Table 1_Histological and biological evaluation of wheat straw–derived nanocellulose in a rat model of cutaneous wound healing.docx

BackgroundHealing of cutaneous wound is a complex biological process that requires the migration of fibroblasts, production of extracellular matrix (ECM) component, angiogenesis and a highly regulated expression pattern of inflammatory mediators. Owing to the interest in wound dressings based on renewable biomaterials, much attention has been paid to their biocompatibility and sustainability. Within these materials, nanocellulose features the physical and chemical properties to promote important cellular processes for tissue regeneration.
MethodsWheat straw–derived nanocellulose was isolated and its nanostructure and physicochemical properties were characterised using FESEM, XRD, EDX, and FTIR analyses. In vitro, its biological activity was evaluated in NIH-3T3 fibroblasts through cell viability, migration, and expression of wound-healing–related genes and proteins (n = 3). The effects of nanocellulose on wound healing were further evaluated using a rat full-thickness skin wound model (n = 10 per group), with macroscopic and histological assessments conducted at 3, 7, and 14 days after wounding.
ResultsThe extracted nanocellulose exhibited a cellulose I crystalline structure and showed no cytotoxic effects on fibroblasts (p > 0.05). Nanocellulose-conditioned medium significantly enhanced fibroblast migration compared with control conditions (p < 0.001) and upregulated the expression of Col1a1 (p = 0.0093), Col3a1 (p = 0.0308), and Vegfa (p = 0.0175), accompanied by increased VEGF protein secretion (p = 0.0007) without concurrent elevation of inflammatory marker IL-6 (p > 0.05). In the rat wound model, nanocellulose treatment significantly accelerated wound closure at days 3, 7, and 14 (p < 0.01–0.0001) and improved histological features of healing, including reduced inflammatory cell infiltration, more organised granulation tissue formation, enhanced angiogenesis, and earlier re-epithelialisation.
ConclusionThese results suggest that nanocellulose derived from wheat straw can promote cutaneous wound healing by stimulating fibroblast-mediated matrix synthesis and angiogenesis without resulting in excess inflammatory stimulation. Taken together, the in vitro and in vivo findings demonstrate that nanocellulose is not only a renewable biomaterial but also an active biological material for use as functional wound-healing dressings.