Harnessing nanomaterials to overcome antimicrobial resistance in Gram-positive bacteria: a systematic review

Background: Antimicrobial resistance (AMR) among Gram-positive bacteria has emerged as a significant global health threat, with pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) exhibiting increasing resistance to conventional antibiotics. This systematic review evaluates new advances in nanomaterial-based antimicrobial agents as innovative solutions to combat AMR in Gram-positive bacteria. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, studies published between 2014 and 2024 were systematically screened and analysed from databases including PubMed, Scopus, Google Scholar, and HINARI. From an initial 1,405 articles, 131 experimental studies that met the inclusion criteria were systematically analysed to harness the advances in nanomaterial-based antimicrobial agents in combating AMR in Gram-positive bacteria. Results: The included studies demonstrated that various nanomaterials, including silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), zinc oxide nanoparticles (ZnO NPs), copper and copper oxide nanoparticles (Cu/CuO NPs), as well as polymeric and hybrid systems, exhibited potent antibacterial and antibiofilm activities. Key mechanisms of action included bacterial membrane disruption, reactive oxygen species (ROS) generation, intracellular interference, and targeted drug delivery. Many nanomaterials showed enhanced efficacy and synergistic effects when combined with conventional antibiotics, effectively reducing bacterial load and inhibiting biofilm formation in resistant strains like MRSA. Discussion: Nanomaterials offer a multifaceted approach to overcome the evolving resistance mechanisms in Gram-positive pathogens, showing significant preclinical and clinical success. Despite these substantial preclinical results, challenges such as cytotoxicity, environmental impact, scalability, and the potential for resistance adaptation remain unaddressed. Furthermore, important translational barriers persist, most notably insufficient pharmacokinetic data and unclear regulatory pathways. Future efforts must focus on standardized manufacturing, comprehensive toxicity studies, and robust clinical trials to bridge the gap between laboratory innovation and practical therapeutic application.