Magnetic and Folate Functionalization Enables Rapid Isolation and Enhanced Tumor-Targeting of Cell-Derived Microvesicles.

Cell-derived microvesicles (MVs), which are biogenic nanosized membrane-bound vesicles that convey bioactive molecules between cells, have recently received attention for use as natural therapeutic platforms. However, the medical applications of MV-based delivery platforms are limited by the lack of effective methods for the efficient isolation of MVs and the convenient tuning of their targeting properties. Herein, we report the development of magnetic and folate (FA)-modified MVs based on a donor cell-assisted membrane modification strategy. MVs inherit the membrane properties of their donor cells, which allows them to be modified with the biotin and FA on their own membrane. By conjugating with streptavidin-modified iron oxide nanoparticles (SA-IONPs), the MVs can be conveniently, efficiently, and rapidly isolated from the supernatant of their donor cells using magnetic activated sorting. Moreover, the conjugated magnetic nanoparticles and FA confer magnetic and ligand targeting activities on the MVs. Then, the MVs were transformed into antitumor delivery platforms by directly loading doxorubicin via electroporation. The modified MVs exhibited significantly enhanced antitumor efficacy both in vitro and in vivo. Taken together, this study provides an efficient and convenient strategy for the simultaneous isolation of cell-derived MVs and transformation into targeted drug delivery nanovectors, thus facilitating the development of natural therapeutic nanoplatforms.