Chemical sterilization of allograft dermal tissues

Abstract

Common terminal sterilization methods are known to alter the natural structure and properties of soft tissues. One approach to providing safe grafts with preserved biological properties is the combination of a validated chemical sterilization process followed by an aseptic packaging process. This combination of processes is an accepted method for production of sterile healthcare products as described in ANSI/AAMI ST67:2011. This article describes the validation of the peracetic acid and ethanol-based (PAAE) chemical sterilization process for allograft dermal tissues at the Musculoskeletal Transplant Foundation (MTF, Edison, NJ). The sterilization capability of the PAAE solution used during routine production of aseptically processed dermal tissue forms was determined based on requirements of relevant ISO standards, ISO 14161:2009 and ISO 14937:2009. The resistance of spores of Bacillus subtilis, Clostridium sporogenes, Mycobacterium terrae, Pseudomonas aeruginosa, Enterococcus faecium, and Staphylococcus aureus to the chemical sterilization process employed by MTF was determined. Using a worst-case scenario testing strategy, the D value was calculated for the most resistant microorganism, Bacillus. The 12D time parameter determined the minimum time required to achieve a SAL of 10. Microbiological performance qualification demonstrated a complete kill of 10 spores at just a quarter of the full cycle time. The validation demonstrated that the PAAE sterilization process is robust, achieves sterilization of allograft dermal tissue to a SAL 10, and that in combination with aseptic processing secures the microbiological safety of allograft dermal tissue while avoiding structural and biochemical tissue damage previously observed with other sterilization methods such as ionizing irradiation.

Processing of collagen based biomaterials and the resulting materials properties

“…The sterilant has to be completely exchanged by sterile PBS or saline solution, and this exchange has to be performed under sterile conditions. The method is permitted by the authorities to sterilize implants, though it is not an end product sterilization [451, 465, 466]. Therefore, it is required to remove all remnants of PAA by aseptic washing steps.…”

A New Technology of Bactericidal Processing of Koch's Bacillus on the Basis of Pulsed Electromagnetic Radiation

“…Nowadays, there are chemical and physical means of controlling pathogens of infectious diseases that are found in the air, on the surface of various objects, indoors and so on [1][2][3][4][5][6][7]. Application of chemical methods for sterilizing objects of various physical nature along with the use of the necessary equipment is a potential danger itself, since various chemical reactions that lead to changes in physical-chemical and biological properties of the processed objects can be initiated [1], [2].…”

Acellular Dermal Matrix–Associated Complications in Implant-Based Breast Reconstruction: A Multicenter, Prospective, Randomized Controlled Clinical Trial Comparing Two Human Tissues

“…AlloDerm undergoes a terminal sterilization process that includes electron beam irradiation and is sterile to a sterility assurance level of 10 −3 , whereas FlexHD is aseptically processed to comply with the requirements of United States Pharmacopeia sterility tests, going through a validated chemical sterilization process to achieve a sterility assurance level of 10 −6 . 14 Complications have long been a primary concern related to the use of acellular dermal matrices. Early reports suggested an increased risk of postoperative complications, most notably seroma and infection, after human acellular dermal matrix-associated implant-based breast reconstruction when compared with total muscle coverage.…”

“…AlloDerm undergoes a terminal sterilization process that includes electron beam irradiation and is sterile to a sterility assurance level of 10 −3 , whereas FlexHD is aseptically processed to comply with the requirements of United States Pharmacopeia sterility tests, going through a validated chemical sterilization process to achieve a sterility assurance level of 10 −6 . 14…”