Mandibular defect repair by TGF-beta and IGF-1 released from a biodegradable osteoconductive hydrogel.
OBJECTIVE
Bone regeneration is crucial in the healing of defects in the craniofacial complex. The ability of transforming growth factor-beta1 (TGF-beta1) and insulin-like growth factor-1 (IGF-1), incorporated into a hydrogel scaffold to induce bone regeneration, was evaluated in a rat mandible defect model.


METHODS
Hydrogel scaffolds containing either transforming growth factor-beta1 (TGF-beta1), insulin-like growth factor-1 (IGF-1), TGF-beta+ IGF-1, or saline, were implanted in rat mandibular bone defects. In a control group the defects were treated by saline alone. Bone defect healing was tested after 3 and 6 weeks by radiology and morphology.


RESULTS
Soft tissue radiographs indicated that the area of new bone formation increased gradually after 3 and at 6 weeks. The percentage of closure after 3 weeks was less than the percentage closure after 6 weeks. The amount of calcified material in the TGF-beta and TGF-beta+IGF-1-treated groups had increased more than in the saline-containing hydrogel and control (saline-treated) defects. The percentages of defect closures were 37, 38, 24, 14, and 11% after 3 weeks, and 94, 91, 84, 72, and 29% after 6 weeks, in the TGF-beta+IGF-1, TGF-beta, IGF-1, saline containing hydrogel and saline-treated animals, respectively. Three-dimensional computerized tomography (3D CT) images showed that the 3D shape of the bones was restored. Morphological analysis of the defects treated with hydrogel containing TGF-beta, IGF-1 or TGF-beta+IGF-1 revealed significant bone formation after 6 weeks.


CONCLUSIONS
It is concluded that the hydrogel scaffold impregnated with growth factors can induce bone regeneration and is therefore a promising surgical tool for enhancement of surgical repair of bone defects.
Srouji
Samer
S
Department of Oral and Maxillofacial Surgery, Carmel Medical Centre, Haifa, Israel.
Rachmiel
Adi
A
Blumenfeld
Israel
I
Livne
Erella
E
D020341:Absorbable Implants; D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D004337:Drug Carriers; D020100:Hydrogels; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000494:pharmacology*; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D019647:Oral Surgical Procedures / Q000379:methods*; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000494:pharmacology*
D004337:Drug Carriers; D020100:Hydrogels; D016212:Transforming Growth Factor beta; D007334:Insulin-Like Growth Factor I