Silicon hydroxyapatite

Vallet-Regi, M. and Arcos D. (2005) Silicon substituted hydroxyapatites. A method to upgrade calcium phosphate based implants. Journal of Materials Chemistry, 15, 1509—1516. 

The solid bases CaO and hydroxyapatite catalyze the hydrosilylation of benz-aldehyde by triethoxysilane at 90° in yields of 59% and 72% within one and two hours, respectively.323,324 These reductions also very likely involve activation by valence expansion of the silicon hydride reagent. 

Fig. 16.7. SEM micrographs of hydroxyapatite (b) Cross-section of substrate shown in (a), (c) spherulites deposited upon porous silicon Deposition adjacent to anodized region after...

Biomimetic hydroxyapatite deposition routes were investigated on titanium oxide surfaces (Xia etal., 2011), silicon nitride (Chaves Guedes e Silva etal., 2008), wollastonite (Huang, Jiang and Tan, 2004), canasite (Ca5Na3K3Si12O30(OH,F)4) glass ceramic (Miller etal., 2002) and also pyrolytic carbon and carbon-carbon composite (CCC) ceramics (Hoppe etal., 2013). 

A.H., and Bressiani, J.C. (2008) Hydroxyapatite coating on silicon nitride surfaces using the biomimetic method. Mater. Res., 11 (1), 47-50. 

Hijon, N., Victoria Cabanas, M., Pena, J., and Vallet-Regi, M. (2006b) Dip coated silicon-substituted hydroxyapatite films. Acta Biomater., 2 (5), 567-574. 

Porter, A.E., Best, S.M., and Bonfield, W. (2004) Ultrastructural comparison of hydroxyapatite and silicon-substituted hydroxyapatite for biomedical applications. J. Biomed. Mater. Res. A, 68 (1), 133—141. Pourbaghi-Masouleh, M. and Asgharzadeh,... 

Zhang, E., Zou, C.M., and Zang, S.Y. (2009) Preparation and characterization of silicon-substituted hydroxyapatite coating by a biomimetic process on titanium substrate. Surf. Coat. TechnoL, 203 (8), 1075-1080. 

A metal foil such as Ti6Al4V attached to a copper block by a 1 2 mixture of a silicone sealant (Dow Corning 732) and copper powder (ALCAN 154, grain size range < 44 pm) will act as a heat sink. The adhesive is cured at ambient temperature for 12 h. Then the foil is coated by plasma spraying, for example with either hydroxyapatite or a hydroxyapatite top coat/titania bond coat system (Heimann, 1999). The procedure is shown in Figure 7.27. 

Zhang, E. and Zou, C.M. (2009) Porous titanium and silicon-substituted hydroxyapatite biomodification prepared by a biomimetic process characterization and in vivo evaluation. Acta Biomater., 5 (5), 1732-1741. 

Ceramics used in fabricating implants can be classified as nonabsorbable (relatively inert), bioactive or surface reactive (semi-inert) [Hench, 1991,1993] and biodegradable or resorbable (non-inert) [Hentrich et al., 1971 Graves et al., 1972]. Alumina, zirconia, silicone nitrides, and carbons are inert bioceramics. Certain glass ceramics and dense hydroxyapatites are semi-inert (bioreactive) and calcium phosphates and calcium aluminates are resorbable ceramics [Park and Lakes, 1992]. 

Gibson IR, Best SM, Bonfield W. Chemical characterization of silicon-substituted hydroxyapatite. J Biomed Mater Res. 1999 44 422-8. 

See Carbon black Ebonex SC-5. See Bone black Ebonex Bone Ash. See Hydroxyapatite Ebonex Cosmic Black. See Bone black Ebony Novacite. See Novaculite E-BR 8405. See Polybutadiene EC. See Ethylcellulose E-C-2. See PEG-2 cocamine EC-209. See Polyaluminum chloride ECA. See Ethyl 2-cyanoacrylate Cyanoethylethyl aniline 2-ECA. See 2-Ethyl butenal ECC 440, ECC 443] ECC 450, ECC 453. See Silicone... 

Antimony trioxide-brominated PC [30], silicones [46, 47] and hydroxyapatite [48] have all been studied as flame-retardants for PC. Figure 6.1 shows the perceived flame retardancy mechanism occurring during the thermal decomposition of PC containing trifunctional phenyl silicone based additives [47]. This process involves the formation of a p-cumylphenoxy end-structure. 

The term biocompatibility is defined as the ability of a material to perform with an appropriate host response in a specific situation" (Williams 2008). A biocompatible material can be inert, where it would not induce a host immune response and have little or no toxic properties. A biocompatible material can also be bioactive, initiating a controlled physiological response. For porous silicon, bioactive properties were initially suggested based on the observation that hydroxyapatite (HA) crystals grow on microporous silicon films. HA has implications for bone tissue implants and bone tissue engineering (Canham 1995). An extension of this work showed that an applied cathodic current was able to further promote calcification on the surface (Canham et al. 1996). More recently, Moxon et al. showed another example of bioactive porous silicon where the material promoted neuron viability when inserted into rat brains as a potential neuronal biosensor, whereas planar silicon showed significantly fewer viable neurons surrounding the implant site (Moxon et al. 2007). 

In the previous chapter, two examples of multifunetional drag delivery systems applying PSi luminescent and photonic properties were described, but there are many other possibilities to include additional functionalities to the delivery systems. One of the most studied applications is PSi-poljuner composite structures in which PSi have a dual role as a hydroxyapatite growth activator and drag carrier (Mukheijee et al. 2006 Fan et al. 2009, 2011). The composite structures are described in detail in chapter Poljnner-Porous Silicon Composites. ... 

Silanols are utilised for silicon-based polymeric materials and also find use as nucleophilic coupling partners in organic synthesis. Traditional synthetic methods utilise toxic reagents and are non-environmentally friendly, and other recently reported synthetic methods, in the absence of organic solvents, suffer the main drawback of the production of disiloxanes. Recent results by Kaneda et al. overcome this by using water as the solvent, with silver supported in hydroxyapatite with Mtde condensation to the disiloxanes. They show that the reaction can also be catalysed by homogeneous silver, although the supported nanoparticles were superior and reusable without any loss of activity or selectivity. 

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