采用共沉淀法制备了Fe₃O₄并作为SA@Fe₃O₄@SiO₂的磁性核心,从而实现磁靶向。在Fe₃O₄表面包覆介孔二氧化硅得到Fe₃O₄@SiO₂。此外,将海藻酸钠修饰在介孔二氧化硅表面作为pH响应物质,能够实现在低pH下解离并在其他情况下结合在介孔二氧化硅表面阻塞其孔道,防止在中性pH下发生突释。利用傅里叶红外光谱仪(FT-IR)、X射线衍射仪(XRD)、BET分析仪、透射电镜(TEM)、振动样品磁强计(VSM)和Zeta电位分析仪对该药物递送体系进行表征。盐酸阿霉素作为模型药物被负载在药物递送体系的介孔中,用于评估药物递送体系的药物负载和释放能力。药物负载和释放研究表明,载药量和包封率分别为1.62%和24.31%;在pH 7.4和pH 5.0的条件下,SA@Fe₃O₄@SiO₂的累计释放率分别为35.82%和88.51%,表现出良好的pH响应性能。

Fe₃O₄ is synthesized via the coprecipitation method,and utilized as the magnetic core of SA@Fe₃O₄@SiO₂,a drug delivery system,to achieve magnetic targeting.Fe₃O₄@SiO₂ is obtained by coating mesoporous silica onto the surface of Fe₃O₄.Furthermore,sodium alginate is modified on the surface of mesoporous silica as a pH-responsive substance that dissociates at low pH and binds to the surface of mesoporous silica to block its pores and prevent burst release at neutral pH.The properties of this drug delivery system are characterized by means of FT-IR spectroscopy,X-ray diffraction,BET analysis,transmission electron microscopy (TEM),vibrating sample magnetometry (VSM),and zeta potential measurements.Additionally,doxorubicin hydrochloride served as a model drug is loaded into the mesopores of SA@Fe₃O₄@SiO₂ to evaluate the loading and release capacity of this drug delivery system.It is verified that the drug loading rate and encapsulation efficiency are 1.62% and 24.31%,respectively.Moreover,the cumulative release rates of SA@Fe₃O₄@SiO₂@DOX at pH 7.4 and pH 5.0 are 35.82% and 88.51%,respectively,indicating an excellent responsiveness to pH.

朱家建(2002-),男,本科生,研究方向为药物递送,1529423467@qq.com;杜轶君(1980-),女,博士,副教授,研究方向为化学和材料,通讯联系人,7511373@qq.com。