Glycosaminoglycans: From Vascular Physiology to Tissue Engineering Applications

Abstract

Cardiovascular diseases represent the number one cause of death globally, with atherosclerosis a major contributor. Despite the clinical need for functional arterial substitutes, success has been limited to arterial replacements of large-caliber vessels (diameter > 6 mm), leaving the bulk of demand unmet. In this respect, one of the most challenging goals in tissue engineering is to design a “bioactive” resorbable scaffold, analogous to the natural extracellular matrix (ECM), able to guide the process of vascular tissue regeneration. Besides adequate mechanical properties to sustain the hemodynamic flow forces, scaffold’s properties should include biocompatibility, controlled biodegradability with non-toxic products, low inflammatory/thrombotic potential, porosity, and a specific combination of molecular signals allowing vascular cells to attach, proliferate and synthesize their own ECM. Different fabrication methods, such as phase separation, self-assembly and electrospinning are currently used to obtain nanofibrous scaffolds with a well-organized architecture and mechanical properties suitable for vascular tissue regeneration. However, several studies have shown that naked scaffolds, although fabricated with biocompatible polymers, represent a poor substrate to be populated by vascular cells. In this respect, surface functionalization with bioactive natural molecules, such as collagen, elastin, fibrinogen, silk fibroin, alginate, chitosan, dextran, glycosaminoglycans (GAGs), and growth factors has proven to be effective. GAGs are complex anionic unbranched heteropolysaccharides that represent major structural and functional ECM components of connective tissues. GAGs are very heterogeneous in terms of type of repeating disaccharide unit, relative molecular mass, charge density, degree and pattern of sulfation, degree of epimerization and physicochemical properties. These molecules participate in a number of vascular events such as the regulation of vascular permeability, lipid metabolism, hemostasis, and thrombosis, but also interact with vascular cells, growth factors, and cytokines to modulate cell adhesion, migration, and proliferation. The primary goal of this review is to perform a critical analysis of the last twenty-years of literature in which GAGs have been used as molecular cues, able to guide the processes leading to correct endothelialization and neo-artery formation, as well as to provide readers with an overall picture of their potential as functional molecules for small-diameter vascular regeneration.

Decellularization of Porcine Carotid Arteries: From the Vessel to the High-Quality Scaffold in Five Hours

“…Regarding the importance of GAGs for cytokine and growth factor retention in vessels [reviewed in ( Lepedda et al, 2021 )], we also included GAG staining in our study. We showed that native arteries have a high content in tunica media, while, basically, no GAGs are present in the adventitia.…”

Biomimetic natural biomaterials for tissue engineering and regenerative medicine: new biosynthesis methods, recent advances, and emerging applications

“…In another study, Hong et al [ 275 ] confirmed the capability of decellularized brain tissue hydrogel to promote the repair of spinal cord injury. Further studies of decellularized tissue hydrogels from dermal [ 276 ], bone [ 277 ], and blood vessels [ 278 ] indicate this strategy is suitable for regenerating various tissue types.…”

Sweet but Challenging: Tackling the Complexity of GAGs with Engineered Tailor‐Made Biomaterials

“…Vascular reconstruction [ 49,102–117 ] – SDF‐1α, [ 103,104 ] VEGF, [ 102,108–114 ] FGF2, [ 115,116 ] Shh+IL‐10 [ 117 ]…”