Human dental pulp stromal cells (HDPSCs) have the ability to differentiate along multiple lineages, offering promise for their use in regenerative therapies. In order to translate cell-based therapies to clinical reality, a number of challenges remain to be addressed. One such challenge is the need for a non-invasive method to characterise cell phenotype, ascertain the long term health of differentiating HDPSCs and understand their differentiation behaviour. Our aim was to develop a non-invasive methodology for phenotyping HDPSCs in monolayer and when seeded on to 3D scaffolds at different stages of the differentiation pathway.
Method:
We have used NMR spectroscopy coupled with principal component analysis and statistical modelling to characterise HDPSCs in adipogenic and osteogenic culture over time. Cells were grown as monolayers or seeded on to electrospun collagen scaffolds and differentiation induced using adipogenic or osteogenic culture medium in vitro. NMR spectra were collected from the monolayers/constructs at various time points over a period of 6 weeks.
Result:
Cells remained viable and differentiated as normal throughout spectral measurements. Processing the spectra provided information on cell metabolic behaviour within both the monolayers and the constructs. Differences in levels of certain metabolites appeared after differentiation had occurred. Principal component analysis and mathematical modelling of the information obtained has enabled the predication of clusters and data trends for cells differentiating down different lineages, effectively phenotyping the population of cells within each construct.
Conclusion:
We conclude that NMR spectroscopy may offer a non-invasive diagnostic/prognostic tool for stem cell behaviour in regenerative therapies.