Abstract Optomagnetic multifunctional composite has attracted much attention in recent years because of its promising application prospect in bioimaging, analysis, detection, disease diagnosis, and targeted drug delivery. To explore a dual-targeted therapy for cancer, a novel class of optomagnetic multifunctional composite (UCNP-Fe3O4@MSNs-FA) was successfully synthesized by using upconversion nanoparticles (UCNPs) as nucleus, embedding Fe3O4 nanoparticles into the SiO2 coating layer, and modifying the surface with folic acid (FA) to strengthen its tumor targeting performance. The properties of the composite were extensively studied. The obtained composite possessed excellent upconversion fluorescence, good dispersion, high specific surface area (229.347 m2/g), and saturation magnetization value (10.9 A·m 2 /g). Its drug loading content and encapsulation efficiency could reach as high as 14.2% and 47.3%, respectively, using doxorubicin hydrochloride (DOX) as model drug. The DOX-UCNP-Fe3O4@MSNs-FA system showed excellently sustained drug release and strong pH-dependent performance, in which the drug release would be accelerated at the slightly acidic microenvironment in the tumor; thus, the system could realize the targeted treatment of cancers. The viability of L929 cells demonstrated the good biocompatibility of the composite. Furthermore, DOX-UCNP-Fe3O4@MSNs-FA exhibited specific cytotoxicity to folate receptor (FR) positive tumor cells, whereas DOX had weak toxicity to FR-negative cells. Therefore, the as-prepared UCNP-Fe3O4@MSNs-FA can potentially be used as an anti-cancer targeted drug delivery system and enhance the therapeutic efficacy against FR-positive tumor cells.

中文翻译：

---

NaYF4:Yb,Er 上转换纳米颗粒基光磁多功能复合材料用于药物递送系统的合成

摘要 光磁多功能复合材料在生物成像、分析、检测、疾病诊断和靶向给药等方面具有广阔的应用前景，近年来备受关注。为探索癌症的双重靶向治疗，以上转换纳米粒子（UCNPs）为核，将Fe3O4纳米粒子嵌入SiO2涂层，并对其进行修饰，成功合成了一类新型光磁多功能复合材料（UCNP-Fe3O4@MSNs-FA）。表面带有叶酸（FA）以加强其肿瘤靶向性能。对复合材料的性能进行了广泛的研究。所得复合材料具有优异的上转换荧光、良好的分散性、高比表面积（229.347 m2/g）和饱和磁化强度值（10.9 A·m 2 /g）。以盐酸多柔比星（DOX）为模型药物，其载药量和包封率分别高达14.2%和47.3%。DOX-UCNP-Fe3O4@MSNs-FA系统表现出优异的药物缓释和强pH依赖性，在肿瘤微酸性微环境下会加速药物释放；因此，该系统可以实现癌症的靶向治疗。L929 细胞的活力证明了复合材料的良好生物相容性。此外，DOX-UCNP-Fe3O4@MSNs-FA对叶酸受体（FR）阳性肿瘤细胞表现出特异性的细胞毒性，而DOX对FR阴性细胞的毒性较弱。所以，