壳聚糖-mPEG温敏水凝胶载药系统的制备及释药行为

Preparation and in vitro drug release of chitosan-g-mPEG thermosensitive hydrogel drug

壳聚糖-mPEG亲水性好,可制成适合生物大分子药物递送的反向温敏水凝胶给药系统。为改善壳聚糖(CS)在中性条件下水溶性和亲水性,用单甲氧基聚乙二醇(mPEG)修饰壳聚糖,得到带有mPEG支链的改性材料——CS-mPEG)。通过修饰方法优化,得到聚乙二醇(PEG)取代率为21%～25%的CS-mPEG。该CS-mPEG水溶性好,37℃溶胶-凝胶转变时间小于10 min。体外释药结果显示:该CS-mPEG水凝胶对生物大分子溶菌酶及小分子纳曲酮均有较好控释作用,且mPEG支链的亲水作用能保护蛋白活性,显著提高了活性蛋白的累积释放率。

Chitosan-grafted-mPEG（CS-mPEG） was obtained by modifying chitosan with methoxy poly（ethylene glycol）（mPEG） to improve the solubility and hydrophilicity of the material in neutral solutions.The CS-mPEG thermosensitive hydrogel exhibits better hydrophilicity with potential as the injectable polymer matrix for the delivery of biomolecules.Optimization of the modification method gave a CS-mPEG with a PEG-substitution degree of 21% to 25% with good water solubility and reversible thermosensibiliy.The sol-gel transformation finished within 10 min at 37 ℃.The in vitro release profiles show that release of the model biomolecular drug lysozyme（Lys） and the model chemical drug naltrexone（NTX） are well controlled from the CS-PEG hydrogel.Since the hydrophilic mPEG chain prevents inactivation of the biomolecules,the release rate of active lysozyme is markably increased in the chitosan-g-PEG hydrogel compared to the chitosan hydrogel.