Interwoven MOF-Coated Janus Cells as a Novel Carrier of Toxic Proteins.

Two major issues in cell-mediated drug delivery systems (c-DDS) are the availability of free cell surfaces for the binding of the cells to the target or to their microenvironment and internalization of the cytotoxic drug. In this study, the Janus structure, MOF nanoparticles, and tannic acid (TA) are utilized to address these issues. Janus carrier cells coated with metal-organic frameworks (MOFs) are produced by asymmetrically immobilizing the nanoparticles of a MOF based on zinc with cytotoxic enzymes that are internally encapsulated on the surface of carrier cells. By maintaining the biological and structural features of regular living cells, the MOF-coated Janus cells developed in the present study preserve the intrinsic binding capacity of the cells to their microenvironment. Interconnected MOFs loaded onto the other face of the Janus cells cannot penetrate the cell. Therefore, the carrier cells are protected from the cytotoxic drug contained in MOFs. These MOF-Janus carrier cells are demonstrated to successfully eliminate three-dimensional (3D) tumor spheroids when a chemotherapeutic protein of proteinase K is released from the MOF nanoparticles in an acid environment. The ease with which the MOF-Janus carrier cells are prepared (in 15 min), and the ability to carry a variety of enzymes and even multiple ones should make the developed system attractive as a general platform for drug delivery in various applications, including combination therapy.