Vascular Prostheses: Performance Related to Cell-Shear Responses

Preparation and characterization of NaOH treated micro-fibrous polyethylene terephthalate nonwovens for biomedical application

“…Polyethylene terephthalate (PET) fibrous matrices have found a wide variety of applications in different areas, including biotechnology and biomedical (Andrews et al, 2008;Ng et al, 2009). The special intrinsic properties of PET as well as its relatively low cost count for the commercial importance of this polyester.…”

“…This can be applied for surface functionalization of nonwoven fibrous matrices of PET for various purposes including biomedical applications (Basu and Yang, 2005;Inoue et al, 2009). For example, biomolecules can be covalently grafted onto the PET surface via surface functional groups to stimulate a strong cell attachment and also prevent cell loss under shear stress (Andrews et al, 2008). Even, NaOH treatment alone have shown to increase cell adhesion due to increased roughness of the PET fibers (Ng et al, 2009).…”

Tubular bioreactor models that include Onsager–Curie scalar cross-phenomena to describe stress-dependent rates of cell proliferation

“…Poisson's ratio is less than or equal to 0.5 for all materials, indicative of either volume increase or no volume change, respectively, in response to tensile stress. There are practical examples where tensile stress stimulates the growth of muscle cells [17], compressive stress stimulates the growth of bone cells [18,19], and shear accelerates the proliferation of endothelial cells [6]. These effects can be summarized by the change in system volume due to tension, compression, or shear, via the contribution from Poisson's ratio (i.e., 1-2υ), except when systems are truly incompressible such that υ = 1/2.…”

“…Curie's theorem predicts that scalar rates of production of the mass of species i due to chemical reaction should be coupled to the velocity gradient tensor, but this coupling is typically discarded based on physical rather than mathematical arguments [2], even though experiments have not been designed to investigate this unusual coupling [1]. If Curie's theorem is interpreted rigorously, then it becomes possible to describe quantitatively how velocity gradients at the cell/aqueous-medium interface influence the scalar rate of nutrient consumption (via the magnitude of the velocity gradient tensor), because there is a connection between nutrient consumption and anchorage-dependent (i.e., endothelial) cell proliferation, where the latter is stimulated by viscous shear [6]. This phenomenon is not simply described by larger nutrient flux toward the wall at higher shear rates via reduction in the mass transfer boundary layer thickness external to adsorbed cells on the tube wall, because convective enhancement of molecular fluxes is not considered in Curie's theorem [3].…”

Development of an In-Vitro Tissue Engineered Blood Vessel Mimic Using Human Large Vessel Cell Sources

“…Although examples of work using HUVEC and ePTFE exist throughout the literature [38,46,66,67], albeit none using HUVECs on tubular ePTFE scaffolds, it was important that an experiment be conducted specifically at the Cal Poly laboratory to ensure that our lab group and lab facilities could successfully culture, sod, and sustain HUVECs within our in-vitro BVM model. Thus, the goal of Study 5 was to establish whether HUVECs could be pressure-sodded onto ePTFE and to determine an initial sodding density that would create a confluent layer of endothelial cells that could potentially be sodded onto a SMC layer.…”