# Assessment of Corneal Fibroblast Biomechanical Behavior

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 2020 · $84,310

## Abstract

PROJECT SUMMARY
Mechanical interactions between cells and extracellular matrix (ECM) drive fundamental processes such as
morphogenesis, wound healing, and organization of bioengineered tissues. Our research focuses on how
these interactions regulate corneal keratocyte behavior, through development of culture models that mimic the
3-D tissue environment, and use of multi-dimensional imaging approaches in vitro, in situ and in vivo.
Research in the prior period using 3-D culture models demonstrated that matrix composition, stiffness and
structure can influence corneal keratocyte mechanical behavior and patterning in response to wound healing
cytokines and changes in Rho/Rac activation. In addition, using our custom-modified in vivo HRT-RCM
confocal microscope combined with ex vivo fluorescence and second harmonic generation (SHG) imaging, we
demonstrated for the first time that following freeze injury (FI) or lamellar keratectomy (LK) in the rabbit,
migrating fibroblasts within the wounded stroma form long interconnected streams that often run in parallel,
and that alignment of these cell streams is highly correlated with that of the collagen lamellae. In contrast, cells
migrating on top of the stroma following LK form a randomly arranged, interconnected, meshwork.
The biochemical factors which induce myofibroblast transformation and fibrotic tissue generation on top of the
stroma following injury or refractive surgery have been studied extensively. However, little is known about
biochemical and biophysical signals that regulate intra-stromal keratocyte behavior. The lamellar structure of
the cornea, combined with powerful in vivo and ex vivo imaging capabilities, provides us with a unique
opportunity to assess biophysical factors that regulate cell differentiation, migration and patterning within this
tissue. Aim 1 will use in vivo confocal microscopy and in situ fluorescent/SHG imaging in the rabbit to: a)
perform the first comprehensive comparison of intra-stromal and extra-stromal cell differentiation and
patterning following photorefractive keratectomy (PRK), and b) investigate whether intra-stromal and extra-
stromal phenotypes are differentially regulated. Aim 2 will investigate whether changes in ECM structure and
stiffness modulate cell patterning and mechanical phenotype during stromal repopulation by comparing
migration mechanisms in two distinct in vivo injury models. ECM structure and mechanical properties have
become increasingly recognized as key factors in determining cell growth, differentiation and activity
in a variety of cell types; thus our findings should have broad scientific impact. In order to isolate the
specific factors regulating these in vivo processes, Aim 3 will assess how cytokines and downstream Rho/Rac
signaling impact corneal keratocyte patterning, mechanical differentiation, fibronectin deposition and ECM
reorganization using multiple novel experimental models in vitro. With this approach we hope to identify the ...

## Key facts

- **NIH application ID:** 10217723
- **Project number:** 3R01EY013322-18S1
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **Principal Investigator:** W MATTHEW PETROLL
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $84,310
- **Award type:** 3
- **Project period:** 2001-02-01 → 2021-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10217723

## Citation

> US National Institutes of Health, RePORTER application 10217723, Assessment of Corneal Fibroblast Biomechanical Behavior (3R01EY013322-18S1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10217723. Licensed CC0.

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