Absorbable Collagen Sponge Slow-Release Stromal Cell Derived Factor-1/Bone Morphogenetic Protein-2 Applied In Research Of Rabbit Mandibular Distraction Osteogenesis

Distraction osteogenesis(DO)has been accepted as an effective technique for bone lengthening.However,the long treatment period and possible fibrous union or nonunion hampers its further clinical application.Bone regeneration in DO involves multiple stages of repair and coordinated action of multiple cell types.Consequently,it may be possible to enhance bone regeneration through treatment strategies that target more than one repair process or cell types.The potent stem cell homing factor stromal cell-derived factor-1(SDF-1)actively recruits mesenchymal stem cells from circulation and from local bone marrow.It is well established that bone morphogenetic protein-2(BMP-2)induces ectopic and orthotopic bone formation.However,the exact synergistic effects of BMP-2 and SDF-1 in ectopic and orthotopic bone regeneration models have not been fully investigated.Porposes:The goal of this study was to evaluate the potential effects of simultaneous SDF-1 and BMP-2 treatment on bone formation in mandibular DO of rabbits,and to investigate dual delivery of both growth factors can enhance each other,s actions with a synergistic effect.Materials and Methods:Bilateral mandibular in 30 rabbits were lengthened for 10 days at a rate of 1.0mm/day after 6-day lag.At the end of osteotomy,the animals were randomly divided into five groups(n=6)and received nothing,absorbable collagen sponge(ACS),ACS with 2.0ug rhBMP-2 or ACS with 200ugSDF-1,or ACS with both 1.0ug rhBMP-2 and 100 ug SDF-1 at the lengthened segment,respectively.After 4-week consolidation bony healing was assessed using histology.Results:Histological appearances of the lengthened segment was investigated.Bony continuity was observed in group D and group E,In the group A,B,C the distraction gap was partially bridged with tiny trabacular bone.Although both the rhBMP-2(D)and combined treatment(E)groups showed completely bony continuity of the distraction gap,the trabecular bone in the combined treatment group appeared to be more mature.Conclusion : These findings imply that sequence-controlled application of SDF-1 and BMP-2must be further investigated for the enhancement of mandibular osteogenesis in bone defects.