Giving Oncolytic Viruses a Free Ride: Carrier Cells for Oncolytic Virotherapy

Oncolytic viruses (OVs) are an emerging class of therapeutics which combine multiple mechanisms of action, including direct cancer cell-killing, immunotherapy and gene therapy. A growing number of clinical trials have indicated that OVs have an excellent safety profile and provide some degree of efficacy, but to date only a single OV drug, HSV-1 talimogene laherparepvec (T-Vec), has achieved marketing approval in the US and Europe. An important issue to consider in order to accelerate the clinical advancement of OV agents is the development of an effective delivery system. Currently, the most commonly employed OV delivery route is intratumoral; however, to target metastatic diseases and tumors that cannot be directly accessed, it is of great interest to develop effective approaches for the systemic delivery of OVs, such as the use of carrier cells. In general, the ideal carrier cell should have a tropism towards the tumor microenvironment (TME), and it must be susceptible to OV infection but remain viable long enough to allow migration and finally release of the OV within the tumor bed. Mesenchymal stem cells (MSCs) have been heavily investigated as carrier cells due to their inherent tumor tropism, in spite of some disadvantages in biodistribution. This review focuses on the other promising candidate carrier cells under development and discusses their interaction with specific OVs and future research lines.

TEMPO-Oxidized Cellulose Hydrogel Fiber Cell Load, a Cell Support System Proof of Concept

The development of new cell carriers systems are crucial for application in regenerative medicine, once they deliver the cells to the injured tissue to trigger the repair and stimulate the regeneration of the new tissue, and so far various carrier systems have been investigated in this regard. Here we report on the synthesis and characterization of a new cell carrier system in fiber shape where the cells osteo-1 are incorporated into the oxidized cellulose nanofibers suspension and then complexed with calcium ions in a pulling process giving rise to the fiber loaded with cells. The microscopic images showed the success of the proposed method to incorporate the cells into the fibers. The results of the in-vitro viability tests indicated the capability of the fibers to keep the cells alive and to mineralize them, indicating that their osteogenic capability was not affected. In addition, the fiber disintegration studies showed the system is capable of releasing the cells, suggesting the potential of the fibers as a new assembled hydrogel carrier cell therapy.