Development and Characterization of a Porcine Mitral Valve Scaffold for Tissue Engineering

Abstract

Decellularized scaffolds represent a promising alternative for mitral valve (MV) replacement. This work developed and characterized a protocol for the decellularization of whole MVs. Porcine MVs were decellularized with 0.5% (w/v) SDS and 0.5% (w/v) SD and sterilized with 0.1% (v/v) PAA. Decellularized samples were seeded with human foreskin fibroblasts and human adipose-derived stem cells to investigate cellular repopulation and infiltration, and with human colony-forming endothelial cells to investigate collagen IV formation. Histology revealed an acellular scaffold with a generally conserved histoarchitecture, but collagen IV loss. Following decellularization, no significant changes were observed in the hydroxyproline content, but there was a significant reduction in the glycosaminoglycan content. SEM/TEM analysis confirmed cellular removal and loss of some extracellular matrix components. Collagen and elastin were generally preserved. The endothelial cells produced newly formed collagen IV on the non-cytotoxic scaffold. The protocol produced acellular scaffolds with generally preserved histoarchitecture, biochemistry, and biomechanics.

Melt Electrospun Bilayered Scaffolds for Tissue Integration of a Suture‐Less Inflow Cannula for Rotary Blood Pumps

“…It can be noted that the use of cardiac fibroblasts would have provided a superior representation of in vivo cells; however, other cardiovascular studies have also used HFFs . As a preliminary study, human foreskin fibroblast cells were chosen based on a study in bovines that found that neointimal tissues consisted of a large proportion of fibroblast‐like cells .…”

Structure-Function Relationship of Heart Valves in Health and Disease

“…All four valves close rapidly and completely under minimal reverse pressure, stretching to maintain full competence during diastole. During these opening and closing movements, the valve leaflets withstand cyclic strains as high as 50%, whereas despite the pressure difference across the closed valves, which imposes large load on their leaflets, leaflet prolapse is prevented by large coaptation of the leaflets, reaching up to 40% of their surfaces [18,[64][65][66][67][68]. Even though each of the four heart valves has its own individual unique anatomical, structural and constitutional features that are adapted to their specific localization and function, they share common structural, constitutional and functional features.…”

“…Collagen VI has been shown to form distinct structures within the fibrosa, surrounding the dense collagen I fibers of this layer [76]. The total collagen content in normal valve leaflets is approximately 50-63% (dry tissue weight ratio) [68,71,79,80], and the elastin content is approximately 10-11% (dry tissue weight ratio), depending on the valve type (Table 3) [78,[80][81][82][83]. Previous studies have reported the relative percentages of collagen I, III, and V in normal human MV leaflets to be approximately 74, 24 and 2% of the total collagen content, respectively, whereas collagen IV and VI were below the detection limit of the technique used in those studies [72,77].…”

“…Three major GAGs have been identified in varying concentrations in heart valves, including chondroitin sulfate, dermatan sulfate and hyaluronic acid, together with decorin, biglycan and versican, which are chondroitin and dermatan sulfate proteoglycans [51,84,85]. The total content of sulfated GAGs (chondroitin and dermatan sulfate) in normal heart valves has been reported to range between 11 and 27% (dry tissue weight ratio), depending on valve type and site ( Table 3) [68,71,78,79]. Hyaluronic acid is the most abundant GAG in normal heart valves, accounting for up to half of the total leaflet GAG content, with chondroitin and dermatan sulfate accounting for about a quarter of the total GAG content of the leaflet each [86].…”

Tissue Engineering—Bridging the Gap

“…The challenges in translating the data from pre-clinical and clinical pilot trials that will ultimately be faced by all tissue engineering projects are also reviewed [4]. The experimental studies in this issue address a variety of topics within the heart valve field including two papers on the development of decellularised valves [5,6], the chemical fixation of bovine pericardium and the assessment of a new transcatheter heart valve [7,8]. Within the vascular field, there are two papers, the first addresses the use of an in vivo approach that utilises the host reaction to an implanted biomaterial for the generation of completely autologous tissues, while the second examines the use of intravascular echo as a tool to evaluate the changes within tissue-engineered valves implanted into sheep [9,10].…”