title: Enhancing the vascularization of three-dimensional porous alginate scaffolds by incorporating controlled release basic fibroblast growth factor microspheres.
abstract: Site-specific delivery of angiogenic growth factors from tissue-engineered devices should provide an efficient means of stimulating localized vessel recruitment to the cell transplants and would ensure cell survival and function. In the present article, we describe the construction of a novel porous alginate scaffold that incorporates tiny poly (lactic-co-glycolic acid) microspheres capable of controlling the release of angiogenic factors, such as basic fibroblast growth factor (bFGF). The microspheres are an integral part of the solid alginate matrix, and their incorporation does not affect the scaffold porosity or pore size. In vitro, bFGF was released from the porous composite scaffolds in a controlled manner and it was biologically active as assessed by its ability to induce the proliferation of cardiac fibroblasts. The controlled delivery of bFGF from the three-dimensional scaffolds accelerated the matrix vascularization after implantation on the mesenteric membrane in rat peritoneum. The number of penetrating capillaries into the bFGF-releasing scaffolds was nearly fourfold higher than into the control scaffolds (those incorporating microspheric BSA and heparin but not bFGF). At day 10 posttransplantation, capillary density in the composite scaffolds was 45 +/- 3/mm(2) and it increased to 70 +/- 7/mm(2) by day 21. The released bFGF induced the formation of large and matured blood vessels, as judged by the massive layer of mural cells surrounding the endothelial cells. The control over bFGF delivery and localizing its effects to areas of need, may aid in the wider application of bFGF in therapeutic angiogenesis as well as in tissue engineering.
authors.affiliation: Department of Biomedical Engineering, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Perets
authors.forename: Yaacov
authors.initials: Y
authors.lastname: Baruch
authors.forename: Felix
authors.initials: F
authors.lastname: Weisbuch
authors.forename: Gideon
authors.initials: G
authors.lastname: Shoshany
authors.forename: Gera
authors.initials: G
authors.lastname: Neufeld
authors.forename: Smadar
authors.initials: S
authors.lastname: Cohen
mesh_terms: D000464:Alginates; D000818:Animals; D001672:Biocompatible Materials; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003692:Delayed-Action Preparations; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D019344:Lactic Acid; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010316:Particle Size; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D051381:Rats; D011917:Rats, Inbred Lew; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D006603:Hexuronic Acids; D011108:Polymers; D016222:Fibroblast Growth Factor 2; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D020723:Glucuronic Acid