Laser powder bed fusion (L-PBF) is one of the most promising additive manufacturing technologies for creating customised 316L Stainless Steel (SS) implants with biomimetic characteristics, controlled porosity, and optimal structural and functional properties. However, the behaviour of as-fabricated 3D 316L SS structures without any surface finishing in environments that simulate body fluids remains largely unknown. To address this knowledge gap, the present study investigates the surface characteristics, the internal porosity, the corrosion in simulated body fluid (SBF), and the mechanical properties of as-fabricated 316L SS structures manufactured by L-PBF with rhombitruncated cuboctahedron (RTCO) unit cells with two distinct relative densities (10 and 35%).
View Article and Find Full Text PDFThis study aimed to develop multifunctional nanoplatforms for both cancer imaging and therapy using superparamagnetic iron oxide nanoparticles (SPIONs). Two distinct synthetic methods, reduction-precipitation (M) and co-precipitation at controlled pH (M), were explored, including the assessment of the coating's influence, namely dextran and gold, on their magnetic properties. These SPIONs were further functionalized with gadolinium to act as dual T1/T2 contrast agents for magnetic resonance imaging (MRI).
View Article and Find Full Text PDFBiodegradable metals have been extensively studied due to their potential use as temporary biomedical devices, on non-load bearing applications. These types of implants are requested to function for the healing period, and should degrade after the tissue heals. A balance between mechanical properties requested at the initial stage of implantation and the degradation rate is required.
View Article and Find Full Text PDFBiodegradable magnesium (Mg)-based metal matrix composites are promising candidates for orthopaedic applications since magnesium is an abundant mineral in the human body. To improve the bioactivity and cytocompatibility of these Mg composites, hydroxyapatite nanoparticles (HAP) and fluorapatite (FA) microparticles synthesised by a citrate-derived hydrothermal method were introduced into a Mg matrix. These innovative Mg/HAP/FA composites were produced by multi-pass upward friction stir processing (UFSP).
View Article and Find Full Text PDFPolymeric platforms obtained by three-dimensional (3D) printing are becoming increasingly important as multifunctional therapeutic systems for bone treatment applications. In particularly, researchers aim to control bacterial biofilm on these 3D-platforms and enhance re-growing bone tissue, at the same time. This study aimed to fabricate a 3D-printed polylactic acid platform loaded with hydroxyapatite (HA), iron oxide nanoparticles (IONPs) and an antibiotic (minocycline) with tuneable properties and multistimuli response.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
October 2020
The development of biomaterials that mimicking the hydroxyapatite nanoparticles existent in the immature bone tissue is crucial, especially to accelerate the bone remodeling and regeneration. In this work, it was developed for the first time, hydroxyapatite nanoparticles (NPs) incorporating citrate and zinc (cit-Zn-Hap) in their composition towards a one-step hydrothermal procedure. For comparison purposes, hydroxyapatite NPs incorporating only zinc (Zn-Hap) or citrate (cit-Hap), as well as hydroxyapatite without any of these elements (Hap) were synthesised.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
August 2020
The presence of a biomimetic HAP coating on titanium surface, which reduces the structural stiffness, is essential to improve implants biocompatibility and osteointegration. In this study, new citrate-HAP (cHAP) coatings were produced by a simple hydrothermal method on pure titanium (Ti) surface, without requiring any additional pretreatment on this metal surface. The formed cHAP coatings consisting of nanorod-like hydroxyapatite particles, conferred nanoroughness and wettability able to endow improved biological responses.
View Article and Find Full Text PDFConsecutive layers of Ni(OH) and Co(OH) were electrodeposited on stainless steel current collectors for preparing charge storage electrodes of high specific capacity with potential application in hybrid supercapacitors. Different electrodes were prepared consisting on films of Ni(OH), Co(OH), NiCo(OH) and layered films of Ni(OH) on Co(OH) and Co(OH) on Ni(OH) to highlight the advantages of the new architecture. The microscopy studies revealed the formation of nanosheets in the Co(OH) films and of particles agglomerates in the Ni(OH) films.
View Article and Find Full Text PDFCurrent transient evolution and in situ electrochemical AFM were used to study the initial stages of growth of electrochemically deposited nickel cobalt hydroxide films for energy storage applications. Current transients were taken at constant potentials, from -700 mV to -1000 mV, with a step of 50 mV. The current transients were fitted with three different nucleation models: Scharifker-Hill, Scharifker-Mostany and Mirkin-Nilov-Heerman-Tarallo and the results revealed that film growth was governed by a 3D instantaneous nucleation mechanism.
View Article and Find Full Text PDFThis work reports the fabrication, by electrodeposition and post-thermal annealing, of hybrid electrodes for high rate electrochemical energy storage composed of nickel manganese oxide (Ni0.86Mn0.14O) nanosheets over 3D open porous dendritic NiCu foams.
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