title: Ectopic bone formation via rhBMP-2 delivery from porous bioabsorbable polymer scaffolds.
abstract: Drug delivery devices have received considerable interest in the field of tissue engineering due to the advent of proteins that can induce proliferation and differentiation of various cells to form specific tissues and organs, for example, bone morphogenetic protein (BMP-2) for osteogenesis. In this work the delivery of a clinically relevant bioactive factor, recombinant human rhBMP-2, was tested in vivo in a rat ectopic bone induction assay. Contact radiography and radiomorphometry showed significantly more radiopacity (1798+/-183 mm2 versus. 784+/-570 mm2 radiopaque area/g scaffold) in the BMP scaffolds than controls (p < 0.002). De novo woven bone and abundant osteoid formation were confirmed from histological sections while controls contained minimal amounts of tissue. Histomorphometry revealed significantly more bone (124+/-93 mm2 versus 7+/-12 mm2) and osteoid (72+/-43 mm2 versus 20+/-21 mm2) in the BMP implants (p < 0.001). These scaffolds demonstrated the ability to deliver viable rhBMP-2 and to induce bone formation in an ectopic site.
authors.affiliation: Division of Biological Materials, Northwestern University Dental School, Chicago, Illinois 60611-3008, USA.
authors.forename: K
authors.initials: K
authors.lastname: Whang
authors.forename: D C
authors.initials: DC
authors.lastname: Tsai
authors.forename: E K
authors.initials: EK
authors.lastname: Nam
authors.forename: M
authors.initials: M
authors.lastname: Aitken
authors.forename: S M
authors.initials: SM
authors.lastname: Sprague
authors.forename: P K
authors.initials: PK
authors.lastname: Patel
authors.forename: K E
authors.initials: KE
authors.lastname: Healy
mesh_terms: D000042:Absorption; D000818:Animals; D001704:Biopolymers; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D001842:Bone and Bones / Q000166:cytology* / Q000000981:diagnostic imaging*; D002828:Choristoma / Q000139:chemically induced; D004337:Drug Carriers; D006801:Humans; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D019736:Prostheses and Implants; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D016212:Transforming Growth Factor beta
chemical_list: C525718:BMP2 protein, human; D001704:Biopolymers; C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D004337:Drug Carriers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2