Abstract: This invention provides a method of preparing microsphere composite of collagen and bioceramic powder. This method first mixes a collagen solution with bioceramic powder and alginate, and squeezes the mixture solution to spherical droplets being discharged into a divalent cation solution undergoing gelling to form microspheres. Next, the microsphere is coated with a chitosan solution. Then, interior alginate and surface chitosan of the microsphere are liquefied and washed out with an aqueous buffer solution such as phosphate based buffer, and collagen in the microsphere is reconstituted to fiber network at the same time. The prepared microsphere composite has similar composition components of bone tissue, and the collagen thereof has a network of reconstituted fibers. The microsphere composite of this invention provides a similar growth environment of bone tissue cells, is used as a carrier to carry cells, coat and fix bone growth factors, and is applied in bone repair.

Abstract: This invention relates to a method of polymerization of lactide or glycolide (GA) monomers and in particular to a method of polymerizing one type of the monomers or two types of the monomers using alkyl aluminum catalyst to proceed with bulk or solution polymerization to prepare biodegradable homopolymers or copolymers, and high-molecular-weight homopolymers of polylactide (PLA), polyglycolide (PGA), or copolymers of lactide/glycolide prepared thereof.