title: Augmentation of osteoinduction with a biodegradable poly(propylene glycol-co-fumaric acid) bone graft extender. A histologic and histomorphometric study in rats.
abstract: We investigated the feasibility of enhancing the regeneration of skeletal tissues by augmenting bone grafts with a composite biodegradable bone graft extender material based on the polymer poly(propylene fumarate), PPF. The material was mixed with autograft and allograft and placed directly into a cylindrical metaphyseal defect made in the rat tibia. These formulations were compared to defects without any graft material, autografts, allografts and PPF alone. Nine animals were included in each group. Animals were sacrificed at 1 and 4 weeks postoperatively. Implantation sites were then evaluated using histologic and histomorphometric methods. Results of this study showed that defects did not heal in sham operated animals. In the experimental groups, there was early new woven bone formation in the autograft group with near complete healing of the defect at four weeks. When PPF was used alone, gradual ingrowth of new bone was seen. Mixing of the PPF bone graft extender with either allograft or autograft material resulted in enhancement of new bone formation with both allo- and autograft. However, significantly more new bone formation than in the autograft group was only seen when the PPF bone graft extender was mixed with fresh autograft. Histomorphometry corroborated these findings. Results of this study suggest that a PPF-based material may be used to increase the volume of smaller amounts of bone grafts supporting the concept of "bone graft extenders" by application of engineered biodegradable porous scaffolds.
authors.affiliation: Orthopaedic Research Laboratories, Massachusetts General Hospital, Boston 02114, USA.
authors.forename: K U
authors.initials: KU
authors.lastname: Lewandrowski
authors.forename: S
authors.initials: S
authors.lastname: Bondre
authors.forename: J D
authors.initials: JD
authors.lastname: Gresser
authors.forename: A E
authors.initials: AE
authors.lastname: Silva
authors.forename: D L
authors.initials: DL
authors.lastname: Wise
authors.forename: D J
authors.initials: DJ
authors.lastname: Trantolo
mesh_terms: D020341:Absorbable Implants; D000704:Analysis of Variance; D000818:Animals; D001843:Bone Cements / Q000737:chemistry*; D001861:Bone Regeneration / Q000502:physiology*; D016025:Bone Transplantation / Q000473:pathology* / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D005240:Feasibility Studies; D005500:Follow-Up Studies; D005650:Fumarates / Q000737:chemistry*; D006097:Granulation Tissue / Q000473:pathology; D008297:Male; D010012:Osteogenesis / Q000502:physiology; D011126:Polypropylenes / Q000737:chemistry*; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D013977:Tibia / Q000473:pathology / Q000601:surgery; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous; D014945:Wound Healing
chemical_list: D001843:Bone Cements; D020099:Coated Materials, Biocompatible; D005650:Fumarates; D011126:Polypropylenes; C097850:poly(propylene fumarate)