Beauveria bassiana facilitated silver nanoparticles in cosmetic formulation: Antimicrobial, antioxidant, and photocatalytic activity

In line with the UN Sustainable Development Goals 3 and 12 which are focused on good health and sustainable production respectively, we report the green synthesis of silver nanoparticles using Beauveria bassiana extracts and their role as active nanocosmeceutical ingredients. In this study, optimal conditions for B. bassiana- mediated nanoparticle (BbAgNP) synthesis were evaluated, and the functional properties of the materials were characterised via UV-Vis, Fourier transform infrared spectroscopy, Particle size analyser, Electron microscopy, Thermogravimetric analysis, Differential scanning calorimetry, etc. Subsequently, the antioxidant (DPPH assay), antimicrobial activities (broth microdilution method) as well as toxicity (brine shrimp lethality) were investigated. Furthermore, the effect of BbAgNPs on the sun protection and stability of cosmetic formulation was also studied. Results indicate that the highest efficiency of BbAgNP synthesis was achieved with the extracellular extract at pH 10.0, 60°C and 3 h. BbAgNP was also recorded to have an average size of 41 nm, zeta potential of −23.2 ±1.1 mV and face-centred crystalline structure. Furthermore, thermal analysis showed that it was stable between 25°C and 100°C. Similarly, BbAgNP was recorded to have an IC 50 of 400.22 μg/mL against DPPH radicals, remarkable broad antimicrobial spectrum (Gram -positive, Gram-negative bacteria, and yeasts), low toxicity on brine shrimps and low photocatalytic activity. The addition of BbAgNP to the cream formulation was observed to increase the sun protection ability of the cream by 2.6-fold without any detrimental effect on its short-term stability. These findings support the potential of fungi-mediated nanoparticles as valuable ingredients in the cosmeceutical industries. • Optimised synthesis of B. bassiana -mediated Ag nanoparticles (BbAgNPs) at pH 10.0, 60°C & 3 h. • Size, Zeta potential & degradation temp onset were ∼41±0.88 nm, −23.2±1.1 mV & 100°C, respectively. • BbAgNPs displayed DPPH scavenging activity & broad-spectrum bioactivity against bacteria and yeasts. • BbAgNPs showed low photocatalytic activity (4.66 %) & low brine shrimp toxicity (1507.32 μg/mL). • Improved functionality of cosmetic fortified with BbAgNPs (Sun protection factor = 4.74).