An open-pored gelatin/hydroxyapatite composite as a potential bone substitute.

Gelatin matrix composites reinforced with fine hydroxyapatite (HA) dispersants were investigated in an exploratory study for their suitability as surgical implants. The criteria for the candidate implant material were that it: (1) be benign, (2) have useful mechanical properties under quasi-in vivo environmental conditions, (3) be dimensionally stable, (4) be sterilizable, (5) be completely assimilable, and (6) exhibit contiguous porosity to encourage invasion by the live host tissue. The synthesis of a composite comprised of a HA particulate reinforcement of a cross-linked gelatin matrix was undertaken to provide preliminary data on its swelling behavior and compressive stiffness that is retained after extended immersion in normal saline solution. A new approach leading to a tailorable, open pore microstructure is described. At a sufficiently high ratio of HA to gelatin the attainable compressive stiffness and the resistance to swelling suggests that this composite system offers potential as a versatile surgical implant material. Suggestions for further studies are offered.