ECM-Based Materials in Cardiovascular Applications: Inherent Healing Potential and Augmentation of Native Regenerative Processes

Abstract

The in vivo healing process of vascular grafts involves the interaction of many contributing factors. The ability of vascular grafts to provide an environment which allows successful accomplishment of this process is extremely difficult. Poor endothelisation, inflammation, infection, occlusion, thrombosis, hyperplasia and pseudoaneurysms are common issues with synthetic grafts in vivo. Advanced materials composed of decellularised extracellular matrices (ECM) have been shown to promote the healing process via modulation of the host immune response, resistance to bacterial infections, allowing re-innervation and reestablishing homeostasis in the healing region. The physiological balance within the newly developed vascular tissue is maintained via the recreation of correct biorheology and mechanotransduction factors including host immune response, infection control, homing and the attraction of progenitor cells and infiltration by host tissue. Here, we review the progress in this tissue engineering approach, the enhancement potential of ECM materials and future prospects to reach the clinical environment.

Leveraging “Raw Materials” as Building Blocks and Bioactive Signals in Regenerative Medicine

“…Healos FX Ò , Collapat II Ò , and Biostite Ò are collagen type Ibased medical products used clinically for various applications. 136 However, most attribute the failure of many other tissue engineering strategies to lie in the distinction between medical devices and combination products, respectively. 176,177 Combination products often employ the use of biologics-cells, drugs, or growth factors-and must be proven in animal studies and a series of three clinical trials, likely spanning over 8 years before approval.…”

“…132,135 Studies have shown that SIS contains over 90% collagen by dry weight, with a majority being collagen type I. 136 Depending on the type of decellularization method used, SIS can maintain GAGs and growth factors present in the native tissue. 132,135 In addition to these native ECM molecules, the collagen fiber orientation that is maintained after the decell process has also attracted attention.…”

Tissue-Engineered Extracellular Matrices (ECMs) as Adjuvant Scaffolds for Endovascular Aneurysmal Repair (EVAR)

“…These interleukins promote graft acceptance and prevent the activation of neighbouring inflammatory macrophages (Bach et al 1997, Chen andField 1995) . Activation of the Th2 pathway also promotes effective tissue remodelling, structural repair and functional recovery of the injured tissue after graft acceptance (Piterina AV 2009). Undoubtedly, activation of this humoral response is encouraging as activation of the alternate lymphocytic pathway (i.e.…”

Vascular replacement using a layered elastin-collagen vascular graft in a porcine model: one week patency versus one month occlusion

“…5 As a result, research has turned to the field of regenerative medicine including the application of natural molecules. 6 The main components of the native vascular wall include the extracellular matrix proteins elastin and type I collagen, which supply elasticity and strength, respectively. Elastic fibers are prominently present in arteries to facilitate blood flow and propagation of pressure waves.…”