Human dental pulp stem cells--isolation and long term cultivation

Area of Science:

• Stem Cell Biology
• Regenerative Medicine
• Dental Research

Background:

• Mesenchymal stem cells (MSCs) reside in various adult tissues and possess differentiation potential.
• Human dental pulp stem cells (DPSCs) were first isolated in 2000, with subsequent isolation from exfoliated teeth.
• Understanding the characteristics and therapeutic potential of DPSCs is crucial.

Purpose of the Study:

• To establish a protocol for isolating and cultivating DPSCs from both adult and exfoliated teeth.
• To compare the biological characteristics and stem cell properties of DPSCs with bone marrow-derived mesenchymal progenitor cells (MPCs).
• To assess the proliferative capacity and cytogenetic stability of DPSCs during long-term culture.

Main Methods:

• Isolation and cultivation of DPSCs from deciduous and permanent teeth.
• Isolation of human bone marrow-derived MPCs from the proximal femur.
• Cultivation of both cell types under identical conditions using specific growth factors (PDGF, EGF) and low FCS concentration.
• Long-term culture of DPSCs for over 60 population doublings.
• Karyotype analysis to assess chromosomal stability.
• Doubling time and proliferation potential analysis using regression analysis.

Main Results:

• DPSCs were successfully cultivated from both deciduous and permanent teeth and demonstrated high proliferation rates.
• DPSCs maintained a normal karyotype even after exceeding the Hayflick limit (over 60 population doublings).
• The proliferation potential of DPSCs showed a slow decrease with increasing passage number.
• DPSCs exhibited similar biological characteristics and stem cell properties to bone marrow MPCs.
• Two distinct DPSC populations with differing morphologies were potentially isolated.
• Both DPSCs and MPCs were identified as highly proliferative, clonogenic, and cytogenetically stable cells.

Conclusions:

• DPSCs are highly proliferative and clonogenic adult stem cells with significant potential for therapeutic applications.
• DPSCs can be expanded extensively in vitro beyond the Hayflick limit while retaining cytogenetic stability.
• DPSCs represent an easily accessible and attractive alternative source of adult stem cells compared to bone marrow MPCs.
• Further investigation into the distinct DPSC populations may reveal unique therapeutic advantages.