Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Colloids Surf B Biointerfaces. 2021 Mar;199:111507. doi: 10.1016/j.colsurfb.2020.111507. Epub 2020 Dec 4.
The purpose of this study is to achieve a simpler and safer surface modification of substrates using a photoreactive polymer in an aqueous environment. We synthesized water-soluble photoreactive polymers with both phenylazide groups and phosphorylcholine groups, poly(2-methacryloyloxyethyl phosphorylcholine-co-4-methacryl tetra(ethylene glycol)oxycarbonyl-4-phenylazide) (PMEPAz), via reversible addition fragmentation chain transfer polymerization. PMEPAz with different polymerization degrees were synthesized with a well-defined structure. To immobilize PMEPAz on the substrate surface by photoreaction, it is necessary to adsorb the polymer on the substrate surface in an aqueous solution because the phenylazide groups chemically bind to the substrate via a hydrogen abstract reaction. The relationship between the polymer solubilization state in the aqueous solution and the adsorption behavior at the surface was investigated. PMEPAz began to form unstable molecular aggregates at a concentration of 10 mg/mL and formed stable aggregates at 10 mg/mL. At a concentration of 10 mg/mL, unstable molecular aggregates of PMEPAz were formed in the aqueous solution, resulting in the maximization of the amount of adsorbed polymer and effective photoreaction with the substrate. The thickness of the reacted polymer layer on the substrate increased with an increase in the polymerization degree, a uniform polymer layer with a thickness of 3.4 nm was formed when the polymerization degree was 400. After surface modification, the hydrophobic surfaces of the original substrates became hydrophilic. Additionally, fibrinogen adsorption and platelet adhesion were effectively suppressed based on the characteristics of the phosphorylcholine unit.
本研究旨在通过在水相环境中使用光反应性聚合物，实现对基底的更简单、更安全的表面改性。我们通过可逆加成-断裂链转移聚合合成了具有苯甲酰基叠氮基团和磷酰胆碱基团的水溶性光反应性聚合物，聚（2-甲基丙烯酰氧基乙基磷酰胆碱-co-4-甲基丙烯四（乙二醇）氧基羰基-4-苯甲酰基叠氮）（PMEPAz）。通过该方法可以合成具有明确结构的不同聚合度的 PMEPAz。为了通过光反应将 PMEPAz 固定在基底表面上，有必要在水溶液中吸附聚合物到基底表面上，因为苯甲酰基叠氮基团通过氢提取反应与基底化学结合。研究了聚合物在水溶液中的溶解状态与表面吸附行为之间的关系。当浓度为 10 mg/mL 时，PMEPAz 开始形成不稳定的分子聚集体，而在 10 mg/mL 时形成稳定的聚集体。在 10 mg/mL 的浓度下，PMEPAz 的不稳定分子聚集体在水溶液中形成，导致吸附聚合物的量最大化，并与基底发生有效光反应。基底上反应聚合物层的厚度随聚合度的增加而增加，当聚合度为 400 时形成厚度为 3.4nm 的均匀聚合物层。表面改性后，原始基底的疏水面变得亲水。此外，基于磷酰胆碱单元的特性，有效地抑制了纤维蛋白原的吸附和血小板的黏附。
