The effect of γ‐irradiation on collagen molecules, isolated α‐chains, and crosslinked native fibers

Abstract

This study shows how collagen molecules are readily damaged by γ-radiation at dosages commonly used for sterilizing biomedical products. At 1 Mrad, while the reported effectiveness of the radiation at such a low dosage to completely sterilize a material is questionable, less damage was caused to the collagen peptide backbone. Above such dosage, however, significant damage was clearly demonstrated with collagen alone and collagen in a chemically crosslinked tissue matrix. The enzyme digestion study showed that the material exposed to a very high dosage of radiation resisted degradation by pronase. However, molecular weight analysis showed a significant number of peptide bonds being cleaved by the radiation which could cause considerable changes in the long-term characteristics of the material. Therefore, tissues exposed to high dosages of γ-radiation should be tested for long term functional changees. We want to caution against the usag of the enzyme degradation assay as a universal test for all bioprosthetic derived from biological tissues.