# OPTICS AND PHOTOTOXICITY OF SKIN IN PHOTOMEDICINE

> **NIH NIH R01** · MASSACHUSETTS GENERAL HOSPITAL · 1988 · $31,594

## Abstract

The proposed research is further development of basic optical spectroscopic
models for skin and the application of this knowledge to study cutaneous
photobiologic responses, improve or develop new phototherapies, and provide
needed diagnostic techniques.  Recently derived optical models describing
radiation transfer through human skin will be refined, extended, and
examined experimentally in vitro and in vivo.  These models can be used to
reconstruct, from noninvasive measurements, the radiation densities within
each skin layer and cutaneous blood vessels.  Thus, they are central to
designing phototherapy and explaining any photobiologic response
quantitatively.  The models include absorption coefficients and
concentrations of the major skin pigments as variables and will be used to
measure melanin content and dermal microvascular blood volumes, both of
which are altered by ultraviolet irradiation.  Noninvasive monitoring of
blood and tissue levels of drugs with distinctive optical absorption
spectra will be examined.  Pulsatile distentions of superficial cutaneous
vessels can be measured optically, and will be used to noninvasively
measure microvascular compliance.  This is of potential importance in
artersclerosis diabetes, and collagen diseases.  Skin autoluminescence has
never been optically examined, yet is of proven diagnostic value.  We will
identify the spectra and fluorophores involved.  Tryptophan, demosine and
other fluorophores will be studied as diagnostic probes.  Two unique
methods for producing and studying the phototoxic and therapeutic effects
of psoralen-DNA monoadducts vs. crosslinks in humans are proposed.  We have
shown in humans that microvascular damage and a host of hemodynamic effects
can be selectively caused by pulsed laser exposures of human skin.  Our
theoretical approach to both the optical and thermal transfer involved has
never been used in medical application of lasers before, and its potential
extends well beyond the initial goal of treating benign vascular skin
tumors.  We propose to complete basic studies elucidating mechanisms, and
to similarly test the XeF laser as a means for producing specific pigment
cell damage.

## Key facts

- **NIH application ID:** 3155306
- **Project number:** 3R01AR025395-08S1
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **SAM.gov UEI:** FLJ7DQKLL226
- **Principal Investigator:** John A. Parrish
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $31,594
- **Award type:** 3
- **Project period:** 1979-07-01 → 1988-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155306

## Citation

> US National Institutes of Health, RePORTER application 3155306, OPTICS AND PHOTOTOXICITY OF SKIN IN PHOTOMEDICINE (3R01AR025395-08S1). Retrieved via MORVS 2026-10-26 from https://api.morvs.ai/grant/nih/3155306. Licensed CC0.

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