Preparation and Characterization of Poly(l-lactide-co-glycolide-co-ε-caprolactone) Porous Microspheres

Porous microspheres have interconnecting external and internal pore structure resulting in enormous specific surface area and have drawn attention for drug delivery. In this work, poly(l-lactide-co-glycolide-co-ε-caprolactone) (PLLGC) porous microspheres were prepared by a combined solvent evaporation and particle leaching method using gelatin as a porogen. The effects of preparation parameters on the morphologies of the porous microspheres were studied. The resultant microspheres showed porous surfaces and a three-dimensional internal network structure with interconnecting pores. The porous microsphere size decreased with increasing stirring speed and decreasing PLLGC concentration. There were fewer micropores on the surfaces of the microspheres with increasing temperature. The number of the pores and pore size on the surface of the microspheres increased with increasing gelatin content. By appropriate control of these factors (stirring speed 300 rpm, PLLGC solution concentration 1.0 wt%, temperature 0 °C, and gelatin concentration 7.5 wt%), a suitable porous microsphere, with a mean diameter of 200 μm, was prepared as a potential drug delivery agent.