Biophotonic Effects of Low-Level Laser Therapy at Different Wavelengths for Potential Wound Healing

Round 1

Reviewer 1 Report

The manuscript entitled: “Biophotonics Effects of low-level laser therapy at different wavelengths for potential wound healing” by Li-Chern Pan, et al, presents the recent progresses of their laboratory in improving the resulst obtained by low-level laser therapy on the cell cultures of fibroblast cells, decreasing the relative expression of matrix metallopeptidase (MMP)-1, -2, and -9 and increasing levels of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF). The topic is timely, the work is sound and the results are remarkable. However, the introduction should be checked thoroughly. Overall, the work is certainly publishable and contributes to research area of laser therapy for wound healing. I recommend this manuscript for publication in "Photonics” after minor revisions as follow.

1) The introduction of the report is adequate, helps to go deep into the issue reported herein and the paragraphs are linked each other resulting in a very clear introduction. However, I miss in some cases more specific reference about the work done so far.

2) Which is the difference between low-level laser therapy and common laser therapy? It should be mentioned in the introduction.

    3) It would be thankfully to add latest references and with higher impact factor that one’s included in the bibliography.

      4) In line 112 the word “emittance” is written down in order to explain how it was monitored. Is “emittance” the most appropriate word? Would it not be better to write down “emission” instead of “emittance”?

    5) In line 136 appears for the first time “LDH”. It should be mentioned the meaning of “LDH” before.

    6) In line 207 “the definitive dose of LLLT irradiation” was mentioned, what exactly does that mean? Are you referring to an energy dose of LLLT? If it is an amount of energy dose, it should be mentioned.

    7) The decrease in the relative expression of MMP-1, -2, and -9 is inversely proportional to the increase in the wavelength of the diode lasers. Why? Which is the main reason? It should be explained in the discussion section. The reason could be due to the light penetration capability thorough tissues depending on the excitation wavelength. The lower excitation wavelenght (higher energy), the deeper penetration of the light will be. Some explanation like that must be included in the discussion section together with an appropiate reference as well as the reasons given by the authors. Same explanation can be used to discuss why fibroblast collagen type I production increases togheter with the laser wavelenght.

    8) The first four paragraphs of the discussion section should bet better located at the introduction. The explanations given in these paragraphs have nothing to do with the work done by the authors. This bibliographic search making reference to previous work done by other authors differing in the experimental section should be refocused in the introduction.

     9) I would remark more the better results obtained with LLLT regarding to the previous work in conclusions rather than doing a brief summary of the work. Conclusions done by the authors should be refocused.

Author Response

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Reviewer 2 Report

I have a fundamental problem with this manuscript: on the one hand, it shows interesting clinincal results. On the other hand, the in-vitro experiements do not support and match the clinical findings which is expectable: while the clinical study used a 400 mW laser which might (!) result in an intensity of several 100 mW/cm² - unfortunatly the value is not give - while in the in-vitro experiements only 3 mW/cm² were used. In-vitro different wavelength were used, in vivo only one. Those points must be fixed for further review.

Small other remarks:
-  The state of the art is very short, the work should compared better with exisiting results: what parameters were used, what was the outcome, then compare the presented work with these results.
- How was the clinical study supervised by a ethics committee? It should be mentioned in a footnote.
- The conclusions drawn are not really supported by the contents.
- Some minor english inaccuracies e.g.:
          line 36: "Increasing research is delving into the probability of using the light-emitting diode"
    line 158: "using a 400 mW potency"

Author Response

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Round 2

Reviewer 2 Report

Thanks for providing the necessary information for a review and implementing already to comments from the first review round. The authors worked with an irradiance of 3 mW/cm² which is indeed a typical value used by LLLT. While I still have some concerns about LLLT, the results look ok.

Some minor remark: as the authors nicely introduce irradicance and fluence/dose, it should be also used in the remainder of the article instead of energy/power density etc.

Author Response

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