Tracking the formation of vaterite particles containing aminopropyl-functionalized silsesquioxane and their structure for bone regenerative medicine.

Vaterite particles containing aminopropyl-functionalized silsesquioxane (SiV) were prepared as osteogenic devices for bone regeneration. The SixV particles (x = 0, 2.6 and 4.9 wt%) were synthesized by reacting a slurry of calcium hydroxide with carbon dioxide gas in the presence of γ-aminopropyltriethoxysilane (APTES), a source of soluble silica which would genetically enhance osteogenesis. The obtained Si2.6V and Si4.9V particles were monodispersed with a diameter of 1.4 and 1.5 μm, respectively. The Si2.6V particles showed spherical morphologies. On the surface of the Si4.9V particle small particles were aggregated, resulting in the formation of irregular textures. Transmission electron microscopy of a sectioned Si2.6V particle revealed that the vaterite particles were present as lamellae with a length of 5-20 nm and surrounded by silsesquioxane from APTES. Moreover, the vaterite lamellae were relatively orientated to the c face of the unit lattice, where it is known to be highly polarized, compared to pure vaterite, due to the exposure of the uni-ionic plane with positive (Ca2+) or negative (CO3 2-) charge. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) revealed the co-existence of amorphous calcium carbonate (ACC) in the SiV particles. On contact with physiological pH buffer solution, the vaterite was transiently stabilized and subsequently dissolved and released after the dissolution of silsesquioxane from the particles. This stabilization time was significantly increased with the increase in silicon content. The vaterite was observed in Si2.6V particles up to 3 h of soaking, which extended up to 12 h in Si4.9V particles. The formation of the particles from the precursor gel was monitored by laser Raman spectroscopy and ATR-FTIR. During the initial 1 to 2 h of the aging step, maturation of ACC into vaterite and condensation of monomeric APTES molecules were found to begin simultaneously. These reactions proceeded up to 7 h of the analysis period. The condensation of hydrolyzed APTES is suggested to occur in the vicinity of growing vaterite, which might play a role in the enclosure of vaterite in silsesquioxanes.

[1]  Aldo R Boccaccini,et al.  A review of the biological response to ionic dissolution products from bioactive glasses and glass-ceramics. , 2011, Biomaterials.

[2]  A. Obata,et al.  Effect of preparation route on the degradation behavior and ion releasability of siloxane-poly(lactic acid)-vaterite hybrid nonwoven fabrics for guided bone regeneration. , 2011, Dental materials journal.

[3]  D. Mooney,et al.  Growth factor delivery-based tissue engineering: general approaches and a review of recent developments , 2011, Journal of The Royal Society Interface.

[4]  João F. Mano,et al.  Polymer/bioactive glass nanocomposites for biomedical applications: A review , 2010 .

[5]  A. Obata,et al.  Electrospun microfiber meshes of silicon-doped vaterite/poly(lactic acid) hybrid for guided bone regeneration. , 2010, Acta biomaterialia.

[6]  M. Bohner,et al.  Silicon-substituted calcium phosphates - a critical view. , 2009, Biomaterials.

[7]  David J Mooney,et al.  Controlled Growth Factor Delivery for Tissue Engineering , 2009, Advanced materials.

[8]  Maryam Tabrizian,et al.  Delivery of recombinant bone morphogenetic proteins for bone regeneration and repair. Part B: Delivery systems for BMPs in orthopaedic and craniofacial tissue engineering , 2009, Biotechnology Letters.

[9]  Shu-Chen Huang,et al.  Effect of Molecular Weights of Poly(acrylic acid) on Crystallization of Calcium Carbonate by the Delayed Addition Method , 2008 .

[10]  M. Antonietti,et al.  Uniform Hexagonal Plates of Vaterite CaCO3 Mesocrystals Formed by Biomimetic Mineralization , 2006 .

[11]  W. Bonfield,et al.  Silicon-substituted hydroxyapatite (SiHA): A novel calcium phosphate coating for biomedical applications , 2006 .

[12]  M. Antonietti,et al.  Superstructures of Calcium Carbonate Crystals by Oriented Attachment , 2005 .

[13]  P. K. Ajikumar,et al.  Synthesis and Characterization of Monodispersed Spheres of Amorphous Calcium Carbonate and Calcite Spherules , 2005 .

[14]  Julian R. Jones,et al.  Nodule formation and mineralisation of human primary osteoblasts cultured on a porous bioactive glass scaffold. , 2004, Biomaterials.

[15]  Steve Weiner,et al.  Taking Advantage of Disorder: Amorphous Calcium Carbonate and Its Roles in Biomineralization , 2003 .

[16]  F. Meldrum,et al.  The role of magnesium in stabilising amorphous calcium carbonate and controlling calcite morphologies , 2003 .

[17]  W. Bonfield,et al.  A comparative study on the in vivo behavior of hydroxyapatite and silicon substituted hydroxyapatite granules , 2002, Journal of materials science. Materials in medicine.

[18]  S. Vilminot,et al.  Structural characterisations of a lamellar organic–inorganic nickel silicate obtained by hydrothermal synthesis from nickel acetate and (aminopropyl)triethoxysilane , 2002 .

[19]  J. Aizenberg,et al.  Factors involved in the formation of amorphous and crystalline calcium carbonate: a study of an ascidian skeleton. , 2002, Journal of the American Chemical Society.

[20]  L L Hench,et al.  Gene-expression profiling of human osteoblasts following treatment with the ionic products of Bioglass 45S5 dissolution. , 2001, Journal of biomedical materials research.

[21]  Larry L. Hench,et al.  Bioglass ®45S5 Stimulates Osteoblast Turnover and Enhances Bone Formation In Vitro: Implications and Applications for Bone Tissue Engineering , 2000, Calcified Tissue International.

[22]  A. Klibanov,et al.  FTIR characterization of the secondary structure of proteins encapsulated within PLGA microspheres. , 1999, Journal of controlled release : official journal of the Controlled Release Society.

[23]  T. Park,et al.  Protein delivery from poly(lactic-co-glycolic acid) biodegradable microspheres: release kinetics and stability issues. , 1998, Journal of microencapsulation.

[24]  B. Riegel,et al.  Kinetic investigations of hydrolysis and condensation of the glycidoxypropyltrimethoxysilane/aminopropyltriethoxy-silane system by means of FT-Raman spectroscopy I , 1998 .

[25]  H. Okabayashi,et al.  Kinetics of interaction of 3-aminopropyltriethoxysilane with silica gel using elemental analysis and 29Si NMR spectra , 1997 .

[26]  K. Sawada The mechanisms of crystallization and transformation of calcium carbonates , 1997 .

[27]  A. Golub,et al.  γ-APTES Modified Silica Gels: The Structure of the Surface Layer , 1996 .

[28]  J. Sonnefeld,et al.  Aminopolysiloxane gels: production and properties , 1996 .

[29]  Chikara Ohtsuki,et al.  Dependence of apatite formation on silica gel on its structure : effect of heat treatment , 1995 .

[30]  K. Nakanishi,et al.  Apatite Formation Induced by Silica Gel in a Simulated Body Fluid , 1992 .

[31]  S. Milonjić A relation between the amounts of sorbed alkali cations and the stability of colloidal silica , 1992 .

[32]  A. Dent,et al.  An EXAFS study of uranyl ion in solution and sorbed onto silica and montmorillonite clay colloids , 1992 .

[33]  K. Takaoka,et al.  Telopeptide‐depleted bovine skin collagen as a carrier for bone morphogenetic protein , 1991, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[34]  J. Koenig,et al.  The structure of aminofunctional silane coupling agents: 1. γ-Aminopropyltriethoxysilane and its analogues , 1982 .

[35]  C. L. Frye,et al.  Oligomeric silsesquioxanes, (HSiO3/2)n , 1970 .

[36]  A. V. Cleave,et al.  Adsorption and flotation studies with quartz: Part I. Adsorption of calcium, hydrogen and hydroxyl ions on quartz , 1965 .

[37]  John F. Brown,et al.  Preparation and Characterization of the Lower Equilibrated Phenylsilsesquioxanes , 1964 .

[38]  J. Clarkson,et al.  Role of metastable phases in the spontaneous precipitation of calcium carbonate , 1992 .

[39]  H. Ishida,et al.  Studies of the simulation of silane coupling agent structures on particulate fillers; the pH effect , 1984 .

[40]  J. Koenig,et al.  Raman studies of the hydrolysis of silane coupling agents , 1975 .