Materials and methods for expansion of stem cells

Abstract

The subject invention concerns novel and translatable materials and methods for expansion of stem cells, such as mesenchymal stem cells (MSC), that significantly improve translational success of the cells in the treatment of various conditions, such as stroke. The subject invention utilizes cell self-aggregation as a non-genetic means to enhance their therapeutic potency in a microcarrier bioreactor. The subject invention integrates a cell aggregation process in a scalable bioreactor system. In one embodiment of the method, thermally responsive microcarriers (TRMs) are utilized in conjunction with a bioreactor system. Cells are cultured in a container or vessel in the presence of the TRMs wherein cells adhere to the surface of the TRMs. Once cells are adhered to the TRMs they can be cultured at a suitable temperature for cell growth and expansion, e.g., at about 37° C. After a period of time sufficient for cell growth and expansion on the TRMs, the cell culture temperature is reduced so that the cells detach from the TRMs. The detached cells are allowed to form cell clusters that are then cultured under conditions such that the clusters aggregate to form 3D aggregates. The 3D aggregates can be collected and treated to dissociate the cells (e.g., using enzymatic treatment, such as trypsinization). Dissociated cells can then be used for transplantation in methods of treatment or for in vitro characterization and study.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The present application claims the benefit of U.S. Provisional Application Ser. No. 61 / 946,415, filed Feb. 28, 2014, which is hereby incorporated by reference herein in its entirety, including any figures, tables, nucleic acid sequences, amino acid sequences, or drawings.BACKGROUND OF THE INVENTION[0002]Human mesenchymal stem or stromal cells (hMSCs) have been tested in over 400 clinical trials in a wide range of diseases (clinicaltrials.gov). As hMSCs translate into clinics, there is an increasing demand on technology for scalable production of therapeutically competent hMSCs in scalable bioreactor system. However, rapid hMSCs expansion has been found to induce cellular senescence and reduce their therapeutic potency. As a result, hMSC expansion technology must not only meet the demand in quantity but also preserve hMSC therapeutic potency during expansion.[0003]Recent studies have shown that hMSC have unique properties to self-assemble i...

AI Technical Summary

Benefits of technology

The invention is about a way to make stem cells, like MSCs, better at treating various conditions like heart and brain injuries. It uses microcarriers and a bioreactor to make the cells grow and aggregate in a 3D way, which makes them more effective. The method is not genetic and can be done in a scalable way. The cells can be dissociated and used for treatment or study. The technical effect is better quality stem cells for use in regenerative medicine.

Problems solved by technology

However, rapid hMSCs expansion has been found to induce cellular senescence and reduce their therapeutic potency.

Transplantation of culture-expanded hMSC has very low engraftment and homing efficiency, with less than 0.001% of total injected cells survived and homed to the ischemic cortex in rats.

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