Atherosclerosis models with cell-mediated calcification

Abstract

This protocol describes a novel chronic total occlusion (CTO) model that features cell-mediated calcium deposits in rabbit femoral arteries. CTO is the most severe case of atherosclerosis, and it remains a big challenge in cardiology. There are urgent needs to establish a CTO animal model in order to develop new devices and drugs. The purpose of this protocol is to provide such a platform for advancing the treatment of CTOs. Our CTO model features the following four prominent characteristics of a clinical calcified atherosclerosis: (1) The occlusion site occurs gradually. (2) Calcium deposits are mediated by cells and they progress over time. (3) Acute and chronic inflammation at occlusion sites. (4) Recanalization (new vessel formation) at occlusion sites. These facts indicate that our model bears great similarities to clinical CTO disease. The strategy we apply here is to implant tissue-engineering scaffolds into rabbit femoral arteries and induce the cells on scaffolds to deposit calcium themselves. In this chapter, we first describe a detailed protocol of scaffold fabrication, growth factor coating on scaffolds, and the initiation of cellular calcification. We then provide easy-to-follow steps to implant cellular constructs into animal arteries using interventional techniques. Finally, we describe the methods to detect calcium in CTOs and the staining approaches to identify other pathological characteristics at the occlusion sites. Additionally, we provide notes to highlight the critical steps in order to successfully carry out this protocol. An animal CTO model generated by the above techniques will provide a useful platform to develop new devices and test novel drugs for treatment of the most severe case of atherosclerotic calcification. © 2012 Springer Science+Business Media, LLC.