Development of Novel 3D Stem Cell Sheet for Periodontal Regeneration

Abstract

Objective: To assess the regenerative capacity of 3D periodontal ligament stem cell (PDLSC) sheet in vivo.

Method: Single culture and co-culture cell sheets were prepared by using PDLSCs and Human umbilical vein endothelial cells (HUVECs) in thermo-responsive culture dishes. Scanning electron microscopy (SEM) was used to observe the ultra-structure of single and co-culture groups of cell sheets. Cells were labeled with cell-tracker dyes (PDLSCs-Green, HUVECs-Red) and seeded in different ratios to assess the time dependent modulation of vascular network formation on Matrigel (4 and 8 hours). Tooth root fragments were coated with PDLSC sheets and implanted into the subcutaneous space of SCID mice. After 2 weeks, implants were retrieved and processed for histological evaluation.

Result: SEM results showed the ultra-structural arrangement and preserved extracellular matrix (ECM) of layered cell sheet constructs. Furthermore, increased ECM deposition was observed in co-culture groups. PDLSCs and HUVECs seeded on Matrigel showed initiation of vessel like structure formation after 4 hours. Extensive lattice of vessel like structures was formed in 1:2 and 1:5 groups compared to other groups. However, after 8 hours all the groups showed formation of island like cell aggregations. In vivo, H&E sections exemplified the successful integration of implanted PDL cell sheet coated roots with host tissues after 2 weeks. Periodontal ligament-like arrangement was observed around root surface in cell sheet groups compared to control groups.

Conclusions: 3D cell sheet model demonstrated a promising regenerative potential in vivo and this approach would be useful in future periodontal bioengineering strategies. This abstract is based on research that was funded entirely or partially by an outside source: Seed Funding for Basic Research 201111159191 The University of Hong Kong