Synthesis, characterization, and evaluation of chitosan nanoparticles: Antimicrobial Activities and cytotoxicity Impact on cosmetics

Abd El-Ghany, Mohamed N.; El-Sheikh, Rawan A.

doi:10.21608/nasj.2025.370274.1006

Synthesis, characterization, and evaluation of chitosan nanoparticles: Antimicrobial Activities and cytotoxicity Impact on cosmetics

Document Type : Original Article

Authors

¹ Botany and Microbiology Department, Faculty of Science, Cairo University, Giza, 12613, Egypt

² Faculty of Biotechnology- MSA University

10.21608/nasj.2025.370274.1006

Abstract

Cosmetic products are prone to microbial contamination, with studies showing that 40–70% of used cosmetics contain harmful fungi like Penicillium spp., Aspergillus fumigatus, and Candida albicans, posing infection risks, especially for immunocompromised individuals. This study aims to synthesize and characterize chitosan nanoparticles (CS-NPs) to prevent microbial contamination in cosmetics and determine the minimum effective dose required for complete fungal inhibition. CS-NPs were synthesized via chitin deacetylation and characterized using Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), and Zeta potential analysis. TEM confirmed spherical nanoparticles of 100–110 nm, while DLS showed a polydisperse system with a peak near 100 nm. Zeta potential analysis indicated around 25 mV surface charges, suggesting minimal electrostatic repulsion. The antifungal efficacy of CS-NPs was tested using a spore germination inhibitory assay against Aspergillus flavus, the most potent fungus from cosmetic samples. Germination decreased with increasing CS-NP concentration. The Minimum inhibitory concentration was at 20–30 µg/mL. CS-NPs also showed an inhibitory effect against Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Candida albicans, and Aspergillus niger using the agar well diffusion method, showing inhibition zones comparable to standard antibiotics. TEM analysis of Aspergillus flavus spores revealed severe structural malformation, including cell wall damage, cytoplasmic leakage, and membrane collapse. Cytotoxicity assessment via MTT assay on A375 melanocyte cells demonstrated an IC50 of 20–30 µg/mL, indicating selective antimicrobial activity with minimal toxicity. These findings highlight CS-NPs as a promising antimicrobial agent for cosmetics and biomedical applications.

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