Photodynamic Therapy Effect on Synovial Fibroblast Viability
Keturkienė, Jurgita Bumblauskaitė, Andrius Kleinauskas, Saulius Bagdonas, Giedrė Streckytė, Narūnas Porvaneckas, Ričardas Rotomskis
Aim. To evaluate photodynamic therapy effect on synovial fibroblast (SF) viability of inflammatory rheumatoid arthritis (RA) and degenerative osteoarthritis (OA).
Materials and methods. The samples of synovial tissue were taken from the joints of the patients that underwent surgical treatment. SF were cultivated in vitro. Endogenous porphyrins were used as photosensitizers and were produced in the cells from aminolevulinic acid (ALA) and its methyl ester (m-ALA). Cells were irradiated by the blue light of light-emitting diod (5 mJ/cm2) with light doses of 50 and 150 mJ/cm2. The effect of photosensitization was assessed by determining features characteristic of fibroblasts and in the normal culture medium RA-SF exhibited higher viability indicators than OA-SF (p<G.G5). The investigation of the impact of two ALA and m-ALA concentrations (G.5 mM and l.G mM) on SF viability in the dark showed, that the highest impact had 1 mM m-ALA solution, but it affected selectively only OA fibroblasts by reducing their viability parameters 5 times (p<G.GGl). The impact of light alone and photosensitization on synovial fibroblasts were investigated using two light doses: 5G mJ/cm2 and 15G mJ/cm2. RA-SF and OA-SF had similar viability parameters when incubated with 1 mM ALA and m-ALA solutions and irradiated by 5G mJ/cm2 light dose. The viability indicator values of both groups of fibroblasts, incubated with 1 mM ALA or m-ALA solutions and irradiated with three times higher light dose (15G mJ/cm2), were close to zero. The most suitable conditions for in vitro photosensitzation of aggressive RA-FS were established.
Conclusions. Viability parameters of inflammed RA synovial fibroblasts were significantly higher than these of OA fibroblasts when the cells were incubated in normal culture medium or with G.5 mM and l.G mM ALA or m-ALA solutions. Irradiation of not sensitized fibroblasts with blue light of 15G mJ/cm2 dose, had higher impact on more proliferous RA-SF. The most suitible conditions for in vitro photosensitization of aggressive RA-FS are following: incubation with the solution of G.5 mM m-ALA and irradiation with 15G mJ/cm2 light dose. In this context, the viability of RA-SF is almost completely inhibited down to G.GG2±G.GG r.u. compared to nonirradiated RA-SF (1.95±G.G6 r.u.) at the same conditions.
Keywords: rheumatoid arthritis, osteoarthritis, synovitis, cell viability, photosensitization, aminolevulinic acid.