Cordial connections: molecular ensembles and structures of adhering junctions connecting interstitial cells of cardiac valves in situ and in cell culture.

Remarkable efforts have recently been made in the tissue engineering of heart valves to improve the results of valve transplantations and replacements, including the design of artificial valves. However, knowledge of the cell and molecular biology of valves and, specifically, of valvular interstitial cells (VICs) remains limited. Therefore, our aim has been to determine and localize the molecules forming the adhering junctions (AJs) that connect VICs in situ and in cell culture.

Aortic root and ascending aortic replacement.

The Ross procedure is occasionally favoured in young adults, with the implantation of a mechanical conduit remaining a competing option when simultaneous replacement of the ascending aorta is indicated. Eighteen patients with replacement of the ascending aorta, in addition to the Ross procedure (Ross), and 20 patients with a mechanical composite graft (composite) were compared retrospectively. The Short Form Health Survey (SF36) was used to assess quality of life (QoL).

Determinants of bioartificial myocardial graft survival and engraftment in vivo.

Background: The specific interactions between tissue-engineered grafts and host tissue are frequently neglected. The aim of this study was to describe and quantify the fate of a tissue-engineered cardiac graft in vivo.

Methods: Neonatal rat cardiomyocytes were cast into a collagen mesh, forming a bioartificial myocardial tissue (AMT).

Who needs 'bridge' to transplantation in the presence of the Eurotransplant high-urgency heart transplantation program?

Introduction: The purposes of this study are to identify a patient cohort that would benefit from the use of mechanical circulatory support (MCS) in the presence of the Eurotransplant high-urgency (HU) program.

Methods: Sixty-five patients (heart transplantation (HTx) group, 77%) underwent heart transplantation and 17 patients (D group, 20%) died while on the HU waiting list. These 82 patients were included in this retrospective study.

Myocardial tissue engineering: the extracellular matrix.

More than a decade after the first reports on successful three-dimensional cardiac cell culture for experimental and potential therapeutic application, the interest and experimental efforts in the field of myocardial tissue engineering continues to grow. The hope that tissue cultures may one day act as graft substitute for malfunctioning myocardium continues to drive current scientific activity. Against this background interest seem to have progressively shifted towards the aim of engineering single tissue components.

Stem cells used for cardiovascular tissue engineering.

Stem cell research and tissue engineering have become leading fields in basic research worldwide. Especially in cardiovascular medicine, initial reports on the potential of using stem cells to recover cardiac function and replace organ subunits such as heart valves seemed to offer the promise of widespread clinical use in the near future. However, the broad application of this new therapy failed due to safety and efficacy concerns.

Sternal microcirculation after skeletonized versus pedicled harvesting of the internal thoracic artery: a randomized study.

Objective: In human patients the influence of skeletonized internal thoracic artery harvesting on the sternal microcirculation in the perioperative phase has not been well investigated.

Methods: Twenty-four consecutive male patients who were scheduled for isolated coronary artery bypass grafting were prospectively randomized into 2 groups. The left internal thoracic artery was harvested by using the skeletonized technique in group 1, and it was harvested with a pedicle in group 2.

[Tissue engineering: in vitro creation of tissue substitutes].

Tissue engineering is a young, multidisciplinary scientific field which aims at generating bioartificial tissues in vitro to restore diseased human organs. This fledgling sector of biosciences emerged few years ago but draws scientific and public attention increasingly, as the recent accomplishments are impressive and promise alternative therapeutic concepts to replace or enhance failing human organs. Tissue engineering using either polymers or decellularized native allogeneic or xenogeneic matrices may provide the techniques to develop the ideal graft.

Bioartificial grafts for transmural myocardial restoration: a new cardiovascular tissue culture concept.

Objective: Survival of bioartificial grafts that are destined to restore cardiac function stands and falls with their nutrient supply. Engineering of myocardial tissue is limited because of lack of vascularization. We introduce a new concept to obtain bioartificial myocardial grafts in which perfusion by a macroscopic core vessel is simulated.

Pulsatile perfusion and cardiomyocyte viability in a solid three-dimensional matrix.

Background: The manufacture of full thickness three-dimensional myocardial grafts by means of tissue engineering is limited by the impeded cellular viability in unperfused in vitro systems. We introduce a novel concept of pulsatile tissue culture perfusion to promote ubiquitous cellular viability and metabolism.

Methods: In a novel bioreactor we established pulsatile flow through the embedded three-dimensional tissue culture.

[Ross procedure with combined replacement of the ascending aorta: impact on autograft root function and distensibility].

Background: The safety and effectiveness of combined aortic root autograft replacement in combination with ascending aorta replacement has been demonstrated recently. Replacement of the ascending aorta with a vascular prosthesis results in an increase in aortic root distension, and aortic root wall stress. In this study we aimed to assess the autograft root dimensions, distensibility, and autograft valve function in patients after Ross operation combined with replacement of the ascending aorta compared to patients who underwent Ross operation only.

Clinically established hemostatic scaffold (tissue fleece) as biomatrix in tissue- and organ-engineering research.

Various types of three-dimensional matrices have been used as basic scaffolds in myocardial tissue engineering. Many of those are limited by insufficient mechanical function, availability, or biocompatibility. We present a clinically established collagen scaffold for the development of bioartificial myocardial tissue.

Carboxyfluorescein diacetate succinimidyl ester facilitates cell tracing and colocalization studies in bioartificial organ engineering.

Background: We demonstrate a method that includes colocalization studies to analyze cell suspensions after isolation and to characterize 3-dimensional grafts consisting of cells and matrix in vitro and in vivo.

Materials And Methods: Neonatal rat cardiomyocytes were labelled by CFDA-SE after harvest. Cells in the isolated cell suspension, the embodied cells in the seeded scaffolds were characterized measuring features such as viability and distribution of the cell types.

Mechanical stretch regimen enhances the formation of bioengineered autologous cardiac muscle grafts.

Background: Surgical repair of congenital and acquired cardiac defects may be enhanced by the use of autologous bioengineered muscle grafts. These tissue-engineered constructs are not optimal in their formation and function. We hypothesized that a mechanical stretch regimen applied to human heart cells that were seeded on a three-dimensional gelatin scaffold (Gelfoam) would improve tissue formation and enhance graft strength.

A novel bioartificial myocardial tissue and its prospective use in cardiac surgery.

Background: Congenital heart defects such as atrial septal defect, ventricular septal defect, double outlet ventricles and the hypoplastic left heart syndrome as well as ischemic heart disease are associated with aplastic, defective or necrotic myocardial structures. In many of these instances patch closure, reconstruction of the defect or revascularization is required. We have developed a contractile bioartificial myocardial tissue, which offers new perspectives for various reconstructive surgical interventions, including congenital heart surgery.

Traveling after heart transplantation.

Background: With evolving medical techniques and post-operative care, the quality of life after cardiac transplantation is improving over the recent years. However, the need for continuous immunosuppressive therapy may result in restrictions from some social and recreational activities, including traveling. The aim of this study was to analyze traveling activities and complications in a large cohort of heart transplant recipients, with the intention to develop adequate safety and behavioral guidelines.

In vitro engineering of heart muscle: artificial myocardial tissue.

Introduction: Myocardial infarction followed by heart failure represents one of the major causes of morbidity and mortality, particularly in industrialized countries. Engineering and subsequent transplantation of contractile artificial myocardial tissue and, consequently, the replacement of ischemic and infarcted areas of the heart provides a potential therapeutic alternative to whole organ transplantation.

Methods: Artificial myocardial tissue samples were engineered by seeding neonatal rat cardiomyocytes with a commercially available 3-dimensional collagen matrix.