Silver Nanoparticle Interactions in Biological Systems

Silver nanoparticles (AgNPs) represent a class of engineered nanomaterials widely investigated for their potent antimicrobial activity and emerging biomedical applications. Upon introduction into physiological environments, AgNPs undergo rapid adsorption of biomolecules to form a protein corona, which dictates their biological identity, cellular uptake and biodistribution. Cellular internalisation typically proceeds via endocytic pathways, leading to localisation within endosomes and lysosomes, where partial dissolution releases bioactive Ag+ ions. These ions interact with thiol-bearing proteins, generate reactive oxygen species and disrupt key metabolic enzymes, accounting for both antimicrobial efficacy and cytotoxicity. Particle size, shape and surface chemistry critically influence protein binding profiles, dissolution rates and membrane interactions, thereby modulating the balance between therapeutic benefit and adverse effects. Understanding these interrelationships is essential for the rational design of AgNP-based antimicrobials, drug delivery vectors and diagnostic tools, as well as for assessing environmental impact and long-term safety.

Research from Nature Portfolio

Recent studies have elucidated the molecular targets of Ag+ within bacterial cells, identifying numerous protein binding partners via proteomic and crystallographic techniques. Silver ions engage multiple enzymes, notably 6-phosphogluconate dehydrogenase, disrupting central metabolic pathways and imposing multi-target stress. This mode of action enhances the potency of conventional antibiotics and reinstates susceptibility in resistant strains, offering a sustainable approach to combat drug-resistant pathogens. These mechanistic insights inform the development of nanosilver formulations that combine broad-spectrum antimicrobial efficacy with reduced propensity for resistance development.

Silver Nanoparticle Interactions in Biological Systems publication trend

The graph below shows the total number of articles in silver nanoparticle interactions in biological systems across all publications each year (not limited to Nature Index journals).

Technical terms

Protein corona: A layer of biomolecules, primarily serum proteins, that adsorbs onto nanoparticle surfaces upon exposure to biological fluids, altering particle identity and interactions.

Ag+ dissolution: The release of silver ions from nanoparticle cores into the surrounding medium, driving bioactivity and potential toxicity.

Surface ligand: A molecule chemisorbed on the nanoparticle surface that governs colloidal stability, protein adsorption and cellular interactions.

Endocytosis: A cellular uptake mechanism whereby particles are internalised within vesicles formed from the plasma membrane.

References

1. Multi-target mode of action of silver against Staphylococcus aureus endows it with capability to combat antibiotic resistance. Nature Communications (2021).
2. Silver nanoparticle protein corona and toxicity: a mini-review. Journal of Nanobiotechnology (2015).
3. Visualization, quantification and coordination of Ag + ions released from silver nanoparticles in hepatocytes. Nanoscale (2016).
4. Surface properties modulate protein corona formation and determine cellular uptake and cytotoxicity of silver nanoparticles. Nanoscale (2021).
5. The Impact of Surface Functionalization on the Biophysical Properties of Silver Nanoparticles. Nanomaterials (2019).