title: Tailoring of multilayered core-shell nanostructure for multicomponent administration and controllable release of biologically active ions.
abstract: The biomaterials that can control the active ions delivery to enhance cell activity are regarded as promising bone regenerative materials. In this study, a new approach aiming to layer-by-layer (LbL) assemble the bioavailable zinc ions in the core-shell-like silica@octacalcium phosphate (OCP) nanosphere and to analyze its efficacy on improving controlled-release was reported. Firstly, a pH-responsive electrostatic interaction was used to adsorb zinc ions on silica nanospheres with different zinc concentration, which was followed by coating silica gel layer. Then the nanospheres were LbL assembled with zinc ions and silica gel alternately until the desired multilayered nanospheres were achieved. Finally, the porous OCP shells were capped onto the outside surface of the nanospheres tailored by poly(aspartic acid) sodium molecules. The ion release tests in Tris buffers in vitro indicated that zinc release was controlled by pH and storage capacity, and silicon release was regulated by the OCP shell barrier. A temporal gradient within short times and sustained-dosage for a prolonged time toward the zinc and silicon ions could be obtained in this multilayer system. The results of this organized active ion assembly might open a promising future direction for effective delivery of trace elements in bone defect therapy.
authors: Department of Materials Science and Engineering, Zhejiang University, Zheda Road 37, Hangzhou 310027, China.
authors: Zhongru
authors: Z
authors: Gou
authors: Wenjian
authors: W
authors: Weng
authors: Piyi
authors: P
authors: Du
authors: Gaorong
authors: G
authors: Han
authors: Weiqi
authors: W
authors: Yan
mesh_terms: D000327:Adsorption; D002021:Buffers; D002118:Calcium / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D003692:Delayed-Action Preparations; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000008:administration & dosage* / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry
chemical_list: D002021:Buffers; D002130:Calcium Phosphates; D003692:Delayed-Action Preparations; D012996:Solutions; C022045:octacalcium phosphate; D010758:Phosphorus; D012822:Silicon Dioxide; D015032:Zinc; D002118:Calcium; D012825:Silicon