Radiation Modification of Natural Polymers to Enhance Structure and Bioactivity

Abstract

A technique was developed for the radiation crosslinking of lyophilised demineralised bone matrix (DBM). The crosslinked demineralised bone matrix (DBM*) shows a marked enhancement in osteogenic potential in both the rate of new bone formation and the strength of the ensuing new bone. A further advantage of the crosslinking of the DBM* substrate in crosslinked collagen, is its increased mechanical strength and relative insolubility, ensuring it does not wash away upon implantation. The dry crosslinked DBM* and collagen mixture is stored under inert nitrogen gas, eliminating oxidative degradation and obviating the need to transport and store the product under refrigerated conditions, resulting in a shelf-life of at least five years.

Keywords:

• Bone growth
• natural polymers
• osteoinductivity
• radiation

Acknowledgments

The authors wish to express their appreciation to the National Tissue Bank at the University of Pretoria for their involvement in this project, Dr. Malan de Villiers from Southern Medical for his valuable support and Ms. J. R. Tasker for her valuable contribution to the alkaline phosphatase analyses.