A Novel Alternative to Cryopreservation for the Short-Term Storage of Stem Cells for Use in Cell Therapy Using Alginate Encapsulation

Abstract

Efficient transport of stem/progenitor cells without affecting their survival and function is a key factor in any practical cell-based therapy. However, the current approach using liquid nitrogen for the transfer of stem cells requires a short delivery time window is technically challenging and financially expensive. The present study aims to use semipermeable alginate hydrogels (crosslinked by strontium) to encapsulate, store, and release stem cells, to replace the conventional cryopreservation method for the transport of therapeutic cells within world-wide distribution time frame. Human mesenchymal stem cell (hMSC) and mouse embryonic stem cells (mESCs) were successfully stored inside alginate hydrogels for 5 days under ambient conditions in an air-tight environment (sealed cryovial). Cell viability, of the cells extracted from alginate gel, gave 74% (mESC) and 80% (hMSC) survival rates, which compared favorably to cryopreservation. More importantly, the subsequent proliferation rate and detection of common stem cell markers (both in mRNA and protein level) from hMSCs and mESCs retrieved from alginate hydrogels were also comparable to (if not better than) results gained following cryopreservation. In conclusion, this new and simple application of alginate hydrogel encapsulation may offer a cheap and robust alternative to cryopreservation for the transport and storage of stem cells for both clinical and research purposes.

Low temperature cell pausing: an alternative short-term preservation method for use in cell therapies including stem cell applications

“…Cell pausing is clearly becoming accepted as a potential technology to preserve and transport mammalian cells. The research by Chen et al (2013) in particular, proves that the process of cell pausing can be successfully applied to stem cells, which holds great potential for its application to future cell therapies.…”

“…A current success in cell pausing under ambient conditions used human mesenchymal stromal cells (hMSC) and mouse embryonic stem cells (mESC) entrapped in a semi-permeable alginate hydrogel (Chen et al 2013). …”

“…Very few cell pausing studies have focussed on stem cells (see Table 1). However, research which has applied the process to potent cells show significant potential (Heng et al 2006;Ginis et al 2012;Chen et al 2013). Current advancements using devices such as the PetakaG3 and alginate gel entrapment to store cells at ambient temperatures are encouraging but limited for the storage and transport of cells at large scale.…”

The role of biopreservation in cell and gene therapy bioprocessing

“…Unlike cryopreservation and, to a lesser extent, chilled preservation, the research with ambient temperature preservation is not as extensive and has only become an area of interest in light of the potential advantages this preservation method confers over the aforementioned preservation techniques. The potential of this technique is demonstrated by Chen et al (2013) who demonstrated that they were able to store hMSCs and mouse ESCs (mESCs) inside alginate hydrogels for 5 days in ambient conditions in an air-tight environment. Cell viability post-preservation was found to be 80% and 74% for the hMSCs and mESCs respectively [47].…”

“…The potential of this technique is demonstrated by Chen et al (2013) who demonstrated that they were able to store hMSCs and mouse ESCs (mESCs) inside alginate hydrogels for 5 days in ambient conditions in an air-tight environment. Cell viability post-preservation was found to be 80% and 74% for the hMSCs and mESCs respectively [47]. Similarly, Swioklo et al (2016) showed human adipose-derived stem cells could be encapsulated and stored at a range of temperatures, from 4-23C, although 15C was found to be the optimal [48].…”