Grafting antibacterial polymer brushes from titanium surface via polydopamine chemistry and activators regenerated by electron transfer ATRP

An environmentally benign and convenient approach to impart titanium (Ti) surfaces with antibacterial functionalities was described in this work. Polydopamine (PDA) was first deposited onto an alkali activated Ti substrates. Then 2-bromoisobutyryl bromide (BIBB) was immobilized on the surface of PDA coated Ti. Finally, the BIBB functionalized Ti initiated the polymerization of N, N-diethylaminoethyl methacrylate (DEAEMA) and N, N-dimethylaminoethyl methacrylate (DMAEMA) to obtain [email protected] brushes by activators regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP). The prepared PDEAEMA and PDMAEMA brushes on Ti surfaces would be subsequently quaternized by using 1-bromooctane, which would impart the obtained products with quaternary ammonium groups. The surface compositions of the functionalized Ti were characterized by X-ray photoelectron spectroscopy (XPS). The hydrophilic/hydrophobic properties of the functionalized Ti surfaces were determined by static water contact angle measurements, and morphologies were characterized by scanning electron microscope (SEM). Antibacterial abilities of quaternized PDEAEMA and PDMAEMA coated Ti were evaluated by the contact killing test, in which live/dead cell staining method was employed. The results showed that the quaternized polymer decorated Ti exhibited good bactericidal effects against Escherichi coli (E. coli), and its inhibition rate of E. coli were observed to be nearly 90%.