Hyaluronic acid-doxycycline-based injectable hydrogel for joint bearing of osteoarthritis cases

Osteoarthritis (OA) is degenerative disease of the knee joint that causes excruciating pain. It is resulted stiffness and limited range of the joint motion. Therapy using hyaluronic acid hydrogel only is not optimal yet for osteoarthritis. The HA-DOX hydrogel may be associated with increased viscoelasticity and anti-inflammatory effect as the background of this study. This study aims are to determine the in vitro characterization of hyaluronic acid-doxycycline (HA-DOX) with variations of (A) HA Only, (B) HA-DOX 0.71?mg; (C) HA-DOX 1.43?mg; and (D) HA-DOX 2.86?mg as joint bearing hydrogel through the test of Scanning electron Microscope (SEM), Fourier-transform infrared spectroscopy (FTIR) tensile strength test, and injectability test and to know the best composition of the entire sample as a candidate for injectable hydrogel as the treatment of OA. The fabrication of HA-DOX samples using the freeze-thawing method succeed to conduct hydrogel, and the fabrication of the hydrogel films using the drying method. The HA sample is showed clear gel looks like appearance. HA-DOX samples were slightly yellowed. FTIR result is showed that each sample were represent the functional group of hyaluronic acid and doxycycline such as N-H, C-H, C=O, CH2 bending, CH3 bending. The SEM results were showed that the smooth surface of the samples, well interface. The tensile strength results were showed in sample without DOX had lower tensile strength compared with hydrogel sample with DOX and Zn2+ ions. The injectability test on HA only and HA-DOX samples showed good results, such as A) 94.07%, B) 97.69%, C) 95.78%, and D) 94.97%. Based on the results of the cytotoxicity test, all samples were showed good result of viability cell percentage. HA only (A) sample was 83.93%, while others 3 HA-DOX samples were also showed good percentage of viable cell, which were 73.74%; 72.46%; and 70.29% subsequently. It can be concluded due to the tensile strength test, SEM test, cytotoxicity test and injectability test, that the HA-DOX sample with 0.71?mg DOX variation (B sample) was the best sample as a candidate for injectable hydrogel as a joint bearing for osteoarthritis cases.