Preparation of nanohydroxyapatite–gelatin porous scaffold and mechanical properties at cryogenic environment

Abstract

Highly porous and machinable nanohydroxyapatite–gelatin scaffold was prepared through the freeze casting technique. Mechanical properties, particularly compressive strength, were improved after curing in liquid nitrogen. Cryogenic temperature (77K) reduced the hydrocarbon bond length, anchored the nanorod HAp particles within organic matrix of original scaffolds and altered the stress–strain characteristics. The compressive strength of 75vol% porous scaffold was increased up to 6MPa but strength was decreased beyond 5h cryogenic treatment because of abrupt porosity increase, excessive internal stress and micro-cracking. Crack wake bridging of high damage tolerant scaffold was observed at optimum cryogenic condition.