Tissue-Engineered Acellularized Valve Xenografts: A Comparative Animal Study between Plain Acellularized Xenografts and Autologous Endothelial Cell Seeded Acellularized Xenografts

Abstract

Background Acellularized valve xenografts are considered a promising way of overcoming the inherent limitations of current prosthetic valves. The aim of this study was to compare the biological responses of an autologous endothelial cell seeded acellularized xenograft (AAX) and a plain acellularized xenograft (PAX) implanted in the pulmonary valve leaflet in the same animal. Methods Endothelial cells were isolated and cultured from the jugular vein of goats. Porcine valve leaflets were acellularized with Nacl-SDS, and for AAX, leaflets were then seeded with autologous endothelial cells. A PAX and an AAX were implanted as double pulmonary valve leaflet replacement in the same animal in a goat model (n=6). After sacrifice, the implanted valve leaflet tissues were retrieved and analyzed visually and under a light microscope. Results and Conclusions Six animals were sacrificed as scheduled during the short-term (6 and 24 hours), mid-term (1 week and 1 month) and long-term (3 and 6 months). Gross and ultrasonographic examinations revealed good valve function with no thrombosis but with slight thickening. Microscopic analysis of the leaflets showed abundant cellular ingrowth into the acellularized leaflets over time. The role of endothelial cell seeding remains controversial. This animal experiment demonstrates the practical feasibility of using acellularized valve xenografts.

In Vivo Recellularization of Plain Decellularized Xenografts With Specific Cell Characterization in the Systemic Circulation: Histological and Immunohistochemical Study

“…For the tissue engineering of heart valves or vessels, several different strategies have been considered in the use of biodegradable scaffolds or decellularized biological scaffolds seeded with the cellular tissue component either in vitro or in vivo (6–10). The major disadvantages of in vitro seeding with autologous cells are additional surgical invasion and the complicated nature of the process.…”

“…So far, Leyh et al demonstrated in a sheep model that plain decellularized porcine valve matrix conduits were repopulated in vivo with valve‐specific cell characterization in the pulmonary circulation (9). Kim et al reported in a goat model that plain decellularized porcine valve leaflets with or without seeding of autologous endothelial cells (ECs) in vitro showed similar biological reactions concerning cell characterization and antithrombogenicity in the pulmonary circulation (10). However, the role and necessity of autologous cell seeding remain controversial (8–10).…”

“…Kim et al reported in a goat model that plain decellularized porcine valve leaflets with or without seeding of autologous endothelial cells (ECs) in vitro showed similar biological reactions concerning cell characterization and antithrombogenicity in the pulmonary circulation (10). However, the role and necessity of autologous cell seeding remain controversial (8–10). In addition, qualitative differences in cell populations and characteristics exist between pulmonary and systemic circulation (11), and little information is available on the recellularization of plain decellularized biological scaffolds in the systemic circulation.…”

Novel Cartilage‐derived Biomimetic Scaffold for Human Nucleus Pulposus Regeneration: a Promising Therapeutic Strategy for Symptomatic Degenerative Disc Diseases

“…An ideal scaffold should help to retain cells in the desired location and provide appropriate biochemical signals in the same way as the natural ECM for which it substitutes. A variety of decellularized tissues including ligaments, heart valves, blood vessels, skin, nerves, and urinary bladder have been investigated for tissue engineering applications. A DCM‐derived scaffold has been successfully developed and used for cartilage tissue engineering.…”