School of Life Sciences, Anhui University, Hefei 230601, Anhui, China; Key Laboratory of Eco-engineering and Biotechnology of Anhui Province, Hefei 230601, Anhui, China.
School of Life Sciences, Anhui University, Hefei 230601, Anhui, China; Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, Anhui, China; Key Laboratory of Eco-engineering and Biotechnology of Anhui Province, Hefei 230601, Anhui, China.
Int J Pharm. 2019 Jan 30;555:291-302. doi: 10.1016/j.ijpharm.2018.11.058. Epub 2018 Nov 22.
Polyphosphates are important polyanionic electrolytes that play a major role in stabilization and consolidation of colloids surface and interior microstructures. In this study, the polyelectrolyte complexes (PEC) microcapsules (sodium cellulose sulfate-chitosan hydrochloride, sample 1), and the patched ones via sodium tripolyphosphate (sample 2), sodium pyrophosphate (sample 3) and sodium hexametaphosphate (sample 4) were fabricated under mild conditions. The effects of polyphosphates on the formation of the PEC microcapsules were investigated systematically. Scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM) observation showed that both of the sample 2 and sample 3 had more compact interior microstructures with higher fluorescence intensity, compared with the sample 4 with macroporous ones and sample 1 with irregular ones. Fourier transform-infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) showed the electrostatic interactions occurred among the -NH groups, -SO groups, HPO groups, PO groups and HPO groups, and the sample 2 and sample 3 had a more thermal stability comparatively. The sample microcapsules showed good capacity of drug loading and encapsulation efficiency (max. 66.9 ± 4.6% and 74.2 ± 5.1%). In the in vitro release studies showed that the sample 2 and sample 3 had a larger accumulative drug release rate of 5-aminosalicylic acid (5-ASA) at the same time point and released completely at 12 h; the drug release mechanisms analysis indicated that the sample 1 and sample 3 were mainly diffusion controlled, while the sample 2 and sample 4 were followed the mechanism of non-Fickian transport. Under the polyphosphate's consolidation, the PEC microcapsules fabricated with sustained drug release profiles could be used as the promising drug vehicles.
多聚磷酸盐是重要的多阴离子电解质，在胶体表面和内部微观结构的稳定和固结中起主要作用。在这项研究中，在温和条件下制备了聚电解质复合物（PEC）微胶囊（硫酸纤维素钠-盐酸壳聚糖，样品 1），以及通过三聚磷酸钠（样品 2）、焦磷酸钠（样品 3）和六偏磷酸钠（样品 4）进行修补的微胶囊。系统研究了多聚磷酸盐对 PEC 微胶囊形成的影响。扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）观察表明，与具有大孔的样品 4 和具有不规则结构的样品 1 相比，样品 2 和样品 3 的内部微观结构更加紧密，荧光强度更高。傅里叶变换红外光谱（FT-IR）和热重分析（TGA）表明-NH 基团、-SO 基团、HPO 基团、PO 基团和 HPO 基团之间发生了静电相互作用，样品 2 和样品 3 具有更高的热稳定性。样品微胶囊表现出良好的载药能力和包封效率（最大 66.9±4.6%和 74.2±5.1%）。体外释放研究表明，在相同时间点，样品 2 和样品 3 具有更大的 5-氨基水杨酸（5-ASA）累积释放率，在 12 小时内完全释放；药物释放机制分析表明，样品 1 和样品 3 主要为扩散控制，而样品 2 和样品 4 遵循非菲克扩散机制。在多聚磷酸盐的固结作用下，具有持续药物释放特性的 PEC 微胶囊可用作有前途的药物载体。
