Study On The Preparation And Applications Of New Style Poly (Lactic Acid) Microspheres

PLA is a biodegradable polymer with good biocompatibility and biodegradability, which has been widely employed in biomedical field.The hollow porous poly (lactic acid) microspheres (HPPLAs) were prepared by multiple emulsion (W_in/O/W_out) -solvent evaporation method and the influence of stabilizer Span80 concentration in oil phase on morphology was investigated. It was found that most HPPLAs were sized about 2μm in diameter when the content of Span80 solutions was 3.5wt%. Using these HPPLAs as degradable template, we had successfully synthesized Litchi-like polystyrene (PS) microspheres sized about 2μm in diameter by emulsion method. Moreover, the functional porous poly (lactic acid) microspheres (HPLAs) sized about 2μm in diameter with uniform particle diameter were prepared by O/W emulsion solvent evaporation method.The functional porous aspirin/PLA microspheres were prepared by multiple emulsion(W_in/O/W_out)-solvent evaporation method. The microspheres can control the release of aspirin, which may reduce the disadvantages of the vatious gastrointestinal side effects. The microspheres were sized about 2μm in diameter and the size of these microspheres agrees well with sustained-release formula tule. Higuchi equation was Q = 28.900+6.6844 t^1/2,ρ=0.999, It was obvious that aspirin was released from the microspheres in a sustained fashion.