Nonthermal plasma approaches for combating implant-associated infections: A compendious review

Bacterial resistance to antibiotic therapies, coupled with the propensity of microbes to develop highly recalcitrant biofilms on medical devices, which are primary cause of implant failures. These infections necessitate complex revision surgeries and contribute to morbidity and mortality rates in healthcare. Despite the limitations inherent in various targeted sterilization approaches, nonthermal plasma (NTP) has emerged as a highly potent and versatile technology for the decontamination of medical device surfaces. In our review, initially, we discussed comprehensively the implant surface physicochemical attributes that cause the attachment of bacteria, which advances to biofilms on the medical device surfaces. Key findings discuss various antimicrobial approaches, distinctly categorizing plasma interventions. Plasma surface modification (PSM) is highlighted for altering surface wettability and immobilizing antimicrobial agents. Furthermore, the review evaluates plasma-activated liquids (PALs) for their role in delivering reactive species to complex geometries. In contrast, direct NTP approaches emphasize the immediate gaseous-phase interaction of reactive oxygen and nitrogen species (RONS) with the device surface to achieve acute infection control. The review analyses the overall NTPs in vitro studies, mostly using plasma-treated liquids, and in vivo by infiltration of ROS, generating oxidative stress and DNA leakage from the cell walls, as demonstrated efficiently against a broad range of bacteria. The review concludes with the challenges, such as standardization of plasma type and its process parameters.