Surface functionalization of hydrogel by thiol-yne click chemistry for drug delivery

Although hydrogel has some outstanding performance, traditional hydrogel still has some drawbacks in the application of drug delivery field. Herein, we attempted to utilize the thiol-yne photopolymerization, which had advantages of high efficiency, mild reaction condition and low toxicity as a type of click chemistry, to realize beta-cyclodextrin(beta-cp) functionalized hydrogel in order to improve its performance for drug delivery. As a prerequisite, alkynylation was conducted on the per-formed hydrogel. The above-mentioned synthesis was verified by the results of atomic concentration from X-ray Photoelectron Spectroscopy (XPS) characterization and semiquantitative analysis of Fourier-transformed infrared spectroscopy (FTIR) spectra. Similarly, the optimum reaction condition including optimal reaction time and feeding molar ratio were also determined by semiquantitative analysis of FTIR spectra and XPS results. The alkynylation resulted in higher contact angle, lower equilibrium water and coarser surface. Then, 3CD functionalization was beneficial to the hydrophilicity and protein resistant property of hydrogel. With respect to drug delivery performance, an increasing drug concentration and beta-CD molecules that grafted onto hydrogel benefited to aggregating orfloxacin molecules in hydrogels. The loading drug concentration as well as beta-CD content on hydrogel exerted influences upon drug release behaviors. (C) 2015 Elsevier B.V. All rights reserved.