近年来，间充质干细胞（MSCs）被认为是一种极具前景的新型肿瘤靶向传递载体。然而，利用天然MSCs作为载体构建的靶向传递系统却依然面临着诸多问题，比如对肿瘤组织的靶向效率以及对细胞载体在体内的动态示踪等都存在着一定的不足。因此，本项目将通过制备新型的铁磁性纳米材料来改良天然的MSCs，并以该磁性MSCs为载体构建新一代多功能肿瘤靶向传递系统。该系统可利用磁性MSCs良好的磁动力学性质进行磁靶向传递，并结合MSCs自身的肿瘤归巢特性实现对肿瘤组织的高效靶向。同时，利用磁性MSCs的铁标记和内源性细胞进行区分，进而通过MRI等技术实现对载体细胞在体内命运的实时监视。此外，通过磁转染技术和磁分选技术，使该细胞载体高效携载自杀基因，从而有效杀伤肿瘤细胞。最后，利用磁性MSCs良好的磁热效应实现对肿瘤的磁热辅助治疗，发挥协同抗肿瘤作用。本项目有望为改善基于MSCs的肿瘤靶向传递系统提供新的策略。

Recently, mesenchymal stem cells (MSCs) have been regarded as promising candidates for novel tumor-targeting carriers. However, the application of using MSCs to prepare a tumor-targeting delivery system is still hampered by several obstacles, such as the relative ineffective tumor-targeting ability and the difficulty for dynamic tracing of cells in vivo. Therefore, the current project aims to synthesize a novel ferromagnetic nano-material to improve the natural MSCs, and to prepare a new generation of multifunctional tumor-targeting delivery system based on these magnetic MSCs. The well magnetic dynamic property of these magnetic cells enables a magnetic-targeting delivery. Together with the inherent tumor-homing ability of MSCs, the delivery system can achieve a more effective tumor-targeting capability. Furthermore, the labeling with ferromagnetic nano-material makes the magnetic MSCs detectable and leads to a difference between magnetic MSCs and endogenous cells, thereby the cellular fate of magnetic MSCs in vivo can be monitored by MRI. Besides, the loading efficiency of suicide genes in MSCs is also increased by applying magnetofection and magnetic sorting, thus leads to an effective killing effect to tumor cells. At last, the magnetic MSCs can play a synergistic antitumor effect through their well magnetothermal effect. Therefore, the present project may provide an innovative strategy for preparing an improved tumor-targeting delivery system based on MSCs.