Monitoring of Carbonated Hydroxyapatite Growth on Modified Polycrystalline CVD-Diamond Coatings on Titanium Substrates

Production of diamond coatings on titanium substrates has demonstrated as a promising strategy for applications ranging from biosensing to hard tissue engineering. The present study focuses on monitoring the nucleation and growth of bone-like carbonated-hydroxyapatite (C-HA) on polycrystalline diamond (PCD) synthetized on titanium substrate by means of a hot filament chemical vapor deposition (HF-CVD) method. The surface terminations of diamond coatings were selectively modified by oxidative treatments. The process of the C-HA deposition, accomplished by precipitation from simulated body fluid (SBF), was monitored from 3 to 20 days by Raman spectroscopy analysis. The coupling of morphological and structural investigations suggests that the modulation of the PCD surface chemistry enhances the bioactivity of the produced materials, allowing for the formation of continuous C-HA coatings with needle-like texture and chemical composition typical of those of the bone mineral. Specifically, after 20 days of immersion in SBF the calculated carbonate weight percent and the Ca/P ratio are 5.5% and 2.1, respectively. Based on these results, this study brings a novelty in tailoring the CVD-diamond properties for advanced biomedical and technological applications

Self-standing 3D-printed PEGDA–PANIs electroconductive hydrogel composites for pH monitoring

Additive manufacturing (AM), or 3D printing processes, is introducing new possibilities in electronic, biomedical, sensor-designing, and wearable technologies. In this context, the present work focuses on the development of flexible 3D-printed polyethylene glycol diacrylate (PEGDA)- sulfonated polyaniline (PANIs) electrically conductive hydrogels (ECHs) for pH-monitoring applications. PEGDA platforms are 3D printed by a stereolithography (SLA) approach. Here, we report the successful realization of PEGDA–PANIs electroconductive hydrogel (ECH) composites produced by an in situ chemical oxidative co-polymerization of aniline (ANI) and aniline 2-sulfonic acid (ANIs) monomers at a 1:1 equimolar ratio in acidic medium. The morphological and functional properties of PEGDA–PANIs are compared to those of PEGDA–PANI composites by coupling SEM, swelling degree, I–V, and electro–chemo–mechanical analyses. The differences are discussed as a function of morphological, structural, and charge transfer/transport properties of the respective PANIs and PANI filler. Our investigation showed that the electrochemical activity of PANIs allows for the exploitation of the PEGDA–PANIs composite as an electrode material for pH monitoring in a linear range compatible with that of most biofluids. This feature, combined with the superior electromechanical behavior, swelling capacity, and water retention properties, makes PEGDA–PANIs hydrogel a promising active material for developing advanced biomedical, soft tissue, and biocompatible electronic applications

Nanodiamond-mediated crystallization in fibers of PANI nanocomposites produced by template-free polymerization : conductive and thermal properties of the fibrillar networks

The detonation nanodiamond is a novel versatile nanomaterial with tunable properties and surface chemistry. In this work, we report on a template-free method to synthesize polyaniline based nanocomposite fibers during a chemical oxidative precipitation polymerization where the cooperative interactions between nanodiamond and polyaniline nucleates trigger the final morphology of the nanocomposite. FE–SEM and TEM observations evidence the prominent growth of fibril-like structures assembled in 2-D networks of tightly woven, partially oriented fibers. Optical and Raman spectroscopy and X-ray diffraction analyses reveal that the polymer chains are in a protonated emeraldine form and organize themselves in a highly ordered 3-D spatial arrangement. Conductivity measurements performed on isolated fibers by a conductive tip of an AFM apparatus highlight that the diamond filler does not affect the conductive properties of the polyaniline matrix while increases the thermal stability of the polymer as confirmed by TGA studies

A special section on nanodiamonds for biomedical applications

The past years have seen an explosive growth of research activities in the field of nanodiamond technology, propelled by the belief that the class of nanostructured C-sp3 materials represents a new approach able to revolutionise many industrial sectors and everyday life. Presently the rate of activity in this field shows no sign of slowing down, as is evident from the outstanding researches published each week on the best-reputed international scientific journals. We are now publishing a special section of Journal of Nanoscience and Nanotechnology covering several aspects of nanodiamond (ND) applications in biomedical and other bio-related fields. Many experts have been invited to participate, to give a rather comprehensive view of today situation and of foreseen evolution. The special section has been organized in such a way to incorporate several different aspects regarding the use of nanodiamonds in bio-related applications. Because of the wide proliferation of information relative to biologically functional nanodiamonds, it was felt that a review summarizing the key points of this research area would be useful

Carbon Nanomaterials for Gas Adsorption

The increasing interest in new technological solution for gas storage, requiring the development of novel solid state media, induced to benchmark carbon nanomaterials as one of the ongoing strategic research areas in science and technology. In such a context, research in adsorption of gases by carbon nanomaterials has experienced considerable growth in recent years, with increasing interest for practical applications. Many research groups are now producing or using such materials for gas adsorption, storage, purification, and sensing. This book provides a selected overview of some of the most interesting scientific results regarding the outstanding properties of carbon nanomaterials for gas adsorption and of interest both for basic research and technological applications. Topics receiving special attention in this book include storage of H, purification of H, storage of rare gases, adsorption of organic vapors, gas trapping and separation, and metrology of gas adsorption. © 2013 Pan Stanford Publishing Pte. Ltd. All rights reserved

Enzyme Mimics Based on Guanidinocalix[4]arene/ Nanodiamond Hybrid Systems with Phosphodiesterase Activity

Diamond nanoparticles are an extremely promising class of carbon-based nanomaterials. Because of their versatility, they have an interest in a large variety of applications, however, their use in the fabrication of enzyme mimics was not previously investigated. In this study, we realized hybrid systems based on guanidinium derivatives and diamond nanoparticles by simple adsorption of the organic material on their surface. The guanidinium derivatives chosen for this study are calix[4]arenes, blocked in the cone conformation via functionalization at the lower rim with alkyl chains, and decorated with guanidinium or arginine units at the upper rim. The corresponding monofunctional counterparts were also investigated as model compounds. These materials were characterized with different experimental techniques, i. e. thermogravimetric analysis, dynamic light scattering, ζ-potential measurements and IR/Raman spectroscopy. Their catalytic properties in the cleavage of phosphodiesters were investigated by an in-depth kinetic analysis. The whole experimental picture points to conclude that these compounds are stably adsorbed onto the nanodiamonds surface and are active in the transesterification reaction of the RNA model compound 2-hydroxypropyl pnitrophenyl phosphate in water, with a notable advantage over their catalytic performances at the same concentration in solution