scholarly journals Oscillatory fluid-induced mechanobiology in heart valves with parallels to the vasculature

2020 ◽  
Vol 2 (1) ◽  
pp. R59-R71
Author(s):  
Chia-Pei Denise Hsu ◽  
Joshua D Hutcheson ◽  
Sharan Ramaswamy
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Vascular Diseases ◽  
Cell Types ◽  
The Body ◽  
Plaque Morphology ◽  
Cardiovascular Development ◽  
Hemodynamic Forces ◽  
Similarities And Differences ◽  
Molecular Signals

Forces generated by blood flow are known to contribute to cardiovascular development and remodeling. These hemodynamic forces induce molecular signals that are communicated from the endothelium to various cell types. The cardiovascular system consists of the heart and the vasculature, and together they deliver nutrients throughout the body. While heart valves and blood vessels experience different environmental forces and differ in morphology as well as cell types, they both can undergo pathological remodeling and become susceptible to calcification. In addition, while the plaque morphology is similar in valvular and vascular diseases, therapeutic targets available for the latter condition are not effective in the management of heart valve calcification. Therefore, research in valvular and vascular pathologies and treatments have largely remained independent. Nonetheless, understanding the similarities and differences in development, calcific/fibrous pathologies and healthy remodeling events between the valvular and vascular systems can help us better identify future treatments for both types of tissues, particularly for heart valve pathologies which have been understudied in comparison to arterial diseases.

scholarly journals Molecular and functional characteristics of heart-valve interstitial cells

2007 ◽  
Vol 362 (1484) ◽  
pp. 1437-1443 ◽  
Author(s):  
Adrian H Chester ◽  
Patricia M Taylor
Keyword(s):  
Endothelial Cells ◽  
Heart Valve ◽  
Heart Valves ◽  
Cell Types ◽  
Interstitial Cells ◽  
Individual Characteristics ◽  
The Body ◽  
Integral Role ◽  
Valve Function ◽  
And Function

The cells that reside within valve cusps play an integral role in the durability and function of heart valves. There are principally two types of cells found in cusp tissue: the endothelial cells that cover the surface of the cusps and the interstitial cells (ICs) that form a network within the extracellular matrix (ECM) within the body of the cusp. Both cell types exhibit unique functions that are unlike those of other endothelial and ICs found throughout the body. The valve ICs express a complex pattern of cell-surface, cytoskeletal and muscle proteins. They are able to bind to, and communicate with, each other and the ECM. The endothelial cells on the outflow and inflow surfaces of the valve differ from one another. Their individual characteristics and functions reflect the fact that they are exposed to separate patterns of flow and pressure. In addition to providing a structural role in the valve, it is now known that the biological function of valve cells is important in maintaining the integrity of the cusps and the optimum function of the valve. In response to inappropriate stimuli, valve interstitial and endothelial cells may also participate in processes that lead to valve degeneration and calcification. Understanding the complex biology of valve interstitial and endothelial cells is an important requirement in elucidating the mechanisms that regulate valve function in health and disease, as well as setting a benchmark for the function of cells that may be used to tissue engineer a heart valve.

Dental Pulp Stem Cells for Tissue Engineered Heart Valve

2020 ◽  
Author(s):  
Soontaree Petchdee ◽  
Wilairat Chumsing ◽  
Suruk Udomsom ◽  
Kittiya Thunsiri
Keyword(s):  
Stem Cells ◽  
Mitral Valve ◽  
Heart Valve ◽  
Heart Valves ◽  
Cell Types ◽  
Tensile Tests ◽  
Deciduous Teeth ◽  
Essential Information ◽  
Acquired Heart Disease ◽  
Tissue Engineered Heart Valves

Myxomatous mitral valve degeneration is the most acquired heart disease in dogs. To reduce the clinical progression of mitral valve degeneration and achieve the hemodynamic outcomes, many medical or surgical treatments have been motivated. The objectives of this study is to investigate the suitability of puppy deciduous teeth stem cells as a cell source for tissue engineered heart valves in dog with degenerative valve disease. Puppy deciduous teeth stem cells (pDSCs) were seeded on the scaffolds which made from polylactic acid (PLA), polycaprolactone (PLC) and silicone. The mechanical properties of the tissue engineered heart valves leaflets were characterized by biaxial tensile tests. Results showed that, deciduous teeth stem cells capable of differentiating into a variety of cell types. However, the ability of puppy deciduous teeth stem cells to differentiate declined with increasing passage number which correspond to the number of protein surface marker detection have been shown to decrease substantially by the fifth passage. PLA scaffold is significantly higher tensile strength than other materials. However, silicone showed the highest flaccidity. The results from this study may provide high regenerative capability and the essential information for future directions of heart valve tissue engineering.

scholarly journals DESIGN AND DEVELOPMENT OF IMPURITIES FREE PYROLYTIC COATED MECHANICAL BI-LEAFLET HEART VALVE PROTOTYPE

2021 ◽  
Vol 54 (3) ◽  
pp. 277-284
Author(s):  
Natasha Mukhtiar ◽  
Murtaza Najabat Ali ◽  
Hafsa Inam
Keyword(s):  
Heart Valve ◽  
Hemolytic Activity ◽  
Smooth Surface ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
The Body ◽  
Cnc Machine ◽  
Mechanical Prosthesis ◽  
Coating Materials ◽  
Tissue Ingrowth

Heart valve problems affect more than 100 million people worldwide. According to statistics, around 55% of valvular diseases are treated by a mechanical prosthesis. The first heart valve replaced model was the caged-ball valve, more than 50 models of heart valves designed by different companies. Each design has different aspects such as valve geometry, leaflets design, materials used for model manufacturing, coating techniques, and coating materials. Depending on the patient's need and condition, the native heart valve either replaced by a biological or mechanical heart valve. Biological valves are made of living tissues whereas mechanical valves manufactured by the biomaterials, which are biocompatible and do not causes any reaction inside the body. The prototype discussed in this paper provides good hemocompatibility, because of the biomaterial used in this prototype manufacturing. It will reduce tissue ingrowth, due to the enhanced leaflet ear of the orifice ring. Moreover, it will cause less thrombotic effects into the host due to greater contact angel of graphite and smooth surface of graphite after pyrolytic coating. The significant evolution of mechanical valve designs consists of valve geometry, coating technique, and materials. In this research, the 3D-CAD model of Bileaflet Mechanical Mitral Heart Valve was designed using SOLID WORKS 2016 and fabricated by 5-axis Computer Numeric Control (CNC) machine. Graphite was used for the fabrication of prototype and Pyrolytic Carbon (PyC) coating was performed with Chemical Vapor deposition (CVD) technique. Scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) were used to determine the effects of CVD on surface topography and chemical structure of graphite model before and after coating. Furthermore, hemocompatibility of graphite and PyC analyzed through in-vitro hemolytic activity. The Characterization results showed that the Bileaflet Mechanical Mitral Heart valve prototype after PyC coating provides a smooth surface with improved hemocompatibility and less adhesion. Besides, the Mechanical Heart valves showed no hemolysis during the hemolytic activity. By virtue of its smooth and nonporous surface, it is antithrombotic and provides good hemodynamics. The advance long leaflet ear design reduces the tissue ingrowth around the orifice which will further limit the leaflets movement.

scholarly journals The Body’s Cellular and Molecular Response to Protein-Coated Medical Device Implants: A Review Focused on Fibronectin and BMP Proteins

2020 ◽  
Vol 21 (22) ◽  
pp. 8853
Author(s):  
Yi-Fan Chen ◽  
Clyde Goodheart ◽  
Diego Rua
Keyword(s):  
Revision Surgery ◽  
Manufacturing Process ◽  
Tissue Repair ◽  
Cell Types ◽  
Glucose Sensors ◽  
The Body ◽  
Molecular Response ◽  
Marked Rise ◽  
Retinal Implants ◽  
Molecular Signals

Recent years have seen a marked rise in implantation into the body of a great variety of devices: hip, knee, and shoulder replacements, pacemakers, meshes, glucose sensors, and many others. Cochlear and retinal implants are being developed to restore hearing and sight. After surgery to implant a device, adjacent cells interact with the implant and release molecular signals that result in attraction, infiltration of the tissue, and attachment to the implant of various cell types including monocytes, macrophages, and platelets. These cells release additional signaling molecules (chemokines and cytokines) that recruit tissue repair cells to the device site. Some implants fail and require additional revision surgery that is traumatic for the patient and expensive for the payer. This review examines the literature for evidence to support the possibility that fibronectins and BMPs could be coated on the implants as part of the manufacturing process so that the proteins could be released into the tissue surrounding the implant and improve the rate of successful implantation.

scholarly journals Acellular matrix as a substrate for tissue-engineered graft of heart valve

2013 ◽  
Vol 1 (1) ◽  
pp. 52-55 ◽  
Author(s):  
A. Popandopulo ◽  
M. Petrova
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Heart Valve ◽  
Heart Valves ◽  
Three Dimensional ◽  
Tissue Scaffolds ◽  
The Body ◽  
Heart Regeneration ◽  
Acellular Matrix ◽  
Living Materials

In many cases heart valve prosthetics is the only solution to save patient’s life. All mechanical prosthetics currently used are not able to perform function in the body fully because non-living materials are used for their production. Tissue engineering provides the reconstruction of viable valves using stem cells. Acellularized three-dimensional tissue scaffolds as a matrix for autologous cells do improve function of heart valves and promote heart regeneration.

The Influence of Manufacturing Methods on the Function and Performance of a Synthetic Leaflet Heart Valve

1995 ◽  
Vol 209 (1) ◽  
pp. 65-69 ◽  
Author(s):  
M E Leat ◽  
J Fisher
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
The Body ◽  
Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Thermal Forming ◽  
Manufacturing Methods ◽  
And Performance ◽  
Hydrodynamic Function

There is considerable interest in polyurethane synthetic leaflet heart valves for both ventricular assist devices and direct implantation in the body. Two different manufacturing methods, thermal forming, and dip casting, of the leaflets have been investigated. There were only small differences in the hydrodynamic function of the valves made by the two methods. However, the durability of dip cast valves was far superior to the thermally formed film fabricated leaflets, with all of the dip cast valves reaching 160 million cycles without failure. This study indicates that a correctly designed and manufactured polyurethane synthetic leaflet heart valve has the potential for long-term implantation in the body.

scholarly journals Biomaterials-Based Modulation of the Immune System

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Austin B. Gardner ◽  
Simon K. C. Lee ◽  
Elliot C. Woods ◽  
Abhinav P. Acharya
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Immune Responses ◽  
Viral Infections ◽  
Cell Types ◽  
The Body ◽  
Antigen Delivery ◽  
Delivery Vehicles ◽  
Foreign Materials ◽  
Molecular Signals

The immune system is traditionally considered from the perspective of defending against bacterial or viral infections. However, foreign materials like implants can also illicit immune responses. These immune responses are mediated by a large number of molecular signals, including cytokines, antibodies and reactive radical species, and cell types, including macrophages, neutrophils, natural killer cells, T-cells, B-cells, and dendritic cells. Most often, these molecular signals lead to the generation of fibrous encapsulation of the biomaterials, thereby shielding the body from these biomaterials. In this review we will focus on two different types of biomaterials: those that actively modulate the immune response, as seen in antigen delivery vehicles for vaccines, and those that illicit relatively small immune response, which are important for implantable materials. The first serves to actively influence the immune response by co-opting certain immune pathways, while the second tries to mimic the properties of the host in an attempt to remain undetected by the immune system. As these are two very different end points, each type of biomaterial has been studied and developed separately and in recent years, many advances have been made in each respective area, which will be highlighted in this review.

scholarly journals Extracellular-Vesicle-Based Coatings Enhance Bioactivity of Titanium Implants—SurfEV

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1445
Author(s):  
Taisa Nogueira Pansani ◽  
Thanh Huyen Phan ◽  
Qingyu Lei ◽  
Alexey Kondyurin ◽  
Bill Kalionis ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Titanium Surface ◽  
Wound Closure ◽  
Cell Types ◽  
Extracellular Vesicle ◽  
Tissue Growth ◽  
Titanium Implants ◽  
The Body ◽  
High Concentrations ◽  
And Migration

Extracellular vesicles (EVs) are nanoparticles released by cells that contain a multitude of biomolecules, which act synergistically to signal multiple cell types. EVs are ideal candidates for promoting tissue growth and regeneration. The tissue regenerative potential of EVs raises the tantalizing possibility that immobilizing EVs on implant surfaces could potentially generate highly bioactive and cell-instructive surfaces that would enhance implant integration into the body. Such surfaces could address a critical limitation of current implants, which do not promote bone tissue formation or bond bone. Here, we developed bioactive titanium surface coatings (SurfEV) using two types of EVs: secreted by decidual mesenchymal stem cells (DEVs) and isolated from fermented papaya fluid (PEVs). For each EV type, we determined the size, morphology, and molecular composition. High concentrations of DEVs enhanced cell proliferation, wound closure, and migration distance of osteoblasts. In contrast, the cell proliferation and wound closure decreased with increasing concentration of PEVs. DEVs enhanced Ca/P deposition on the titanium surface, which suggests improvement in bone bonding ability of the implant (i.e., osteointegration). EVs also increased production of Ca and P by osteoblasts and promoted the deposition of mineral phase, which suggests EVs play key roles in cell mineralization. We also found that DEVs stimulated the secretion of secondary EVs observed by the presence of protruding structures on the cell membrane. We concluded that, by functionalizing implant surfaces with specialized EVs, we will be able to enhance implant osteointegration by improving hydroxyapatite formation directly at the surface and potentially circumvent aseptic loosening of implants.

scholarly journals High-throughput screening of circRNAs reveals novel mechanisms of tuberous sclerosis complex-related renal angiomyolipoma

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Yang Zhao ◽  
Hao Guo ◽  
Wenda Wang ◽  
Guoyang Zheng ◽  
Zhan Wang ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Tuberous Sclerosis ◽  
Tuberous Sclerosis Complex ◽  
Regulatory Network ◽  
High Throughput Screening ◽  
Kidney Tissue ◽  
Cell Types ◽  
The Body ◽  
Differentially Expressed ◽  
Renal Angiomyolipoma

Abstract Objective Tuberous sclerosis complex (TSC) is a rare autosomal dominant disease characterized by lesions throughout the body. Our previous study showed the abnormal up-regulation of miRNAs plays an important part in the pathogenesis of TSC-related renal angiomyolipoma (TSC-RAML). circRNAs were known as important regulators of miRNA, but little is known about the circRNAs in TSC-RAMLs. Methods Microarray chips and RNA sequencing were used to identify the circRNAs and mRNAs that were differently expressed between the TSC-RAML and normal kidney tissue. A competitive endogenous RNA (ceRNA) regulatory network was constructed to reveal the regulation of miRNAs and mRNAs by the circRNAs. The biological functions of circRNA and mRNA were analyzed by pathway analysis. Microenvironmental cell types were estimated with the MCP-counter package. Results We identified 491 differentially expressed circRNAs (DECs) and 212 differentially expressed genes (DEGs), and 6 DECs were further confirmed by q-PCR. A ceRNA regulatory network which included 6 DECs, 5 miRNAs, and 63 mRNAs was established. Lipid biosynthetic process was significantly up-regulated in TSC-RAML, and the humoral immune response and the leukocyte chemotaxis pathway were found to be down-regulated. Fibroblasts are enriched in TSC-RAML, and the up-regulation of circRNA_000799 and circRNA_025332 may be significantly correlated to the infiltration of the fibroblasts. Conclusion circRNAs may regulate the lipid metabolism of TSC-RAML by regulation of the miRNAs. Fibroblasts are enriched in TSC-RAMLs, and the population of fibroblast may be related to the alteration of circRNAs of TSC-RAML. Lipid metabolism in fibroblasts is a potential treatment target for TSC-RAML.

scholarly journals Glucocorticoid Receptor β (GRβ): Beyond Its Dominant-Negative Function

2021 ◽  
Vol 22 (7) ◽  
pp. 3649
Author(s):  
Patricia Ramos-Ramírez ◽  
Omar Tliba
Keyword(s):  
Current Knowledge ◽  
Inflammatory Diseases ◽  
Cell Communication ◽  
Cell Types ◽  
The Body ◽  
Dominant Negative ◽  
Negative Effects ◽  
Independent Manner ◽  
Distinct Cell ◽  
Induced Apoptosis

Glucocorticoids (GCs) act via the GC receptor (GR), a receptor ubiquitously expressed in the body where it drives a broad spectrum of responses within distinct cell types and tissues, which vary in strength and specificity. The variability of GR-mediated cell responses is further extended by the existence of GR isoforms, such as GRα and GRβ, generated through alternative splicing mechanisms. While GRα is the classic receptor responsible for GC actions, GRβ has been implicated in the impairment of GRα-mediated activities. Interestingly, in contrast to the popular belief that GRβ actions are restricted to its dominant-negative effects on GRα-mediated responses, GRβ has been shown to have intrinsic activities and “directly” regulates a plethora of genes related to inflammatory process, cell communication, migration, and malignancy, each in a GRα-independent manner. Furthermore, GRβ has been associated with increased cell migration, growth, and reduced sensitivity to GC-induced apoptosis. We will summarize the current knowledge of GRβ-mediated responses, with a focus on the GRα-independent/intrinsic effects of GRβ and the associated non-canonical signaling pathways. Where appropriate, potential links to airway inflammatory diseases will be highlighted.

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