Porous biomedical composite microspheres developed for cell delivering scaffold in bone regeneration

Microspherical particles have attracted great interest as a delivery system of tissue cells in regenerative engineering. For hard tissue regeneration, here we exploited porous biomedical composite microspheres of hydroxyapatite–polycaprolactone (HA–PCL). The pore channels within the microsphere was facilitated by using camphene as the porogen, where the initial HA–PCL–camphene mixture in chloroform was solidified and the camphene was then sublimed to leave pore channels within the HA–PCL microspheres. The pore size increased with increasing camphene concentration, resulting in the generation of macropores (> 50 μm). Rat bone marrow mesenchymal stem cells were shown to proliferate actively on the porous microspheres penetrating deeply into the pore channels. Results suggest future applications of the porous composite microsphere as a cell delivery scaffold for bone tissue regeneration.