Preparation and characterization of lysine-modified polylactic acid microspheres

Lysine-modified polylactic acid microspheres were prepared by ammonolysis combined with emulsification and thermally induced phase separation technique. Lysine molecules have been successfully grafted onto the molecular chain of polylactic acid microspheres. The microspheres prepared under the optimum reaction condition have a desired homogeneous nanofibrous structure and improved hydrophilicity. Amino-modified polylactic acid nanofibre microspheres with a high porosity, large specific surface area, strong adsorption capacity, and rich in active amino groups were prepared for drug delivery applications by aminolysis combined with emulsion and thermally induced phase separation technique from a ternary ethylenediamine aqueous solution/PLLA-dioxane/propanetriol system.