Effect of Cold-Sintering Parameters on Structure, Density, and Topology of Fe-Cu Nanocomposites.

The design of advanced nanostructured materials with predetermined physical properties requires knowledge of the relationship between these properties and the internal structure of the material at the nanoscale, as well as the dependence of the internal structure on the production (synthesis) parameters. This work is the first report of computer-aided analysis of high pressure consolidation (cold sintering) of bimetallic nanoparticles of two immiscible (Fe and Cu) metals using the embedded atom method (EAM). A detailed study of the effect of cold sintering parameters on the internal structure and properties of bulk Fe-Cu nanocomposites was conducted within the limitations of the numerical model.

Synthesis of antimicrobial AlOOH-Ag composite nanostructures by water oxidation of bimetallic Al-Ag nanoparticles.

The facile one-step synthesis of AlOOH-Ag nanocomposite has been performed. Bimetallic Al-Ag nanoparticles prepared by electrical explosion of Al and Ag wires were used as a precursor. AlAg nanoparticles consisted of a supersaturated Al-6 at% Ag solid solution and Ag-rich Guinier-Preston zone several nanometer in diameter that were not detected by XRD due to their extremely small size and peculiarities of their crystal structure.

Crumpled Aluminum Hydroxide Nanostructures as a Microenvironment Dysregulation Agent for Cancer Treatment.

Owing to their unique physicochemical properties, nanomaterials have become a focus of multidisciplinary research efforts including investigations of their interactions with tumor cells and stromal compartment of tumor microenvironment (TME) toward the development of next-generation anticancer therapies. Here, we report that agglomerates of radially assembled Al hydroxide crumpled nanosheets exhibit anticancer activity due to their selective adsorption properties and positive charge. This effect was demonstrated in vitro by decreased proliferation and viability of tumor cells, and further confirmed in two murine cancer models.

Microstructure, mechanical characteristics and cell compatibility of β-tricalcium phosphate reinforced with biodegradable Fe-Mg metal phase.

The use of beta-tricalcium phosphate (β-TCP) ceramic as a bioresorbable bone substitute is limited to non-load-bearing sites by the material׳s brittleness and low bending strength. In the present work, new biocompatible β-TCP-based composites with improved mechanical properties were developed via reinforcing the ceramic matrix with 30 vol% of a biodegradable iron-magnesium metallic phase. β-TCP-15Fe15Mg and β-TCP-24Fe6Mg (vol%) composites were fabricated using a combination of high energy attrition milling, cold sintering/high pressure consolidation of powders at room temperature and annealing at 400 °C.

Osseointegration of Ti-6Al-4V alloy implants with a titanium nitride coating produced by a PIRAC nitriding technique: a long-term time course study in the rat.

This study examined bone tissue responses to Ti-6Al-4V alloy implants with a hard TiN coating applied by an original powder immersion reaction-assisted coating (PIRAC) nitriding method. Progression of implant fixation in the distal epiphysis and within the medullary cavity of the rat femur was evaluated between 3 days and 6 months postimplantation by scanning electron microscopy, oxytetracycline incorporation, and histochemistry. After 6 months, successful osseointegration was achieved in both epiphyseal and diaphyseal sites.

β-TCP-polylactide composite scaffolds with high strength and enhanced permeability prepared by a modified salt leaching method.

A modified particulate leaching method for fabrication of strong calcium phosphate-polymer composite scaffolds with improved pore interconnectivity is reported. The scaffolds were produced by mixing precompacted composite granules (β-TCP with 40vol% PLA) of different size and density with salt particles followed by high pressure consolidation (at room temperature or 120°C) and porogen dissolution. The scaffolds' compressive strength and Darcy's permeability were found to be inversely related and to be strongly dependent on the processing parameters.

Mesenchymal stem cell proliferation and differentiation on load-bearing trabecular Nitinol scaffolds.

Bone tissue regeneration in load-bearing regions of the body requires high-strength porous scaffolds capable of supporting angiogenesis and osteogenesis. 70% porous Nitinol (NiTi) scaffolds with a regular 3-D architecture resembling trabecular bone were produced from Ni foams using an original reactive vapor infiltration technique. The "trabecular Nitinol" scaffolds possessed a high compressive strength of 79 MPa and high permeability of 6.

Strong bioresorbable Ca phosphate-PLA nanocomposites with uniform phase distribution by attrition milling and high pressure consolidation.

Highly dense bioresorbable Ca-deficient HA-PLA (CDHA-PLA) and β-TCP-PLA nanocomposite materials with high (up to 80 vol%) contents of the calcium phosphate (CaP) phase and homogeneous phase distribution were prepared via attrition milling followed by high pressure consolidation at ambient temperature. The microstructure and mechanical properties of the materials obtained were studied as a function of milling time and PLA amount. Attrition milling resulted in disintegration of β-TCP powder agglomerates down to 50-150 nm, disintegration of CDHA agglomerates and refinement of 15 × 150 nm(2) CDHA nanoparticles to a size of 8 × 20 nm(2), and in a uniform distribution of the polymer component.

Phosphonate-anchored monolayers for antibody binding to magnetic nanoparticles.

Targeted delivery of magnetic iron oxide nanoparticles (IONPs) to a specific tissue can be achieved by conjugation with particular biological ligands on an appropriately functionalized IONP surface. To take best advantage of the unique magnetic properties of IONPs and to maximize their blood half-life, thin, strongly bonded, functionalized coatings are required. The work reported herein demonstrates the successful application of phosphonate-anchored self-assembled monolayers (SAMs) as ultrathin coatings for such particles.

Biomimetic calcium phosphate coating on Ti wires versus flat substrates: structure and mechanism of formation.

Biomimetic calcium phosphate (Ca-P) coatings improve the osteoconductivity of orthopedic implants and show promise as slow delivery systems for growth factors. This paper compares the structure and composition of biomimetic coatings on flat titanium coupons and on Ti wires/thin pins that are often used as model implants in small animal in vivo models. Ca-P coatings were grown on alkali-treated Ti substrates using a two-step deposition procedure.

Protein incorporation within Ti scaffold for bone ingrowth using Sol-gel SiO2 as a slow release carrier.

Porous titanium structures hold considerable promise as scaffolds for bone ingrowth in load bearing locations provided they are made osteoinductive by incorporation of bone growth factors. The purpose of the present research was to incorporate soybean trypsin inhibitor (STI) imitating growth factor into a porous Ti scaffold using sol-gel silica as a slow-release protein carrier. Alcohol-free TMOS-based sols (of pH 2 or 5) with dissolved STI were injected into Ti wire scaffolds yielding SiO(2) coating on the wire struts and SiO(2) beads entrapped in-between the wires.

Bonelike apatite formation on niobium metal treated in aqueous NaOH.

The essential condition for a biomaterial to bond to the living bone is the formation of a biologically active bonelike apatite on its surface. In the present work, it has been demonstrated that chemical treatment can be used to create a calcium phosphate (CaP) surface layer, which might provide the alkali treated Nb metal with bone-bonding capability. Soaking Nb samples in 0.