Bone formation in transforming growth factor beta-1-coated porous poly(propylene fumarate) scaffolds.
This study determined the bone growth into pretreated poly(propylene fumarate) (PPF) scaffolds implanted into a subcritical size, rabbit cranial defect. PPF scaffolds were constructed by using a photocrosslinking-porogen leaching technique. These scaffolds were then either prewetted (PPF-Pw), treated with RF glow-discharge (PPF-Gd), coated with fibronectin (PPF-Fn), or coated with rhTGF-beta1 (PPF-TGF-beta1). One of each scaffold type was then placed into the cranium of nine rabbits. The rabbits were sacrificed after 8 weeks, and the scaffolds were retrieved for histological analysis. The most bone formation was present in the PPF-TGF-beta1 implants; the newly formed bone had a trabecular appearance together with bone marrow-like tissue. Little or no bone formation was observed in implants without rhTGF-beta1. These histological findings were confirmed by image analysis. Bone surface area, bone area percentage, pore fill percentage, and pore area percentage were significantly higher in the rhTGF-beta1-coated implants than in the noncoated implants. No statistical difference was seen between the PPF-Fn, PPF-Pw, or PPF-Gd scaffolds for these parameters. Quadruple fluorochrome labeling showed that in PPF-TGF-beta1 implants bone formation mainly started in the interior of a pore and proceeded toward the scaffold. We conclude that (a) PPF-TGF-beta1 scaffolds can indeed adequately induce bone formation in porous PPF, and (b) PPF scaffolds prepared by the photocrosslinking-porogen leaching technique are good candidates for the creation of bone graft substitutes.
Vehof
Johan W M
JW
Department of Biomaterials, College of Dental Science, University Medical Center Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
Fisher
John P
JP
Dean
David
D
van der Waerden
Jan-Paul C M
JP
Spauwen
Paul H M
PH
Mikos
Antonios G
AG
Jansen
John A
JA
D000818:Animals; D001672:Biocompatible Materials; D001846:Bone Development / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005456:Fluorescent Dyes; D005650:Fumarates / Q000737:chemistry*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008856:Microscopy, Fluorescence; D008970:Molecular Weight; D011126:Polypropylenes / Q000737:chemistry*; D016062:Porosity; D019736:Prostheses and Implants; D011817:Rabbits; D012886:Skull / Q000254:growth & development; D012995:Solubility; D013268:Stimulation, Chemical; D016707:Tissue Fixation; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1
D001672:Biocompatible Materials; D005456:Fluorescent Dyes; D005650:Fumarates; D011126:Polypropylenes; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C097850:poly(propylene fumarate)