EVALUATION OF THE INTERACTION BETWEEN FUNCTIONALIZED NANODIAMONDS AND CELL MEMBRANE MIMETIC MODELS OF GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA

• Grant number: 24/00313-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: December 31, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Pedro Henrique Benites Aoki
• Grantee: Giovanna Eller Silva Sousa
• Host Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil
• Associated research grant: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis, AP.TEM

Abstract

Bacterial infections pose a significant global public health challenge, as pathogens can cause diseases ranging from mild to life-threatening. The escalating bacterial resistance to current generations of antibiotics necessitates the exploration of alternative treatment strategies. Bacteria employ their membranes as part of their defense mechanisms, but their strategies exhibit variations. Structural disparities in the cell membranes of Gram-positive and Gram-negative bacteria play a pivotal role in their responses to antimicrobial agents.Gram-negative bacteria utilize outer membrane proteins, including porins, to facilitate the passage of small molecules. Conversely, Gram-positive bacteria employ approaches such as thickening the cell wall with peptidoglycan and producing enzymes that degrade antibiotics. Nanostructures, notably nanodiamonds (NDs), are emerging as promising alternatives for combating infections, particularly in cases of bacterial resistance.The functionalization of these nanostructures with carboxyl groups, generating NDCOOHs, has demonstrated efficient antimicrobial activity by affecting the bacterial membrane and inducing cell death. Nevertheless, the mechanisms involved in this process are not fully understood, and in vitro and in vivo methods do not permit direct investigations of the interactions between these nanostructures and bacterial cell membranes at the molecular level. A comprehensive understanding of these processes is imperative for the development of effective prevention and treatment strategies, addressing the global challenge of bacterial resistance.In this context, cell membrane models, such as Langmuir monolayers and Langmuir-Schaefer (LS) multilayers, have been extensively utilized to study these interactions. These models will be employed in this project to investigate the molecular mechanisms by which NDCOOHs interact with cell membranes of Gram-negative and Gram-positive bacteria. The focus will be on two prominent classes of pathogenic bacteria, Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Emphasizing the utilization of Langmuir films, LS, and spectroscopic techniques such as FTIR and UV-Vis absorption, this research aims to provide fundamental information for exploring new strategies to combat antibiotic-resistant bacterial infections.