Perspectives in Engineered Mesenchymal Stem/Stromal Cells Based Anti- Cancer Drug Delivery Systems

Understanding and apprehension of the characteristics and circumstances in which mesenchymal stem cells (MSCs) affect and make alterations (enhance or reduce) to the growth of tumors and metastasis spread is pivotal, not only for reaching the possibility to employ MSCs as drug delivery systems, but also for making forward movement in the existing knowledge of involvement of major factors (tumor microenvironment, soluble signaling molecules, etc.) in the process of carcinogenesis. This capability is reliable because MSCs present a great basis for engineering and constructions of new systems to target cancers, intended to secrete therapeutic proteins in the tumor region, or for delivering of oncolytic viruses' directly at the tumor site (targeted chemotherapy with enzyme prodrug conversion or induction of tumor cell apoptosis). MSCs as a crucial segment of the tumor surroundings and their confirmed tumor tropism, are assumed to be an open gateway for the design of promising drug delivery systems. The presented paper reviews current publications in this fieldwork, searches out the most recent patents that were published after 2012 (WO2014066122, US20140017787, WO2015100268, US20150086515), and tries to present the current progress and future prospective on the design and development in anti-cancer drug delivery systems based on MSCs. Keywords: Cancer therapy, cellular therapy, drug delivery, mesenchymal stem cells, oncolytic viruses, pro-drug, target therapy.