3D-printed hydrogels based on amphiphilic chitosan derivative loaded with levofloxacin for wound healing applications

Skin wounds not only cause physical pain to patients but also pose an economic burden to society. Consequently, effective approaches to promote skin repair remain a challenge. Specifically, chitosan-based hydrogels are ideal candidates to promote wound healing at different stages and while diminishing the factors that impede this process (such as excessive inflammatory and chronic wound infection). Furthermore, the unique biological properties of a chitosan-based hydrogel enable it to serve as both a wound dressing and a drug delivery system (DDS). In the present work, chitosan (CS) graft copolymer with [2-(methacryloyloxy)ethyl] trimethyl ammonium chloride (CS-MTAC), a cationic monomer with promising antibacterial properties, was synthesized. The successful synthesis of the copolymer was confirmed, while it was studied for its swelling ability and water absorption capacity, as well as for its biocompatibility and antibacterial properties. Expecting to improve its printability, the copolymer was blended with elastin (EL), collagen (COL), and increasing concentrations of gelatin (GEL). The hydrogel with 6% w/v CS, 4% w/w EL, 4% w/w COL and 1% w/v GEL was selected for its potential to be 3D-printed and was neutralized with ammonia vapors or ethanol/sodium hydroxide solution and loaded with levofloxacin. The feasibility of CS-MTAC/EL/COL/GEL bioink, loaded with Levo, as a suitable candidate for wound healing and drug delivery applications, has been demonstrated.