A novel dual-functional coating based on curcumin/APEG polymer with antibacterial and antifouling properties

Infection associated with implants and devices is a problem in medicine, especially when bacterial colonization leads to the formation of biofilms on the implant surface. Here, we report an effective strategy to develop dual-functional coatings on titanium implants with antibacterial and antifouling properties to combat biofilm infections. Coating monomers with antibacterial and antifouling blocks were prepared by conjugating curcumin-derived curcumin carboxylic acid (Cur-COOH) with different chain lengths of allyl polyethylene glycol (APEG; MW 1200 or 2400). The coating monomer (APEG1200/2400-Cur) was grafted onto the surface of the titanium implant through azobisisobutyronitrile (ABIN)-induced radical polymerization to form dual-functional coatings with antibacterial and antifouling properties. Scanning electron microscopy & energy dispersive spectroscopy (SEM & EDS), contact angle (CA), and X-ray spectroscopy (XPS) confirmed successful grafting of coupling compounds. The coatings exhibited excellent antibacterial activity against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) and prevented biofilm formation. The coatings also reduced the adsorption of proteins and the adhesion of platelets, indicating their excellent antifouling properties. Notably, the coatings also exhibited favorable biocompatibility with mammalian erythrocytes and pre-osteoblasts. In summary, this dual-functional coating showed remarkable potential for application in preventing and treating infections caused by biofilms.