ObjectiveTo study absorbed mechanism of free bone auto-graft in cranium.MethodsTwenty-four adult New Zealand rabbits were randomly divided into two groups of twelve each. Cranium graft or rib graft was implanted on each side of the cranium. The onlay graft was harvested at the 12th and 24th week, and the collagen fibers were scrutinized under scanning electron microscope. ResultsThe number of the bone collagen fibrils at twenty- fourth week was more than that of the twelfth week, the arrangement of collagen fibrils at the twenty- fourth week was more regular than that of the twelfth week, and the collagen fibrils of the cranium graft were more numberous and regular than those of the rib graft observed at the twelfth week, but they were similar at twenty - fourth week. ConclusionRemoding time of cranium graft is shorter than that of rib graft, but bone remoding of both cranium and rib has finished in 24th week after operated.

OBJECTIVETo explore a feasible method to repair full-thickness skin defects with tissue engineered techniques.

METHODSThe skin specimens were cut from the Changfeng hybrid swines' abdomen, then keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA and type II collagenase. The cells were seeded in petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with dispase II (keratinocytes) or trypsin (fibroblasts) to separate them from the floor of the tissue culture dishes. A biodegradable material-pluronic F-127 was prefabricated and mixed with these cells, and then the cells-pluronic compounds were seeded evenly into polyglycolic acid (PGA). Tinally the constructs were replanted to autologous animals to repair full-thickness skin defects. Histological changes were observed in 1, 2, 4 and 8 weeks postsurgery.

RESULTSThe cells-pluronic F-127-PGA compounds could repair autologous full-thickness skin defects. Histologically, the tissue engineered skin was similar to normal skin with stratified epidermis overlying a moderately thick collageneous dermis.

CONCLUSIONTissue engineered skin can repair autologous full-thickness skin defects with primary-cultured keratinocytes and fibroblasts as seed cells and PGA as a cell carrier.

Animals ; Female ; Fibroblasts ; physiology ; Male ; Polyglycolic Acid ; pharmacology ; Skin Transplantation ; Skin, Artificial ; Swine ; Tissue Engineering