# A Sprayable Tissue-Binding Hydrogel to Prevent Postsurgical Cardiac Adhesions

> **NIH NIH R43** · KARIOS TECHNOLOGIES, LLC · 2022 · $998,222

## Abstract

Summary. Currently, there are no approved and available products to prevent postsurgical cardiac adhesions
and hence no standard of care. This is a large unmet need since there are >500,000 open-heart surgeries/year
(projected to grow to >850,000 by 2030) and >100,000 of these are reoperations and ~30,000 are on children
with congenital heart defects. Reoperations in cardiac surgery have increased surgical risks due to cardiac
adhesions, which increase the difficulty of sternal reentry, hinder visibility of mediastinal tissues, and increase
potential injury to cardiovascular tissues. Injuries occurring to adhesion removal triples the mortality of
reoperation patients, increase operation time and hospital costs. This is especially relevant for pediatric patients
with congenital heart defects who will experience multiple surgeries over their lifetime. Cardiac adhesions have
also become a common problem in adults who experience multiple surgeries to repair or replace valves or to
undergo coronary revascularization procedures. Two main approaches exist for reducing or attempting to
prevent cardiac adhesions: pharmacological therapy and physical barriers. Drugs that prevent or reverse
adhesion processes disrupt biochemical pathways of inflammation and fibrin deposition. Unfortunately, these
processes are also vital for wound healing. Achieving adequate drug concentration at the site of action is also
challenging due to fluid drains. A more viable approach is the use of a physical barrier to prevent fusion of the
heart to surrounding tissues. The barriers can be either preformed membranes or injectable hydrogels (fast
gelling liquids). Preformed anti-adhesive materials need to be cut before application to the tissue, and must be
sutured/packed into place to prevent slippage. Injectable hydrogels allow the freedom of applying material where
needed with spraying. The precursor components are capable of quickly reacting, forming a protective gel on
the surface of the tissue. While a variety of different materials have been investigated in animals and humans,
no materials, to date, have been capable of preventing adhesion formation post-cardiac surgery. Herein, we
propose a new approach to prevent postsurgical cardiac adhesions using TissueShield™, which is composed of
a rapidly forming poly(ethylene glycol) (PEG) hydrogel that is cross-linked by oxime bonds and includes a tissue
binding moiety to ensure the product remains adhered to the heart. Our approach is a 3-polymer system that
can be easily sprayed directly onto the heart forming a robust anti-adhesion layer within seconds. This system
has already been optimized to control the degree of swelling and degradation time to prevent adhesions and not
interfere with cardiac function in rat cardiac adhesions models and an initial small pilot study in a porcine model.
No product has been shown to have our features (tissue binder, low swelling, and lifespan). The objective herein
is to optimize the delivery ...

## Key facts

- **NIH application ID:** 10546558
- **Project number:** 1R43HL164136-01A1
- **Recipient organization:** KARIOS TECHNOLOGIES, LLC
- **Principal Investigator:** Gregory Grover
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $998,222
- **Award type:** 1
- **Project period:** 2022-09-09 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10546558

## Citation

> US National Institutes of Health, RePORTER application 10546558, A Sprayable Tissue-Binding Hydrogel to Prevent Postsurgical Cardiac Adhesions (1R43HL164136-01A1). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10546558. Licensed CC0.

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