基于葫芦[8]脲主-客体作用的温度及pH敏感壳聚糖超分子凝胶制备与性能

1. 福建医科大学药学院 福州 350004
• 投稿日期:2012-07-17 发布日期:2012-10-10
• 通讯作者: 林友文 E-mail:linhumor@sina.com
• 基金资助:
项目受福建省自然科学基金计划项目(No. 2011J01289)和福建省科技计划重点项目(No. 2011Y0031)资助.

Preparation and Properties of Temperature and pH Sensitive Chitosan Supramolecular Gel Based on Host-guest Interaction of Cucurbit[8]uril

Lin Youwen, Li Lifan, Li Guangwen

1. College of Pharmacy, Fujian Medical University, Fuzhou 350004, China
• Received:2012-07-17 Published:2012-10-10
• Supported by:
Project supported by the Natural Science Foundation of Fujian Province of China (No. 2011J01289) and the Key Project Foundation of Technology Plan of Fujian Province of China (No. 2011Y0031).

Chitosan (CS) which is a non-toxic, biocompatible, and biodegradable material and a good candidate for hydrogel formation was modified. A chitosan derivative, N-(4-dimethylaminobenzyl)chitosan (MBCS), was synthesized by the reaction of 4-(dimethylamino)benzaldehyde and chitosan to fabricate supramolecular gel system. The new family of macrocyclic host molecules, cucurbit[n]urils (Q[n], n＝6～8) with its hydrophobic central cavity and negatively charged carbonyl portals, can bind to a variety of cationic organic guest molecules and neutral species to form the clathrate compounds with high affinity, and shows great potential applications in drug delivery system due to its low toxicity and good thermal stability. Cucurbit[8]uril (Q[8]) has a larger hydrophobic cavity volume of 479 ?3 and can include two aromatic rings. In this paper a novel supramolecular gel was prepared by utilizing the host-guest interaction between Q[8] and MBCS. The physical properties and structure of supramolecular gel and MBCS were characterized via IR, UV, 1H NMR, X-ray powder diffraction (XRD), thermogravimetric method (TG) and differential scanning calorimetry (DSC). The morphology of network structure of the xerogel was observed via an environmental scanning electron microscope (SEM). The spectrum of 1H NMR demonstrated that the host-guest interaction between Q[8] and guest units on the side chain of MBCS in the Q[8]/MBCS system resulted in the formation of the supramolecular gel. Q[8] acted as a cross-linker for supramolecular interactions (noncovalent crosslinking referring to electrostatic action, Van der Waals force and hydrophobic action, etc.). The Q[8]/MBCS supramolecular gel showed pH-sensitive and thermosensitive properties. 5-Fluorouracil (5-Fu) was taken as a model drug. The release characteristics of drug-loaded gels were studied in mediums with three different pH values. The results showed that the Q[8]/MBCS supramolecular gel system had obviously sustained-release for 5-Fu in acidic condition in vitro, suggesting that the Q[8]/MBCS supramolecular gel could be a new potential carrier for stimuli-responsive drug delivery system.