Fabrication of Sandwich Biomass Films via Soft Spraying for Drug Release

Natural polymer gel films exhibit excellent biocompatibility, biodegradability, and low cost and are widely used in the development of biomedical materials. In this work, we utilized a soft-spray-assisted technique to construct sandwich-structured gel films (G-B-G) via layer-by-layer assembly at the miscible quasi-interface by taking advantage of the rapid gelation properties of natural polymers and the superiority of soft spray technology. Tetracycline was first incorporated into the guar gum/boric acid gel film, which was subsequently encapsulated with a Gel-ADH/HA-CHO gel film. The resulting G-B-G gel films have been demonstrated to effectively regulate the release performance of tetracycline, significantly mitigating the initial burst release phenomenon. The initial drug release range (38–82%) can be precisely controlled by adjusting the monomer content to meet different requirements. Furthermore, the drug release mechanism is molecular diffusion, which is consistent with first-order kinetics ( R 2 > 0.99). This enhanced performance is primarily attributed to the sandwich structure acting as an effective barrier for drug diffusion.