Elastic Fiber Matrices: Biomimetic Approaches to Regeneration and Repair

Abstract

Elastin is a physiologically important protein, present in the extracellular matrix (ECM) and found in a wide range of vital tissues, such arteries, pelvic floor tissues, dermis, etc, to meet its primary mechanical and biological tissue-specific functions. In fact, it provides tissue elasticity and mediates cell proliferation, morphology, migration, and chemo taxis for diverse range of cells. Moreover,
while the elastin deposition occurs during embryonic and childhood stages with a half-life of 74 years, its biosynthesis is a highly controlled, coordinated, multicomponent, and multistep hierarchical process. This process includes the intercellular synthesis of soluble tropoelastic monomers, their extracellular release, aggregation via coacervation, and deposition onto microfibrillar scaffolds, to facilitate tropoelastin cross linking and mature fiber formation. Microfibrils consist of fibrillins, large modular glycoproteins that, having a remarkable high cysteine content, provide long-range elasticity to dynamic connective tissues, regulating also the growth factor signalling, by specific cellsurface receptors. Elastin is, therefore, not only a structural protein influencing the architecture and
biomechanical properties of ECM, but it plays also an important role in various physiological processes. At this purpose, various biological and environmental factors, such as aging, injuries, genetic defects, inflammation, UV exposure, and cigarette smoking, negatively impact the cross-linked elastin matrix, resulting in degradation of the tissue with a loss of elastic fibers. Thus the necessity and modality to repair, replace, and regenerate elastin, have to be currently investigated through different approaches.