Complete Static Repopulation of Decellularized Porcine Tissues for Heart Valve Engineering: An in vitro Study

Abstract

To date, a completely in vitro repopulated tissue-engineered heart valve has not been developed. This study focused on sequentially seeding 2 cell populations onto porcine decellularized heart valve leaflets (HVL) and pericardia (PER) to obtain fully repopulated tissues. For repopulation of the interstitium, porcine valvular interstitial cells (VIC) and bone marrow-derived mesenchymal stem cells (BM-MSC) or adipose tissue-derived stem cells (ADSC) were used. In parallel, the culture medium was supplemented with ascorbic acid 2-phosphate (AA) and its effect on recolonization was investigated. Subsequently and in order to obtain an endothelial surface layer similar to those in native HVL, valvular endothelial cells (VEC) were seeded onto the scaffolds. It was shown that VIC efficiently recolonized HVL and partially also PER. On the other hand, stem cells only demonstrated limited or no subsurface cell infiltration of HVL and PER. Interestingly, the addition of AA increased the migratory capacity of both stem cell populations. However, this was more pronounced for BM-MSC, and recolonization of HVL appeared to be more efficient than that of PER tissue. VEC were demonstrated to generate a new endothelial layer on HVL and PER. However, scanning microscopy revealed that these endothelial cells were not allowed to fully spread onto PER. This study provided a proof of concept for the future generation of a bioactive tissue-engineered heart valve by showing that bioactive HVL could be generated in vitro within 14 days via complete repopulation of the interstitium with BM-MSC or VIC and subsequent generation of an entirely new endothelium.

Extracellular Vesicles from Adipose Tissue Stem Cells in Diabetes and Associated Cardiovascular Disease; Pathobiological Impact and Therapeutic Potential

“…It was also noted that co-incubation of smooth muscle cells with ADSCs pre-differentiated towards smooth muscle cells presents better functional traits compared to smooth muscle cells monoculture due to the initial paracrine function of ADSCs and their latter differentiation into fully functional smooth muscle cells. In experiments using static repopulation of acellular valves, ADSCs migrated only superficially [164], highlighting the need of mechanical stimulation for ADSCs migration and differentiation.…”

Xenotransplantation of decellularized pig heart valves—Regulatory aspects in Europe

“…Similar to decellularized human allografts, decellularized porcine heart valves (dpHV) are intended as scaffolds for in situ tissue engineering, being physiologically fully assimilated by the recipient minimizing the incidence of follow‐up replacement surgeries. These valves differ significantly from glutaraldehyde‐fixed bioprostheses being vital matrices, open for recellularization, and the resulting physiologic remodeling of the implant 6,26,27 . Even if undergoing a decellularization procedure, the presence of resilient DNA 27‐29 and cells that survive the decellularization procedures were reported 30‐32 .…”

Sterilization and Cross-Linking Combined with Ultraviolet Irradiation and Low-Energy Electron Irradiation Procedure: New Perspectives for Bovine Pericardial Implants in Cardiac Surgery

“…10,28,31,41,42 For a more detailed investigation of collagen fiber structure and alignment, as it was shown for SULEEI-treated porcine pericardium, scanning electron microscopy will be used in ongoing studies. 31,48,49 The preservation of SULEEI-treated bovine tissue morphology led to the assumption that the biodegradability and biomechanical behavior of the SULEEI-treated bovine pericardium would be equivalent to that of the clinically available patch material. Unlike glutaraldehyde-fixed samples, which were barely digested by collagenase, more than half of the SULEEI-treated pericardium was degraded within 19 hours of incubation.…”