Chitosan/reduced graphene oxide/papain nanocomposite: a bioactive platform for skincare and biomedical applications

This work introduces a bioactive chitosan-based nanocomposite incorporating reduced graphene oxide and papain (CS/rGO/Pa), designed for wound healing and cosmetic facial mask applications. The nanocomposite was fabricated via ionic gelation and characterized by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Differential Light Scattering (DLS). Subsequently, the porosity, swelling, degradation of CS/rGO/Pa and papain release/activity was evaluated. In vitro assays assessed its anti-oxidant, anti-inflammatory, anti-bacterial, and proliferation properties. The results of FTIR, XRD, SEM and DLS indicated that the nanoparticles were synthesized correctly with an approximately spherical morphology, an average size of around 100 nm, a hydrodynamic diameter of 553 nm, and zeta potential of - 2.97 mV. The results showed that adsorption of papain on CS/rGO decreased papain activity from 7.3 to 0.57 U/mg which can be favorable for wounded epithelial tissues and skin care applications, requiring low and sustained enzymatic action. The release rate results indicated a higher release rate in a basic environment (pH 8.4), and the Korsmeyer-Peppas model for the release of papain. The results of CS/rGO/Pa properties indicated proper porosity, swelling and degradation, with 93% anti-inflammatory, 20% anti-oxidant activity, high anti-bacterial effect, and cell growth up to 7.91-fold for 7 days. In conclusion, the outcomes represented that the CS/rGO/Pa nanocomposite can be a favorable and effective material for using in skincare and biomedical applications.