Enhanced therapeutic neovascularization by CD31-expressing cells and embryonic stem cell-derived endothelial cells engineered with chitosan hydrogel containing VEGF-releasing microtubes

Abstract

Various stem cells and their progeny have been used therapeutically for vascular regeneration. One of the major hurdles for cell-based therapy is low cell retention in vivo, and to improve cell survival several biomaterials have been used to encapsulate cells before transplantation. Vascular regeneration involves new blood vessel formation which consists of two processes, vasculogenesis and angiogenesis. While embryonic stem cell (ESC)-derived endothelial cells (ESC-ECs) have clearer vasculogenic potency, adult cells exert their effects mainly through paracrine angiogenic activities. While these two cells have seemingly complementary advantages, there have not been any studies to date combining these two cell types for vascular regeneration. We have developed a novel chitosan-based hydrogel construct that encapsulates both CD31-expressing BM-mononuclear cells (BM-CD31+ cells) and ESC-ECs, and is loaded with VEGF-releasing microtubes. This cell construct showed high cell survival and minimal cytotoxicity in vitro. When implanted into a mouse model of hindlimb ischemia, it induced robust cell retention, neovascularization through vasculogenesis and angiogenesis, and efficiently induced recovery of blood flow in ischemic hindlimbs. This chitosan-based hydrogel encapsulating mixed adult and embryonic cell derivatives and containing VEGF can serve as a novel platform for treating various cardiovascular diseases.

Stroke Repair via Biomimicry of the Subventricular Zone

“…Chitosan nanoparticles loaded with acetyl-11-keto-β-boswellic acid, a resin extract which may control inflammatory responses, demonstrate a neuroprotective effect in a MCAO rat model, reducing infarct volume and cell death (Ding et al, 2016). In addition, the encapsulation of ESC derived ECs into a chitosan-based hydrogel loaded with VEGF microtubes presents minimal cytotoxicity in vivo and high cell survival, inducing neovascularization in hind limb ischemia mouse models (Lee et al, 2015). Chitosan-based biomaterials continue to be explored for the use in nerve repair for brain injury due to the lack of immune response post injection.…”

Pathomorphism of Limb Major Vessels in Experimental Atherogenic Inflammation. The Role of Adventitial Intimal Relations (Review)

“…In fact, any biodegradable copolymers containing chitosan are able to bind and release angiogenic growth factors resulting, in their biodegradability, in the formation and growth of vascular tissue [161,162]. When using chitosan biopolymers, VEGFs and those of the vessels proper, as well as multipotent cells being reviews a part of a hydrogel, are safely protected by a chitosan polymer against temperature factors and the effect of hydrolyzing enzymes [126].…”

“…Local administration of chitosan copolymer containing endothelial cells of the umbilical vein to the mice with experimental lower limb ischemia within 2 weeks clearly formed a new vascular net in the arterial trunk [125]. Endothelial cells reprogrammed from embryonic stem cells encapsulated in chitosan hydrogel in combination with VEGF, when administered locally in animals with lower limb ischemia model, resulted in neovascularization through the mechanisms of vasculogenesis and angiogenesis, with effective blood flow recovery in ischemic tissues [126]. In addition to therapeutic angiogenesis effect, chitosan copolymers create a direct contact with an atherogenic construction in the subendothelial space of major arteries due to electrostatic, concentration and affine relations and, more precisely, with cholesterol-containing molecules of both: a lipid nucleus of soft plaques, and also foam cells of an intimal layer.…”

Morphological Reconstruction of Main Arteries by Perivascular Implantation of Sulfated Chitosan in Experimental Atherosclerosis

“…However, in numerous publications, the cholesterollowering effect of chitosan was demonstrated with enteral introduction of the biopolymer or in test studies in vitro. In addition to this effect, various chitosan-containing medications promote angiogenesis in ischemic tissues, which leads to improved blood flow [12][13][14]. However, the problem of managing atherogenic inflammation in the walls of main arteries remains unsolved as there is no technology of targeted transporting the biopolymers having affinity for cholesterol to the area of segmental lesions to launch simultaneously both the mechanism of therapeutic angiogenesis and the mechanism of soft plaque resorption in the sub-intimal layer of the vessel.…”