High pressure pasteurization: Simultaneous native tissue decellularization and sterilization

Terminal sterilization is important for the clinical applicability of decellularized xenografts. High hydrostatic pressurization (HHP) process is a potential strategy for decellularization and decontamination of xenografts; however, its disinfection efficiency remains poorly elucidated. This study investigated the disinfection efficacy of the HHP process at physiologically relevant 36 °C against difficult-to-kill spore-forming bacteria. Bacillus atrophaeus and Geobacillus stearothermophilus were suspended in a pressurization medium with or without antibiotic agents and pressurized under two different HHP procedures: repeated and sustained pressurization. The sustained pressurizing conditions, exploited for the conventional tissue decellularization, did not effectively eliminate the bacteria; however, repeated pressurization greatly increased the disinfection effect. Moreover, the antibiotic-containing pressurization medium further increased the disinfection efficiency to the level required for sterilization. The optimized high hydrostatic pressurization can be used to sterilize biological tissues during the decellularization process and is a promising strategy for manufacturing tissue-derived healthcare products.