Ciprofloxacin releasing gellan gum/polydopamine based hydrogels with near infrared activated photothermal properties

In this work, with the aim to obtain a wound dressing hydrogel, an amine derivative of gellan gum was crosslinked in the presence of 4arm-polyethylenglycole-vinylsulfone. Through this easy and reproducible chemical procedure, a hydrogel with advanced elastic properties and hydrolytic resistance under physiological conditions was obtained. The incorporation of different quantities of polydopamine in the gelling solutions allows to obtain different hydrogels with marked photothermal properties when irradiated with a laser in the near infrared at 810 nm. The organic nanoparticles, reacting with the amino groups of the polysaccharide derivative, contribute to increase the storage moduli of the hydrogels. Ciprofloxacin was loaded into the hydrogel with higher amount of polydopamine and drug delivery experiments were performed to investigate the effect of irradiation on the antibiotic release profile. Antimicrobial studies, evaluated against S. aureus and P. aeruginosa, revealed that generated hyperthermia exerts a direct inhibition on the pathogens growth and, in the case of S. aureus, adjuvates the ciprofloxacin antimicrobial effect.