title: [Ectopic osteogenesis of stromal cell-derived factor 1 combined with simvastatin-loaded collagen scaffold in vivo].
abstract: OBJECTIVE
  To construct and evaluate a novel tissue-engineered bone composed of murine stromal cell-derived factor 1(mSDF-1), simvastatin (SIM) and collagen scaffold (Bio-Oss®), serving as a cell-homing approach for bone formation.
  
  
  METHODS
  In the study, 32 ICR mice were randomly divided into 4 groups,each group including 8 mice. The drug-loaded collagen scaffolds were implanted subcutaneously onto the cranium of each mouse according to the groups: (1) 1:50 (volume ratio) dimethyl sulfoxide (DMSO)/phosphate-buffered saline (PBS) solution + collagen scaffold (blank control group); (2) 10⁻³ mol/L SIM solution + collagen scaffold (SIM group); (3) 200 mg/L mSDF-1 solution + collagen scaffold (mSDF-1 group); and (4) 10® mol/L SIM +200 mg/L mSDF-1 solution + collagen scaffold (SIM + mSDF-1 group). One week after implantation, the mice were treated by injecting the same drug solution mentioned above around the scaffold once a day for two days. The specimens were harvested 6 weeks after implantation and the bone formation was evaluated by soft X-ray analysis, HE staining and immunohistochemical staining. Angiogenesis of each group was checked by calculation of vessels in each tissue section.
  
  
  RESULTS
  Six weeks after implantation, the collagen scaffolds were retrieved. The value of gray scale for the SIM+mSDF-1 group [(421 836.5 ± 65 425.7)pixels] was significantly higher than that of the blank control group[(153 345.6 ± 45 222.2) pixels, P<0.01], the SIM group [(158 119.2 ± 100 284.2)pixels, P<0.01], and the mSDF-1 group[(255 529.5 ± 152 142.4)pixels, P<0.05]; HE staining analysis revealed that significant bone formation was achieved in the SIM + mSDF-1 group; The immunohistochemical staining showed the existence of osteopontin and osteocalcin in the SIM + mSDF-1 group; There were more vessels in the SIM+mSDF-1 group[(46 ± 8)vessels/mm²] than in the blank control group [(23 ± 7) vessels/mm2, P<0.01], and the SIM group[(24 ± 6) vessels/mm2, P<0.01].
  
  
  CONCLUSIONS
  The novel tissue-engineered bone composed of mSDF-1, SIM and collagen scaffolds has the potential to form bone subcutaneously in vivo. It represents a novel method of in vivo bone re-generation without seed cell delivery.
authors: Third Clinical Division, Peking University School and Hospital of Stomatology, Beijing 100083, China; Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Meng-reng
authors: MR
authors: Ou
authors: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Xiao
authors: X
authors: Zhang
authors: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Yun-song
authors: YS
authors: Liu
authors: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Yan-jun
authors: YJ
authors: Ge
authors: Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China; National Engineering Lab for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Yong-sheng
authors: YS
authors: Zhou
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D054377:Chemokine CXCL12 / Q000494:pharmacology*; D003094:Collagen / Q000737:chemistry; D051379:Mice; D008813:Mice, Inbred ICR; D008903:Minerals / Q000737:chemistry*; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D053495:Osteopontin / Q000378:metabolism; D019821:Simvastatin / Q000494:pharmacology*; D012886:Skull; D023822:Tissue Engineering
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D054377:Chemokine CXCL12; C515256:Cxcl12 protein, mouse; D008903:Minerals; C506896:Spp1 protein, mouse; D015675:Osteocalcin; D053495:Osteopontin; D003094:Collagen; D019821:Simvastatin