A new era for sterilization based on supercritical CO₂ technology

Abstract

The increasing complexity in morphology and composition of modern biomedical materials (e.g., soft and hard biological tissues, synthetic and natural‐based scaffolds, technical textiles) and the high sensitivity to the processing environment requires the development of innovative but benign technologies for processing and treatment. This scenario is particularly applicable where current conventional techniques (steam/dry heat, ethylene oxide, and gamma irradiation) may not be able to preserve the functionality and integrity of the treated material. Sterilization using supercritical carbon dioxide emerges as a green and sustainable technology able to reach the sterility levels required by regulation without altering the original properties of even highly sensitive materials. In this review article, an updated survey of experimental protocols based on supercritical sterilization and of the efficacy results sorted by microbial strains and treated materials was carried out. The application of the supercritical sterilization process in materials used for biomedical, pharmaceutical, and food applications is assessed. The opportunity of supercritical sterilization of not only replace the above mentioned conventional techniques, but also of reach unmet needs for sterilization in highly sensitive materials (e.g., single‐use medical devices, the next‐generation biomaterials, and medical devices and graft tissues) is herein unveiled.

An efficient and inexpensive method for functionalizing metallic biomaterials used in orthopedic applications

“…Compared to plasma and ethylene oxide, steam sterilization could be an interesting alternative for large-scale sterilization. Thus, steam sterilization appears as the gold standard technique for sterilizing metal-based biomaterials and is widely used in hospitals and medical divisions [42]. Steam sterilization presents several advantages as it is nontoxic, inexpensive, bactericidal, has short treatment time and good penetration [43].…”

“…A new sterilization approach has been recently developed based on supercritical carbon dioxide (ScCO 2 ). This technique is efficient on temperature-sensitive materials but, to date, no specific international standard protocol has been developed for using this procedure, whereas steam sterilization is a well-established method for sterilizing biomaterial (ISO 17665-1:2006 "Moist heat/ Steam sterilization method") [42].…”

Use of supercritical carbon dioxide technology for fabricating a tissue engineering scaffold for anterior cruciate ligament repair

“…Ultrastructural morphology of Sc-CO 2 treated tendons was considered intact, when examined by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Notably, the authors did not evaluate the effect of Sc-CO 2 treatment alone, neither they tested different parameters, such as pressure, temperature, treatment time, which are known to be of paramount importance for the efficacy of the supercritical treatment 21 . Also, they acknowledged that tendon decellularization could not be achieved with their protocols despite the use of two different additives.…”

“…In addition, compressed CO 2 can also be used in biomaterial sterilization processes because it has the ability to kill bacteria, without altering the composition and the properties of the materials 20 . Sc-CO 2 technology has been proposed for the sterilization of highly-sensitive materials, such as medical devices, polymeric biomaterials, and grafts 21 .…”

Solvent-Free Approaches for the Processing of Scaffolds in Regenerative Medicine

“…Compared to other sintering methods, the main advantage relies on the ability to fabricate cell-seeded scaffolds in a single-step process [57,58]. Nevertheless, the well-known sterilization ability of CO 2 constrains the cell loading to scaffolds processed at high pressures or long expositions times [59]. Despite the advantages of the method, a paucity of research has been published and mainly focused on skeletal and cartilage tissue regeneration [60][61][62].…”