Development of Bioactive Cellulose Films from Drynaria quercifolia Rhizome: A Sustainable Approach to Advanced Natural Materials

Investigating underutilized botanical resources for developing cellulose-based polymers has gained momentum due to the need for sustainable biomaterials. With the added potential of phytochemical infusion, Drynaria quercifolia , a traditionally prized medicinal fern, provides an unexplored source for cellulose isolation. This study explores the green isolation of cellulose from the rhizome part of D. quercifolia using the alkaline peroxide method, which produced a yield of 27.41 ± 4.65% (%w/w) cellulose. The resultant biopolymer was fabricated into glycerol plasticized films with 70% ethanolic extract. After functional property evaluation and physicochemical characterization, the isolated cellulose proved suitable for hydration-based applications by exhibiting high water retention capacity and settling volume compared to commercial cellulose. While Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) showed promising thermal stability, powder X-Ray Diffraction (XRD) verified the crystalline cellulose I structure. A porous fibrous surface that promotes film formation was depicted via Scanning Electron Microscopy (SEM) imaging. Cytocompatibility was verified by in vitro tests using RAW 264.7 macrophages, which proved > 80% cell viability and no morphological anomalies. Qualitative scratch assay results confirmed cell migration, although the quantitative wound closure could not be obtained due to the optical interference from the film. Alkaloids, flavonoids, glycosides, and carbohydrates were detected through phytochemical analysis and UV-Vis spectroscopy, which verified the phytochemical release into PBS at pH 7.4 over 24 h. The value of D. quercifolia rhizome, which has long been utilized in medicine but is rarely investigated in biomaterial science, as a dual-purpose source of cellulose and bioactive compounds, makes this study novel.