Anti-adhesive Properties of Epoxy-Treated Xenopericardium Modified with Polyvinyl Alcohol: Study of Leukocyte Adhesion in the Pulsatile Flow Model.

Unlabelled: is to assess protective capabilities of the polymer coating made of polyvinyl alcohol to prevent leukocyte adhesion to epoxy-treated bovine pericardium, which is used in production of bioprosthetic heart valves.

Materials And Methods: Fragments of unmodified (control) and modified with polyvinyl alcohol epoxy-treated bovine pericardium were incubated in the dedicated chambers connected to a pulsatile flow system (Ibidi GmbH, Germany). During 48 h incubation was conducted in whole donor plasma containing 310 of mononuclear fraction cells.

Electrospun bioresorbable polymer membranes for coronary artery stents.

Percutaneous coronary intervention, a common treatment for atherosclerotic coronary artery lesions, occasionally results in perforations associated with increased mortality rates. Stents coated with a bioresorbable polymer membrane may offer an effective solution for sealing coronary artery perforations. Additionally, such coatings could be effective in mitigating neointimal hyperplasia within the vascular lumen and correcting symptomatic aneurysms.

Enhancing decellularized vascular scaffolds with PVDF and PCL reinforcement: a fused deposition modeling approach.

Background: Decellularized xenogenic scaffolds represent a promising substrate for tissue-engineered vascular prostheses, particularly those with smaller diameters (<6 mm). Despite their benefits, a notable limitation presents itself during decellularization, namely, the diminished mechanical strength that introduces the risk of aneurysmal dilations in the early post-implantation period. This study introduces a strategy for modification the mechanical properties of these biological scaffolds through the forming of an external polymeric reinforcement via thermal extrusion.

Embedding and Backscattered Scanning Electron Microscopy (EM-BSEM) Is Preferential over Immunophenotyping in Relation to Bioprosthetic Heart Valves.

Hitherto, calcified aortic valves (AVs) and failing bioprosthetic heart valves (BHVs) have been investigated by similar approaches, mostly limited to various immunostaining techniques. Having employed multiple immunostaining combinations, we demonstrated that AVs retain a well-defined cellular hierarchy even at severe stenosis, whilst BHVs were notable for the stochastic degradation of the extracellular matrix (ECM) and aggressive infiltration by ECM-digesting macrophages. Leukocytes (CD45) comprised ≤10% cells in the AVs but were the predominant cell lineage in BHVs (≥80% cells).

Comparison of the Patency and Regenerative Potential of Biodegradable Vascular Prostheses of Different Polymer Compositions in an Ovine Model.

The lack of suitable autologous grafts and the impossibility of using synthetic prostheses for small artery reconstruction make it necessary to develop alternative efficient vascular grafts. In this study, we fabricated an electrospun biodegradable poly(ε-caprolactone) (PCL) prosthesis and poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(ε-caprolactone) (PHBV/PCL) prosthesis loaded with iloprost (a prostacyclin analog) as an antithrombotic drug and cationic amphiphile with antibacterial activity. The prostheses were characterized in terms of their drug release, mechanical properties, and hemocompatibility.

[Respiratory disorders of post-COVID-19 syndrome].

Aim: Assess the functional state of trespiratory system and effectiveness of therapeutic tactics for broncho-obstructive syndrome (BOS) in patients in the post-COVID period.

Materials And Methods: A two-center cohort prospective study included 10 456 and 89 patients, respectively. A comprehensive assessment of the respiratory system included clinical, laboratory and functional data, spirometry, body plethysmography, and a study of diffusive capacity of the lungs (DLCO).

New Tissue-Engineered Vascular Matrix Based on Regenerated Silk Fibroin: Study.

Unlabelled: was to make a vascular patch based on regenerated silk fibroin (SF) and study its physical and mechanical characteristics, biocompatibility and matrix properties in comparison with polyhydroxybutyrate/valerate/polycaprolactone with incorporated vascular endothelial growth factor (PHBV/PCL/VEGF) and commercial bovine xenopericardium (XP) flap in experiments .

Materials And Methods: Tissue-engineered matrices were produced by electrospinning. The surface structure, physical and mechanical characteristics, hemocompatibility (erythrocyte hemolysis, aggregation, adhesion and activation of platelets after contact with the material) and matrix properties of vascular patches (adhesion, viability, metabolic activity of EA.

Proteolytic Degradation Is a Major Contributor to Bioprosthetic Heart Valve Failure.

Background Whereas the risk factors for structural valve degeneration (SVD) of glutaraldehyde-treated bioprosthetic heart valves (BHVs) are well studied, those responsible for the failure of BHVs fixed with alternative next-generation chemicals remain largely unknown. This study aimed to investigate the reasons behind the development of SVD in ethylene glycol diglycidyl ether-treated BHVs. Methods and Results Ten ethylene glycol diglycidyl ether-treated BHVs excised because of SVD, and 5 calcified aortic valves (AVs) replaced with BHVs because of calcific AV disease were collected and their proteomic profile was deciphered.

Early Postoperative Immunothrombosis of Bioprosthetic Mitral Valve and Left Atrium: A Case Report.

A 72-year-old female patient with mixed rheumatic mitral valve disease and persistent atrial fibrillation underwent mitral valve replacement and suffered from a combined thrombosis of the bioprosthetic valve and the left atrium as soon as 2 days post operation. The patient immediately underwent repeated valve replacement and left atrial thrombectomy. Yet, four days later the patient died due to the recurrent prosthetic valve and left atrial thrombosis which both resulted in an extremely low cardiac output.

Advantages of Fibrin Polymerization Method without the Use of Exogenous Thrombin for Vascular Tissue Engineering Applications.

Fibrin is widely used in vascular tissue engineering. Typically, fibrin polymerization is initiated by adding exogenous thrombin. In this study, we proposed a protocol for the preparation of completely autologous fibrin without the use of endogenous thrombin and compared the properties of the prepared fibrin matrix with that obtained by the traditional method.

Biomaterials Based on Carbon Nanotube Nanocomposites of Poly(styrene--isobutylene--styrene): The Effect of Nanotube Content on the Mechanical Properties, Biocompatibility and Hemocompatibility.

Nanocomposites based on poly(styrene--isobutylene--styrene) (SIBS) and single-walled carbon nanotubes (CNTs) were prepared and characterized in terms of tensile strength as well as bio- and hemocompatibility. It was shown that modification of CNTs using dodecylamine (DDA), featured by a long non-polar alkane chain, provided much better dispersion of nanotubes in SIBS as compared to unmodified CNTs. As a result of such modification, the tensile strength of the nanocomposite based on SIBS with low molecular weight (M = 40,000 g mol) containing 4% of functionalized CNTs was increased up to 5.

[Screening analysis of proteolytic enzymes and their inhibitors in the leaflets of epoxy-treated bioprosthetic heart valves explanted due to dysfunction].

Bioprosthetic heart valves (BHVs) are known for their lower thrombogenicity rates and excellent hemodynamic parameters similar to native valves. However, the lifespan of these medical devices is limited to 15 years due to the structural valve degeneration. One of the mechanisms underlying functional impairment and calcification of BHVs includes proteolytic degradation of biomaterials.

Calciprotein Particles Link Disturbed Mineral Homeostasis with Cardiovascular Disease by Causing Endothelial Dysfunction and Vascular Inflammation.

An association between high serum calcium/phosphate and cardiovascular events or death is well-established. However, a mechanistic explanation of this correlation is lacking. Here, we examined the role of calciprotein particles (CPPs), nanoscale bodies forming in the human blood upon its supersaturation with calcium and phosphate, in cardiovascular disease.

A Technology for Anti-Thrombogenic Drug Coating of Small-Diameter Biodegradable Vascular Prostheses.

Unlabelled: was to develop a technology for anti-thrombogenic drug coating of biodegradable porous scaffolds and to evaluate the physicomechanical and hemocompatible properties of functionally active vascular prostheses with and without a drug coating.

Materials And Methods: Vascular prostheses from polyhydroxybutyrate/valerate and polycaprolactone with the incorporated vascular endothelial growth factor, the main fibroblast growth factor, and the chemoattractant SDF-1α were made by emulsion electrospinning. Additional surface modification of the prostheses was carried out by forming a hydrogel coating of polyvinylpyrrolidone capable of binding drugs as a result of complexation.

EMbedding and Backscattered Scanning Electron Microscopy: A Detailed Protocol for the Whole-Specimen, High-Resolution Analysis of Cardiovascular Tissues.

Currently, an ultrastructural analysis of cardiovascular tissues is significantly complicated. Routine histopathological examinations and immunohistochemical staining suffer from a relatively low resolution of light microscopy, whereas the fluorescence imaging of plaques and bioprosthetic heart valves yields considerable background noise from the convoluted extracellular matrix that often results in a low signal-to-noise ratio. Besides, the sectioning of calcified or stent-expanded blood vessels or mineralised heart valves leads to a critical loss of their integrity, demanding other methods to be developed.

Modeling of an irrigation system in a virtual physical space.

One of the major challenges that smart agriculture is expected to address is the efficient use of water resources. The conservation and the efficient use of clean water is a long-term strategy worldwide. Modeling of smart agriculture systems is an important factor because the processes there are very slow and sometimes it takes a year or more for a full crop cycle.

Tissue-Engineered Carotid Artery Interposition Grafts Demonstrate High Primary Patency and Promote Vascular Tissue Regeneration in the Ovine Model.

Tissue-engineered vascular graft for the reconstruction of small arteries is still an unmet clinical need, despite the fact that a number of promising prototypes have entered preclinical development. Here we test Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)Poly(ε-caprolactone) 4-mm-diameter vascular grafts equipped with vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and stromal cell-derived factor 1α (SDF-1α) and surface coated with heparin and iloprost (PHBV/PCL[VEGF-bFGF-SDF], = 8) in a sheep carotid artery interposition model, using biostable vascular prostheses of expanded poly(tetrafluoroethylene) (ePTFE, = 5) as a control. Primary patency of PHBV/PCL[VEGF-bFGF-SDF] grafts was 62.

bFGF and SDF-1α Improve In Vivo Performance of VEGF-Incorporating Small-Diameter Vascular Grafts.

Tissue-engineered vascular grafts are widely tested as a promising substitute for both arterial bypass and replacement surgery. We previously demonstrated that incorporation of VEGF into electrospun tubular scaffolds from poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(ε-caprolactone) enhances formation of an endothelial cell monolayer. However, an overdose of VEGF can induce tumor-like vasculature; thereby, other bioactive factors are needed to support VEGF-driven endothelialization and successful recruitment of smooth muscle cells.

Calciprotein Particles Cause Endothelial Dysfunction under Flow.

Calciprotein particles (CPPs), which increasingly arise in the circulation during the disorders of mineral homeostasis, represent a double-edged sword protecting the human organism from extraskeletal calcification but potentially causing endothelial dysfunction. Existing models, however, failed to demonstrate the detrimental action of CPPs on endothelial cells (ECs) under flow. Here, we applied a flow culture system, where human arterial ECs were co-incubated with CPPs for 4 h, and a normolipidemic and normotensive rat model (10 daily intravenous injections of CPPs) to simulate the scenario occurring in vivo in the absence of confounding cardiovascular risk factors.

Ultrastructural Pathology of Atherosclerosis, Calcific Aortic Valve Disease, and Bioprosthetic Heart Valve Degeneration: Commonalities and Differences.

Atherosclerosis, calcific aortic valve disease (CAVD), and bioprosthetic heart valve degeneration (alternatively termed structural valve deterioration, SVD) represent three diseases affecting distinct components of the circulatory system and their substitutes, yet sharing multiple risk factors and commonly leading to the extraskeletal calcification. Whereas the histopathology of the mentioned disorders is well-described, their ultrastructural pathology is largely obscure due to the lack of appropriate investigation techniques. Employing an original method for sample preparation and the electron microscopy visualisation of calcified cardiovascular tissues, here we revisited the ultrastructural features of lipid retention, macrophage infiltration, intraplaque/intraleaflet haemorrhage, and calcification which are common or unique for the indicated types of cardiovascular disease.

Biocompatible Nanocomposites Based on Poly(styrene--isobutylene--styrene) and Carbon Nanotubes for Biomedical Application.

In this study, we incorporated carbon nanotubes (CNTs) into poly(styrene--isobutylene--styrene) (SIBS) to investigate the physical characteristics of the resulting nanocomposite and its cytotoxicity to endothelial cells. CNTs were dispersed in chloroform using sonication following the addition of a SIBS solution at different ratios. The resultant nanocomposite films were analyzed by X-ray microtomography, optical and scanning electron microscopy; tensile strength was examined by uniaxial tension testing; hydrophobicity was evaluated using a sessile drop technique; for cytotoxicity analysis, human umbilical vein endothelial cells were cultured on SIBS-CNTs for 3 days.

Degeneration of Bioprosthetic Heart Valves: Update 2020.

The implantation of bioprosthetic heart valves (BHVs) is increasingly becoming the treatment of choice in patients requiring heart valve replacement surgery. Unlike mechanical heart valves, BHVs are less thrombogenic and exhibit superior hemodynamic properties. However, BHVs are prone to structural valve degeneration (SVD), an unavoidable condition limiting graft durability.

Biodegradable Patches for Arterial Reconstruction Modified with RGD Peptides: Results of an Experimental Study.

Modification by Arg-Gly-Asp (RGD) peptides is a promising approach to improve the biocompatibility of biodegradable vascular patches for arteriotomy. In this study, we evaluated the performance of vascular patches electrospun using a blend of polycaprolactone (PCL) and polyhydroxybutyrate/valerate (PHBV) and additionally modified with RGDK, AhRGD, and c[RGDFK] peptides using 1,6-hexamethylenediamine or 4,7,10-trioxa-1,13-tridecanediamine (TTDDA) linkers. We examined mechanical properties and hemocompatibility of resulting patches before implanting them in rat abdominal aortas to assess their performance in vivo.

A New Nanocomposite Copolymer Based On Functionalised Graphene Oxide for Development of Heart Valves.

Polymeric heart valves seem to be an attractive alternative to mechanical and biological prostheses as they are more durable, due to the superior properties of novel polymers, and have the biocompatibility and hemodynamics comparable to tissue substitutes. This study reports a comprehensive assessment of a nanocomposite based on the functionalised graphene oxide and poly(carbonate-urea)urethane with the trade name "Hastalex" in comparison with GORE-TEX, a commercial polymer routinely used for cardiovascular medical devices. Experimental data have proved that GORE-TEX has a 2.

[Infective Endocarditis Causing Native and Prosthetic Heart Valve Dysfunction].

Infective endocarditis (IE) is the disease that has high inhospital mortality. Heart valves dysfunction - both native and prosthetic - is the primary IE complication requiring a surgical intervention. The IE causes and its course have been discussed in this review.