title: Neovascularization induced by porous collagen scaffold implanted on intact and cryoinjured rat hearts.
abstract: The potential of collagen scaffolds for promoting angiogenesis/arteriogenesis was studied in vivo by implantation on healthy or cryoinjured left ventricles of rats up to 60 days post-injury. Blood vessels content and extra-vascular cell infiltration were evaluated within the collagen scaffold, the cryoinjured areas, and the "border zones" of the myocardium facing the cryoinjured zones. The collagen cardiac patches were almost completely absorbed in 60 days and became populated by new arterioles and capillaries in both intact and cryoinjured heart (arterioles in cryoinjured vs. intact zones were about 2,3-fold higher; capillaries in cryoinjured vs. intact zones were 1.7-fold higher). Collagen cardiac patches exerted a "trophic" effect on the organizing granulation tissue that emerged from the wound-healing process, increasing vessel density of 2.7-fold for arterioles and 4-fold for capillaries. Interstitial cells in collagen cardiac patches rarely (<1%) expressed cardiogenic stem cells markers such as Sca-1- or MDR1, whereas markers of neural crest cells GFAP(+)/nestin(+) cells ranged from 3/30% to 30/70% in collagen cardiac patches placed on intact vs. cryoinjured heart, respectively. Myofibroblasts and cardiomyocytes (CM) were absent but macrophages populated the collagen scaffolds even after 60 days from implantation. Western blotting of collagen cardiac patches after implantation on intact/cryoinjured hearts confirmed that markers of endothelial and smooth muscle cells, but not of CM, were expressed. The porous collagen scaffold was able to elicit a powerful angiogenetic and arteriogenetic response in the intact and cryoinjured hearts, representing an ideal tool for therapeutic angio-arteriogenesis and a potentially useful substrate for stem cell seeding.
authors: Department of Biomedical Sciences, University of Padua, Italy.
authors: Andrea
authors: A
authors: Callegari
authors: Sveva
authors: S
authors: Bollini
authors: Laura
authors: L
authors: Iop
authors: Angela
authors: A
authors: Chiavegato
authors: Gianluca
authors: G
authors: Torregrossa
authors: Michela
authors: M
authors: Pozzobon
authors: Gino
authors: G
authors: Gerosa
authors: Paolo
authors: P
authors: De Coppi
authors: Nicola
authors: N
authors: Elvassore
authors: Saverio
authors: S
authors: Sartore
mesh_terms: D000818:Animals; D003094:Collagen / Q000494:pharmacology* / Q000648:ultrastructure; D006335:Heart Injuries; D008855:Microscopy, Electron, Scanning; D009389:Neovascularization, Pathologic / Q000139:chemically induced* / Q000473:pathology*; D010641:Phenotype; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003094:Collagen