A tissue‐engineered aneurysm model for evaluation of endovascular devices

Abstract

Endovascular stent grafts used for treatment of arterial aneurysms require preclinical testing for investigation of biological responses following implantation. The preclinical evaluation process related to the safety and efficacy of these devices is limited by the absence of an in vitro aneurysmal blood vessel equivalent capable of providing high-throughput, cost-effective assessments. With this in mind, the focus of this work was to develop an aneurysm model consisting of human blood vessel cells. To create aneurysmal scaffolds, expanded polytetrafluoroethylene vascular grafts were dilated utilizing an angioplasty balloon. Stromal vascular fraction cells isolated from human adipose tissue were integrated with the scaffolds, and luminal flow of nutrient medium was executed for 14 days in a vascular bioreactor. Following bioreactor perfusion, histology verified that a neointimal lining of human tissue had formed. Immunohistochemistry and scanning electron microscopy revealed a flow-contacting layer of smooth muscle cells, characterizing the model as a representation of neointimal formation in an injured or diseased vessel. This study has demonstrated the engineering of a vascular construct containing an aneurysmal dilation. A tissue-engineered aneurysm model could provide an alternative to current nonbiological in vitro aneurysm models and serve as a practical tool in the progression of new devices toward in vivo studies.

Exploring smooth muscle phenotype and function in a bioreactor model of abdominal aortic aneurysm

“…An in vivo porcine model of infrarenal aneurysm has been investigated [17], and porcine carotid arteries have previously been used ex vivo in a bioreactor to study the effect of stent implantation [18]. More recently, an in vitro bioreactor model of aneurysm has been described [19] in which PTFE grafts were firstly dilated with a balloon catheter and subsequently seeded with human SMC which over 14 days formed a full “neointima” over the dilated vessel.…”

Ethical Issues in the Use of Animal Models for Tissue Engineering: Reflections on Legal Aspects, Moral Theory, Three Rs Strategies, and Harm–Benefit Analysis

“…For this purpose, there are already studies showing the feasibility of TEBVs as an evaluation method for endovascular devices. [95][96][97][98] Two promising novel technologies add even more potential to the use of TE as an alternative to animal experimentation: three-dimensional bioprinting and organ-ona-chip. Bioprinting is a process that aims to deposit cells suspended in polymeric hydrogels onto a substrate, in a layer-by-layer manner, to build three-dimensional constructs analogous to tissues or organs.…”

Biodegradation evaluation of poly (lactic acid) for stent application: Role of mechanical tension and temperature

“…Study on stent materials can be conducted through in vitro and in vivo models. While animal models provide a complete biological environment, they are expensive and time consuming and this is difficult to perform studies with a high number of individuals 23,24 . In this case, bioreactors are widely used to represent a native surrounding and make it possible to observe and determine the influence of physiochemical environment 25 .…”