The present invention includes a vanillyl alcohol-containing copolyoxalate copolymer (PVAX). The present invention also includes a PVAX microparticle comprising PVAX. In one aspect, the compositions of the invention can be used as a drug delivery system, an antioxidant or anti-inflammatory composition, a composition for preventing or treating ischemic disease, a composition for inhibiting the side effects of anticancer drugs, a contrast agent, and/or a composition for diagnosing ischemic disease.
