Zwitterionic-phosphonate block polymer as anti-fouling coating for biomedical metals

Antifouling ability and blood compatibility are critically important in the development of medical metallic implants for clinical applications. Here, we report the zwitterionic-phosphonate block polymer as a new type of high-efficiency antifouling coating for metallic substrates. Six block polymers (pSBMA-b-pDEMMP) with different segment lengths (nSBMA: nDEMMP = 10:25, 40:25, 100:25, 75:5, 75:40, 75:100) were prepared and anchored on titanium alloy (TC4) substrates. 1H nuclear magnetic resonance (NMR) results clearly showed the precise preparation of the block polymers. XPS analysis and water contact angle measurement indicated the successful construction of the block polymer on TC4 substrates. The relationship between the antifouling performance of the polymer coating and the length of pDEMMP and pSBMA segments in the block polymer was established. Results showed that the polymer containing the pSBMA segment above 40 repeat units could significantly inhibit protein adsorption, platelet adhesion, bacterial adhesion and cell adhesion, while the pDEMMP segment above 5 repeat units is able to generate stable zwitterionic polymer coating on TC4 substrates. This ease of production and high-efficiency antifouling modification strategy elucidated here may find broad application for biomedical implants and devices in clinical applications.