title: Biomineralization of stable and monodisperse vaterite microspheres using silk nanoparticles.
abstract: The influence of silk fibroin (SF) on calcium carbonate (CaCO3) biomineralization has been investigated; however, the formation of small, uniform SF-regulated vaterite microspheres has not been reported. In this work, spherical CaCO3 was synthesized via coprecipitation in the presence of SF. SF nanostructures were first tuned by self-assembly at 60 °C to provide better control of the nucleation of CaCO3. Subsequently, monodisperse vaterite microspheres about 1.1 μm were generated by controlling aggregation and growth of CaCO3 under appropriate concentrations of SF and Ca ions. In contrast to unstable vaterite, the microspheres generated in the present study have sufficient stability in aqueous solution for at least 8 days without transformation into calcite, due to the electrostatic interactions between the Ca ions and the preassembled SF nanostructures. The microspheres as drug carriers of doxorubicin (DOX) were assessed and found to have good encapsulation efficiency, sustained drug release without burst release, and pH sensitivity. These new SF/CaCO3 hybrids may provide new options for various biomedical applications.
authors.affiliation: National Engineering Laboratory for Modern Silk & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215123, People's Republic of China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Liu
authors.forename: Xiuli
authors.initials: X
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Guozhong
authors.initials: G
authors.lastname: Lu
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.forename: Hesun
authors.initials: H
authors.lastname: Zhu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lu
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry; D004317:Doxorubicin / Q000737:chemistry*; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000737:chemistry; D016503:Drug Delivery Systems / Q000295:instrumentation*; D005349:Fibroins / Q000737:chemistry*; D007700:Kinetics; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D011108:Polymers; D004317:Doxorubicin; D005349:Fibroins; D002119:Calcium Carbonate
keywords: biomaterials; drug release; pH sensitivity; silk; vaterite