# Mechano-active annular repair device for treating disc herniation

> **NIH VA I21** · PHILADELPHIA VA MEDICAL CENTER · 2021 · —

## Abstract

Symptomatic lumbar disc herniations occur in 0.5 to 2 % of the adult population annually, with a
higher incidence in individual exposed to strenuous activities in their work environments, including
active duty military personnel. A lumbar microdiscectomy is very effective at addressing the
extruded disc fragment and alleviating radicular leg pain. However, there is currently no
established method to repair the annular defect. The injured annulus fibrosus has altered
mechanical properties, and it is well recognized that larger annular defects are associated with
an increased risk of recurrent disc herniation at that interspace. With this loss of AF function, the
motion segment is also at risk for further degeneration, and loss of disc space height and further
degeneration is a common sequelae of lumbar disc herniations. There are currently no effective
clinical interventions targeted at repairing the annulus fibrous in a manner that recapitulates the
native disc. The objective of this project is to develop a novel tension activated annular repair
scaffold (TARS) to treat defects in the annulus fibrosus (AF) associated with herniations, with the
goal of closing the annular defect and stimulating native tissue repair to restore disc mechanical
function. Three Specific Aims are pursued: Two Specific Aims are pursued: Specific Aim 1:
Develop tension-actuated AF repair scaffolds. A novel mechanically activated microcapsule
(MAMC) will be included in electrospun scaffolds to create the TARS. Scaffold properties and
MAMC attributes will be varied to optimize material fabrication and to tune release in response to
tensile loading. We will create two classes of MAMCs: 1) containing chemotactic cell recruitment
agents designed to activate under low levels of physiologic loading and 2) matrix-promoting
agents housed within MAMCs designed to burst sequentially with long term loading. Both
populations will include an anti-inflammatory agent to improve regeneration. Bioactivity of the
MAMCs will also be confirmed via in vitro bioreactor assays. Specific Aim 2: Evaluate the TARS
in models of intervertebral disc repair under physiologic loading. Box defects in the AF will be
created in cadaveric goat spinal motion segments, and the TARS sutured in place. Ex vivo, multi-
axial (compression, flexion, extension and torsion) dynamic loading will be applied to demonstrate
that physiologic spinal loading causes sequential release from the two MAMC populations.
Outcomes will include confocal microscopy analysis of MAMC release and analysis of motion
segment mechanical properties. Next, we will carry out a pilot study in our goat cervical spine
model in which the in vivo repair capacity of the TARS will be evaluated. Outcomes at 3 months
will include histological analysis of the scaffold and cell infiltration and MRI and mechanical
properties of the repaired motion segment.It is anticipated that the proposed study will yield a
novel repair for defects of the AF and an in...

## Key facts

- **NIH application ID:** 10273132
- **Project number:** 5I21RX003447-02
- **Recipient organization:** PHILADELPHIA VA MEDICAL CENTER
- **Principal Investigator:** Harvey E. Smith
- **Activity code:** I21 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2021
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2020-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10273132

## Citation

> US National Institutes of Health, RePORTER application 10273132, Mechano-active annular repair device for treating disc herniation (5I21RX003447-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10273132. Licensed CC0.

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