Antibacterial non-woven nanofibers of curcumin acrylate oligomers

Abstract

Two new (meth)acrylate monomers, namely, 4-((1E,6E)-7-(4′-hydroxy-3-methoxyphenyl)-3,5-dioxohepta-1,6-dienyl)-2-methoxyphenyl acrylate or curcumin monoacrylate (CmA) and 4-((1E,6E)-7-(4′-hydroxy-3-methoxyphenyl)-3,5-dioxohepta-1,6-dienyl)-2-methoxyphenyl methacrylate or curcumin monomethacrylate (CmMA), are synthesized by reacting (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione (curcumin) with acryloyl chloride and methacryloyl chloride, respectively. The respective derivatives are polymerized by free radical polymerization using an initiator, 2,2-azobisisobutyrontrile (AIBN), to obtain the oligomer of curcumin monoacrylate (OCM) and the oligomer of curcumin monomethacrylate (OCMA). The oligomers are characterized by FTIR, ¹H NMR and UV-vis spectroscopy. The molecular weights of the oligomers are determined by GPC to range between 2000 and 5500 Da. The melting temperature (T_m) and degradation temperature of the respective oligomers are evaluated by thermal analysis. The melting temperature of the oligomers ranged from 195 to 197 °C. Antibacterial studies are evaluated against Staphylococcus aureus, in which the minimum inhibitory concentration (MIC) of OCA1 is 27 mg mL⁻¹. The blends of the individual oligomers with poly(lactic acid) are electrospun to obtain the respective non-woven nanofiber mats. Nanofibers are formed, with the diameter ranging from 400 to 750 nm, and the nanofiber mats are porous. Because the nanofiber mats are antibacterial and highly porous, they may have potential application as a wound dressing material for tissue regeneration.