Grant of the Month | July 2009

Stephen Badylak and Michael Sacks

Thomas Gilbert

Mechanobiology and Regenerative Medicine

Regenerative medicine approaches for the reconstitution of missing or injured tissues and organs involves the use of scaffolds, cells, and bioactive molecules.  The use of biologic scaffolds seeded with cells is a common approach and several applications have been successfully translated to clinical medicine including lower urinary tract, gastrointestinal tract, musculotendinous, and dermal skin regeneration.  The principles that guide tissue remodeling and regeneration are only partially understood but the influence of biomechanical loading upon the remodeling process is accepted as an important variable.  However, there is an almost complete absence of systematic, quantitative studies to determine the effect of this controllable factor upon tissue remodeling, especially tissues with a smooth muscle wall component. 

The present proposal seeks support to conduct a quantitative, hypothesis driven study that determines the effects of mechanical loading upon smooth muscle phenotype in vitro and in vivo and the related changes to the architecture of the scaffold upon which they are seeded.  A biologic scaffold derived from the extracellular matrix (ECM) of a porcine urinary bladder will be seeded with smooth muscle cells derived from different sources: the vascular wall, urinary bladder, and esophagus.  The influence of those organ specific mechanical loading regimens upon the remodeling process and the ability to modulate the remodeling process by changing the mechanical loading pattern will be investigated.  Two specific aims are described in which: 1) ECM seeded with the three different types of smooth muscle will be subjected to carefully selected mechanical loading regimens and the effect upon cell phenotype and matrix organization will be quantitatively evaluated and 2) two smooth muscle cells types will be evaluated upon ECM used within an organ culture model (rat bladder wall) to evaluate the effect of cellular and ECM remodeling when adjacent normal tissue cells are present.

NIH

05/15/09 – 14/30/11

$361,332 (Year 1), $723,556 (total for 2 years)

Grant of the Month | June 2009

PI

Steven Little, PhD

Title

Temporal Delivery of Growth Factors for Wound Healing Using Porous Hollow Fibers

Description

Our objective is to optimize wound healing through temporal delivery of growth factors using porous hollow fibers extending into a wound site.  As an extension to the wound-cap technology (artificial capillary bed delivery system), these fibers can be made from materials that dissolve in the presence of a chemical or temperature-based trigger following the wound healing process.  Because angiogenesis is, in many cases, one of the first steps towards wound healing, we propose to demonstrate enablement of this technology by mimicking the natural sequence of stimuli that directs angiogenesis.  Our hypothesis is that sequential delivery of appropriate angiogenesis-promoting factors from our externally-regulated delivery system, as opposed to simultaneous delivery of multiple factors, will result in more mature and integrated neo-vasculature.

Source

PTEI via DOD

Term

April 1, 2009 – September 30, 2010

$91,667

Grant of the Month | May 2009

PI

Thomas Gilbert, PhD

Title

Cardiac Remodeling with Organ Specific Extracellular Matrix Scaffolds

Description

Improved materials for cardiac reconstruction of congenital defects and heart failure are needed. Current surgical approaches for cardiac reconstruction utilize synthetic materials that slow the progression of disease, but do not provide any contractile function and do not have the ability to grow with the patient. Recently, porcine urinary bladder matrix (UBM) has been used to repair myocardial tissue. The remodeled UBM contributed to regional function in both canine and porcine models, but did not fully restore myocardial tissue. Cardiac extracellular matrix (C-ECM) may promote faster reconstruction of functional tissue by providing a scaffold with a composition and architecture similar to the tissue that it is intended to replace. The proposed study will determine the morphologic and functional differences in cardiac remodeling after repair with C-ECM, UBM, and Dacron patches. Furthermore, the study will include analysis of the recruitment and fate of bone marrow derived progenitor cells at the site of remodeling.  The study will be conducted in collaboration with Drs. Badylak, Wagner, and Tobita, and members of their respective laboratories.

Source

NIH-NIBIB – RO3

Term

June 1, 2009—May 31, 2011

$145,400

Grant of the Month | April 2009

PI

Johnny Huard

Title

Tissue Engineered Skeletal Muscle (TESM) from Muscle Progenitor Cells: A Model for Studying Insulin Resistance and Muscle Metabolism

Description

The overall specific aims are as follows:

• To optimize a protocol for the isolation and differentiation of human MPC
• To develop a regimen and bioreactor for development of a tissue engineered skeletal muscle model (TESM) from MPC that will provide a means to study nutrient metabolism and insulin function
• To utilize human MPC and the TESM system to analyze pathways involved with glucose homeostasis and fatty acid uptake in healthy and insulin resistant phenotypes

Source

Pfizer

Term

March 1, 2009 – February 28, 2011

$475,000

Grant of the Month | March 2009

Steven Belle and Kyong-Mi Chang

Robert Carithers, Adrian Di Bisceglie, Michael Fried, Marc Ghany, Steven Han, E. Jenny Heathcote, W. Ray Kim, Daryl Lau, William Lee, Anna Lok, Mitchell Shiffman, KathleenSchwarz, and Norah Terrault

Multi-Center Clinical Trials of Novel Therapies and Diagnostics for Patients with Chronic Hepatitis B

In establishing the Hepatitis B Research Network, the NIDDK wishes to consider the potential application of diagnostics and therapeutics for patients of all ages with chronic hepatitis B. The overall goal of the Hepatitis B Network will be to perform clinical, epidemiological and therapeutic research in patients with chronic hepatitis B using a standardized and coordinated approach to the evaluation and therapy of chronic hepatitis B and to provide sufficient numbers of patients for the research. This will be done by development of a database on chronic hepatitis B patients including clinical information as well as liver, serum and DNA samples.

National Institute of Diabetes and Digestive and Kidney Diseases

2009 - 2016

$11 million

Grant of the Month | February 2009

Steven F. Badylak, DVM, PhD, MD

Regenerative Medicine Approach to the Treatment of Abdominal Compartment Syndrome in a Dog Model

This study involves a combination of preclinical animal work and the treatment of clinical patients at Fort Sam Houston in San Antonio, Texas at the Institute for Surgical Research.  The work is based upon the bioinductive properties of an extracellular matrix (ECM) scaffold derived from porcine urinary bladder.  This biologic scaffold contains a bimodal surface architecture which is supportive of epithelial cell growth on one surface and integration into an exposed wound on the opposite surface.  The preclinical animal studies show the ability of the material to integrate into the full thickness wound bed.  Seven patients have been treated and results show that the preclinical studies were predictive of the excellent biointegration that occurred in these patients.  Complete epithelialization with no contracture was observed when the material was used to treat the donor sites of patients requiring split thickness skin grafts.  This pilot safety study sets the stage for subsequent clinical applications and primary full thickness wounds in patients.

PTEI (STRaC)

9/1/08 – 11/30/08

$95,000 add-on

Grant of the Month | January 2009

Rick Koepsel

Sharon Marx and Gabriel Amitai

Temperature responsive modification of microfiber tissue perfusion devices.

Tissue perfusion devices based on hollow fibers have been developed for use in bioreactors and for wound healing.  In both cases the perfusion devices are in direct contact with cells and tissues.  The hollow fiber tubing that makes up the devices is fabricated from hydrophilic materials, which resist the direct attachment of cells and proteins in the short term but over time cells will attach to the devices.  With cells and tissue attached to the device, removal of the device can disrupt the structure of the tissue that was the intended when the device was implanted.  This project will extend the development of tissue perfusion devices by providing smart polymer coatings which, when activated, will facilitate the removal of the device.

Smart polymers are materials that exhibit a response to a physical stimulus.  For this project we will concentrate on the temperature responsive polymer poly (N-isopropylacrylamide) (pNIPAAm).  As with many temperature responsive materials, pNIPAAm in aqueous solution changes structure at a temperature called the lower critical solution temperature (LCST).  In the case of pNIPAAm the LCST is about 320C, below the LCST the polymer is soluble in aqueous solution while above the LCST a change in the polymer structure causes the polymer to be come hydrophobic and form micelles in solution.  When pNIPAAm is immobilized on a surface it still responds to temperature.  A surface coated with pNIPAAm is hydrophobic below the LCST but becomes hydrophilic above the LCST.  Cells grown on tissue culture dishes coated with pNIPAAm will attach and proliferate normally while the dishes are kept at 370C but when the temperature is lowered below the LCST the cells are sloughed off of the surface.  If the cells have grown to a confluent monolayer, they will come off the surface as a cohesive sheet showing that the underlying protein layer to which the cells are attached is also sloughed from the surface. Applying a layer of pNIPAAm to the hollow fiber perfusion tubing should therefore allow a temperature change to eliminate the adhesions between the cells or tissues and the perfusion device allowing the device to be removed with considerably less trauma to the insertion site.

PTEI/DOD

11/1/08 – 10/31/09