Porous and degradable hyaluronic acid (HA) microparticles was synthesized in a single step using different ratio of crosslinker, divinylsulfone (DVS) ranging between 2.5 and 100% mole ratio of HA repeating unit. HA particles less than 25% (<= 10%) crosslinker ratio were found to be mesoporous and provided the highest surface area, calculated as 21.54 +/- 10.31 m(2)/g for 2.5% crosslinked HA particles via BET analysis. Hydrolytic degradation of 2.5% crosslinked HA microparticles in PBS (pH 7.4) and at 37.5 (sic)C revealed a linear weight loss up to 20 days and 94.5 +/- 4.5% weight loss for 30 days was attained. A wide spectrum antibiotic, Vancomycin as a model drug was loaded to mesoporous HA particles via directly loading from aqueous corresponding solution and by chemical conjugation method to obtain controllable and sustained release profiles from HA particles. Up to 168 h linear vancomycin release (50.5 +/- 4.2 mg/g) was accomplished from 2.5% DVS crosslinked HA particles.