title: Processing and characterization of diatom nanoparticles and microparticles as potential source of silicon for bone tissue engineering.
abstract: Silicon plays an important role in bone formation and maintenance, improving osteoblast cell function and inducing mineralization. Often, bone deformation and long bone abnormalities have been associated with silica/silicon deficiency. Diatomite, a natural deposit of diatom skeleton, is a cheap and abundant source of biogenic silica. The aim of the present study is to validate the potential of diatom particles derived from diatom skeletons as silicon-donor materials for bone tissue engineering applications. Raw diatomite (RD) and calcined diatomite (CD) powders were purified by acid treatments, and diatom microparticles (MPs) and nanoparticles (NPs) were produced by fragmentation of purified diatoms under alkaline conditions. The influence of processing on the surface chemical composition of purified diatomites was evaluated by X-ray photoelectron spectroscopy (XPS). Diatoms NPs were also characterized in terms of morphology and size distribution by transmission electron microscopy (TEM) and Dynamic light scattering (DLS), while diatom MPs morphology was analyzed by scanning electron microscopy (SEM). Surface area and microporosity of the diatom particles were evaluated by nitrogen physisorption methods. Release of silicon ions from diatom-derived particles was demonstrated using inductively coupled plasma optical emission spectrometry (ICP/OES); furthermore, silicon release kinetic was found to be influenced by diatomite purification method and particle size. Diatom-derived microparticles (MPs) and nanoparticles (NPs) showed limited or no cytotoxic effect in vitro depending on the administration conditions.
authors.affiliation: Department of Industrial Engineering, University of Trento, Trento, Italy; BIOtech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy.
authors.forename: Thi Duy Hanh
authors.initials: TDH
authors.lastname: Le
authors.affiliation: Department of Industrial Engineering, University of Trento, Trento, Italy; BIOtech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy; Interuniversity Consortium for Science and Technology of Materials, Trento Research Unit, Trento, Italy.
authors.forename: Walter
authors.initials: W
authors.lastname: Bonani
authors.affiliation: Center for Materials and Microsystems, PAM-SE, Fondazione Bruno Kessler, Trento, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Speranza
authors.affiliation: Department of Industrial Engineering, University of Trento, Trento, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Sglavo
authors.affiliation: Department of Industrial Engineering, University of Trento, Trento, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ceccato
authors.affiliation: Department of Industrial Engineering, University of Trento, Trento, Italy; BIOtech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy; Interuniversity Consortium for Science and Technology of Materials, Trento Research Unit, Trento, Italy.
authors.forename: Devid
authors.initials: D
authors.lastname: Maniglio
authors.affiliation: Department of Industrial Engineering, University of Trento, Trento, Italy; BIOtech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy; Interuniversity Consortium for Science and Technology of Materials, Trento Research Unit, Trento, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Motta
authors.affiliation: Department of Industrial Engineering, University of Trento, Trento, Italy; BIOtech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy; Interuniversity Consortium for Science and Technology of Materials, Trento Research Unit, Trento, Italy. Electronic address: claudio.migliaresi@unitn.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: Migliaresi
mesh_terms: D016475:3T3 Cells; D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones; D017377:Diatoms / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D018786:Bone Substitutes; D012825:Silicon
keywords: Bone regeneration; Diatom nanoparticles; Diatomite; Silica; Silicon release