Exploring the Biocompatibility of Zwitterionic Copolymers for Controlling Macrophage Phagocytosis of Bacteria

This paper provides a biomaterial derived from zwitterionic polymer for controlling macrophage phagocytosis of bacteria. A series of zwitterionic copolymers, named DMAPS-co-AA, are synthesized with 3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate (DMAPS) and acrylic acid (AA). The biocompatibility of DMAPS-co-AA copolymers can be adjusted by adjusting the DMAPS-content or pH value. As the DMAPS-content increases, the biocompatibility of zwitterionic copolymer increases. The zwitterionic copolymers with DMAPS content above 30 wt% have higher biocompatibility. Moreover, the biocompatibility also increases significantly as the pH increases from 3.4 to 7.2. By adjusting the pH above 5.8, the zwitterionic copolymer with lower DMAPS-content also shows higher biocompatibility. Importantly, after incubation with the DMAPS-co-AA copolymer solutions at different pH values, phagocytosis behavior of macrophage RAW264.7 cells can also be adjusted. The phagocytosis of bacteria is enhanced at pH = 7.2. Thus, it is proposed that zwitterionic copolymers can be used for controlling phagocytosis of bacteria.