# Development of a Novel Engineered Tendon Graft to Assist in Repair of Rotator Cuff Injuries

> **NIH NIH R44** · PRO THERAPEUTICS LLC · 2024 · $893,555

## Abstract

PROJECT SUMMARY/ABSTRACT
Introduction: Skeletal Tissue Engineering Laboratories (STEL) Technologies, LLC is a woman-owned, Michigan-
based regenerative medicine company founded in 2013. STEL’s first product, the CGEMTM graft, is a unique
biological replacement for the anterior cruciate ligament (ACL) injuries. The researchers have since adapted this
graft technology with the goal of treating Rotator Cuff (RC) injuries increasingly prevalent in the aging population.
Significance: RC tears are a major orthopedic challenge in the US with over 460,000 surgeries performed
annually resulting in a market cost of over $523M[1,46]. The failure rate of current RC repair procedures ranges
from 20-95%, with a major contributing factor being the inability to restore native biomechanical properties at the
enthesis, resulting in repairs characterized by a weaker, less organized fibrovascular scar tissue that is prone to
failure[54]. Various tissue-engineering strategies are being developed to improve surgical outcomes and promote
tendon healing, especially at the enthesis. Current approaches focus on the development of biological or
synthetic scaffold devices to reinforce the mechanical strength of the tendon-to-bone connection, but they do not
promote enthesis regeneration. There is significant demand for alternative technologies for RC repair.
Vision for Commercial Product: The ETG-RC is devitalized allogeneic engineered multi-phasic tissue that
regenerates the enthesis and provide an underlayment that allows the migration of endogenous cells, enhancing
the regenerative capacity of the repair site. ETG-RC will lead to enhanced restoration of normal biomechanics
and mobility, resulting in lower cost and decreased risk of re-injury and arthritis. An “off-the-shelf” tissue graft for
RC repair will enhance the standard of care double row suture technique and deliver superior patient outcomes.
Goals of Proposed Research: The goals of this SBIR Project are to establish the feasibility of fabricating a fully
biologic “off-the-shelf” tissue-engineered rotator cuff tendon graft that can restore biomechanical properties of
the tendon-humerus enthesis; and to de-risk the commercial viability of ETG-RC in order to advance the
translatability of this technology for use in human patients.
Specific Aims: The proposed project addresses the several pressing issues that must be resolved prior to
bringing this technology to the FDA for clinical trials: development of a fabrication and decellularization protocol
(Aim 1) and establishment of storage methods to determine shelf life (Aim 2). It then seeks to establish a master
cell bank for fabrication of grafts for the Phase 1-3 clinical trials (Aim 3). CGMP quality ETG-RC grafts fabricated
from the established master cell bank will be tested for safety and efficacy by NAMSA (Aim 4). Positive data
from these studies will support filing of an IND-packet with FDA, enabling a Phase I clinical trial. Success of the
SBIR project will r...

## Key facts

- **NIH application ID:** 10868771
- **Project number:** 5R44AR082790-02
- **Recipient organization:** PRO THERAPEUTICS LLC
- **Principal Investigator:** Thomas Bollenbach
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $893,555
- **Award type:** 5
- **Project period:** 2023-07-01 → 2027-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10868771

## Citation

> US National Institutes of Health, RePORTER application 10868771, Development of a Novel Engineered Tendon Graft to Assist in Repair of Rotator Cuff Injuries (5R44AR082790-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10868771. Licensed CC0.

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