Cellulose Based Aerogels Derived From Rice Agro Wastes with Enhanced Antifungal Activity for Topical Management of Vulvovaginal Candidiasis

Abstract

With the increased cultivation of rice crop, the problem of accumulating waste biomass after harvesting is becoming a huge challenge, disposal of which through land filling and burning leads to global warming. In this work, abundantly available rice straw waste is strategically functionalized through delignification-cum-phosphorylation route to produce smart-responsive and ultra-light weight aerogels for topical management of vulvovaginal candidiasis. The prepared aerogels show low density (0.028 g cm⁻³), high water absorption capacity ∼2381.71%, and charge content (1850 mmol kg⁻¹) of phosphate groups covalently linked to cellulose backbone as evident from XPS and FTIR spectroscopy studies. The aerogels with porous morphology also show cyclic mechanical compressibility and thermal stability due to presence of phosphate groups as evident from high char content (28.5% at 700 °C). The negatively charged aerogels show prolonged storage and release profile of clotrimazole with synergistically strong antifungal response against several Candida species with lowered MIC of ∼0.02µg ml⁻¹. Interestingly, post-phosphorylation the functionalized aerogels show improved biodegradation of ∼83% within 92 days under soil conditions. This study proposes a low-cost, facile, eco-friendly, sustainable approach to convert waste rice biomass into functionalized high-performance aerogels for potential treatment of vaginal infections improving female reproductive health.