A bacterial nanocellulose hydrogel with moderate antioxidant activity: Reducing the loss of Phellinus igniarius polysaccharides by aminosilane modification

Moderate levels of reactive oxygen species (ROS) are beneficial for normal wound healing, but excessive ROS can hinder this process. Applying exogenous antioxidants to the wound site can effectively mitigate ROS. However, one of the challenges in incorporating exogenous antioxidants into hydrogels is minimizing or preventing the loss of active ingredients. In this study, homogeneous polysaccharides were extracted from the fruiting body of Phellinus igniarius, with an average molecular weight of 1.4183 x 103 kDa, and an antioxidant hydrogel dressing (A-m-BNC/PiP) was developed by covalently crosslinking bacterial nanocellulose with P. igniarius polysaccharides. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectra confirmed the modified crosslinking effect of BNC surface. Compared to pure BNC, A-m-BNC/PiP exhibited a higher swelling rate, greater tensile strength, and lower crystallinity. The polysaccharides fixation test demonstrated that it could effectively reduce polysaccharides loss in BNC. Additionally, the functional modification endowed BNC with antioxidant activity. In a wound-simulated fluid environment, A-m-BNC/PiP demonstrated moderate scavenging abilities against DPPH center dot, ABTS+, and center dot OH free radicals. This innovative hydrogel dressing can provide effective support in wound healing by offering moderate antioxidant capacity to alleviate excessive ROS at the wound site.