Dental Pulp Stem Cells: Current Advances in Isolation, Expansion and Preservation

Abstract

Dental pulp stem cells (DPSCs) are mesenchymal stem cells with high self-renewal potential that have the ability to differentiate into several cell types. Thus, DPSCs have become a promising source of cells for several applications in regenerative medicine, tissue engineering, and stem cell therapy. Numerous methods have been reported for the isolation, expansion, and preservation of DPSCs. However, methods are diverse and do not follow specific rules or parameters, which can affect stem cell properties, adding more variation to experimental results. In this review, we compare and analyze current experimental evidence to propose some factors that can be useful to establish better methods or improved protocols to prolong the quality of DPSCs. In addition, we highlight other factors related to biological aspects of dental tissue source (e.g., age, genetic background) that should be considered before tooth selection. Although current methods have reached significant advances, optimization is still required to improve culture stability and its maintenance for an extended period without losing stem cell properties. In addition, there is still much that needs to be done toward clinical application due to the fact that most of DPSCs procedures are not currently following good manufacturing practices. The establishment of optimized general or tailored protocols will allow obtaining well-defined DPSCs cultures with specific properties, which enable more reproducible results that will be the basis to develop effective and safe therapies.

Keywords: Banking; Cell culture; Cryopreservation; Differentiation; Enrichment; Stemness.

Fig. 1

Schematic representation of critical steps followed from tooth selection to DPSCs cryopreservation and applications. Each step summarizes critical factors that should be considered for optimization in order to improve DPSCs culture and stability during manufacturing. For tooth selection, several factors related to donor characteristics must be considered to establish specific criteria according to research interests. As we can see, many key factors fall into cell culture formulation suggesting that this issue is one of the most important to establish general or tailored protocols and obtain DPSCs with specific properties, as well as the long-term maintenance of cultures. Homogeneous populations of DPSCs may be cryopreserved or directly applied to basic or clinical research, either previous or simultaneous molecular and biochemical characterization. A quality control assessment (blue box) should be required not only for banking, but also to ensure the safety of these stem cells before application. (Color figure online)