Plasma and nanomaterials for antimicrobial properties (PLASNANOBIAL)

• Grant number: 25/05217-5
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2025
• End date: September 30, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Physics of Fluids, Plasma Physics and Electrical Discharge
• Principal Investigator: Elidiane Cipriano Rangel da Cruz
• Grantee: Elidiane Cipriano Rangel da Cruz
• Principal researcher abroad: Amael Caillard
• Institution abroad: Université d'Orléans, France
• Host Institution: Instituto de Ciência e Tecnologia. Universidade Estadual Paulista (UNESP). Campus de Sorocaba. Sorocaba , SP, Brazil
• Associated researchers: Cristiane Yumi Koga Ito ; José Roberto Ribeiro Bortoleto ; Konstantin Georgiev Kostov ; Nilson Cristino da Cruz ; Tânia Aguiar Passeti ; William Chiappim Junior

Abstract

Antimicrobial resistance (AR), mostly caused by indiscriminate use of antibiotics, is an extremely worrying issue. In 2019, AR was associated to nearly 5 million deaths world-wide and it is estimated it could kill 10 million people per year in 2050. The reversion of such scenario, considered "terrible" by the World Health Organization in 2014, demands significant effort on multiple fronts, ranging from the establishment of proper antibiotics usage practices to the development of new antimicrobial agents. In this context, cold plasmas can be an immensely useful tool. In this type of discharge, the application of high electric fields can excite, ionize, and dissociate molecules of a gas or gas mixture, produc-ing a myriad of highly reactive species. Such species can interact with a material nearby or in contact with the plasma endowing it new chemical and physical characteristics. In this proposal the production of non-antibiotic bactericidal materials will be investigated using both atmospheric- and low- pressure plasmas. In one approach, atmospheric plasma jets fed with vapors of natural extracts, such as eugenol (extracted from cloves) and car-vacrol (oregano), will be used to incorporate reactive species into water and physiological solutions, to render liquids with expressive antimicrobial properties. Additionally, the same experimental setup will be used to coat materials, such as metals and polymers, with thin films derived from the extracts, to produce surfaces able to inhibit the adhesion and proliferation of microorganisms. On the other hand, low pressure plasmas, more specifi-cally, magnetron sputtering, will be applied to synthesize multimetallic nanoparticles (NPs) in different liquids. It will be investigated the effect of the fluid used as support on the physicochemical and antimicrobial properties of the NPs. The bactericidal and bacteriostatic effects of the NPs will be evaluated with in vitro microbiological tests using standard strains of Gram positive and Gram negative bacteria. In such tests, commercial nylon suture threads will be used as scaffolds for the multimetallic NPs. To this end, the threads will be immersed in the prepared colloidal sus-pensions immediately after activation with atmospheric pressure plasma jets fed with N2 and O2 mixtures. In vivo and in vitro microbiological tests will be conducted to evaluated the antimicrobial performance of the treated threads. (AU)