title: Bioactivity of porous biphasic calcium phosphate enhanced by recombinant human bone morphogenetic protein 2/silk fibroin microsphere.
abstract: To prepare a bioactive bone substitute, which integrates biphasic calcium phosphate (BCP) and rhBMP-2/silk fibroin (SF) microsphere, and to evaluate its characteristics. Hydroxyapatite and β-tricalcium phosphate were integrated with a ratio of 60–40%. RhBMP-2/SF (0.5 μg/1 mg) microsphere was prepared, and its rhBMP-2-release kinetics was assed. After joining pore-forming agent (Sodium chloride, NaCl), porous BCP/rhBMP-2/SF were manufactured, and its characteristics and bioactivity in vitro were evaluated. Mean diameter of rhBMP-2/SF microsphere was 398.7 ± 99.86 nm, with a loading rate of 4.53 ± 0.08%. RhBMP-2 was released in a dual-phase pattern, of which fast-release (nearly half of protein released) focused on the initial 3 days, and slow-release sustained more than 28 days. With the increase in concentration of NaCl, greater was porosity and pore size, but smaller mechanical strength of BCP/rhBMP-2/SF. Material with 150% (w/v) NaCl had an optimal performance, with a porosity of 78.83%, pore size of 293.25 ± 42.77μm and mechanical strength of 31.03 MPa. Proliferation of human placenta-derived mesenchymal stem cells (hPMSCs) on leaching extract medium was similar to the normal medium (P = 0.89), which was better than that on control group (P = 0.03). Activity of alkaline phosphatase on BCP/rhBMP-2/SF surface was higher than on pure BCP at each time point except at 1 day (P < 0.05). RhBMP-2 has a burst release on early times and a sustaining release on later times. BCP/rhBMP-2/SF with 150% (w/v) pore-forming agent has excellent porosity, pore size and mechanical strength. The biomaterial induces proliferation and differentiation hPMSCs effectively.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Gu
authors.forename: Yu
authors.initials: Y
authors.lastname: Feng
authors.forename: Xue-Song
authors.initials: XS
authors.lastname: Zhu
authors.forename: Chun-Zeng
authors.initials: CZ
authors.lastname: Wang
authors.forename: Hai-Long
authors.initials: HL
authors.lastname: Liu
authors.forename: Hai-Yun
authors.initials: HY
authors.lastname: Niu
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Yang
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D012831:Bombyx; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D001842:Bone and Bones / Q000378:metabolism; D002130:Calcium Phosphates / Q000737:chemistry*; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D017886:Durapatite / Q000737:chemistry; D005260:Female; D005349:Fibroins / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D059630:Mesenchymal Stem Cells / Q000166:cytology; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010920:Placenta / Q000378:metabolism; D016062:Porosity; D011247:Pregnancy; D011994:Recombinant Proteins / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C485817:beta-tricalcium phosphate; C499469:recombinant human bone morphogenetic protein-2; D012965:Sodium Chloride; D005349:Fibroins; D017886:Durapatite; C020243:calcium phosphate