Biomimetic composites by surface-initiated polymerization of cyclic lactones at anorganic bone: preparation and in vitro evaluation of osteoblast and osteoclast competence.

Biomimetic composites were constructed using anorganic bone to initiate the polymerization of cyclic lactones. The resulting anorganic bone/polylactone composites preserve the inorganic structure and the mechanical properties of the original bone. Thermal conditions used to prepare the anorganic bone were shown to control the surface functionalities, surface area, and crystallinity, all of which influence the rates of subsequent polymerizations.

Quantized magnetoresistance in atomic-size contacts.

When the dimensions of a metallic conductor are reduced so that they become comparable to the de Broglie wavelengths of the conduction electrons, the absence of scattering results in ballistic electron transport and the conductance becomes quantized. In ferromagnetic metals, the spin angular momentum of the electrons results in spin-dependent conductance quantization and various unusual magnetoresistive phenomena. Theorists have predicted a related phenomenon known as ballistic anisotropic magnetoresistance (BAMR).

Electrochemical preparation of chitosan/hydroxyapatite composite coatings on titanium substrates.

Composite coatings containing brushite (CaHPO(4). 2H(2)O) and chitosan were prepared by electrochemical deposition. The brushite/chitosan composites were converted to hydroxyapatite/chitosan composites in aqueous solutions of sodium hydroxide.

Reversible electrochemical generation of a rhodium(II) porphyrin: thwarting disproportionation with weakly coordinating anions.

We report electrochemical generation of a stable Rh(II) porphyrin (Rh(II)(F(28)TPP)) from a four-coordinate Rh(I) precursor [Rh(I)(F(28)TPP)](-) dissolved in weakly coordinating electrolyte solutions. This work provides the first example of an unambiguously reversible one-electron electrochemical oxidation of a Rh(I)(por), and demonstrates that electrochemical oxidation can be performed under conditions that are compatible with alkane activation. These studies begin to classify those media capable of supporting a stable Rh(II)(por), and those that induce disproportionation.

Characterization of electrolytically prepared brushite and hydroxyapatite coatings on orthopedic alloys.

Details of a procedure for electrolytically preparing highly pure brushite (CaHPO4.2H2O) coatings on high surface area metal substrates are provided. The influence of current density and deposition time on coating morphology is described.