Jahan Most Nusrat, Alam Md Ashraful, Rahman Md Mahabur, Hoque S Manjura, Ahmad Hasan
Department of Chemistry, Research Laboratory of Polymer Colloids and Nanomaterials, Rajshahi University Rajshahi 6205 Bangladesh
Department of Chemistry, Pabna University of Science and Technology 6600 Pabna Bangladesh.
RSC Adv. 2024 Jul 26;14(32):23560-23573. doi: 10.1039/d4ra03160a. eCollection 2024 Jul 19.
pH-responsive polymer microspheres undergoing reversible changes in their surface properties have been proved useful for drug delivery to targeted sites. This paper is aimed at preparing pH-responsive polymer-modified magnetic mesoporous SiO particles. First, mesoporous magnetic (FeO) core-particles are prepared using a one-pot solvothermal method. Then, magnetic FeO particles are covered with a C[double bond, length as m-dash]C functional mesoporous SiO layer before seeded emulsion polymerization of 2-carboxyethyl acrylate (2-CEA). The composite polymer particles are named FeO/SiO/P(2-CEA). The average diameters of the FeO core and FeO/SiO/P(2-CEA) composite polymer particles are 414 and 595 nm, respectively. The mesoporous (pore diameter = 3.41 nm) structure of FeO/SiO/P(2-CEA) composite polymer particles is confirmed from Brunauer-Emmett-Teller (BET) surface analysis. The synthesized FeO/SiO/P(2-CEA) composite polymer exhibited pH-dependent changes in volume and surface charge density due to deprotonation of the carboxyl group under alkaline pH conditions. The change in the surface properties of FeO/SiO/P(2-CEA) composite polymer particles following pH change is confirmed from the pH-dependent sorption of cationic methylene blue (MB) and anionic methyl orange (MO) dye molecules. The opening of the pH-responsive P(2-CEA) gate valve at pH 10.0 allowed the release of loaded vancomycin up to 99% after 165 min and -acetamido phenol (-AP) up to 46% after 225 min. Comparatively, the amount of release is lower at pH 8.0 but still suitable for drug delivery applications. These results suggested that the mesoporous FeO/SiO composite seed acted as a microcapsule, while P(2-CEA) functioned as a gate valve across the porous channel. The prepared composite polymer can therefore be useful for treating intestine/colon cancer, where the pH is comparatively alkaline.
表面性质发生可逆变化的pH响应性聚合物微球已被证明可用于将药物递送至靶向部位。本文旨在制备pH响应性聚合物修饰的磁性介孔二氧化硅颗粒。首先，采用一锅法溶剂热法制备介孔磁性（FeO）核颗粒。然后，在2-丙烯酸羧乙酯（2-CEA）的种子乳液聚合之前，用含碳碳双键的功能性介孔二氧化硅层覆盖磁性FeO颗粒。复合聚合物颗粒被命名为FeO/SiO/P(2-CEA)。FeO核和FeO/SiO/P(2-CEA)复合聚合物颗粒的平均直径分别为414和595 nm。通过布鲁诺尔-埃米特-特勒（BET）表面分析证实了FeO/SiO/P(2-CEA)复合聚合物颗粒的介孔结构（孔径 = 3.41 nm）。合成的FeO/SiO/P(2-CEA)复合聚合物在碱性pH条件下由于羧基去质子化而表现出体积和表面电荷密度的pH依赖性变化。通过阳离子亚甲基蓝（MB）和阴离子甲基橙（MO）染料分子的pH依赖性吸附，证实了FeO/SiO/P(2-CEA)复合聚合物颗粒在pH变化后表面性质的变化。pH响应性P(2-CEA)闸阀在pH 10.0时打开，使得负载的万古霉素在165分钟后释放高达99%，对乙酰氨基酚（-AP）在225分钟后释放高达46%。相比之下，在pH 8.0时释放量较低，但仍适用于药物递送应用。这些结果表明，介孔FeO/SiO复合种子起到微胶囊的作用，而P(2-CEA)则作为跨多孔通道的闸阀发挥作用。因此，制备的复合聚合物可用于治疗肠道/结肠癌，因为该部位的pH相对呈碱性。
