Chemical structure of antibiotics determines their release rate from drug-loaded poly(vinyl alcohol)/sodium sulfated alginate nanofibrous wound dressings

Antibiotics are widely used for treatment of infected wounds; however, their application through a local and controlled release system may cause more effectiveness and fewer side-effects. In this study, we fabricated drugloaded poly(vinyl alcohol)/sodium sulfated alginate (PVA/SSA) nanofibrous mats incorporating cationic antibiotic drugs, i.e., salts of gentamicin, tetracycline, ciprofloxacin and minocycline, and examined their physicochemical and biological properties. The results of FTIR spectroscopy showed that cationic drugs have different interactions with carboxylate and sulfate functional groups of SSA depending on their chemical structure. Furthermore, the results of viscometry and conductivity analyses of the solutions revealed that the solutions with drugs with more electrical charge or/and higher functional groups resulted in a lower viscosity and conductivity compared to other drugs, due to the ability to form more hydrogen bonds. The release profiles of drug-loaded nanofibrous mats showed a burst release and then, a sustained release for 5 days, where the burst release of tetracycline (30.0 +/- 0.3 %) from crosslinked mats was noticeably lower than other drugs. Biological assays confirmed the cytocompatibility, antibacterial activity and non-hemolytic behavior of all drug-loaded mats. Finally, ciprofloxacin-loaded nanofibrous mat was used as wound dressing for full-thickness wounds on rats and its efficacy was confirmed.