Chitosan-Based Silver Nanocomposites for Antimicrobial Applications

Chitosan-based silver nanocomposites combine the biocompatible, film-forming and cationic properties of chitosan with the potent antimicrobial activity of silver nanoparticles. Chitosan, a deacetylated derivative of chitin, serves both as a reducing and stabilising agent in green synthetic routes, enabling the in situ generation of uniformly dispersed silver nanoparticles within a biodegradable polymer matrix. The resulting hybrid materials exhibit sustained silver-ion release, enhanced colloidal stability and synergistic bactericidal effects against a broad spectrum of Gram-positive and Gram-negative pathogens, including biofilm-forming species. Their tunable physicochemical characteristics—particle size, zeta potential, surface charge and porosity—allow optimisation for diverse applications such as wound dressings, coatings for medical devices, food-packaging films and water-disinfection membranes. Recent advances have addressed challenges including nanoparticle aggregation, cytotoxicity to mammalian cells and large-scale reproducibility. By integrating complementary antimicrobial components—such as polyphenols or essential oils—and by employing microfluidic or electrospinning techniques, researchers are achieving finely controlled nanocomposite architectures that maximise antibacterial efficacy while minimising adverse effects. This class of materials holds global significance for curbing antimicrobial resistance and for extending the shelf-life of perishable goods, thereby contributing to both human health and food security.

Research from Nature Portfolio

Recent studies have demonstrated a green synthetic approach in which chitosan, in combination with seaweed-derived polyphenols, mediates the bioreduction of silver ions to form 10–15 nm nanoparticles within a chitosan matrix. The resulting nanocomposite exhibits long-term colloidal stability and a strong negative zeta potential, and shows markedly enhanced bactericidal activity compared with uncoated silver nanoparticles. A parallel line of work has used fungal biomass to produce biogenic silver cores that are subsequently capped with chitosan, yielding composite particles of several hundred nanometres with high positive surface charge. These constructs prevent nanoparticle aggregation, display low cytotoxicity to mammalian cells and achieve sub-microgram per millilitre inhibitory concentrations against key bacterial pathogens. Both efforts underscore the role of chitosan in stabilisation, synergistic action and biocompatibility, advancing nanocomposite design for antimicrobial applications.

Chitosan-Based Silver Nanocomposites for Antimicrobial Applications publication trend

The graph below shows the total number of articles in chitosan-based silver nanocomposites for antimicrobial applications across all publications each year (not limited to Nature Index journals).

Technical terms

Chitosan: A biodegradable, cationic polysaccharide derived from chitin, used as a stabiliser and reducing agent in nanoparticle synthesis.

Silver nanoparticle: A colloidal silver particle, typically 1–100 nm in diameter, noted for its broad-spectrum antimicrobial activity.

Nanocomposite: A hybrid material in which nanoparticles are dispersed within a continuous matrix, combining properties of both phases.

Zeta potential: The electrostatic potential at the slipping plane of a particle in suspension, indicative of colloidal stability.

Biofilm: A structured community of microbial cells, adherent to surfaces and embedded in an extracellular polymeric matrix, often resistant to conventional antimicrobials.

References

1. A novel green one-step synthesis of silver nanoparticles using chitosan: catalytic activity and antimicrobial studies. Applied Nanoscience (2012).
2. Synergistic effects of combinatorial chitosan and polyphenol biomolecules on enhanced antibacterial activity of biofunctionalized silver nanoparticles. Scientific Reports (2020).
3. Biosynthesis of silver nanoparticles for the fabrication of non cytotoxic and antibacterial metallic polymer based nanocomposite system. Scientific Reports (2021).
4. Chitosan-Stabilized Ag Nanoparticles with Superior Biocompatibility and Their Synergistic Antibacterial Effect in Mixtures with Essential Oils. Nanomaterials (2018).
5. Microfluidic assisted synthesis of silver nanoparticle–chitosan composite microparticles for antibacterial applications. International Journal of Pharmaceutics (2016).
6. Silver Nanoparticles on Chitosan/Silica Nanofibers: Characterization and Antibacterial Activity. International Journal of Molecular Sciences (2019).