School of Chemical Engineering, Department of Chemical System Engineering, Separation Process Laboratory, State University of Campinas, Av. Albert Einstein, 500, Bloco A, Cidade Universitária, Campinas, SP 13083-852, Brazil.
Carbohydr Polym. 2012 Oct 15;90(3):1216-25. doi: 10.1016/j.carbpol.2012.06.051. Epub 2012 Jun 26.
The preparation and characterization of natural polymer-based hydrogels that contain 50-nm diameter magnetite (i.e., FeO:Fe(2)O(3)) nanoparticles are described herein. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the efficiency of the polysaccharide-modifying process. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and compressive moduli demostrate that the presence of magnetite improves thermal and mechanical resistance. Transient diffusion of water in magnetic hydrogels was analyzed via boundary layer mass transfer across an expaning interface, and the degree of swelling of these polysaccharide hydrogels decreases in the presence of magnetite, with no variation in the binary diffusion mechanism. The absence of hysteresis loops and coercivity observed via magnetometry suggests that magnetic hydrogels are useful for remote-controlled drug release, as demonstrated by magnetic-field-induced release of curcumin. Experiments reveal that magnetic hydrogels with greater magnetic susceptibility have the potential to release larger concentrations of drugs from the hydrogel network.
本文描述了含有 50nm 直径磁铁矿（即 FeO:Fe(2)O(3)）纳米粒子的天然聚合物基水凝胶的制备和特性。傅里叶变换红外光谱（FTIR）分析证实了多糖修饰过程的有效性。热重分析（TGA）、差示扫描量热法（DSC）和压缩模量表明，磁铁矿的存在提高了热和机械阻力。通过扩展界面的边界层质量传递分析了水在磁性水凝胶中的瞬态扩散，并且在存在磁铁矿的情况下，这些多糖水凝胶的溶胀程度降低，二元扩散机制没有变化。通过磁强计观察到不存在滞后环和矫顽力表明，磁性水凝胶可用于远程控制药物释放，这通过磁场诱导姜黄素的释放得到了证明。实验表明，具有更大磁化率的磁性水凝胶有可能从水凝胶网络中释放出更高浓度的药物。
