Quintanilla de Stéfano Juan Carlos, Abundis-Correa Vanessa, Herrera-Flores Sergio Daniel, Alvarez Alejandro J
School of Engineering and Sciences, Tecnologico de Monterrey, Av. Eugenio Garza Sada 2501, Monterrey 64849, NL, Mexico.
Polymers (Basel). 2020 Aug 31;12(9):1974. doi: 10.3390/polym12091974.
The drug release behavior of pH-sensitive starch-based hydrogels was systematically studied. Hydrogels were synthesized by copolymerization of acrylic acid (AA) and other acrylate comonomers onto the starch backbone. The hydrophilic agents 2-hydroxy ethyl methacrylate (HEMA), and acrylamide (AAm), as well as the hydrophobic butyl-methacrylate (BMA), were utilized as comonomers. Methylene-bisacrylamide (MBA) was employed as a crosslinking agent. The synthesized hydrogels were loaded with caffeine as a model drug. The effects of the hydrophobic/hydrophilic character of the comonomers and chemical crosslinking on the swelling capacity and the release rate of caffeine were investigated. The use of the crosslinking agent and hydrophobic monomers decreased the swelling capacity of the hydrogels. The release rate of caffeine increased with the presence of a hydrophobic monomer. The fastest release was obtained with the AA/BMA/AAm formulation, and the slowest release was observed with the AA/HEMA/AAm formulation. The transport mechanism was controlled by Fickian diffusion in formulations containing AAm, and controlled by the polymer-relaxation mechanism in formulations containing MBA. Overall, our results showed that the swelling and drug delivery behavior can be tuned by varying the chemical composition of the copolymer formulations. These starch-based hydrogels can be useful as drug delivery devices in many biomedical applications.
系统研究了pH敏感型淀粉基水凝胶的药物释放行为。通过将丙烯酸（AA）和其他丙烯酸酯共聚单体接枝到淀粉主链上合成水凝胶。亲水剂甲基丙烯酸2-羟乙酯（HEMA）、丙烯酰胺（AAm）以及疏水性甲基丙烯酸丁酯（BMA）被用作共聚单体。亚甲基双丙烯酰胺（MBA）用作交联剂。将咖啡因作为模型药物载入合成的水凝胶中。研究了共聚单体的疏水/亲水特性以及化学交联对水凝胶溶胀能力和咖啡因释放速率的影响。交联剂和疏水单体的使用降低了水凝胶的溶胀能力。咖啡因的释放速率随着疏水单体的存在而增加。AA/BMA/AAm配方的释放速度最快，而AA/HEMA/AAm配方的释放速度最慢。在含有AAm的配方中，传输机制受菲克扩散控制，而在含有MBA的配方中，传输机制受聚合物松弛机制控制。总体而言，我们的结果表明，可以通过改变共聚物配方的化学成分来调节溶胀和药物递送行为。这些淀粉基水凝胶在许多生物医学应用中可用作药物递送装置。
