Title:
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Metallization and remineralization strategies
based on bovine dentine
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Bovine dentine has been used as a template for the electrochemical crystallization of
copper microwires, and as a target surface for two amorphous calcium phosphate
(ACP) mediated remineralization vectors. When used as a macroporous template,
spatially separated co-aligned arrays of copper microwires were synthesized within the
dentine tubules by electrochemical deposition. The high-aspect ratio wires were
continuous throughout the dentine matrix, 1-4 11m in thickness and rendered the
composite material electrically conductive with enhanced mechanical hardness. A
macromolecular-rich, coacervate phase, self assembled from the mixing of aqueous
solutions of poly(diallyldimethylammonium) chloride (PDDA) and poly(ethylene glycol)
4-nonylphenyl 3-sulfopropyl ether potassium salt (51) was used as a synthetic medium
and delivery vector for ACP nanoparticles to the dentine surface. Physical
characterization of the coacervate phase showed dispersions of droplets of differing
surface charge, water content and size could be prepared by alteration of initial
component stoichiometries. The high concentration of macromolecules present within
the coacervate phase enhanced the meta-stability of the amorphous particles and
imparted morphological control on the ACP spherules. Preliminary studies to
determine viability of the coacervate as a delivery vector for the ACP-mediated
occlusion of dentine tubules showed improved mineral penetration and tubule
occlusion in comparison with control assays. The remineralization capacity of hybrid,
electrospun mats of the polymer poly(vinylpyrrolidone) (PVP) and stabilized (ACP)
particles was determined. The ACP particles were characterized by a range of
techniques which showed they were amorphous and prone to aggregation. When
electrospun from ethanol based solutions with the polymer composite mats
comprising amorphous particles 48 % by mass were produced. Assessment of the
efficacy of the mats as a vector for the ACP-mediated occlusion of dentine tubules
showed the delivery of micrometre scale particles to the dentine surface, which did
not form a contiguous surface coverage, or result in tubule occlusion.
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