Ryan Ettner
Pronouns: they/them
Research Mentor(s): Lisa Larkin
Research Mentor School/College/Department: University of Michigan / Medicine
Program: UROP
Session: Session 4 (1:40pm – 2:30pm)
Authors: Ryan Ettner, Eileen Su, Christopher Kennedy, Makayla Kelley, Luisa Nierhoff, Emmanuel Vega-Soto, Claudia Loebel, Lisa Larkin
Abstract
INTRODUCTION: Volumetric Muscle Loss (VML) is characterized as a permanent loss of 30% or more of skeletal muscle. In this study, commercially available poly(ethylene glycol) (PEG), methacrylated gelatin (Gel-MA), and hyaluronic acid (HA) hydrogels as well the tissue engineered SMUs in combination with HA were assessed for rates of innervation in recovery from a VML. METHODS: The study used sheep divided into 6 study groups: VML only, VML + PEG, VML + Gel-MA, and VML + HA, SMU+VML only, and SMU+VML+HA, n=5 per group. Following a 6-week recovery period from the 30% VML, peroneus tertius muscles were dissected, weighed, and prepared for histological analysis. Sections were immunostained for neurofilament and neuromuscular junctions, then imaged and analyzed, with significance indicated by p0.05. RESULTS: Histological analysis revealed increased collagen content, indicating fibrosis, and more regenerated fibers were found in the PEG and HA groups. Neuromuscular junction imaging is still in progress, and more data needs to be collected before we are able to determine the difference in the number of NMJs between control and graft sites in each group. CONCLUSION/SIGNIFICANCE: Further analysis needs to be conducted to draw any evidence-based conclusions on the effects of HG on the formation of NMJs in VML injuries. We are more likely to find evidence of innervation and NMJ formation in the PEG and HA groups which, if found, could suggest new treatment options for VMLs at a scale clinically relevant to humans.
