Feng Meixi, Gu Chuanhai, Bao Chaoling, Chen Xiuqiong, Yan Huiqiong, Shi Zaifeng, Liu Xiaohong, Lin Qiang
Key Laboratory of Water Pollution Treatment & Resource Reuse of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University Haikou 571158 Hainan P. R. China
Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University Haikou 571158 Hainan P. R. China.
RSC Adv. 2018 Oct 8;8(60):34397-34407. doi: 10.1039/c8ra04300k. eCollection 2018 Oct 4.
TiO nanoparticles (nano-TiO) as one of the most extensively used nanoscale materials easily undergo spontaneous aggregation and gravity sedimentation ascribed to their high adsorption energy, which significantly restricts their actual applications. For this reason, a benzyl-grafted alginate derivative (BAD) with good colloidal interface activity, prepared by a bimolecular nucleophilic substitution (S2) reaction, was used as the dispersant to stabilize nano-TiO. The structure and colloidal properties of BAD was evaluated by FT-IR spectroscopy, H NMR spectroscopy, thermal gravimetric analysis (TGA) and dynamic light scattering (DLS). The effects of pH and ionic strength on the dispersion stability of BAD/nano-TiO suspensions were also examined by DLS. To further probe its feasibility as a drug delivery system, the BAD/nano-TiO complex was applied as particulate emulsifiers to fabricate drug-loaded Pickering emulsions. Meanwhile, the morphology properties and the sustained release performance of the drug-loaded Pickering emulsions were also investigated. Experimental results showed that the adsorption of BAD on nano-TiO was achieved by an intermolecular hydrogen bond between the carboxylic functional groups of BAD and the Ti-OH of TiO. The adsorption of BAD enhanced the electrostatic repulsion and steric hindrance between nano-TiO improving the dispersion stability of nano-TiO at different pH and ionic strength. Additionally, the obtained Pickering emulsions displayed good drug-loading capacity and sustained release performance with the release mechanism of non-Fickian transport, which exhibited great potential in the pharmaceutical field.
二氧化钛纳米颗粒（纳米TiO）作为应用最为广泛的纳米材料之一，由于其高吸附能，容易发生自发聚集和重力沉降，这显著限制了它们的实际应用。因此，通过双分子亲核取代（S2）反应制备的具有良好胶体界面活性的苄基接枝藻酸盐衍生物（BAD）被用作分散剂来稳定纳米TiO。通过傅里叶变换红外光谱（FT-IR）、核磁共振氢谱（1H NMR）、热重分析（TGA）和动态光散射（DLS）对BAD的结构和胶体性质进行了评估。还通过DLS研究了pH值和离子强度对BAD/纳米TiO悬浮液分散稳定性的影响。为了进一步探究其作为药物递送系统的可行性，将BAD/纳米TiO复合物用作颗粒乳化剂来制备载药Pickering乳液。同时，还研究了载药Pickering乳液的形态性质和缓释性能。实验结果表明，BAD在纳米TiO上的吸附是通过BAD的羧基官能团与TiO的Ti-OH之间的分子间氢键实现的。BAD的吸附增强了纳米TiO之间的静电排斥和空间位阻，提高了纳米TiO在不同pH值和离子强度下的分散稳定性。此外，所制备的Pickering乳液具有良好的载药能力和缓释性能，其释放机制为非菲克传输，在制药领域具有巨大潜力。
