TO EVALUATE THE QUALITY OF CRYOPRESERVED GAMMA-STERILIZED DOG SKULL AT TISSUE CRYOPRESERVATION UNIT - HUE UNIVERSITY OF MEDICINE AND PHARMACY HOSPITAL

Abstract

Objective: To evaluate the effect of gamma sterilization and the changes in the durability and the histological structure of cryopreserved gamma-sterilized dog skull. Subjects and methods: 50 dog skull fragments had the same size (4 x 4 cm), which were taken at parieto-frontal region, symmetrically through the midline of the skull were divided into two lots. Evident lot consisting of 50 fragments were just cryopreserved, not irradiated by gamma rays. Experimental lot which composed of 50 fragments were cryopreserved and exposed to 25 kGy of gamma radiation. Afterwards, evaluating the changes in the durability, microscopic structure and the effectiveness of sterilization on the dog skull after being cryopreserved at -85 0C in 3 months and exposed a gamma sterilization. Results: The durability was decreased of 8.28% compared with the lot of dog skull just cryopreserved at -85 0C and not exposed a gamma sterilization. On histological structure, no difference was found between the two lots and there was no structural change in the irradiated dog skull. All gamma-sterilized dog skull fragments were negative with bacteria culture test. The gamma ray had the ability to kill bacteria completely in the type of bacteria commonly infected tissue. Conclusion: After being cryopreserved at -85 0C in 3 months and exposed a gamma sterilization dose of 25 KGy, the durability of dog skull was insignificantly decreased and the microscopic structure was not changed. All irradiated dog skull fragments were negative with bacteria culture test. Key words: dog skull, gamma, durability, irradiated