Carbon dioxide-assisted bioassembly of cell-loaded scaffolds from polymeric porous microspheres

A cell-friendly strategy based on the subcritical carbon dioxide (Sub-CO 2 ) sintering was developed for convenient single-step bioassembly of scaffolds from cellularized poly(lactic-co-glycolic acid) (PLGA) porous microspheres. The method has provided a versatile strategy to utilize the hierarchical voids of the scaffold, which allowed seeded cells to proliferate for 14   days (cartilage cells) and 21   days (fibroblasts), respectively. Furthermore, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) images indicated that the cartilage cells favored the surface of the porous microspheres, while the fibroblasts tended to grow into the porous microspheres and attach onto the walls of the inner pores. This modular strategy provides a convenient way to seed cells prior to bulk scaffold fabrication as the Sub-CO 2 processing is benign to cells, which will potentially find widespread applications in tissue engineering and regenerative medicine.