A polydioxanone electrospun valved patch to replace the right ventricular outflow tract in a growing lamb model

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Congenital Heart Surgery

Background:

• Congenital heart surgery faces challenges with right ventricular outflow tract (RVOT) reconstruction due to a lack of effective replacement materials.
• Existing biomaterials often fail to create a functional, tri-layered RVOT, necessitating repeat surgeries.

Purpose of the Study:

• To evaluate the functional, histological, and regenerative potential of polydioxanone (PDO) electrospun valved patches seeded with mesenchymal stem cells (MSCs) for RVOT reconstruction.
• To assess the long-term performance and tissue integration of these engineered patches in a lamb model.

Main Methods:

• Autologous blood-derived MSCs were labeled and seeded onto PDO electrospun valved patches.
• Patches were implanted into the RVOT of 6 growing lambs, with follow-up for 8 months.
• Assessment included echocardiography, MRI, histology, immunohistochemistry, and biochemical assays.

Main Results:

• Tissue-engineered RVOTs showed no stenosis or aneurysm, exhibiting growth potential with reduced fibrosis, calcification, and no thrombus compared to PTFE-pericardial patches.
• The PDO scaffold biodegraded and was replaced by a viable, three-layered, endothelialized tissue with elastic fibers similar to native tissue.
• Quantum dot labeling indicated successful engraftment and potential contribution of seeded cells.

Conclusions:

• Polydioxanone electrospun tissue-engineered valved transannular patches are a promising solution for RVOT reconstruction.
• This approach could lead to improved treatments for congenital RVOT diseases by restoring a living, functional outflow tract.