College of Chemistry and Materials Science, Ludong University, Yantai 264025, China.
Int J Biol Macromol. 2013 Apr;55:69-74. doi: 10.1016/j.ijbiomac.2012.12.048. Epub 2013 Jan 8.
Thermo- and pH-sensitive ionic-crosslinked hollow spheres from self-assembly of chitosan-graft-poly(N-isopropylacrylamide) (CS-g-PNIPAM) for controlled release of 5-fluorouracil were studied. CS-g-PNIPAM aggregated into core-shell micelles with collapsed PNIPAM as the core and CS as the shell at the temperature above LCST. Ionic crosslinking reagent sodium tripolyphosphate (TPP) was used to crosslink the shell to form hollow spheres after cooling to room temperature. The size of hollow spheres was manipulated by changing pH or temperature of the environment. The CS-g-PNIPAM hollow spheres with plenty of inner cavities showed high loading capacity for 5-fluorouracil due to the polymer-drug interactions. Release of 5-fluorouracil from nanoparticles was accelerated at the temperature above LCST ascribed to the destruction of polymer-drug interactions and the decrease of particles size. Changing pH or ionic strength deformed the structure hollow spheres, which led to the increase of drug release. These hollow nanoparticles with environmentally sensitive properties are expected to be utilized in the field of intelligent drug delivery.
研究了壳聚糖接枝聚 N-异丙基丙烯酰胺（CS-g-PNIPAM）自组装形成的温敏和 pH 敏感离子交联空心球，用于 5-氟尿嘧啶的控制释放。在 LCST 以上温度下，CS-g-PNIPAM 聚集形成具有塌陷 PNIPAM 核和 CS 壳的核壳胶束。离子交联试剂三聚磷酸钠（TPP）在冷却至室温后用于交联壳以形成空心球。通过改变环境的 pH 值或温度来操纵空心球的大小。由于聚合物-药物相互作用，具有大量内腔的 CS-g-PNIPAM 空心球表现出对 5-氟尿嘧啶的高负载能力。由于聚合物-药物相互作用的破坏和颗粒尺寸的减小，5-氟尿嘧啶从纳米颗粒中的释放在 LCST 以上温度下加速。改变 pH 值或离子强度会使空心球的结构变形，从而导致药物释放增加。这些具有环境敏感特性的空心纳米粒子有望在智能药物输送领域得到应用。
