title: CaSiO₃ microstructure modulating the in vitro and in vivo bioactivity of poly(lactide-co-glycolide) microspheres.
abstract: Poly(lactide-co-glycolide) (PLGA) microspheres have been used for regenerative medicine due to their ability for drug delivery and generally good biocompatibility, but they lack adequate bioactivity for bone repair application. CaSiO₃ (CS) has been proposed as a new class of material suitable for bone tissue repair due to its excellent bioactivity. In this study, we set out to incorporate CS into PLGA microspheres to investigate how the phase structure (amorphous and crystal) of CS influences the in vitro and in vivo bioactivity of the composite microspheres, with a view to the application for bone regeneration. X-ray diffraction (XRD), N₂ adsorption-desorption analysis, and scanning electron microscopy (SEM) were used to analyze the phase structure, surface area/pore volume, and microstructure of amorphous CS (aCS) and crystal CS (cCS), as well as their composite microspheres. The in vitro bioactivity of aCS and cCS-PLGA microspheres was evaluated by investigating their apatite-mineralization ability in simulated body fluids (SBF) and the viability of human bone mesenchymal stem cells (BMSCs). The in vivo bioactivity was investigated by measuring their de novo bone-formation ability. The results showed that the incorporation of both aCS and cCS enhanced the in vitro and in vivo bioactivity of PLGA microspheres. cCS/PLGA microspheres improved better in vitro BMSC viability and de novo bone-formation ability in vivo, compared to aCS/PLGA microspheres. Our study indicates that controlling the phase structure of CS is a promising method to modulate the bioactivity of polymer microsphere system for potential bone tissue regeneration.
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland 4059, Australia.
authors.forename: Chengtie
authors.initials: C
authors.lastname: Wu
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Fan
authors.forename: Xuebin
authors.initials: X
authors.lastname: Ke
authors.forename: Xuye
authors.initials: X
authors.lastname: Hu
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yin
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D000327:Adsorption / Q000187:drug effects; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects; D017610:Calcium Compounds / Q000737:chemistry* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D019344:Lactic Acid / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects; D051379:Mice; D016513:Mice, SCID; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D008903:Minerals; D010012:Osteogenesis / Q000187:drug effects; D011100:Polyglycolic Acid / Q000494:pharmacology*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity / Q000187:drug effects; D011208:Powders; D017640:Silicates / Q000737:chemistry* / Q000494:pharmacology*; D012996:Solutions; D013696:Temperature; D014961:X-Ray Diffraction; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D008903:Minerals; D011208:Powders; D017640:Silicates; D012996:Solutions; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C031293:calcium silicate