Sprayable Cellulose and Mannan Nanocrystals from Ivory Nuts for Treatment of Skin Diseases in Mice

Atopic dermatitis (AD) and diabetic wounds are chronic inflammatory skin conditions with limited treatment options. This study investigates the therapeutic potential of sprayable colloidal suspensions composed of cellulose and mannan nanocrystals (CNC/MN) derived from ivory nuts in preclinical models of AD and diabetic wound healing. AD was induced in BALB/c mice using 2,4-dinitrochlorobenzene (DNCB), while diabetes was induced in Swiss mice via streptozotocin before dorsal wounds were created. AD severity was assessed through clinical scoring, scratching behavior, histopathology, oxidative stress markers, inflammatory profiling, and emotional domain evaluation. Wound closure rates, bacterial burden, and histological analysis were used to evaluate diabetic wound healing. CNC/MN-based suspensions alleviated DNCB-induced inflammatory skin damage (back: around 48%, and dorsal skin: around 78%) and reversed depressive-like behavior (around 50%) without affecting locomotor activity. The formulation with higher MN content showed superior efficacy in reducing erythema, edema, and neutrophilic infiltration while restoring antioxidant enzyme activity. In diabetic wounds, suspensions with lower MN or without MN content exhibited the best results, enhancing wound closure, collagen deposition, and reducing inflammation. The CNC/MN-based suspension with lower MN content significantly reduced bacterial colonization in the wound site (around 23%). These findings demonstrate that CNC/MN colloidal suspensions are promising sprayable biomaterials for treating inflammatory skin disorders, mitigating cutaneous and neuropsychiatric AD symptoms while promoting tissue regeneration in diabetic wounds. This study highlights their dual therapeutic potential and sustainable origin, offering an innovative treatment alternative for chronic skin disease.