A three-phase, fully resorbable, polyester/calcium phosphate scaffold for bone tissue engineering: Evolution of scaffold design.

Bone tissue engineering strategies are fundamentally based upon porous scaffold materials that serve as a support for ingrowth of host cells and/or provide a substrate for exogenously delivered cells. Here we report the application of a surface calcium phosphate (CaP) mineral layer to a macroporous polymeric/CaP composite biomaterial, with a macroporous interconnectivity, and its subsequent in vivo evaluation in a rodent femoral defect. The application of the mineral layer eliminates the fibrous tissue encapsulation and foreign body giant cell response commonly seen at the interface of polymeric materials, yet retains the unique characteristics of the parent material as being macroporous, completely biodegradable and possessing a high degree of interconnectivity. This represents the third generation of this scaffold material, incorporating iterative changes to the scaffold design in response to both materials and biological design criteria to produce a material with enhanced in vitro and in vivo performance.