以电纺丝蛋白纤维为模板的pH响应性介孔SiO2纳米管的制备及药物释放

以资源丰富的家蚕丝为原料，氯化钙/甲酸为溶解体系，利用静电纺丝法制得丝素蛋白（SF）纳米纤维；以SF纤维为模板在其表面涂覆SiO₂，经煅烧后获得了介孔SiO₂纳米管（MSNTs）；在MSNTs管壁上接枝醛基（-CHO），利用醛基与盐酸阿霉素（DOXHCl）氨基之间的动态共价键制得了pH响应性药物释放体系。通过SEM、TEM、TG、比表面积（BET）分析、FTIR及紫外-可见吸收（UV-Vis）光谱对MSNTs的微观结构、功能化及载药体系的pH响应性进行了表征。结果表明:当SF浓度在15wt%~17wt%时，可获得圆柱状且直径在（113±27）~（134±32）nm范围内可调的SF纤维模板；通过调整涂覆液中十六烷基三甲基溴化铵（CTAB）的浓度来调节MSNTs管壁的厚度，当CTAB用量从1.25 mg/mL增加到3.75 mg/mL时，MSNTs管壁厚度从30~39 nm增加到63~65 nm，对应的比表面积从154 m2/g下降到98 m2/g，介孔平均孔径从12.5 nm下降到10.0 nm；醛基修饰的MSNTs载DOXHCl（MSNT-CHO-DOX）体系，在pH值分别为7.4、6.5和5.5的磷酸氢二钾-磷酸二氢钾（PB）缓冲溶液中进行释放，100 h时释药率分别达到23%、35%和75%，实现了MSNT-CHO-DOX载药体系的pH响应性释放。 

Preparation and drug release of pH-responsive mesoporous SiO2 nanotubes by electrospun silk fibroin nanofibers as templates

The silk fibroin(SF)nanofibers were prepared by electrospinning with rich domestic silk as raw material and calcium chloride/formic acid as dissolve system.The mesoporous SiO2nanotubes(MSNTs)were obtained with calcining after coating SiO2 on SF nanofibers templates.Utilizing dynamic covalent bond between aldehyde group(-CHO),which grafting on the wall of MSNTs,and amino group in doxorubicin hydrochloride(DOX·HCl),pH-sensitive drug release system was prepared.The microstructure,functionalization of MSNTs and pH-responsive performance of drug loading system were characterized by SEM,TEM,TG,specific surface area(BET)analysis,FTIR and ultraviolet and visible(UV-Vis)spectroscopy.The results show that when SF concentration is 15wt%-17wt%,cylindrical SF fiber templates can be obtained with adjustable diameters ranging from(113±27)nm to(134±32)nm.The wall thickness of MSNTs can be regulated by adjusting the concentration of cetyl trimethyl ammonium bromide(CTAB)in the coating solution.When the concentration of CTAB increases from 1.25mg/mL to3.75mg/mL,the wall thickness of MSNTs increases from 30-39nm to 63-65nm,the corresponding specific surface area decreasing from 154m2/g to 98m^2/g,and the average mesoporous diameter decreasing from 12.5nm to 10.0nm.The drug release rate of the MSNTs modified by aldehyde loading with DOX·HCl(MSNT-CHO-DOX)reach 23%,35%and 75%respectively at 100h when the release is carried out in dipotassium hydrogen phosphate-potassium phosphate monobasic(PB)buffer solution with pH values of 7.4,6.5and 5.5,respectively,achieving pH-responsive release of MSNT-CHO-DOX system.