Comparison of some properties of tissue grafts sterilized by cold shock and ionizing radiation

The paper compares some essential properties of grafts prepared for clinical grafting by a common procedure (sterilizing by cold shock, preservation by freeze-drying) with those experimental grafts sterilized by 2.5 Mrad gamma rays from a 60Co source before or after preservation by freeze-drying. In rib-bone grafts, the course of re-hydration and the mechanical properties were tested. The results indicate that radiation sterilization is not a suitable method for bone grafts. In rib-cartilage grafts, the rates of weight and volume increasing during re-hydration were examined and the differences compared. The content of potassium and mucoproteins released into the eluate was measured during re-hydration in order to obtain some insight into the type of radiation damage. Sterilization by irradiation was again found unsuitable. In skin, chorion and fascia grafts, the permeability was evaluated. For skin and fascia grafts, the prospect of using ionizing radiation for sterilization purposes seems promising. More data are still needed to reach a definite conclusion. (author)