TEHV

Synthetic biomaterials play a crucial role in developing tissue-engineered heart valves (TEHVs) due to their versatile mechanical properties. Achieving the right balance between mechanical strength and manufacturability is essential. Thermoplastic polyurethanes (TPUs) and elastomers (TPEs) garner significant attention for TEHV applications due to their notable stability, fatigue resistance, and customizable properties such as shear strength and elasticity. This study explores the additive manufacturing technique of selective laser sintering (SLS) for TPUs and TPEs to optimize process parameters to balance flexibility and strength, mimicking aortic valve tissue properties...

Tissue engineering heart valves (TEHVs) are expected to address the limitations of mechanical and bioprosthetic valves used in clinical practice. Decellularized heart valve (DHV) is an important scaffold of TEHVs due to its natural three-dimensional structure and bioactive extracellular matrix, but its mechanical properties and hemocompatibility are impaired. In this study, DHV was cross-linked with three different molecular weights of oxidized hyaluronic acid (OHA) by a Schiff base reaction and presented enhanced stability and hemocompatibility, which could be mediated by the molecular weight of OHA...

Tissue-engineered heart valves can grow, repair, and remodel after implantation, presenting a more favorable long-term solution compared to mechanical and porcine valves. Achieving functional engineered valve tissue requires the maturation of human cells seeded onto valve scaffolds under favorable growth conditions in bioreactors. The mechanical stress and strain on developing valve tissue caused by different pressure and flow conditions in bioreactors are currently unknown. The aim of this study is to quantify the wall shear stress (WSS) magnitude in heart valve prostheses under different valve geometries and bioreactor flow rates...

Valvular endothelial cells (VECs) derived from human induced pluripotent stem cells (hiPSCs) provide an unlimited cell source for tissue engineering heart valves (TEHVs); however, they are limited by their low differentiation efficiency and immature function. In our study, we applied unidirectional shear stress to promote hiPSCs differentiation into valvular endothelial-like cells (VELs). Compared to the static group, shear stress efficiently promoted the differentiation and functional maturation of hiPSC-VELs, as demonstrated by the efficiency of endothelial differentiation reaching 98...

Tissue engineering aims to overcome the current limitations of heart valves by providing a viable alternative using living tissue. Nevertheless, the valves constructed from either decellularized xenogeneic or purely biologic scaffolds are unable to withstand the hemodynamic loads, particularly in the left ventricle. To address this, we have been developing a hybrid tissue-engineered heart valve (H-TEHV) concept consisting of a nondegradable elastomeric scaffold enclosed in a valve-like living tissue constructed from autologous cells...

The heart valve is crucial for the human body, which directly affects the efficiency of blood transport and the normal functioning of all organs. Generally, decellularization is one method of tissue-engineered heart valve (TEHV), which can deteriorate the mechanical properties and eliminate allograft immunogenicity. In this study, removable polyvinyl alcohol (PVA) is used to encapsulate decellularized porcine heart valves (DHVs) as a dynamic template to improve the processability of DHVs, such as suturing. Mechanical tests show that the strength and elastic modulus of DHVs treated with different concentrations of PVA significantly improve...

BACKGROUND: Tissue-engineered heart valves (TEHVs) are promising new heart valve substitutes for valvular heart disease. The Notch signalling pathway plays a critical role in the development of congenital heart valves. OBJECTIVE: To investigate the role of the Notch signalling pathway in the construction of TEHVs. METHODS: The induced endothelial cells, which act as seed cells, were differentiated from adipose-derived stem cells and were treated with Jagged-1 (JAG-1) protein and γ-secretase inhibitor (DAPT, N-[N-(3,5-difluorophenacetyl)-l-alanyl]-s-phenylglycine t-butyl ester) respectively...

Phleboviruses are classified into two main groups: the sandfly fever group (transmitted by sandflies and mosquitoes) and the Uukuniemi group (transmitted by ticks). Old World sandfly-borne viruses (SBVs) are classified into four main serocomplexes; sandfly fever Naples viruses (SFNVs), sandfly fever Sicilian viruses (SFSVs), Karimabad viruses (KARVs), and Salehabad viruses (SALVs). This study addresses current knowledge gaps on SBVs in Iran by focusing on identification and molecular epidemiology. We used PCR to examine DNA/RNA extracts to identify sandfly species and evaluate for SBV presence...

The development of tissue-engineered cardiovascular implants can improve the lives of large segments of our society who suffer from cardiovascular diseases. Regenerative tissues are fabricated using a process called tissue maturation. Furthermore, it is highly challenging to produce cardiovascular regenerative implants with sufficient mechanical strength to withstand the loading conditions within the human body. Therefore, biohybrid implants for which the regenerative tissue is reinforced by standard reinforcement material (e...

The goal of tissue-engineered heart valves (TEHV) is to replace normal heart valves and overcome the shortcomings of heart valve replacement commonly used in clinical practice. However, calcification of TEHV is the major bottleneck to break for both clinical workers and researchers. Endothelialization of TEHV plays a crucial role in delaying valve calcification by reducing platelet adhesion and covering the calcified spots. In the present study, we loaded RunX2-siRNA and VEGF into mesoporous silica nanoparticles and investigated the properties of anti-calcification and endothelialization in vitro...

Tissue-engineered heart valve (TEHV) is a promising alternative to current heart valve substitute. Decellularized porcine aortic heart valves (DAVs) are the most common scaffolds of TEHV. Hard to endothelialization is one of the disadvantages of DAVs. Therefore, we aimed to immobilize endothelial progenitor cell (EPC)-aptamer onto DAVs for accelerating endothelialization. In this study, three groups of scaffolds were constructed: DAVs, aptamer-immobilized DAVs (aptamer-DAVs), and glutaraldehyde crosslinked DAVs (GA-DAVs)...

Tissue-engineered heart valves (TEHVs) are emerging alternatives to current valve prostheses and prospectively a lifelong replacement. Calcification, a pathological complication for biological protheses, has been reported in preclinical TEHV studies. Systematic analysis of its occurrence is missing. This review aims to: 1) systematically review reported calcification of pulmonary TEHVs in large-animal studies; and 2) analyze the influence of engineering methodology (choice of scaffold material, cell preseeding) and animal model (animal species and age) on calcification...

Transcatheter aortic valve replacement (TAVR) technology is quickly advancing in clinic, however, as it expands to low-risk populations and younger patients (age <65 years), device durability is becoming a major challenge. Tissue-engineered heart valves (TEHVs) are a potential alternative. In this study, a bionic tri-layer tissue-engineered heart valve was constructed using poly (L-lactate- co -ε-caprolactone) (PLCL), gelatin (GEL), hyaluronic acid (HA) and silk fibroin (SF), to simulate the fibrosa, spongiosa and ventricular layer of natural heart valves...

INTRODUCTION: Heart valve disease is a growing burden on the healthcare system. Current solutions are insufficient for young patients and do not offer relief from reintervention. Tissue engineered heart valves (TEHVs) offer a solution that grows and responds to the native environment in a similar way to a healthy valve. Stem cells hold potential to populate these valves as a malleable source that can adapt to environmental cues. AREAS COVERED: This review covers current methods of recapitulating features of native heart valves with tissue engineering through use of stem cell populations with in situ and in vitro methods...

Heart valve disease is associated with high morbidity and mortality worldwide resulting in hundreds of thousands of heart valve replacements each year. Tissue engineered heart valves (TEHVs) have the potential to overcome the major limitations of traditional replacement valves; however, leaflet retraction has led to the failure of TEHVs in preclinical studies. Sequentially varying growth factors over time has been utilized to promote maturation of engineered tissues and may be effective in reducing tissue retraction, yet it is difficult to predict the effects of such treatments due to complex between the cells and the extracellular matrix (ECM), biochemical environment, and mechanical stimuli...

Valvular heart disease is a globally prevalent cause of morbidity and mortality, with both congenital and acquired clinical presentations. Tissue engineered heart valves (TEHVs) have the potential to radically shift the treatment landscape for valvular disease by functioning as life-long valve replacements that overcome the current limitations of bioprosthetic and mechanical valves. TEHVs are envisioned to meet these goals by functioning as bioinstructive scaffolds that guide the in situ generation of autologous valves capable of growth, repair, and remodeling within the patient...

Human tissue-engineered matrices (hTEMs) have been proposed as a promising approach for in-situ tissue engineered heart valves (TEHVs). However, there is still a limited understanding on how ECM composition in hTEMs develops over tissue culture time. Therefore, we performed a longitudinal hTEM assessment by 1) multiscale evaluation of hTEM composition during culture time (2, 4, 6-weeks), using (immuno)histology, biochemical assays, and mass spectrometry (LC-MS/MS); 2) analysis of protein pathways involved in ECM development using gene set enrichment analysis (GSEA); and 3) assessment of hTEM mechanical characterization using uniaxial tensile testing...

In situ heart valve tissue engineering approaches have been proposed as promising strategies to overcome the limitations of current heart valve replacements. Tissue engineered heart valves (TEHVs) generated from in vitro grown tissue engineered matrices (TEMs) aim at mimicking the microenvironmental cues from the extracellular matrix (ECM) to favor integration and remodeling of the implant. A key role of the ECM is to provide mechanical support to and attract host cells into the construct. Additionally, each ECM component plays a critical role in regulating cell adhesion, growth, migration, and differentiation potential...

Herpesviruses are important pathogens of tortoises, and several serologically and genetically distinct virus types have been described in these animals. Virus neutralization testing is commonly used in Europe to determine previous infection with the two types most often found in pet European tortoises, testudinid herpesvirus (TeHV) 1 and 3. In this retrospective study, the results of serological testing for antibodies against each of these viruses in serum or plasma samples from 1728 tortoises were evaluated, and antibody detection rates were compared based on virus type, host species, year, season, and country of origin...

Aim    Endothelial progenitor cells (EPCs) play important roles in heart valve replacement surgery. Up-regulation of Grb2‑associated binder 1 (Gab1) promotes hepatocyte growth factor (HGF) - induced endothelial progenitor cell proliferation and migration. This study aimed to investigate the effects of up-regulation of Gab1 in hepatocyte growth factor-induced EPCs in tissue-engineered heart valves (TEHV).Material and methods    Fresh porcine aortic valves were placed in 1 % Triton X-100 and trypsin buffer for decellularization...