Background: Drug delivery technologies adjust drug release profile, absorption, distribution, and elimination for benefiting to the improvement of product efficacy, effectiveness, and safety. The IONPs release drugs via enzymatic activity, changes in physiological conditions such as pH, osmolality radiation, or temperature. In the case of nanoparticles that respond to the magnetic stimulus, the drug directs its action towards the site of a detected magnetic field.

Objective: In this study, the synthesis of a specific drug-delivery system based on magnetic nanocarrier for teniposide as an anticancer drug is reported. The iron oxide@SiO2 core-shell nanoparticles were functionalized with APTS as a spacer then coupling to the DOTA molecules. Anticancer drug of teniposide conjugated to the acidic group of DOTA via an amide bond. Multi-purpose magnetic nanoparticles were synthesized for targeted delivery of teniposide.

Methods: Iron oxide nanoparticles were firstly coated with silica and their surface was then modified with aminopropyltriethoxysilane (APTES) through an in situ method. DOTA-NHS was also coupled to Fe3O4@SiO2-APTES via an amide bond formation. In the final step, teniposide as an anti-cancer drug was conjugated with DOTA through ester bonds, and the final compound of Fe3O4@SiO2- APTES-DOTA-Teniposide was obtained. The obtained nanocarrier was evaluated by various analyses.

Results: The multifunctional Fe3O4@SiO2-APTES-DOTA nanocarriers were successfully synthesized and characterized by XRD, FTIR, TGA, and UV-vis techniques. The silica-coated magnetic nanoparticle functionalized with aminopropyl triethoxysilane (APTES) was reacted with an acid group of DOTA, and teniposide was then coupled to DOTA through ester formation bonds. Drug release experiments showed that most of the conjugated teniposide were released within the first 12h.

Conclusion: The fabricated nano-carriers exhibited pH-sensitive drug release behavior, which can minimize the non-specific systemic spread of toxic drugs during circulation whilst maximizing the efficiency of tumor-targeted anticancer drug delivery for this purpose. The prepared teniposidegrafted Fe3O4@SiO2-APTES-DOTA core–shell structure nanoparticles showed a magnetic property with exposure to magnetic fields, indicating a great potential application in the treatment of cancer using magnetic targeting drug-delivery technology and multimodal imaging techniques.

背景：药物输送技术可调整药物释放曲线，吸收，分配和消除，从而有利于提高产品功效，有效性和安全性。IONP通过酶活性，生理条件（例如pH值，重量克分子渗透压浓度或温度）的变化释放药物。对于响应磁刺激的纳米颗粒，药物将其作用导向检测到的磁场部位。

目的：在这项研究中，报告了基于磁性纳米载体的替尼泊苷作为抗癌药物的特定药物递送系统的合成。用APTS作为间隔基将氧化铁@ SiO2核-壳纳米粒子官能化，然后偶联至DOTA分子。替尼泊苷的抗癌药通过酰胺键与DOTA的酸性基团结合。合成了多用途的磁性纳米颗粒，用于替尼泊苷的靶向递送。

方法：首先将氧化铁纳米颗粒涂有二氧化硅，然后通过原位方法用氨基丙基三乙氧基硅烷（APTES）对其表面进行改性。DOTA-NHS也通过酰胺键形成与Fe3O4 @ SiO2-APTES偶联。在最后步骤中，将teniposide作为抗癌药通过酯键与DOTA偶联，得到最终的Fe3O4 @ SiO2-APTES-DOTA-替尼泊苷化合物。通过各种分析评价获得的纳米载体。

结果：通过XRD，FTIR，TGA和UV-vis技术成功合成并表征了多功能Fe3O4 @ SiO2-APTES-DOTA纳米载体。使用氨基丙基三乙氧基硅烷（APTES）官能化的二氧化硅涂覆的磁性纳米粒子与DOTA的酸基反应，然后将Teniposide通过酯形成键与DOTA偶联。药物释放实验表明，大多数结合的替尼泊苷在最初的12h内被释放。

结论：制备的纳米载体表现出对pH敏感的药物释放行为，可以使有毒药物在循环过程中的非特异性全身性扩散减至最小，同时最大程度地实现针对肿瘤的抗癌药物递送效率。制备的Teniposide接枝的Fe3O4 @ SiO2-APTES-DOTA核-壳结构纳米粒子在暴露于磁场时显示出磁性，这表明使用磁性靶向药物递送技术和多峰成像技术在癌症治疗中具有巨大的潜在应用。