Harnessing biogenic nanoparticles for combating antibiotic resistance: green synthesis, mechanistic insights, and biotechnological applications

Antimicrobial resistance (AMR) continues to escalate worldwide, reducing the effectiveness of existing antibiotics and leading to an urgent need for alternative antimicrobial strategies. Biogenic nanoparticles (BNPs) are nanomaterials synthesized using plants, microorganisms, algae, or isolated biomolecules through biologically mediated processes. These green synthesis routes typically produce nanoparticles that are naturally capped with biological compounds such as phytochemicals, proteins, or polysaccharides, which can influence particle stability, surface chemistry, and biological interactions. The current review summarizes recent advances in the biosynthesis of BNPs, focusing on how biological metabolites regulate metal ion reduction, nucleation, growth, and stabilization, thereby shaping nanoparticle size, morphology, and antimicrobial behavior. BNPs including silver, gold, copper oxide, zinc oxide, iron oxide, titanium dioxide, and selenium have been widely investigated for antibacterial activity. Experimental studies indicate that these materials can act through multiple mechanisms, such as disruption of bacterial membranes, generation of reactive oxygen species, interference with metabolic processes, damage to DNA and proteins, inhibition of quorum sensing, and suppression of biofilm formation. Reported activity spans several WHO-priority and ESKAPE pathogens, largely based on in vitro studies and a limited number of preclinical in vivo models. BNPs have also been explored as adjunct platforms in combination with antibiotics, essential oils, or phytochemicals, where synergistic effects may reduce required drug concentrations and improve activity against resistant strains. In parallel, their physicochemical tunability has supported experimental applications in wound-related systems, antimicrobial coatings, drug delivery research, biosensing, and food-packaging materials. Despite these encouraging findings, major challenges remain. Variability in green synthesis protocols leads to inconsistent physicochemical properties, scalability remains limited, and comprehensive long-term toxicological, pharmacokinetic, and environmental safety data are still lacking. Addressing these issues is essential before BNP-based strategies can progress toward regulatory evaluation and clinical use. In conclusion, biogenic nanoparticles represent a promising but still experimental platform that may contribute to future antimicrobial development if supported by standardized synthesis, rigorous safety assessment, and translational research.