Variation in Cardiac Pulse Frequencies Modulates vSMC Phenotype Switching During Vascular Remodeling.

In vitro perfusion systems have exposed vascular constructs to mechanical conditions that emulate physiological pulse pressure and found significant improvements in graft development. However, current models maintain constant, or set pulse/shear mechanics that do not account for the natural temporal variation in frequency. With an aim to develop clinically relevant small diameter vascular grafts, these investigations detail a perfusion culture model that incorporates temporal pulse pressure variation.

Improved recellularization of ex vivo vascular scaffolds using directed transport gradients to modulate ECM remodeling.

The regeneration of functional, clinically viable, tissues from acellular ex vivo tissues has been problematic largely due to poor nutrient transport conditions that limit cell migration and integration. Compounding these issues are subcellular pore sizes that necessarily requires extracellular matrix (ECM) remodeling in order for cells to migrate and regenerate the tissue. The aim of the present work was to create a directed growth environment that allows cells to fully populate an ex vivo-derived vascular scaffold and maintain viability over extended periods.

The influence of early-phase remodeling events on the biomechanical properties of engineered vascular tissues.

Objectives: During the last decade, the use of ex vivo-derived materials designed as implant scaffolds has increased significantly. This is particularly so in the area of regenerative medicine, or tissue engineering, where the natural chemical and biomechanical properties have been shown to be advantageous. By focusing on detailed events that occur during early-phase remodeling processes, our objective was to detail progressive changes in graft biomechanics to further our understanding of these processes.

Inverted human umbilical arteries with tunable wall thicknesses for nerve regeneration.

Tubular nerve guides have shown a potential to bridge nerve defects, by directing neuronal elongation, localizing growth factors, and inhibiting fibrotic cellular ingrowth. These investigations describe a novel acellular scaffold derived from the human umbilical cord artery that aims to enhance nerve regeneration by presenting a unique mechanical and chemical environment to the damaged nerve ends. A rapid, semiautomated dissection technique is described that isolates the human umbilical artery (HUA) from the umbilical cord, after which the vessel is decellularized using sodium dodecyl sulfate (SDS).