An ultrastructural study of the biocompatibility of poly(2-hydroxyethyl methacrylate) in bone.

Because of the unique properties for swelling in a fluid medium and variable modulus of elasticity, hydrophilic methacrylates may be of potential usefulness for implanting prosthetic devices in bone. To investigate the biocompatibility, electron micrographic studies were done on specimens of poly(2-hydroxyethyl methacrylate) imbedded in bone for varying periods of time. Ultrastructural examination revealed progressive ossification of surrounding connective tissue up to the tissue polymer junction over a 6 month period. There was no evidence of inflammatory response. Based upon this study, it would appear that bone adjusts to an implant of hydrophilic methacrylate by ossification to the implant junction. This supports continued studies into the usefulness of this material as an implant.