Plasma sterilization. Methods and mechanisms

TLDR

Plasma sterilization offers a heat‑sensitive alternative to conventional methods, providing effective sterilization while preserving material integrity. The study investigates the relative contributions of UV photons and reactive species, such as atomic and molecular radicals, to plasma‑based sterilization. The authors analyze the distinct physicochemical processes involved in plasma sterilization by examining spore survival curves and identifying key mechanisms. Under pressures below 10 torr and in oxygen‑rich mixtures, UV photons dominate the inactivation process, with oxygen atoms acting as erosion agents, and as erosion progresses, increased UV photon interaction with genetic material further enhances spore inactivation.

Abstract

Abstract Utilizing a plasma to achieve sterilization is a possible alternative to conventional sterilization means as far as sterilization of heat-sensitive materials and innocuity of sterilizing agents are concerned. A major issue of plasma sterilization is the respective roles of ultraviolet (UV) photons and reactive species such as atomic and molecular radicals. At reduced gas pressure (£10 torr) and in mixtures containing oxygen, the UV photons dominate the inactivation process, with a significant contribution of oxygen atoms as an erosion agent. Actually, as erosion of the spore progresses, the number of UV photons successfully interacting with the genetic material increases. The different physicochemical processes at play during plasma sterilization are identified and analyzed, based on the specific characteristics of the spore survival curves.