composites were implanted into Latissimus dorsi muscles pouches of rabbits. Samples were studied with ALP staining, Von Kossa staining, HE staining, toluidine blue staining and CD31 histochemical labeling of microvessel. Bony samples were then used to repair mandibular defect. The effects were evaluated by X-ray, compressive strength, economycin fluorescence labeling, HE staining, toluidine blue staining and bone quantity analysis. Bone formation induced by collagen/BMP composites was found as woven bone between 4 and 6 weeks; cartilaginous osteogenesis was the main type of bone formation; microvessels could be seen in the bony tissues; and the bone defects were healed completely 6 weeks after operation. Bone formation induced by collagen/BMP composites in the muscles can be used as a donor to repair the bone defect.