# In vivo label-free characterization of aged skin to predict delayed wound healing

> **NIH NIH R01** · UNIVERSITY OF ARKANSAS AT FAYETTEVILLE · 2020 · $347,122

## Abstract

Project Summary:
Age-related delays in wound healing have been attributed to altered dermal microstructure, mitochondrial
dysfunction, and reduced cellular proliferation. However, an inability to non-destructively measure these
characteristics has limited their use in guiding wound care and product development. The long-term goal of
this project is to establish non-invasive, real-time, quantitative optical biomarkers to predict age-related delays
in skin wound healing. The specific objective of this proposal is to utilize label-free multiphoton microscopy
techniques, including two-photon excited fluorescence, fluorescence lifetime imaging, and second harmonic
generation to identify and develop metabolic and microstructural biomarkers of aged skin that are associated
with delayed closure and susceptibility to mechanical re-injury. Our central hypothesis is that the natural
fluorescence of cells and their surrounding matrix can be quantified to provide sensitive biomarkers of age-
related wound healing impairment. To test this hypothesis and evaluate the effect of aging, controlled pre-
clinical studies will be performed using mice with ages ranging from 12.5-75% of their life expectancy,
independent of common chronic wound comorbidities such as diabetes mellitus. In Aim 1, we will non-
invasively monitor wound healing dynamics in individual live mice and identify differences in wound metabolism
during the healing process using the natural fluorescence of NADH and FAD. In Aim 2, we quantify
extracellular matrix organization and composition using multiphoton microscopy to predict wound strength
through image-based multiscale modeling. In Aim 3, we will evaluate the effect of diabetes mellitus on the
age-related optical biomarkers of wound healing developed in Aims 1 and 2. Quantitative comparisons of
cellular and extracellular biomarkers will be made across different ages and validated against histology and
immunohistochemistry. The expected outcome of this project is a set of candidate biomarkers for use in
guiding therapy that are capable of discriminating age-related alterations and common comorbidities known to
impair healing. With multiphoton microscopy technology already making its way into the clinic, the imaging
methods developed here have the potential for immediate impacts in the clinical assessment and management
of wounds.

## Key facts

- **NIH application ID:** 9922191
- **Project number:** 5R01AG056560-04
- **Recipient organization:** UNIVERSITY OF ARKANSAS AT FAYETTEVILLE
- **Principal Investigator:** Kyle Patrick Quinn
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $347,122
- **Award type:** 5
- **Project period:** 2017-09-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9922191

## Citation

> US National Institutes of Health, RePORTER application 9922191, In vivo label-free characterization of aged skin to predict delayed wound healing (5R01AG056560-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9922191. Licensed CC0.

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