Openporous microspheres could provide large specific surface areas for cell adhesion and sustained cell growth. Introduction of cell-loaded microspheres into hydrogel might provide a cell-affinitive environment to maintain cell viabilities and improve cell growth in hydrogel system. Here, the open porous poly(ε-caprolactone) (PCL) microspheres were fabricated via the combinated phase separation of paraffin and emulsion/solvent evaporation method. The microspheres exhibited porous surface and internal connective pore structure. The surface pore size could be altered from 20 μm to 80 μm and the internal porosities were varied from 30% to 70%. The obtained microspheres were evaluated to delivery mesenchymal stem cells (MSCs). It was demonstrated that the cell adhesion and growth enhanced when compared with that of the none-porous microspheres. Subsequently, the MSCs loaded microspheres were introduced into agarose hydrogel. MSCs remained alive and well proliferated in microsphere/agarose composite in 5-day incubation while a decrement of MSCs viabilities was found in agarose hydrogel without microspheres. The results indicated that the microsphere/hydrogel composite had a great potential application in cell therapy and injectable system for tissue regeneration.
