Proc Math Phys Eng Sci
June 2021
As the complexity and heterogeneity of a system grows, the challenge of specifying, documenting and synthesizing correct, machine-readable designs increases dramatically. Separation of the system into manageable parts is needed to support analysis at various levels of granularity so that the system is maintainable and adaptable over its life cycle. In this paper, we argue that operads provide an effective knowledge representation to address these challenges.
View Article and Find Full Text PDFDrug-eluting stents (DESs) are endovascular devices that provide controlled release of compounds to interfere with restenosis, an adverse outcome of angioplasty characterized by thickening of the arterial wall. Accumulating evidence suggests that arterial pharmacokinetics determine the biological effect and potential toxicity of stent-based therapeutics. The aim of this study was to examine how drug polarity, drug load, and protein binding influence release from a polymer film and distribution within arterial tissue.
View Article and Find Full Text PDFLate-term thrombosis associated with drug-eluting stents may be due to the non-selective actions of antimitogenic drugs on endothelial cells, leading to delayed vascular healing after stenting angioplasty. Currently, there is a need for stent-based therapies that can both attenuate neointimal hyperplasia and promote re-endothelialization. The aim of this study was to compare the effects of a resveratrol (R)- and quercetin (Q)-eluting stent with that of a bare metal stent (BMS) on neointimal hyperplasia and re-endothelialization in a rat model of arterial angioplasty and stenting.
View Article and Find Full Text PDFObjective: To expedite the investigation of new devices for inhibiting restenosis, we aimed to develop a modified model of arterial angioplasty and stenting in rats that showed greater face validity than the traditional rat model.
Methods: Carotid arteries from Sprague-Dawley rats fed a normal or an atherogenic diet containing a low dose of cholate underwent balloon pre-dilation followed by placement of a bare metal stent. Vessel patency was followed for 28d using ultrasound.
J Biomed Mater Res B Appl Biomater
November 2011
This study describes the development and evaluation of novel polymer films that provide controlled release of two vascular-protective polyphenols for endovascular devices. Resveratrol (RESV) and quercetin (QUER) have antimigratory and antiproliferative actions on vascular smooth muscle cells (VSMCs), inhibit both platelet and inflammatory cell activation, and promote endothelial cell function. Our aim is to develop and characterize coatings that release these drugs within a therapeutic range.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
April 2010
The ElectroNanospray process (Nanocopoeia, Inc) transforms drugs and polymers into many nanoscale material states including powders, liquids, encapsulated particles, and coatings. This enabling technology platform allows application of polymers and drugs to the surface of medical devices such as coronary stents in a single-stage process. Modification of ElectroNanospray process parameters resulted in surface coatings with rich morphologies ranging in appearance from smooth and heterogeneous to highly porous and rough (open matrix).
View Article and Find Full Text PDFDrug release from therapeutic biomedical films such as drug-polymer composite coatings on drug eluting stents is a highly complex and poorly understood process. The dynamics of drug release and the evolution of surface morphology during release have direct impact on the performance of the device. This information is not easily accessible, and there have been few systematic studies to investigate drug release from biomedical coatings in real time.
View Article and Find Full Text PDFWe have previously shown that trophic factor supplementation (TFS) of University of Wisconsin (UW) solution reduced early apoptotic changes in vascular endothelial cells. Here, we examine the effect of TFS on cell signaling pathways related to cell growth, differentiation, and apoptosis after cold ischemic storage. In this study, the effect of TFS on the phosphorylation of signaling molecules ERK (extracellular regulated-signaling kinase) 1/2 and p38 MAPK (mitogen activated protein kinases) and of HO-1 (hemeoxygenase-1), relative to changes seen in unmodified UW solution, were determined by Western blot in cells stored under cold ischemic conditions.
View Article and Find Full Text PDFWe have previously shown that trophic factor supplementation (TFS) of University of Wisconsin (UW) solution enhanced kidney viability after cold storage. Here, we use an in vitro model to study the effect of TFS on early apoptotic changes after cold ischemic storage. Mitochondrial membrane potential was determined by fluorescence intensity in primary canine kidney tubule cells, Madin-Darby canine kidney cells, and human umbilical vein endothelial cells.
View Article and Find Full Text PDFSubstance use by adolescents and young adults continues to be a serious problem. Marijuana remains the most commonly used illicit substance with close to 50% of high school seniors admitting use at some time. Each year 2.
View Article and Find Full Text PDFWe have previously shown that human corneal epithelial cells sense and react to nanoscale substrate topographic stimuli [Teixeira AI, Abrams GA, Bertics PJ, Murphy CJ, Nealey PF. Epithelial contact guidance on well-defined micro- and nanostructured substrates. J Cell Sci 2003;116(10):1881-92; Karuri NW, Liliensiek S, Teixeira AI, Abrams G, Campbell S, Nealey PF, et al.
View Article and Find Full Text PDFUnderstanding axonal formation and contact guidance are of critical importance for the design of materials that interface with neuronal tissue. Contact guidance of neurites by topographic features is well known, but the role that topography plays in the modulation of neuritogenesis has not been addressed. To test this, we cultured PC12 cells with a range of nerve growth factor (NGF) concentrations on surfaces with ridge widths ranging from 70 to 1900 nm.
View Article and Find Full Text PDFBackground: Cold ischemic injury plays an important role in short- and long-term function of kidneys after transplant. Antimicrobial peptides have not previously been studied for their impact on cold ischemia in transplanted kidneys.
Methods: Bactenecin (L- and D-forms) was added to University of Wisconsin (UW) preservation solution for 3-day cold storage of dog kidneys.
Lens fiber cell differentiation involves extensive reconstruction of the cell's architecture, including the degradation and elimination of all membrane-bound organelles via a process that has been likened to apoptosis. Using caspase reporter assays under conditions in which nonspecific cleavage of the reporter peptides by the proteasome has been inhibited, we investigated whether any specific caspase activities are temporally correlated with this process of organelle loss. Extracts from neonatal mouse lenses contained strong VEID-7-amino-4-trifluoromethylcoumarin (AFC) and minor IETD-AFC and LEVD-AFC cleavage activities, but no DEVD-AFC cleavage activity.
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