Multifunctional 3D-Printed Alginate Emulgel Patches Incorporating Plant Extracts for Potential Burn Wound...

Multifunctional dressings capable of maintaining a moist environment, supporting tissue regeneration, and delivering bioactive compounds are increasingly being explored as promising strategies for burn wound management. In this study, alginate-based emulgel patches incorporating hydrophilic and lipophilic plant extracts were developed by extrusion-based 3D printing as potential topical systems for burn wound applications. The formulation included sodium alginate, hyaluronic acid, and hydroglyceric extracts of Calendula officinalis, Matricaria chamomilla, and Plantago major, as well as oily extracts of Hippophae rhamnoides and Hypericum perforatum. The emulgel was evaluated for pH, rheological behaviour, spreadability, physical stability, apparent hydrodynamic size distribution, zeta potential, total polyphenol content, and antioxidant activity. Following Ca²⁺-induced crosslinking, uniform and flexible 3D-printed patches were obtained and further characterised for pharmacotechnical, physicochemical, structural, functional, and biological properties. The emulgel exhibited suitable characteristics for extrusion-based printing, while the resulting patches showed good dimensional uniformity, flexibility, swelling capacity, water vapour transmission, and surface pH compatible with topical application. FTIR, DLS, SEM, and SEM-EDX analyses supported the formation of a Ca²⁺-crosslinked alginate network and confirmed the presence of structurally heterogeneous domains with homogeneous calcium distribution. The patches retained plant-derived bioactive compounds, with a total polyphenol content of 0.2878 ± 0.016 mg GAE/g hydrated patch, and showed improved antioxidant activity compared with the corresponding emulgel. In vitro release studies indicated the time-dependent diffusion of polyphenols over 24 h, with cumulative release reaching 64.42%. The patches also exhibited a water vapour transmission rate of 1270 ± 93 g/m²/24 h, indicating adequate moisture regulation. HaCaT cell viability remained above 90% at lower tested concentrations, demonstrating a favourable biocompatibility profile. Overall, the developed 3D-printed alginate emulgel patches represent promising multifunctional systems for potential burn wound management and warrant further preclinical investigation.