title: Bioactive apatite incorporated alginate microspheres with sustained drug-delivery for bone regeneration application.
abstract: The strontium-substituted hydroxyapatite microspheres (SrHA) incorporated alginate composite microspheres (SrHA/Alginate) were prepared via adding SrHA/alginate suspension dropwise into calcium chloride solution, in which the gel beads were formed by means of crosslinking reaction. The structure, morphology and in vitro bioactivity of the composite microspheres were studied by using XRD, SEM and EDS methods. The biological behaviors were characterized and analyzed through inductively coupled plasma optical emission spectroscopy (ICP-OES), CCK-8, confocal laser microscope and ALP activity evaluations. The experimental results indicated that the synthetic SrHA/Alginate showed similar morphology to the well-known alginate microspheres (Alginate) and both of them possessed a great in vitro bioactivity. Compared with the control Alginate, the SrHA/Alginate enhanced MC3T3-E1 cell proliferation and ALP activity by releasing osteoinductive and osteogenic Sr ions. Furthermore, vancomycin was used as a model drug to investigate the drug release behaviors of the SrHA/Alginate, Alginate and SrHA. The results suggested that the SrHA/Alginate had a highest drug-loading efficiency and best controlled drug release properties. Additionally, the SrHA/Alginate was demonstrated to be pH-sensitive as well. The increase of the pH value in phosphate buffer solution (PBS) accelerated the vancomycin release. Accordingly, the multifunctional SrHA/Alginate can be applied in the field of bioactive drug carriers and bone filling materials.
authors.affiliation: School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
authors.forename: Haibin
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Jiang
authors.affiliation: School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
authors.forename: Song
authors.initials: S
authors.lastname: Ye
authors.affiliation: School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
authors.forename: Kaiping
authors.initials: K
authors.lastname: Zhu
authors.affiliation: School of Materials Science and Engineering, Tongji University, Shanghai 201804, China. Electronic address: wdpshk@tongji.edu.cn.
authors.forename: Deping
authors.initials: D
authors.lastname: Wang
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D001861:Bone Regeneration / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004337:Drug Carriers / Q000737:chemistry* / Q000633:toxicity; D065546:Drug Liberation; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006882:Hydroxyapatites / Q000737:chemistry; D051379:Mice; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D017550:Spectroscopy, Fourier Transform Infrared; D013324:Strontium / Q000737:chemistry; D014640:Vancomycin / Q000737:chemistry / Q000378:metabolism
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D004337:Drug Carriers; D006603:Hexuronic Acids; D006882:Hydroxyapatites; C076185:strontium hydroxyapatite; D014640:Vancomycin; D020723:Glucuronic Acid; D000469:Alkaline Phosphatase; D013324:Strontium
keywords: Biological performance; Bone regeneration; Composite alginate microspheres; Controlled drug-release; Hydroxyapatite