Preparation, In Vitro Performance, and Therapeutic Efficacy Against Oral Ulcers of Curcumin-Loaded Printable Amino Acid-Based Deep Eutectic Gel Dressings

• • The optimal DES system (proline-lactic acid, 1:12) increased curcumin solubility to 0.789 mg/mL, a >700-fold enhancement over water, enabling effective incorporation of a poorly soluble natural compound into a hydrogel dressing; this solubility enhancement is critical for achieving therapeutic drug concentrations in topical formulations. • • The optimized printing formulation (1% CSMA, 5% GelMA, 0.1% LAP, 0.02% tartrazine, 20% DES, 100 μm layer height, 25 s exposure) produced dressings with a 2.5 N adhesion force at 25 min and ~500% swelling at 6 h, indicating strong mucosal retention and exudate absorption capacity, which are essential for maintaining contact with ulcerated tissue and managing wound moisture. • • In vitro biocompatibility tests showed L929 cell viability >90% and no significant DES cytotoxicity, confirming the safety of the amino acid-based DES components for biomedical applications; this is a prerequisite for clinical translation, as cytotoxic excipients would negate therapeutic benefits. • • In an SD rat oral ulcer model, the curcumin-loaded gel reduced ulcer area by 40% versus controls and decreased neutrophil density and inflammatory infiltration, demonstrating in vivo efficacy; however, the study acknowledges limitations including model relevance to human disease, long-term biosafety of degradation products, and 3D printing scalability and cost challenges that must be addressed for clinical adoption.