Polyvinyl alcohol composite nanofibres containing conjugated levofloxacin-chitosan for controlled drug release

A range of biodegradable drug-nanofibres composite mats have been reported as drug delivery systems. However, their main disadvantage is the rapid release of the drug immediately after application. This paper reports an improved system based on the incorporation of drug conjugated-chitosan into polyvinyl alcohol (PVA) nanoflbers. The results showed that controlled release of levofloxacin (LVF) could be achieved by covalently binding LW to low molecular weight chitosan (CS) via a cleavable amide bond and then blending the conjugated CS with polyvinyl alcohol (PVA) nanofibres prior to electrospinning. PVA/LVF and PVA-CS/LVF nanofibres were fabricated as controls. The conjugated CS-LW was characterized by FTIR, DSC, TGA and H-1 NMR. Scanning electron microscopy (SEM) showed that the blended CS-PVA nanofibres had a reduced fibre diameter compared to the controls. Drug release profiles showed that burst release was decreased from 90% in the control PVA/LVF electrospun mats to 27% in the PVA/conjugated CS-LW mats after 8 bin phosphate buffer at 37 degrees C. This slower release is due to the cleavable bond between LW and CS that slowly hydrolysed over time at neutral pH. The results indicate that conjugation of the drug to the polymer backbone is an effective way of minimizing burst release behaviour and achieving sustained release of the drug, LW. (C) 2016 Elsevier B.V. All rights reserved.