Poly(dopamine) nanoparticles-reinforced bacterial cellulose-fungal carboxymethyl chitosan nanocomposite hydrogel for wearable strain sensing

Bacterial cellulose (BC) offers significant potential in biomedical applications due to its biocompatibility, fibrous structure, flexibility, crystallinity, and mechanical strength. However, it lacks the necessary antibacterial properties and strain-sensing capabilities for electrochemical analysis and conductivity. Hence, a nanocomposite hydrogel consisting of BC impregnated with fungal carboxymethyl chitosan (FC) and reinforced with poly(dopamine) (PDA) nanoparticles (NPs) is developed herein. The resulting BC-FCP nanocomposite hydrogel exhibits enhanced physicochemical properties, as confirmed by the Fourier transform infrared (FTIR) spectra, without altering the BC crystalline structure. The BC-FCP hydrogel also demonstrates superior mechanical performance, with a tensile strength of 1.24 ± 0.06MPa and an elongation of 55.1 ± 1.7% at breaking point. The PDA NPs are uniformly distributed within the BC-FC network, thereby enhancing its swelling properties compared to BC-P. The hydrogel also displays strong antibacterial activity against Escherichia coli and Staphylococcus aureus, preventing infections while maintaining excellent biocompatibility with NIH 3T3 skin fibroblast cells. With an electrical conductivity of 3.18 × 10⁻² S/cm, the BC-FCP hydrogel proves effective in strain sensing, and is able to detect human motion, including finger and wrist movements. This multifunctional hydrogel offers antibacterial, conductive, and biocompatible properties, and is is ideal for wearable sensor applications. [Display omitted]