quantifying-inferior-vena-cava-compliance-distensibility-an-vivo

Quantifying Inferior Vena Cava Compliance and Distensibility in an <i>In Vivo</i> Ovine Model Using 3D Angiography

Synthetic vascular grafts overcome some challenges of allografts, autografts, and xenografts but are often more rigid and less compliant than the native ...

wireless-telemetry-device-implantation-fontan-ovine-model-for

Wireless Telemetry Device Implantation in a Fontan Ovine Model for Continuous and Long-Term Hemodynamic Monitoring

While the Fontan procedure drastically improves life expectancy for patients with single ventricle, it is well recognized that the resulting circulation ...

Nationwide Children's Hospital

Abigail Wexner Research Institute at Nationwide Children's Hospital

Tissue engineering has paved the way for the development of artificial human cardiac muscle patches (hCMPs) and cardiac tissue analogs, especially for treating Myocardial infarction (MI), often by increasing its regenerative abilities. Low engraftment rates, insufficient clinical application scalability, and the creation of a functional vascular system remain obstacles to hCMP implementation in clinical settings. This paper will address some of these challenges, present a broad variety of heart cell types and sources that can be applied to hCMP biomanufacturing, and describe some new innovative methods for engineering such treatments. It is also important to note the injection/transplantation of cells in cardiac tissue engineering.

Advances in Cardiac Tissue Engineering.

As the number of arteriosclerotic diseases continues to increase, much improvement is still needed with treatments for cardiovascular diseases. This is mainly due to the limitations of currently existing treatment options, including the limited number of donor organs available or the long-term durability of the artificial organs. Therefore, tissue engineering has attracted significant attention as a tissue regeneration therapy in this area. Porous scaffolds are one of the effective methods for tissue engineering. However, it could be better, and its effectiveness varies depending on the tissue application. This paper will address the challenges presented by various materials and their combinations. We will also describe some of the latest methods for tissue engineering.

The Application of Porous Scaffolds for Cardiovascular Tissues.

Hydrogels are being investigated for their application in inducing the regeneration of various tissues, and suitable conditions for each tissue are becoming more apparent. Conditions such as the mechanical properties, degradation period, degradation mechanism, and cell affinity can be tailored by changing the molecular structure, especially in the case of polymers. Furthermore, many high-functional hydrogels with drug delivery systems (DDSs), in which drugs or bioactive substances are contained in controlled hydrogels, have been reported. This review focuses on the molecular design and function of biopolymer-based hydrogels and introduces recent developments in functional hydrogels for clinical applications.

Recent Developments in Biopolymer-Based Hydrogels for Tissue Engineering Applications.

Inducing tissue regeneration in many skin defects, such as large traumatic wounds, burns, other physicochemical wounds, bedsores, and chronic diabetic ulcers, has become an important clinical issue in recent years. Cultured cell sheets and scaffolds containing growth factors are already in use but have yet to restore normal skin tissue structure and function. Many tissue engineering materials that focus on the regeneration process of living tissues have been developed for the more versatile and rapid initiation of treatment. Since the discovery that cells recognize the chemical-physical properties of their surrounding environment, there has been a great deal of work on mimicking the composition of the extracellular matrix (ECM) and its three-dimensional network structure. Approaches have used ECM constituent proteins as well as morphological processing methods, such as fiber sheets, sponges, and meshes. This review summarizes material design strategies in tissue engineering fields, ranging from the morphology of existing dressings and ECM structures to cellular-level microstructure mimicry, and explores directions for future approaches to precision skin tissue regeneration.

Recent Tissue Engineering Approaches to Mimicking the Extracellular Matrix Structure for Skin Regeneration.

Advancements in congenital heart surgery have heightened the importance of durable biomaterials for adult survivors. Dystrophic calcification poses a significant risk to the long-term viability of prosthetic biomaterials in these procedures. Herein, we describe the natural history of calcification in the most frequently used vascular conduits, expanded polytetrafluoroethylene grafts. Through a retrospective clinical study and an ovine model, we compare the degree of calcification between tissue-engineered vascular grafts and polytetrafluoroethylene grafts. Results indicate superior durability in tissue-engineered vascular grafts, displaying reduced late-term calcification in both clinical studies (p < 0.001) and animal models (p < 0.0001). Further assessments of graft compliance reveal that tissue-engineered vascular grafts maintain greater compliance (p < 0.0001) and distensibility (p < 0.001) than polytetrafluoroethylene grafts. These properties improve graft hemodynamic performance, as validated through computational fluid dynamics simulations. We demonstrate the promise of tissue engineered vascular grafts, remaining compliant and distensible while resisting long-term calcification, to enhance the long-term success of congenital heart surgeries.

Tissue engineered vascular grafts are resistant to the formation of dystrophic calcification.

Dorset sheep (Ovis aries) are common models in translational cardiovascular research due to physiologic and anatomic similarities to humans. While employing ovine subjects to study single-ventricle physiology, we repeatedly observed position-based changes in central venous pressure (CVP) which could not be explained by hydrostatic (gravitational) effects. Inferior vena cava (IVC) narrowing or compression has been demonstrated in numerous species, and we hypothesised that this phenomenon might explain our observations in O. aries. This study aimed to characterise position-dependent morphology of the IVC in O. aries using catheter-based hemodynamic and dimensional measurements, three-dimensional MRI reconstruction and histological analysis. Baseline measurements revealed a significant reduction in IVC dimensions at the level of the diaphragm (dVC) compared to the abdominal vena cava (aVC) and thoracic vena cava (tVC). We also observed a transdiaphragmatic pressure gradient along the IVC, with higher pressures in the aVC compared to the tVC. We found that variation of position and fluid status altered IVC haemodynamics. Histological data showed variable muscularity along the length of the IVC, with greater smooth muscle content in the aVC than the tVC. These findings will improve understanding of baseline ovine physiology, help refine experimental protocols and facilitate the translation of findings to the clinic.

Dynamic Narrowing of the Diaphragmatic Vena Cava in Ovis aries.

Our goal was to conduct a hemodynamic analysis of a novel animal model of Fontan physiology. Poor late-term outcomes in Fontan patients are believed to arise from Fontan-induced hemodynamics, but the mechanisms remain poorly understood. Recent advances in surgical experimentation have resulted in the development of a chronic sheep model of Fontan physiology; however, detailed analysis of this model is lacking.

Article Total : 2	Year
Publication title	2024
Publication title	2025

Article	Year
Advances in Cardiac Tissue Engineering. Bioengineering (Basel, Switzerland)\| PubMed ID: 36421097	2022
The Application of Porous Scaffolds for Cardiovascular Tissues. Bioengineering (Basel, Switzerland)\| PubMed ID: 36829730	2023
Recent Developments in Biopolymer-Based Hydrogels for Tissue Engineering Applications. Biomolecules\| PubMed ID: 36830649	2023
Recent Tissue Engineering Approaches to Mimicking the Extracellular Matrix Structure for Skin Regeneration. Biomimetics (Basel, Switzerland)\| PubMed ID: 36975360	2023
Tissue engineered vascular grafts are resistant to the formation of dystrophic calcification. Nature communications\| PubMed ID: 38467617	2024
Dynamic Narrowing of the Diaphragmatic Vena Cava in Ovis aries. Anatomia, histologia, embryologia\| PubMed ID: 39403062	2024
Investigation of a chronic single-stage sheep Fontan model. JTCVS open\| PubMed ID: 39534321	2024

Tatsuya Watanabe

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