Application of poly(vinyl alcohol)-assisted silver nanoparticles immobilized β-keratinase composite as topical antibacterial and dehairing agent

For developing an environmentally friendly, antibacterial, dehairing topical formulation, a β-keratinase enzyme (20.1 kDa) purified from Bacillus subtilis strain RM-01 was coupled to silver nanoparticles(AgNPs) of 8.0 ± 2.0 nm dimensions, prepared using poly(vinyl alcohol) matrix. The Plackett–Burman factorial design demonstrated that the pH of the buffer, amount of silver nanoparticles (Ag NPs), and concentration of β-keratinase enzyme play the most significant role in the Ag NP-enzyme-binding process. Biophysical techniques using scanning electron microscope, transmission electron microscope, X-ray diffraction, and Fourier-transform infrared spectroscopy (FT-IR) were used to characterize the free Ag NPs as well as AgNPs immobilized by β-keratinase. Binding of β-keratinase to Ag NPs resulted in a 5.6-fold increase in specific activity, a considerable increase in V max with a corresponding decrease in K m values towards keratin, and a significant improvement of the thermal and storage stabilities of immobilized enzyme compared to free enzyme. The enhanced antibacterial potency, dehairing activity, and organoleptic analysis of AgNPs immobilized with β-keratinase supports the industrial application of β-keratinase-immobilized Ag NPs in the pharmaceutical and cosmetic industries.