pH响应性阿维菌素/介孔硅的一步合成与释放

One-Step Synthesis and Release of pH-responsive Avermectin/Mesoporous Silica

摘要:

以三嵌段共聚物F127（(EO)106(PO)70(EO)106）为模板剂，正硅酸甲酯（TMOS）为硅源，阿维菌素(AVM)为模型药物，通过一步法合成载药介孔硅材料(HOMS)，采用铜、锌、锰3种金属离子改性，形成具有pH响应性的缓释材料AVM/Zn-HOMS、AVM/Cu-HOMS和AVM/Mn-HOMS，借助FTIR、SEM、N2吸附-脱附法和TGA表征了缓释材料，并研究了其在不同pH下的释放行为。结果表明，AVM/Zn-HOMS、AVM/Cu-HOMS和AVM/Mn-HOMS材料表面分别呈现层状、疏松多孔状以及气泡状结构，比表面积分别为308.581、101.218和318.011 m2/g，氮气吸附-脱附等温线类型为具有H2型滞后环的Langmuir Ⅳ型。AVM/Zn-HOMS和AVM/Cu-HOMS呈现良好的pH响应性，AVM/Mn-HOMS则未表现出明显的pH响应性，3种材料的缓释行为均可用Higuchi动力学模型描述，释放过程受扩散机制控制。

Abstract:

By using the F127((EO)106(PO)70(EO)106) as the template agent,methyl silicate(TMOS) as the silicon source and the avermectin as the model drug, the avermectin/mesoporous silica(HOMS) was prepared in the method of one-step synthesis.Copper ion, zinc ion and manganese ion were used during the synthetic process in order to form coordinate bond between avermectin and mesoporous silica,and thus,three kinds of pH-responsive slow-released systems(AVM/Zn-HOMS, AVM/Cu-HOMS and AVM/Mn-HOMS) were build up.The materials’ structures were systematically studied using Fourier transform infrared spectroscopy(FTIR),N2 adsorption-desorption, scanning electron microscopy(SEM) and thermogravimetric analysis(TGA) measurements, and the release behaviour under different pH values was also studied.The results showed that, stratiform structure, multihole structure and bubble structure were observed on the surface appearance of AVM/Zn-HOMS,AVM/Cu-HOMS and AVM/Mn-HOMS, respectively. Compared with AVM/HOMS, the surface areas of AVM/Zn-HOMS, AVM/Cu-HOMS and AVM/Mn-HOMS had an enlargement about 308.581,101.218 and 318.011 m2/g,respectively.The N2 adsorption-desorption isotherms of the systems were H1 hysteresis loops of the type LangmuirⅣ. AVM/Zn-HOMS and AVM/Cu-HOMS showed obvious pH responsiveness, while AVM/Mn-HOMS didn’t exhibited obvious pH responsiveness. The release process could be described by Higuchi kinetic model. The diffusion mechanism dominated the release process.