Biological parameters for quality evaluation of allografts from the Brazilian National Institute of Traumatology and Orthopedics tissue bank

Bone allografts are clinically used in a variety of surgical procedures, and tissue banks are responsible for harvesting, processing, quality testing, storing, and delivering these materials for transplantation. In tissue banks, the bone is processed for the removal of all organic content, remaining only the tissue structure (scaffold). However, several studies have shown that even after using different processing methods, viable cells, functional proteins, and DNA may still persist in the tissue, which constitute the main causes of graft rejection. Therefore, the objective of this study was to establish techniques and biological parameters for quality validation of allografts. To this end, we propose the use of 3 combined methods such as microscopy, histology, and molecular biology techniques to evaluate the quality of allografts harvested and processed by the Brazilian National Institute of Traumatology and Orthopedics (INTO) tissue bank according to the donation criteria of the Brazilian National Health Surveillance Agency and the Brazilian National Transplant System. Bone fragments from different processing stages showed no viable cells on histology, an intact extracellular matrix on scanning electron microscopy, and gradual reduction in DNA amount. Different techniques were used to demonstrate the quality of allografts produced by the INTO tissue bank and to establish biological parameters for ensuring the safety and quality of these products. Future studies need to be undertaken to assess and validate the efficacy of the decellularization process in larger bone grafts with diverse architectural configurations.