assessment of vascular injury following stent retriever retraction in clinically-relevant endothelialized silicone models.

Mechanical thrombectomy devices have potential to injure the vessel during treatment of acute ischemic stroke. The goal of the current work was to tailor in vitro endothelialized silicone models for stent retriever assessment and to evaluate endothelial injury following treatment by various stent retriever designs and sizes. Clinically-relevant neurovascular geometries were first modeled out of silicone, then sterilized, coated with fibronectin, placed in bioreactors, seeded with human endothelial cells, and cultivated under flow.

Evaluation of vessel injury after simulated catheter use in an endothelialized silicone model of the intracranial arteries.

Purpose: Neurothrombectomy catheters can disrupt or injure the vessel wall. This potential injury is often studied in animal or cadaver models, but prior work suggests that endothelialized silicone models may be an option for early in vitro assessment. The purpose of this work was to create a complex, clinically-relevant endothelialized neurovascular silicone model, and to determine the utility of the model for evaluating vessel injury due to catheter simulated use.

SIMPoly: A Matlab-Based Image Analysis Tool to Measure Electrospun Polymer Scaffold Fiber Diameter.

Quantifying fiber diameter is important for characterizing electrospun polymer scaffolds. Many researchers use manual measurement methods, which can be time-consuming and variable. Semi-automated tools exist, but there is room for improvement.

Cellular responses to flow diverters in a tissue-engineered aneurysm model.

Background: Notwithstanding the widespread implementation of flow diverters (FDs) in the treatment of intracranial aneurysms, the exact mechanism of action of these devices remains elusive. We aimed to advance the understanding of cellular responses to FD implantation using a 3D tissue-engineered in vitro aneurysm model.

Methods: Aneurysm-like blood vessel mimics (aBVMs) were constructed by electrospinning polycaprolactone nanofibers onto desired aneurysm-like geometries.

Endothelialized silicone aneurysm models for in vitro evaluation of flow diverters.

Objective: The goal of this work was to endothelialize silicone aneurysm tubes for use as in vitro models for evaluating endothelial cell interactions with neurovascular devices. The first objective was to establish consistent and confluent endothelial cell linings and to evaluate the silicone vessels over time. The second objective was to use these silicone vessels for flow diverter implantation and assessment.

Custom tissue engineered aneurysm models with varying neck size and height for early stage in vitro testing of flow diverters.

Endovascular techniques for treating cerebral aneurysms are rapidly advancing and require testing to optimize device configurations. The purpose of this work was to customize tissue-engineered aneurysm "blood vessel mimics" (aBVMs) for early stage in vitro assessment of vascular cell responses to flow diverters and other devices. Aneurysm scaffolds with varying neck size and height were created through solid modeling, mold fabrication, mandrel creation, and electrospinning.

Tissue-engineered blood vessel mimics in complex geometries for intravascular device testing.

Objective: Intravascular stents are commonly used to treat occluded arteries during coronary heart disease. After coronary stent implantation, endothelial cells grow over the stent, which is referred to as re-endothelialization. Re-endothelialization prevents blood from clotting on the stent surface and is a good predictor of stent success.

Tissue-engineered aneurysm models for in vitro assessment of neurovascular devices.

Purpose: Preclinical testing of neurovascular devices is crucial for successful device design and is commonly performed using in vivo organisms such as the rabbit elastase-induced aneurysm model; however, simple in vitro models may help further refine this testing paradigm. The purpose of the current work was to evaluate, and further develop, tissue-engineered blood vessel mimics (BVMs) as simple, early-stage models to assess neurovascular devices in vitro prior to animal or clinical use.

Methods: The first part of this work used standard straight-vessel BVMs to evaluate flow diverters at 1, 3, and 5 days post-deployment.

Thinking inside the box: keeping tissue-engineered constructs in vitro for use as preclinical models.

Tissue engineers have made great strides toward the creation of living tissue replacements for a wide range of tissue types and applications, with eventual patient implantation as the primary goal. However, an alternate use of tissue-engineered constructs exists: as in vitro preclinical models for purposes such as drug screening and device testing. Tissue-engineered preclinical models have numerous potential advantages over existing models, including cultivation in three-dimensional geometries, decreased cost, increased reproducibility, precise control over cultivation conditions, and the incorporation of human cells.

Assessment of the intimal response to a protein-modified stent in a tissue-engineered blood vessel mimic.

Protein-coated intravascular stents have emerged as potential pro-healing modifications for or alternatives to anti-proliferative drug-eluting stents. To support the development of these devices, preclinical testing is required to evaluate the intimal response to new coatings and modifications. The purpose of this work was to implement a tissue-engineered blood vessel as an in vitro testing system to evaluate extracellular matrix-modified stents with regard to endothelialization of the stent surface.

An automatic algorithm for detecting stent endothelialization from volumetric optical coherence tomography datasets.

Recent research has suggested that endothelialization of vascular stents is crucial to reducing the risk of late stent thrombosis. With a resolution of approximately 10 microm, optical coherence tomography (OCT) may be an appropriate imaging modality for visualizing the vascular response to a stent and measuring the percentage of struts covered with an anti-thrombogenic cellular lining. We developed an image analysis program to locate covered and uncovered stent struts in OCT images of tissue-engineered blood vessels.

Tissue-engineered vascular grafts as in vitro blood vessel mimics for the evaluation of endothelialization of intravascular devices.

The accelerating use of minimally invasive procedures for the treatment of cardiovascular disease, and the commensurate development of intravascular devices such as stents, has lead to a high demand for preclinical assessment techniques. A 3-dimensional in vitro blood vessel mimic (BVM) would be ideal for device testing before animal or clinical studies. This is possible based on current capabilities for the creation of tissue-engineered vascular grafts (TEVGs).