Characterisation of Periodontal Stem Cells Isolated From Osteoporotic Patients

Objectives: Osteoporosis and its medications have possible implications on patients’ periodontal condition and healing. Little is known about the regenerative capacity of osteoporotic periodontal ligament stem cells (OP-PDLSCs). Therefore, the aim of the project is to characterise PDLSCs isolated from postmenopausal osteoporotic patients and compare them to those isolated from healthy individuals. The objectives include the assessment of their ability to form colonies, long-term growth characteristics and their osteogenic differentiation potential in vitro.
Methods: PDLSCs were isolated from healthy and osteoporotic patients. The primary characterisation of PDLSCs was attained by: colony forming unit-fibroblast assay (CFU) after 14 days in culture, and population doubling time (PDT) assay, followed up for 2 months for each cell type. For osteogenic differentiation assessment, passage 6 cells from both groups were seeded and cultured in osteogenic media (basal media +100µM L-ascorbic acid and 10µM dexamethasone) for 2, 3 and 4 weeks (basal media used as control). Cultures were assessed using Alkaline Phosphatase Staining (ALP) assay and Alizarin Red Staining (ARS) and quantitative assay.
Results: The primary characterisation results of CFU indicated an average of 64±23 colonies for healthy PDLSCs and an average of 44±23 colonies for OP-PDLSCs. The average for PDT for all passages was 2.07±0.5 days for healthy PDLSCs and 1.66±0.12 days for OP-PDLSCs. For both the control and osteoporotic donors, ALP staining was more intense under osteogenic conditions. ARS preliminary results indicated that mineralisation was the highest at week 3 in healthy PDLSCs grown in osteogenic conditions (0.025mM±0.004) whereas it remained unchanged in OP-PDLSCs (average 0.0135mM±0.002).
Conclusions: The results suggest that there is a trend of lower clonogenicity, and mineralisation capacity of OP-PDLSCs compared to healthy controls which can affect their regenerative capacity to heal the periodontium.