Synthesis of copolymers using dendronized polyethylene glycol and assay of their blood compatibility and antibacterial adhesion activity

Thrombus formation and microbial invasion are two major complications that impede the widespread application of blood-contacting devices. The development of new materials that have blood compatibility and antibacterial adhesion activity has gained increased attention. In this study, a new class of polymers composed of hydrophilic dendronized polyethylene glycol (PEG) methacrylate and hydrophobic octyne monomethyl ether-glycidyl methacrylate was synthesized via click chemistry and free radical polymerization. Different polymers were synthesized by changing the ratio of the two monomers. The structures of the synthesized polymers were characterized by 1H nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Their physical properties such as molecular weight, polydispersity, and glass transition temperature were determined using gel permeation chromatography and differential scanning calorimetry. The synthesized polymers were coated on glass slides to prepare a series of polymeric surfaces. Contact angle measurements and attenuated total reflection Fourier-transform infrared spectroscopy analysis showed that the polymeric surfaces had long-lasting stability. The introduction of the monomer dendronized PEG methacrylate to the polymers greatly improved the hydrophilicity of the polymeric surfaces. The blood compatibility of the synthesized polymers was evaluated by protein (bovine serum albumin and fibrinogen) adsorption and platelet adhesion assays. Their antibacterial adhesion ability was investigated using the Gram-negative Pseudomonas aeruginosa and the Gram-positive Staphylococcus aureus. The results demonstrated that the amount of adsorbed protein, platelets, and bacteria on the polymeric surfaces decreased with increased content of the hydrophilic monomer dendronized PEG methacrylate in the polymers. However, no obvious difference was observed when such content exceeded 50 mol%. The results suggested that the new kind of polymer could be developed as a promising blood-contact coating material that may have extensive medical applications.