Photothermolysis of sebaceous glands in human skin ex vivo with a 1,708 nm Raman fiber laser and contact cooling

Authors

  • Vinay V. Alexander MSc,

    Corresponding author
    1. Electrical and Computer Engineering Department, University of Michigan, Ann Arbor, Michigan 48109
    • Electrical and Computer Engineering Department, University of Michigan, Solid State Electronics Laboratory, 1301 Beal Avenue, Ann Arbor, MI 48109.
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  • Kevin Ke PhD,

    1. Electrical and Computer Engineering Department, University of Michigan, Ann Arbor, Michigan 48109
    2. Omni Sciences, Inc., Ann Arbor, Michigan 48105
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  • Zhao Xu MSc,

    1. Electrical and Computer Engineering Department, University of Michigan, Ann Arbor, Michigan 48109
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  • Mohammed N. Islam ScD,

    1. Electrical and Computer Engineering Department, University of Michigan, Ann Arbor, Michigan 48109
    2. Omni Sciences, Inc., Ann Arbor, Michigan 48105
    3. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
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  • Michael J. Freeman PhD,

    1. Omni Sciences, Inc., Ann Arbor, Michigan 48105
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  • Bertram Pitt MD,

    1. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
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  • Michael J. Welsh PhD,

    1. Electrical and Computer Engineering Department, University of Michigan, Ann Arbor, Michigan 48109
    2. Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109
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  • Jeffrey S. Orringer MD

    1. Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan 48109
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  • Disclosures: Dr. Mohammed N. Islam is a professor in the Electrical and Computer Engineering Department and the Department of Internal Medicine at the University of Michigan and is also the Founder, President, Chief Technology Officer and consultant to Omni Sciences, Inc. Dr. Kevin Ke was a postdoctoral research fellow at the University of Michigan during part of the research presented in this article and is currently an optical engineer at Omni Sciences, Inc. Dr. Michael J. Freeman is the Director of Research at Omni Sciences, Inc.

Abstract

Background and Objectives

Wavelengths near ∼1,720 nm are of interest for targeting fat/lipid-rich tissues due to the high absorption coefficient of human fat and low water scattering and absorption. In this study, a 1,708 nm laser was built and shown to selectively target fat/lipid adjacent to porcine heart and dermis and then used to damage dermal sebaceous glands in human skin.

Study Design and Materials

An all-fiber 1,708 nm laser with ∼4 W maximum power was designed and built. Selectivity for targeting fat/lipid was studied by exposing porcine heart and skin tissue cross-sections to the 1,708 nm laser. Human skin treatments to damage sebaceous glands were performed both with and without cold window cooling. Histochemical evaluation on the frozen sections was performed using methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay.

Results

Histochemical analysis of porcine tissue cross-sections showed that 1,708 nm laser can selectively damage pericardial fat(heart) and subcutaneous fat(skin) with little to no damage to the myocardium and the dermis, respectively. In human skin, histochemical evaluation without contact cooling showed damage to both epidermis and dermis. With cooling, epidermis was spared and damage was observed in dermis extending ∼0.4–1.65 mm from the skin surface at an average laser fluence of ∼80 J/cm2. Selective damage of sebaceous glands was suggested but not definitively demonstrated.

Conclusions

We have developed an all-fiber 1,708 nm laser capable of damaging majority of the sebaceous glands in the dermis and thus may have potential applications in the treatment of conditions such as acne vulgaris whose pathophysiology involves disorders of sebaceous glands. Lasers Surg. Med. 43:470–480, 2011. © 2011 Wiley-Liss, Inc.

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