Microstructure of early embryonic aortic arch and its reversibility following mechanically altered hemodynamic load release.

In the embryonic heart, blood flow is distributed through a bilaterally paired artery system composed of the aortic arches (AAs). The purpose of this study is to establish an understanding of the governing mechanism of microstructural maturation of the AA matrix and its reversibility, toward the desired macroscopic vessel lumen diameter and thickness for healthy, abnormal, and in ovo repaired abnormal mechanical loading. While matrix-remodeling mechanisms were significantly different for normal versus conotruncal banding (CTB), both led to an increase in vessel lumen.

Asymmetry in Mechanosensitive Gene Expression during Aortic Arch Morphogenesis.

Embryonic aortic arches (AA) are initially bilaterally paired, transitional vessels and failures in remodeling based on hemodynamic and growth-related adaptations cause a spectrum of congenital heart disease (CHD) anatomies. Identifying regulatory mechanisms and cross-talk between the genetic elements of these vessels are critical to understand the ethiology of CHD and refine predictive computational models. This study aims to screen expression profiles of fundamental biological pathways in AA at early stages of chick embryo morphogenesis and correlate them with our current understanding of growth and mechanical loading.

Haemodynamic Recovery Properties of the Torsioned Testicular Artery Lumen.

Testicular artery torsion (twisting) is one such severe vascular condition that leads spermatic cord injury. In this study, we investigate the recovery response of a torsioned ram testicular artery in an isolated organ-culture flow loop with clinically relevant twisting modes (90°, 180°, 270° and 360° angles). Quantitative optical coherence tomography technique was employed to track changes in the lumen diameter, wall thickness and the three-dimensional shape of the vessel in the physiological pressure range (10-50 mmHg).

Time-Series Interactions of Gene Expression, Vascular Growth and Hemodynamics during Early Embryonic Arterial Development.

The role of hemodynamic forces within the embryo as biomechanical regulators for cardiovascular morphogenesis, growth, and remodeling is well supported through the experimental studies. Furthermore, clinical experience suggests that perturbed flow disrupts the normal vascular growth process as one etiology for congenital heart diseases (CHD) and for fetal adaptation to CHD. However, the relationships between hemodynamics, gene expression and embryonic vascular growth are poorly defined due to the lack of concurrent, sequential in vivo data.

Hemodynamic flow visualization of early embryonic great vessels using μPIV.

Microparticle image velocimetry (μPIV) is an evolving quantitative methodology to closely and accurately monitor the cardiac flow dynamics and mechanotransduction during vascular morphogenesis. While PIV technique has a long history, contemporary developments in advanced microscopy have significantly expanded its power. This chapter includes three new methods for μPIV acquisition in selected embryonic structures achieved through advanced optical imaging: (1) high-speed confocal scanning of transgenic zebrafish embryos, where the transgenic erythrocytes act as the tracing particles; (2) microinjection of artificial seeding particles in chick embryos visualized with stereomicroscopy; and (3) real-time, time-resolved optical coherence tomography acquisition of vitelline vessel flow profiles in chick embryos, tracking the erythrocytes.

Decellularization method influences early remodeling of an allogenic tissue scaffold.

Extracellular matrix-based biomaterials are currently pursued as an alternative to autologous transplants for the treatment of gingival recession and periodontal disease. These grafts offer improved tissue regeneration without the need for a second operative procedure used in current treatments to remove nonresorbable synthetic biomaterials. However, while decellularization is necessary to minimize the potential immunological impact, it can significantly modify the materials architectural and biochemical properties.

Biomechanical behavior of oral soft tissues.

Background: Little attention has been given to understanding the variation in biomechanical behavior of oral soft tissues, and this represents an obstacle for the development of biomaterials that perform with appropriate biomechanical characteristics. With this as our motivation, a uniaxial mechanical analysis was performed on lingual and buccal aspects of the attached gingiva, alveolar mucosa, and buccal mucosa to gain insight into human tissue performance and site-specific mechanical variation.

Methods: A discrete quantitative mechanical evaluation of each soft tissue region using tensile, dynamic compression, and stress relaxation analysis was conducted to correlate tissue structure with function as assessed histologically.

Cellular interactions and biomechanical properties of a unique vascular-derived scaffold for periodontal tissue regeneration.

These investigations describe the development of a novel ex vivo three-dimensional scaffold derived from the human umbilical vein (HUV), and its potential as a regenerative matrix for tissue regeneration. Unique properties associated with the vascular wall have shown potential to function as a surgical barrier for guided tissue regeneration, particularly with the regeneration of periodontal tissues. HUV was isolated from umbilical cords using a semiautomated machining technology, decellularized using 1% sodium dodecyl sulfate, and then opened longitudinally to form tissue sheets.