University of Pittsburgh researchers have developed novel, resorbable vascular grafts. These bioinductive vascular grafts are designed to be flexible, inexpensive to produce and with clinically relevant dimensions and surgical handling. Initial studies suggest these cell-free synthetic grafts can promote rapid vascular remodeling in situ without the risk of an immunogenic response and could offer superior treatment options to patients requiring vascular grafts.
Using a poly(glycerol sebacate) microfibrous core and a nanofibrous electrospun polycaprolactone, a novel vascular graft has been fabricated with 4–6 mm inner diameters and length up to 12 mm. These grafts can withstand arterial pressure and promote vascular remodeling.
Description
Vascular grafts have a variety of applications including cardiovascular reconstruction, aneurysm repair and hemodialysis. Currently, the global market for vascular grafts is in the billions of dollars and expected to grow with increasing incidence of cardiovascular and renal diseases. Existing vascular grafts have several shortcomings including production time and high failure rates in smaller diameter vessels. A clinical need exists to develop grafts for small diameter vessels; these novel vascular grafts have an inexpensive and fast production process, can promote regeneration and have the potential to revolutionize the vascular graft market.
Applications
- Bypass surgery to treat heart failure or myocardial infarction
- Hemodialysis for treatment of kidney failure
- Other vascular repair surgery (e.g., aneurysms or varicose veins)
Advantages
Autografts are the gold standard materials for vascular grafts, but challenges around availability and donor site complications lead to the development of alternatives. While showing promise, tissue-engineered vascular grafts can be costly and require long production times, limiting graft availability to patients, and include a risk of immunogenicity. Additionally, most clinically available grafts lack the flexibility to grow with the patient which is particularly important in children. There is also a risk of failure in narrow vessels (<6 mm diameter) potentially leading to thrombosis and neointimal hyperplasia.
These novel grafts overcome such shortfalls. Fabricated using a microporous tube made of fast-degrading, elastomeric poly(glycerol sebacate), known to support arterial regeneration and wrapped in a thin sheath of polycaprolactone nanofibers, a stiffer, slower-degrading polymer was designed to support the mechanical integrity during vascular remodeling. Key benefits of these cell-free, synthetic, biodegradable grafts include suitability for smaller diameter vessels, reduced cost and a more time-effective production process, with no risk of disease transmission or immunogenicity.
Invention Readiness
Grafts with inner diameter 4–6 mm and lengths of up to 12 mm were produced. In animal studies, one year after grafts were inserted, regenerated arteries were observed with similar appearance and tissue architecture to native arteries, including nerves and mature elastin, and comparable mechanical compliance. Residual graft material was also undetectable. Further work could lead to grafts loaded with drugs or growth factors to enhance graft efficacy.
IP Status
https://patents.google.com/patent/US11998439B2
