title: Identification of small molecular compounds and fabrication of its aqueous solution by laser-ablation, expanding primordial cartilage.
abstract: OBJECTIVE
  The discovery of small molecular compounds that expand cartilage is needed. We searched for small molecular compounds that expand cartilage or enhance the actions of bone morphogenetic proteins (BMPs) on cartilage.
  
  
  METHODS
  Metatarsal primordial cartilage explants prepared from 14.5 days postcoitum (d.p.c.) mouse embryos were organ-cultured in the presence or absence of BMPs and/or 4-(5-Benzol[1,3]dioxol-5-yl-4-pyrldin-2-yl-1H-imidazol-2-yl)-benzamide hydrate (BPIB) and its related molecules. The perichondrium was removed from some of the cartilage explants by partial digestion with collagenase. BPIB aqueous solution was prepared by fragmenting BPIB crystals in water with laser irradiation and then added to cartilage explants in organ culture.
  
  
  RESULTS
  We found that small molecular compounds, BPIB, available as SB431542 from Sigma and its related molecules, expand primordial cartilage explants in organ culture. These molecules are transforming growth factor-β (TGF-β) inhibitors, and the addition of excess TGF-β reduced cartilage expansion induced by these molecules. The co-administration of BPIB and BMPs synergistically expanded cartilage explants. Removal of the perichondrium abolished BIPB-induced cartilage expansion but not BMP-induced cartilage-expansion, suggesting that BPIB, but not BMPs, expands cartilage through the perichondrium. Furthermore, we used the laser-ablation technique to generate BPIB aqueous solution in the presence of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) without the use of hazardous dimethyl sulfoxide (DMSO). The laser-ablation-generated BPIB aqueous solution was more stable, expanded cartilage explants more effectively than BPIB colloidal solution prepared with DMSO, and synergistically enhanced BMP-induced cartilage expansion.
  
  
  CONCLUSIONS
  A small molecular compound, BPIB, expands primordial cartilage explants. A BPIB aqueous solution was created by laser-ablation without using DMSO and proved to be biologically active.
authors.affiliation: Department of Bone and Cartilage Biology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Ikegami
authors.forename: T
authors.initials: T
authors.lastname: Iwai
authors.forename: S
authors.initials: S
authors.lastname: Ryo
authors.forename: N
authors.initials: N
authors.lastname: Gu
authors.forename: T
authors.initials: T
authors.lastname: Sugiyama
authors.forename: I
authors.initials: I
authors.lastname: Oh
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: N
authors.initials: N
authors.lastname: Tsumaki
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D002356:Cartilage / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development*; D004149:Dioxoles / Q000494:pharmacology*; D007834:Lasers; D008682:Metatarsal Bones / Q000196:embryology; D051379:Mice; D009924:Organ Culture Techniques; D023822:Tissue Engineering / Q000379:methods*
chemical_list: C459179:4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide; D001549:Benzamides; D019485:Bone Morphogenetic Proteins; D004149:Dioxoles