Synthesis and Characterization of Curcumin Dimethacrylate to Synthesize Biodegradable Poly(B-Amino Ester) Antioxidant Polymers

Curcumin is a well-known antioxidant which has been shown to relieve oxidative stress and assist in the wound healing process. However, previous attempts to deliver curcumin as an antioxidant drug have met with limited success, due to the low bioavailability of curcmin and the rapid degradation of curcumin in the body. Therefore, it is desirable to convert curcumin to biodegradable poly(β-amino ester) (PBAE) polymers which would protect curcumin from this rapid degradation, and which could be applied directly to the wound site. The polymer would release curcumin as the polymer degrades, aiding in the wound healing process. We have previously synthesized PBAE polymers using curcumin diacrylate (CDA). However, given the high reactivity of acrylate groups to primary amines (Michael Addition reaction), polymerization was difficult to control, resulting in polymers with suboptimal physical characteristics and degradation properties. As the methacrylate functional group is typically less reactive than the acrylate analog, it is hypothesized that the polymerization rate can be better controlled by the use of curcumin dimethacrylate (CDMA) versus a diacrylate system.  In this work, CDA and CDMA monomers were synthesized and subsequent polymers are compared qualitatively, visually, and via polymer degradation. We found that CDMA is much less reactive than CDA; so much so, that the CDMA-based PBAE hydrogels degrade much too rapidly, probably because of significantly lower crosslinking.