TECHNOLOGY DISCLOSURE

Title: A Nanofibrous Biocomposite Prosthetic Vascular Graft

Inventors:

 

Matthew D. Phaneuf, B.S.

BioSurfaces

Ashland, MA

(508) 881-8860

biosurfaces@verizon.net

Philip J. Brown, Ph.D.

School of Materials Science and Engineering

Clemson University

 (864) 656-6072

pjb@clemson.edu

Martin J. Bide, Ph.D.

Department of Textiles, Fashion Merchandising and Design

University of Rhode Island

Kingston, RI

(401) 874-2276

mbide@uri.edu,  

 

No clinically available small (< 5mm internal diameter) vascular prosthesis can emulate the biological and physical properties of normal arteries.  Implanted prosthetic grafts of currently available biomaterials fail primarily due to acute thrombosis, attributed to the lack of endothelial cells at the biomaterial/blood interface present in a natural blood vessel.  Additionally, the current materials employed for successful large/medium-diameter prosthetic grafts are relatively stiff and lack circumferential compliance compared to a native artery.  

 

An “off-the-shelf” small vessel prosthesis that better emulates normal arterial walls would greatly improve the treatment of both peripheral vascular disease and coronary artery disease.  Over 500,000 peripheral bypass and coronary artery bypass grafts are implanted annually in the United States: the potential annual market value for this synthetic coronary artery bypass graft could exceed $1.5 billion.  

 

We have developed a novel nanofibrous bioactive small (4mm internal diameter) prosthetic vascular graft using electrospinning technology.  The nanofibrous biocomposite graft wall is comprised of polyester, a biodurable implantable polymer, and Type IV collagen, an extracellular matrix protein.  An automated system is used for uniform application of these components onto various-sized mandrels.  The collagen fibers within the biocomposite graft can be used to link biologically-active proteins, covalently or ionically, that provide natural vessel properties.  

 

The disclosure reveals 

  • The experimental details of the electrospinning solutions and the conditions under which the grafts were spun onto the mandrels. A typical 7cm graft had a consistent 4mm internal diameter throughout the lumen.  
  • Scanning electron microscopy to show the size and distribution of fibers within the spun graft.  Within the graft wall, two independent fibers were evident.  Collagen nanofibers were present throughout the material and were approximately 10-fold smaller than the Dacron fibers
  • The water permeation through the spun material.  This shows the permeation to be 29 ± 11 ml/min/cm2, significantly below the 100 ml/min/cm2 threshold necessary to prevent blood seepage through the graft wall.
  • A staining technique to demonstrate the presence of amine groups in the spun graft.  The presence of collagen provided a significant number of binding sites
  • The methods used to covalently bind proteins to the functional groups on the graft.  Using covalent crosslinkers, model proteins were bound successfully to the graft.

 

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