Xie Xinling, Zhang Youquan, Zhu Yong, Lan Yiling
Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
Nanomaterials (Basel). 2022 Feb 10;12(4):598. doi: 10.3390/nano12040598.
Based on the characteristics of charge reversal around the isoelectric point (pI) of amphoteric starch-containing anionic and cationic groups, amphoteric cassava starch nanoparticles (CA-CANPs) are prepared by a W/O microemulsion crosslinking method using (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride as a cationic reagent and POCl as an anionic reagent, and the effects of preparation conditions on the particle size of the CA-CANPs are studied in detail in the present study. CA-CANPs with a smooth surface and an average diameter of 252 nm are successfully prepared at the following optimised conditions: a crosslinking agent amount of 15 %, an aqueous starch concentration of 6.0 %, an oil-water ratio of 10:1, a total surfactant amount of 0.20 g·mL, and a CHPTAC amount of 4.05 %. The pH-responsive value of the CA-CANPs can be regulated by adjusting the nitrogen-phosphorus molar ratio in the CA-CANPs. By using CA-CANPs with a pI of 6.89 as drug carriers and the paclitaxel (PTX) as a model drug, the maximum loading rate of 36.14 mg·g is achieved, and the loading process is consistent with the Langmuir isotherm adsorption, with the calculated thermodynamic parameters of Δ° = -37.91 kJ·mol, Δ° = -10.96 J·mol·K and Δ° < 0. By testing the release rate in vitro, it is noted that the release rates of PTX in a neutral environment (37.6% after 96 h) and a slightly acidic environment (58.65% after 96 h) are quite different, suggesting that the CA-CANPs have the possibility of being a targeted controlled-release carrier with pH responsiveness for antitumor drugs.
基于含阴离子和阳离子基团的两性淀粉在等电点（pI）附近电荷反转的特性，以（3-氯-2-羟丙基）三甲基氯化铵为阳离子试剂、POCl为阴离子试剂，通过W/O微乳液交联法制备了两性木薯淀粉纳米颗粒（CA-CANPs），并在本研究中详细研究了制备条件对CA-CANPs粒径的影响。在以下优化条件下成功制备了表面光滑、平均直径为252 nm的CA-CANPs：交联剂用量15%、淀粉水溶液浓度6.0%、油水比10:1、表面活性剂总量0.20 g·mL、CHPTAC用量4.05%。CA-CANPs的pH响应值可通过调节CA-CANPs中的氮磷摩尔比来调控。以pI为6.89的CA-CANPs为药物载体、紫杉醇（PTX）为模型药物，实现了36.14 mg·g的最大载药量，载药过程符合Langmuir等温吸附，计算得到的热力学参数为Δ° = -37.91 kJ·mol、Δ° = -10.96 J·mol·K且Δ° < 0。通过体外释放速率测试发现，PTX在中性环境（96 h后为37.6%）和微酸性环境（96 h后为58.65%）中的释放速率差异较大，表明CA-CANPs有可能成为一种具有pH响应性的抗肿瘤药物靶向控释载体。
