AGC Inc. Organic Materials Division, Materials Integration Laboratories, 1-1 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
Soft Materials Chemistry, Institute for Materials Chemistry and Engineering, Kyushu University, Build. CE41, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan; Department of Energy Conversion and Storage, Technical University of Denmark, Elektrovej, Build. 375, 2800 Kongens Lyngby, Denmark.
Biomater Adv. 2023 Oct;153:213573. doi: 10.1016/j.bioadv.2023.213573. Epub 2023 Jul 28.
Hydrophilic materials display "bio-inert properties", meaning that they are less recognized as foreign substances by proteins and cells. Such materials are often water soluble; therefore, one general approach to enable the use of these materials in various applications deals with copolymerizing hydrophilic monomers with hydrophobic ones to facilitate such resulting copolymers water insoluble. However, reducing the hydrophilic monomer amount may reduce the bio-inert properties of the material. The decrease in bio-inert properties can be avoided when small amounts of fluorine are used in copolymers with hydrophilic monomers, as presented in this article. Even in small quantities (7.9 wt%), the fluorinated monomer, 1,1,1,3,3,3-hexafluoropropan-2-yl 2-fluoroacrylate (FAHFiP), contributed to the improved hydrophobicity of the polymers of the long side-chain poly(ethylene glycol) methyl ether methacrylate (mPEGMA) bearing nine ethylene glycol units turning them water insoluble. As evidenced by the AFM deformation image, a phase separation between the FAHFiP and mPEGMA domains was observed. The copolymer with the highest amount of the fluorinated monomer (66.2 wt%) displayed also high (82 %) FAHFiP amount at the polymer-water interface. In contrast, the hydrated sample with the lowest FAHFiP/highest mPEGMA amount was enriched of three times more hydrophilic domains at the polymer-water interface compared to that of the sample with the highest FAHFiP content. Thus, by adding a small FAHFiP amount to mPEGMA copolymers, water insoluble in the bulk too, could be turned highly hydrophilic at the water interface. The high content of intermediate water contributed to their excellent bio-inert properties. Platelet adhesion and fibrinogen adsorption on their surfaces were even more decreased as compared to those on poly(2-methoxyethyl acrylate), which is typically used in medical devices.
亲水材料表现出“生物惰性特性”，这意味着它们被蛋白质和细胞识别为异物的程度较低。这类材料通常水溶性较好；因此，使这些材料在各种应用中得以使用的一种通用方法是，将亲水性单体与疏水性单体共聚，从而使所得共聚物不溶于水。然而，降低亲水性单体的用量可能会降低材料的生物惰性特性。如本文所述，在与亲水性单体的共聚物中少量使用氟原子，可以避免生物惰性特性的降低。即使在少量（7.9wt%）的情况下，含氟单体 1,1,1,3,3,3-六氟-2-丙基 2-氟丙烯酸酯（FAHFiP）也会使具有九个乙二醇单元的长侧链聚（乙二醇）甲基醚甲基丙烯酸酯（mPEGMA）的聚合物的疏水性提高，从而使聚合物不溶于水。正如 AFM 变形图像所示，观察到 FAHFiP 和 mPEGMA 畴之间发生了相分离。共聚物中含氟单体的含量最高（66.2wt%）时，聚合物-水界面处也含有高达 82%的 FAHFiP。相比之下，在聚合物-水界面处，水化样品中 FAHFiP 含量最低（mPEGMA 含量最高）的样品比 FAHFiP 含量最高的样品更富含三倍的亲水性畴。因此，通过向 mPEGMA 共聚物中添加少量 FAHFiP，即使在本体中不溶的共聚物也可以在水界面处变得高度亲水。高含量的中间水有助于其具有优异的生物惰性特性。与通常用于医疗器械的聚（2-甲氧基乙基丙烯酸酯）相比，它们表面的血小板黏附和纤维蛋白原吸附甚至降低更多。
