Effects of pulsing of light on the dentinogenesis of dental pulp stem cells in vitro

Hong Bae Kim1, Ku Youn Baik2, Hoon Seonwoo3, Kyoung-Je Jang1, Myung Chul Lee1, Pill-Hoon Choung4 & Jong Hoon Chung

Conclusions: We clearly showed that pulsing of LPL was more efficient in hDPSC differentiation than continuous wave irradiation. In our experiment, CW mode light did not induce significant changes in hDPSC states, which may be ascribed to the weak sub-mW level power of light we used. However, PW mode irradiation of the same power light induced significant changes in CMP and ALP activity. 30% duty cycle and 300–3000Hz pulse frequencies showed the highest effects on hDPSC function. Tough the mechanism is not clearly known, high production of intracellular ROS and the activation of TGF-β1 signaling pathway should be related to this pulsing mode enhanced hDPSC-dentinogenic differentiation.


Comparison of Therapeutic Effects between Pulsed and Continuous Wave 810-nm Wavelength Laser Irradiation for Traumatic Brain Injury in Mice
Takahiro Ando1,2, Weijun Xuan1,3,4, Tao Xu1,3,5, Tianhong Dai1,3, Sulbha K. Sharma1 , Gitika B. Kharkwal1,3, Ying-Ying Huang1,3,6, Qiuhe Wu1,3,7, Michael J. Whalen8 , Shunichi Sato9 , Minoru Obara2 , Michael R. Hamblin1,3,10*

Results: The 810-nm laser pulsed at 10-Hz was the most effective judged by improvement in NSS and body weight although the other laser regimens were also effective. The brain lesion volume of mice treated with 10-Hz pulsed-laser irradiation was significantly lower than control group at 15-days and 4-weeks post-TBI. Moreover, we found an antidepressant effect of LLLT at 4-weeks as shown by forced swim and tail suspension tests.
Conclusion: The therapeutic effect of LLLT for TBI with an 810-nm laser was more effective at 10-Hz pulse frequency than at CW and 100-Hz. This finding may provide a new insight into biological mechanisms of LLLT.

Photobiomodulation with Pulsed and Continuous Wave Near-Infrared Laser (810 nm, Al-Ga-As) Augments Dermal Wound Healing in Immunosuppressed Rats
Gaurav K. Keshri, Asheesh Gupta*, Anju Yadav, Sanjeev K. Sharma, Shashi Bala Singh

Conclusion: Taken together our findings indicate that PBM with 810 nm laser inhibit excessive inflammation, facilitate cellular proliferation, ECM accumulation, tissue remodeling and bioenergetics activation, which in turn influence the augmented dermal wound healing in immunosuppressed rats (Fig 9). In Addition, healing efficacy of 10 Hz pulsed mode was more promising than CW and 100 Hz pulsed mode. Accordingly, current data may facilitate the understanding of wound healing mechanisms mediated trough NIR pulsed 810 nm LLLT in immunosuppressed rats.

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