Controllable preparation of bioactive open porous microspheres for tissue engineering

-glycolic acid) (PLGA with good biocompatibility approved by the Food and Drug Administration (FDA)) were developed by using a gas-assisted-emulsion and surface-alkalization-treatment technology (GEST). The gas-assisted-emulsion strategy enables the formation of microspheres with a large size of 200-300 μm, meanwhile, the microspheres have a large amount of micropores with diameter in the range of 10-60 μm. The following alkalization-treatment on the surface makes the microspheres form a good porous interconnectivity throughout both the surface and the interior of the microspheres. The good porous interconnectivity endows the microspheres with a highly open pore structure and a large specific surface area for nutrient exchange and cell attachment, thus promoting cell proliferation and nutrient transportation, promising their potential as an ideal cell carrier to increase cell density and bioactivity for cell therapy-based tissue engineering.