EXPOSURE OF BONE TO IONIZING RADIATION

Abstract

Interest in the effects of the action of electromagnetic ionizing radiation on bone arises from medical applications of ionizing radiation. Gamma irradiation is commonly used for preservation and sterilization in bone banking. It is a most popular preservation means in tissue banking. The selection of a sterilization dose is a compromise between a dose that is low enough to preserve important biological properties of tissue allografts and high enough to inactivate as many microorganisms as possible. The problem is additionally complicated by the possible presence of pathogenic viruses such as the human immunodeficiency virus (HIV), hepatitis viruses and others. The currently recommended dose in bone banking is 25-35 k Gy, which inactivates bacteria, but it is ineffective in the case of viruses. The advantage of such sterilization over autoclaving and chemical sterilization is that irradiation neither reduces osteogenic activity nor makes the toxic chemical agent applied in the sterilization remain in bone. Often, prior to irradiation, bone undergoes other treatments such as freeze-drying and lipid extraction, which enables shelf storage of years.