PEG-Dependent Tunable Degradation and Curcumin Release from Curcumin-Based Biomedical Polyurethanes

Curcumin, a plant-derived polyphenolic compound, exhibits diverse pharmacological activities such as antioxidant, anti-inflammatory, anticancer, neuroprotective, and cardiovascular protective effects, and is widely used in food, medicine, and other fields. However, its poor water solubility and easy oxidative degradation limit its extensive application in biomedicine. To solve these problems, a series of biomedical polyurethanes (Cur-PU) with similar molecular weights but different PEG contents were successfully synthesized using HO-PCL-OH and HO-PEG-OH as soft segments and curcumin as a chain extender. The results indicated that increasing the PEG content reduced the T¹_m, T¹_c, and H¹_c of Cur-PU, along with a slower crystallization rate and lower crystallinity. More importantly, a higher PEG content decreased the water contact angle but increased water solubility and water uptake, which, combined with reduced crystallinity, enhanced hydrophilicity, swelling ratio, curcumin release rate, and degradation rate in an enzymatic solution and pH 8.0 buffer. Thus, precise regulation of Cur-PU's degradation and curcumin release was achieved by controlling the PEG content. Biocompatibility tests confirmed that Cur-PU exhibited excellent antioxidant and antibacterial activities, making it a highly promising biomedical material.