Therapeutic Window of Photodynamic Treatment (PDT) in Conservative Periodontal Therapy -Analysis of Cell Migration Within A Three Dimensional Collagen Matrix-

Objectives: The aim of the present study was to investigate the effect of low-level laser irradiation as photodynamic therapy (PDT) on proliferation and differentiation of a human fibroblast cell line, determining the therapeutic window of toluidine blue O (TBO) using the 3-D collagen matrix assay with fibroblasts.

Material and methods: The collagen-based 3-D assay (MetaVi Labs, Bottrop, Germany) combines all the advantages of 3-D collagen matrix assays with the benefits of high-throughput, fully auto-mated (hands-off) tracking technology. Two sets of tests (MetaVì Labs 3-D collagen matrix assay) were performed with human dermal fibroblasts derived from PromoCell (Heidelberg, Germany). Cells do not need to be labelled with any dyes or tags that could interfere with cell motility or inter-act with substances being tested in the assay.

Results: The sensitization of fibroblasts with a physiological concentration of 5% (v:v) TBO and exposure to light from a 810 nm diode laser (1 min, 0.3 W) did not reduce cell viability and migratory activity measured by migration dynamics in comparison to the not sensitized fibroblasts.

Conclusion: The study provided evidence that PDT with a diode laser 810nm and the photosensitizer toluidine blue O does not influence locomotory behavior of human fibroblasts in vitro.

Keywords: Photodynamic therapy (pdt); Toluidine blue O (TBO); Human oral fibroblasts; 3-D collagen based migration assay; Cell activity