title: Combination of growth factors inhibits bone ingrowth in the bone harvest chamber.
abstract: Previous studies using bone harvest chambers have shown that bone morphogenetic protein-2 inhibits bone ingrowth. The authors hypothesized that the combination of bone morphogenetic protein-2 and a potent angiogenic factor, basic fibroblast growth factor, would result in increased bone formation in this model. Five New Zealand White rabbits were surgically implanted with bone harvest chambers in the proximal metaphyseal region of both tibias. The right leg of each rabbit was implanted with a bovine collagen sponge that was impregnated with recombinant human bone morphogenetic protein-2, basic fibroblast growth factor, or a combination of these factors. The left leg chamber was implanted with the collagen sponge with no growth factors as a control. The bone that grew into the chambers was harvested after 2 weeks, and histomorphologic analysis was performed to determine the amount of tissue and bone ingrowth. The tissue chambers were left empty for 2 weeks between test implants, and this tissue also was harvested, analyzed, and compared with the other samples. The results showed decreased bone formation for the bone morphogenetic protein-2, basic fibroblast growth factor, and combination of bone morphogenetic protein-2 and basic fibroblast growth factor treated groups when compared with the control and empty groups. The combination of bone morphogenetic protein-2 and basic fibroblast growth factor showed inhibition of bone formation that was greater than either growth factor individually. The reason for the inhibition of bone formation with the combination of factors is unknown.
authors.affiliation: The Bobst Hospital and Caspary Institute of the Animal Medical Center, New York, NY, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Vonau
authors.forename: M P
authors.initials: MP
authors.lastname: Bostrom
authors.forename: P
authors.initials: P
authors.lastname: Aspenberg
authors.forename: A E
authors.initials: AE
authors.lastname: Sams
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D001861:Bone Regeneration / Q000187:drug effects* / Q000502:physiology; D046508:Culture Techniques; D004359:Drug Therapy, Combination; D005346:Fibroblast Growth Factors / Q000008:administration & dosage*; D008297:Male; D023421:Models, Animal; D011336:Probability; D011817:Rabbits; D012680:Sensitivity and Specificity; D013977:Tibia / Q000187:drug effects / Q000254:growth & development* / Q000473:pathology; D020858:Tissue and Organ Harvesting / Q000009:adverse effects; D016212:Transforming Growth Factor beta
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta; D005346:Fibroblast Growth Factors