Controllable Fabrication of Porous PLGA Microspheres with Adjustable Degradability and Morphology as Cell Carrier

Polylactic acid-glycolic acid (PLGA) porous microspheres have attracted significant scholarly interest as cell carriers, attributed to their exceptional biocompatibility and three-dimensional porous architecture. Nonetheless, the modulation of surface morphology and degradability remains a pivotal factor affecting cell adhesion and proliferation. In this study, PLGA (75:25) was synthesized through an anhydrous, oxygen-free ring-opening polymerization process, employing a lactic acid/glycolide molar ratio of 3:1. Subsequently, PLGA porous microspheres, with diameters ranging from 200 to 250   µm, were fabricated via the double emulsion technique. The microspheres were produced using 4% sodium bicarbonate as the pore-forming agent, with a stirring speed of 300   r/min and a 2% polyvinyl alcohol (PVA) concentration in the outer aqueous phase. The resultant microspheres demonstrated a narrow particle size distribution, uniform surface porosity, and a high pore-forming efficiency. In comparison to solid microspheres, the degradation rate of PLGA porous microspheres was markedly elevated, as evidenced by a decrease in pH from 7.28 to 7.17 over a 28 days period. Additionally, the surface morphology of the microspheres exhibited significant collapse. Furthermore, the viability of L929 cells cultured with PLGA microspheres surpassed 95%, indicating superior biocompatibility and significantly promoting cell adhesion and proliferation. This investigation effectively optimized the preparation process, resulting in PLGA microspheres characterized by uniform particle size and high porosity, thus offering an optimal scaffold material for biomedical applications.