Photoinduced reversible-deactivation radical polymerization (RDRP) has attracted great interest in virtue to their unique inherent advantages, such as low activation energy, environmentally benign reaction conditions and precision synthesis of designable functional polymeric materials. In this work, a facile and efficient strategy for preparing block copolymers was developed by the combination of near-infrared (NIR) light-controlled in-situ bromine-iodine transformation reversible-deactivation radical polymerization (BIT-RDRP) and purple LED light induced ring-opening polymerization (ROP). Herein, the macroinitiator was first synthesized via NIR light-controlled BIT-RDRP by using a bifunctional 2-hydroxyethyl 2-bromo-2-phenylacetate (EBP-OH) as the initiator at room temperature. Subsequently the block copolymers with narrow dispersity (low up to 1.06) were prepared by combination of purple LED light induced ROP through “two step” or “one pot” process. Importantly, the “one pot” strategy can greatly simplify the operation process and improve the synthesis efficiency, which will facilitate the batch preparation of block copolymers.
Antimicrobial resistance is still a major clinical challenge worldwide today and the development of novel antimicrobial agents with high antimicrobial activity and low bacterial resistance is of great importance. In this work, quaternized 2-(dimethylamino) ethylmethacrylates iodonium salt-type monomers with different lengths of pendent alkyl (qDMAEMA(C x ), x = 3, 6 and 8) are synthesized for preparation of a series of cationic porphyrin-based star-shaped (co)polymers by photo-controlled bromine-iodine transformation reversible-deactivation radical polymerization (BIT-RDRP). Especially, qDMAEMA(C x ) not only acts as a monomer but also can be used as an intrinsic catalyst for the BIT-RDRP. In addition, effects of alkyl chain length (x), degree of polymerization and hydrophilic-hydrophobic balance ( H.L.B. ) on the antibacterial activity of the prepared (co)polymers are investigated. The resulting zinc ion coordinated copolymers [email protected] (qDMAEMA(C 8 ) 20 - co -PEGMA 35 ) (denoted as [email protected] ) exhibits good water solubility and is able to be absorbed effectively on the surfaces of bacteria, exhibiting excellent photodynamic inhibition activity against both S. aureus and E. coli under irradiation with 570 nm light source according to the coated plate experiments. The minimum bactericidal concentration (MBC) of [email protected] against S. aureus and E. coli are 1.5 and 2.0 μM, respectively, in the presence of light. Meanwhile, [email protected] shows quite low cytotoxicity and satisfying photolysis ability at working concentrations, displaying promising biological application prospects.