title: Strontium-Doped Amorphous Calcium Phosphate Porous Microspheres Synthesized through a Microwave-Hydrothermal Method Using Fructose 1,6-Bisphosphate as an Organic Phosphorus Source: Application in Drug Delivery and Enhanced Bone Regeneration.
abstract: Nanostructured calcium phosphate porous microspheres are of great potential in drug delivery and bone regeneration due to their large specific surface area, biocompatibility, and similarity to inorganic component of osseous tissue. In this work, strontium (Sr)-doped amorphous calcium phosphate porous microspheres (SrAPMs) were synthesized through a microwave-hydrothermal method using fructose 1,6-bisphosphate trisodium salt as the source of phosphate ions. The SrAPMs showed a mesoporous structure and a relatively high specific area. Compared with the hydroxyapatite nanorods prepared by using Na2HPO4·12H2O as the phosphorus source, the SrAPMs with a higher specific surface area were more effective in drug loading using vancomycin as the antiobiotics of choice and consequently having a higher antibacterial efficiency both on agar plates and in broths. Furthermore, to assess the potential application of SrAPMs in bone defect repair, a novel biomimetic bone tissue-engineering scaffold consisting of collagen (Coll) and SrAPMs was constructed using a freeze-drying fabrication process. Incorporation of the SrAPMs not only improved the mechanical properties, but also enhanced the osteogenesis of rat bone marrow mesenchymal stem cells. The in vivo experiments demonstrated that the SrAPMs/Coll scaffolds remarkably enhanced new bone formation compared with the Coll and APMs/Coll scaffolds in a rat critical-sized calvarial defect model at 8 weeks postimplantation. In summary, SrAPMs developed in this work are promising as antibiotic carriers and may encourage bone formation when combined with collagen.
authors.forename: Weilin
authors.initials: W
authors.lastname: Yu
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences , 1295 Dingxi Road, Shanghai 200050, China.|University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China.
authors.forename: Tuan-Wei
authors.initials: TW
authors.lastname: Sun
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences , 1295 Dingxi Road, Shanghai 200050, China.|University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Qi
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Ding
authors.forename: Huakun
authors.initials: H
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences , 1295 Dingxi Road, Shanghai 200050, China.|University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Daoyun
authors.initials: D
authors.lastname: Chen
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences , 1295 Dingxi Road, Shanghai 200050, China.|University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China.
authors.forename: Ying-Jie
authors.identifier: http://orcid.org/0000-0002-5044-5046
authors.initials: YJ
authors.lastname: Zhu
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Shi
authors.forename: Yaohua
authors.identifier: http://orcid.org/0000-0002-2829-8908
authors.initials: Y
authors.lastname: He
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D002130:Calcium Phosphates; D005632:Fructose; D005635:Fructosediphosphates; D008863:Microspheres; D008872:Microwaves; D010758:Phosphorus; D051381:Rats; D013324:Strontium; D054457:Tissue Scaffolds
chemical_list: D002130:Calcium Phosphates; D005635:Fructosediphosphates; C519480:amorphous calcium phosphate; D010758:Phosphorus; D005632:Fructose; C029063:fructose-1,6-diphosphate; D013324:Strontium
keywords: biomimetic; bone regeneration; calcium phosphate; drug delivery; scaffold