Preparation, In Vitro Performance, and Therapeutic Efficacy Against Oral Ulcers of Curcumin-Loaded Printable Amino Acid-Based Deep Eutectic Gel Dressings
Oral ulcers are among the most prevalent inflammatory lesions of the oral mucosa, characterized by localized burning pain, dysphagia, and high recurrence rates. Conventional dressings, such as ordinary drug films, are low-cost and accessible but create a dry environment that delays epithelial cell migration and impedes healing. This study developed an amino acid-based deep eutectic solvent (DES) gel dressing loaded with curcumin, combining DES and 3D printing technology to create a localized drug delivery platform with efficient drug loading, controlled release, and excellent biocompatibility. The optimal DES system (proline-lactic acid, 1:12) increased curcumin solubility over 700-fold (0.789 mg/mL) compared to water. The optimal printing formulation and process parameters were 1% CSMA, 5% GelMA, 0.1% LAP, 0.02% tartrazine, 20% DES content, 100 μm layer height, and 25 s layer-by-layer exposure time. The resulting gel dressing exhibited excellent mechanical properties, with a 2.5 N adhesion force at 25 min and an approximately 500% swelling ratio at 6 h. In vitro biocompatibility showed L929 cell survival rates above 90%, with no significant cytotoxicity from the DES system. In an SD rat oral ulcer model, the gel achieved localized sustained curcumin release, reducing ulcer area by 40% compared to controls, and effectively decreased neutrophil density and inflammatory infiltration. The study successfully prepared a curcumin-loaded amino acid-based DES gel dressing with good wound adaptability and precise drug release behavior, offering an efficient and safe therapeutic strategy for oral ulcers. However, limitations include differences between the SD rat model and human pathophysiology, long-term biosafety concerns regarding degradation products and DES metabolism, and challenges in cost and scalability for 3D printing clinical translation.