The effects of Twinlight laser treatment on the titanium surface proliferation and osteogenic differentiation of mesenchymal stem cells

BACKGROUND

The study aimed to observe the effects of a Twinlight laser on the titanium surface proliferation of inflammatory Mesenchymal stem cells (MSCs), inflammatory cytokine expression, and osteogenic differentiation.

METHODS

The MSCs were collected from bone tissue of healthy individuals.The cellular inflammatory model was established with 1 μg/mL lipopolysaccharide (LPS).Under the cellular inflammatory model,divided into five groups: the normal control group (C); the inflammatory control group (L); Er:YAG laser group (L + E); Nd:YAG laser group (L + N); Er:YAG laser and Nd:YAG laser group (L + E + N). The treated cells were inoculated onto titanium disks.The normal and inflammatory MSCs on the surface of titanium surface were examined by CCK-8, scanning election microscopy (SEM), quantitative real-time polymerase chain reaction (qRT‑PCR) and other methods for their proliferation, growth pattern, expression of inflammatory factors Interleukin-6 (IL-6), Interleukin-8 (IL-8) and osteogenic genes Runx2 (Runt-related transcription factor 2) and alkaline phosphatase (ALP), providing the theoretical basis and experimental data for the Twinlight laser-assisted treatment of peri-implantitis. Statistical analyses were performed using a Student's t test with SPSS 17.0 software.

RESULTS

Through observation using SEM, the cell densities of the L + E + N, L + E, and L + N groups were similar, but cell bodies in the L + E + N group were fuller and each had more than two pseudopodia. The expression level of IL-6 mRNA in the L, L + N, L + E, and L + E + N groups was higher than in group C (P < 0.05), and the expression level of IL-8 mRNA in the L + E + N group was significantly lower than in group L (P < 0.0001). On day 7, the expression level of ALP mRNA in the L, L + N, L + E, and L + E + N groups was lower than in group C (P < 0.05). On day 14, there was no significant difference in the expression level of ALP mRNA among the L + N, L + E + N, and C groups (P > 0.05). On day 7, the expression level of RUNX2 mRNA in the L + E + N group was higher than in group L (P < 0.001). On day 14, the expression level of RUNX2 mRNA in the L + E + N group was higher than in group L (P < 0.01).

CONCLUSION

Twinlight laser treatment promoted cell proliferation, inhibited the expression of inflammatory cytokines, and effectively enhanced the osteogenic differentiation of cells on a titanium surface.