聚吡咯/壳聚糖-海藻酸钠复合微球的制备及其药物缓释性能

Preparation of polypyrrole/chitosan-sodium alginate composite microspheres and their slow-release properties

开发新型药物控释复合材料在医药、农业等领域具有重要意义。以壳聚糖和海藻酸钠(CS-Alg)凝胶网络为载体,使用原位氧化法将聚吡咯(PPy)引入其中,制备出PPy/CS-Alg复合缓释材料。通过SEM、FTIR、XPS、UV-vis-NIR对其微观结构、结构组成、光热转换性能进行了研究,并以吲哚丁酸(IBA)为模型药物分子,研究了其缓释性能。结果表明:PPy/CS-Alg微球的多孔微观形貌有利于IBA的装载和释放,原位氧化形成的氧化态PPy在CS-Alg凝胶网络可缓慢还原,并从带正电状态变为不带电状态,该种带电状态的改变,可促使IBA从PPy/CS-Alg微球的凝胶网络中缓慢释放,长效释放率可达到56.12%。另外基于PPy的光热效应,模拟太阳光照射下PPy/CS-Alg微球的温度可从26℃最高上升到39℃,这有利于在微球内部到外部形成温度梯度,进一步增强IBA的缓释能力。以PPy的缓慢还原和光热效应开发的植物生长素IBA控释材料在农业领域具有广阔的应用前景。

The development of novel drug controlled release composite materials is of great significance in the fields of medicine and agriculture.Using chitosan and sodium alginate(CS-Alg)gel network as carrier,PPy/CS-Alg composite slow-release material was prepared by in-situ oxidation of polypyrrole(PPy).The microstructure,structure composition and photothermal conversion properties were studied by SEM,FTIR,XPS and UV-vis-NIR.Indolebutyric acid(IBA)was used as a model drug molecule to study its sustained release performance.The results show that the porous morphology of PPy/CS-Alg microspheres is conducive to the loading and release of IBA.The PPy oxidized state formed by in-situ oxidation can be slowly reduced in the CS-Alg gel network,and changes from a positive state to an uncharged state.As a result,IBA can be slowly released from the gel network of PPy/CS-Alg microspheres,with the long-term release rate of 56.12%.In addition,the temperature of PPy/CS-Alg microspheres under simulated sunlight can rise from 26℃ to 39℃ based on the photothermal effect of PPy,which is conducive to the formation of temperature gradients inside and outside the microspheres and further enhancing the slowrelease of IBA.The controlled release material of auxin IBA based on the slow reduction and photothermal effect of PPy has broad application prospects in the agricultural field.