Curcumin has a limited clinical application because of its extremely poor accessibility. In the present study, improved curcumin bioavailability within a castor oil polyurethane/layered double hydroxide (LDH) wound cover was achieved by preparing a curcumin p-sulfonic acid calix[4]arene (SC4A) inclusion complex. Then, it was utilized to intercalate MgAl-layered double hydroxide (MgAl-LDH) nanosheets. The incorporation of the nanostructure into a PU/Cur-SC4A-LDH film provided bacteria-killing performance against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. This finding is due to an increase in curcumin bioavailability in the PU matrix. Furthermore, all PU nanocomposites exhibited appropriate cytocompatibility based on an MTT assay. Mainly, the proliferation of L929 fibroblast cells in contact with the PU/Cur-SC4A-LDH sample was significantly further enhanced than that for other nanocomposites within 7 days. This observation can be related to the better availability of curcumin on the film's surface, which causes an improvement in the proliferation rate of cells. Regarding the histological results, the hematoxylin and eosin (H&E) images showed faster epidermal layer formation and a larger quantity of matured hair follicles for PU/Cur-SC4A-LDH-healed wounds in comparison with those for the negative control over a period of 28 days. Thus, this practical healing ability of the PU/Cur-SC4A-LDH nanocomposite makes it a promising candidate as a wound dressing film.
Keywords: calix[4]arene; curcumin; host−guest chemistry; layered double hydroxide (LDH); polyurethane elastomer; wound dressing.