title: Bone marrow genesis after subcutaneous delivery of rat osteogenic cell-seeded biodegradable scaffolds into nude mice.
abstract: This study describes the generation of an active hematopoietic marrow within the confines of a biodegradable, macroporous polyester scaffold, seeded with rat osteogenic cells, after subcutaneous implantation in nude mice. A macroporous, poly(DL-lactide-co-glycolide) polymer scaffold, into which resorbable calcium phosphate particles were incorporated, was seeded with rat bone marrow-derived cells. Scanning electron microscopy of the cell-seeded scaffold demonstrated confluent cell colonization. Scaffolds seeded with cells were implanted under the dorsum of immunocompromised mice for 5 weeks. Histological analysis revealed bone formation along the scaffold pores creating bony cavities within which a host-derived, hematopoietic marrow was observed which included hematopoietic precursors, megakaryocytes, fat cells, and numerous marrow sinusoids. In those areas where bone was not elaborated on the scaffold surface, no marrow genesis was observed and the scaffold interstices were filled with fibrous tissue. These results demonstrate the utility of this biodegradable scaffold in delivery of a phenotypically functional cell population for bone tissue and bone marrow engineering applications. Moreover, the recapitulation of hematopoietic marrow tissue within the engineered bony cavities also provides a new experimental environment with which to further investigate the interactions of hematopoietic and nonhematopoietic compartments of the marrow microenvironment.
authors.affiliation: Department of Periodontics and Endodontics, Tsurumi University, 2-1-3 Tsurumi, Yokohama 230-8501, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Gomi
authors.forename: Mikimoto
authors.initials: M
authors.lastname: Kanazashi
authors.forename: David
authors.initials: D
authors.lastname: Lickorish
authors.forename: Takashi
authors.initials: T
authors.lastname: Arai
authors.forename: John E
authors.initials: JE
authors.lastname: Davies
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001853:Bone Marrow / Q000254:growth & development* / Q000648:ultrastructure; D001854:Bone Marrow Cells / Q000648:ultrastructure; D016026:Bone Marrow Transplantation / Q000379:methods*; D002478:Cells, Cultured; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000502:physiology; D007279:Injections, Subcutaneous; D019344:Lactic Acid; D051379:Mice; D008819:Mice, Nude; D008855:Microscopy, Electron, Scanning; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D051381:Rats; D016707:Tissue Fixation
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid