A highly macroporous biodegradable composite scaffold for bone tissue engineering applications

A new composite scaffold for bone tissue engineering applications has been prepared by combining biodegradable poly(lactide-co-glycolide) (PLGA) with bioresorbable calcium phosphate cement particles (CaP) through the processes of particle fusion, particle leaching and phase separation. The scaffold is characterized by a high level of interconnected macroporosity, macropores of 0.8∼1.8 mm, porosities ranging from 81 to 91%, improved mechanical properties with respect to the polymer alone, controllable degradation rate and excellent dimensional stability during culture—with or without fibroblast-like cells. Scaffold properties were controlled by adjusting PLGA molar mass and concentration, CaP/PLGA ratio and porogen size. Testing mechanical properties in wet conditions at 37°C is more stringent than in dry conditions, but more relevant for materials to be employed in a biological milieu; the new scaffold was found to exhibit adequate mechanical properties in wet/37°C conditions and withstand the forces of cell contraction. The new composite was also osteoconductive in vivo. It was found that small (<20 μm) CaP particles favored bone ingrowth into, and remodeling of, the scaffold.