Ruiz-Virgen Lazaro, Hernandez-Martinez Miguel Angel, Martínez-Mejía Gabriela, Caro-Briones Rubén, Herbert-Pucheta Enrique, Río José Manuel Del, Corea Mónica
Laboratorio de Investigación en Polímero y Nanomateriales, ESIQIE, Instituto Politécnico Nacional, Av. Luis Enrique Erro S/N, Unidad Profesional Adolfo López Mateos, Zacatenco, Alcaldía Gustavo A. Madero, Mexico City 07738, Mexico.
Escuela Superior de Ingeniería Mecánica y Eléctrica, ESIME, Instituto Politécnico Nacional, Av. Luis Enrique Erro S/N, Unidad Profesional Adolfo López Mateos, Zacatenco, Alcaldía Gustavo A. Madero, Mexico City 07738, Mexico.
Gels. 2024 Aug 20;10(8):541. doi: 10.3390/gels10080541.
The pH- and thermo-responsive behavior of polymeric hydrogels MC-co-MA have been studied in detail using dynamic light scattering DLS, scanning electron microscopy SEM, nuclear magnetic resonance (H NMR) and rheology to evaluate the conformational changes, swelling-shrinkage, stability, the ability to flow and the diffusion process of nanoparticles at several temperatures. Furthermore, polymeric systems functionalized with acrylic acid MC and acrylamide MA were subjected to a titration process with a calcium chloride CaCl2 solution to analyze its effect on the average particle diameter Dz, polymer structure and the intra- and intermolecular interactions in order to provide a responsive polymer network that can be used as a possible nanocarrier for drug delivery with several benefits. The results confirmed that the structural changes in the sensitive hydrogels are highly dependent on the corresponding critical solution temperature CST of the carboxylic (-COOH) and amide (-CONH) functional groups and the influence of calcium ions Ca2+ on the formation or breaking of hydrogen bonds, as well as the decrease in electrostatic repulsions generated between the polymer chains contributing to a particle agglomeration phenomenon. The temperature leads to a re-arrangement of the polymer chains, affecting the viscoelastic properties of the hydrogels. In addition, the diffusion coefficients D of nanoparticles were evaluated, showing a closeness among with the morphology, shape, size and temperature, resulting in slower diffusions for larger particles size and, conversely, the diffusion in the medium increasing as the polymer size is reduced. Therefore, the hydrogels exhibited a remarkable response to pH and temperature variations in the environment. During this research, the functionality and behavior of the polymeric nanoparticles were observed under different analysis conditions, which revealed notable structural changes and further demonstrated the nanoparticles promising high potential for drug delivery applications. Hence, these results have sparked significant interest in various scientific, industrial and technological fields.
使用动态光散射（DLS）、扫描电子显微镜（SEM）、核磁共振（H NMR）和流变学详细研究了聚合物水凝胶MC-co-MA的pH和热响应行为，以评估在几个温度下纳米颗粒的构象变化、溶胀-收缩、稳定性、流动能力和扩散过程。此外，用丙烯酸MC和丙烯酰胺MA功能化的聚合物体系用氯化钙（CaCl2）溶液进行滴定过程，以分析其对平均粒径Dz、聚合物结构以及分子内和分子间相互作用的影响，从而提供一种响应性聚合物网络，该网络可作为具有多种优势的药物递送纳米载体。结果证实，敏感水凝胶的结构变化高度依赖于羧基（-COOH）和酰胺基（-CONH）官能团的相应临界溶解温度（CST）以及钙离子（Ca2+）对氢键形成或断裂的影响，以及聚合物链之间产生的静电排斥力的降低，这导致了颗粒团聚现象。温度导致聚合物链重新排列，影响水凝胶的粘弹性。此外，评估了纳米颗粒的扩散系数D，结果表明其与形态、形状、尺寸和温度密切相关，较大粒径的颗粒扩散较慢，相反，随着聚合物尺寸减小，在介质中的扩散增加。因此，水凝胶对环境中的pH和温度变化表现出显著响应。在这项研究中，在不同分析条件下观察了聚合物纳米颗粒的功能和行为，揭示了显著的结构变化，并进一步证明了纳米颗粒在药物递送应用中具有很高的潜力。因此，这些结果在各个科学、工业和技术领域引起了极大的兴趣。
