Magnesium whitlockite nanoparticles: Hydrothermal synthesis, anti-inflammatory and anti-cancer potential.

This study revealed the potential of magnesium whitlockite [WH: Ca18Mg2(HPO4)2(PO4)12] nanoparticles (WH NPs) for anti-inflammatory and anti-cancer therapies. Although magnesium whitlockite possesses promising biological properties, its effects on inflammation and cancer remain unexplored. In this study, we address this gap by synthesizing WH NPs and demonstrating their multifaceted functionalities. Through detailed characterization, we revealed the synthesis pathway involving brushite as a precursor, with magnesium ions incorporated during hydrothermal treatment. WH NPs exhibited anti-inflammatory properties by significantly reducing the production of key inflammatory markers (NO, TNF-α, and IL-6). Furthermore, they display promising anti-cancer activity by inhibiting the proliferation of MDA-MB-231 breast cancer cells. Our findings not only establish a deeper understanding of WH NP synthesis but also highlight their potential for the development of innovative cancer and inflammatory treatments.

Photoelectrochemical Determination of Cardiac Troponin I as a Biomarker of Myocardial Infarction Using a Bi2S3 Film Electrodeposited on a BiVO4-Coated Fluorine-Doped Tin Oxide Electrode.

A sensitive and selective label-free photoelectrochemical (PEC) immunosensor was designed for the detection of cardiac troponin I (cTnI). The platform was based on a fluorine-doped tin oxide (FTO)-coated glass photoelectrode modified with bismuth vanadate (BiVO4) and sensitized by an electrodeposited bismuth sulfide (Bi2S3) film. The PEC response of the Bi2S3/BiVO4/FTO platform for the ascorbic acid (AA) donor molecule was approximately 1.6-fold higher than the response observed in the absence of Bi2S3. The cTnI antibodies (anti-cTnI) were immobilized on the Bi2S3/BiVO4/FTO platform surface to produce the anti-cTnI/Bi2S3/BiVO4/FTO immunosensor, which was incubated in cTnI solution to inhibit the AA photocurrent. The photocurrent obtained by the proposed immunosensor presented a linear relationship with the logarithm of the cTnI concentration, ranging from 1 pg mL-1 to 1000 ng mL-1. The immunosensor was successfully employed in artificial blood plasma samples for the detection of cTnI, with recovery values ranging from 98.0% to 98.5%.

Physical, morphological and bioactive properties of Co-Cr-W-Ta alloys: Influence of insertion of tantalum and surface thermochemical treatment on bioactivity.

The development of bioactivity in bioinert metallic alloys is a field of interest aiming to improve some aspects of these materials for implant applications. New Co63 Cr28 W9-x Tax alloys with different Ta concentrations (x = 0, 2, 4, 6, and 9% w/w) were synthesized in the work reported here. The alloys were characterized by x-ray diffraction, volumetric density, Vickers microhardness, atomic force microscopy, scanning electron microscopy (SEM), and energy-dispersion x-ray spectroscopy (EDS). Bioactivity properties were evaluated by in vitro tests with simulated body fluid (SBF). In vivo assays were performed to assess biocompatibility. The influence of surface thermochemical treatment and Ta insertion on the bioactive properties of the alloys was investigated. The results showed that the alloy structure comprises εCo and αCo phases, with cobalt as a matrix with Cr, W, and Ta as a solid solution. TaCo2 phase is observed in the alloys with 4, 6, and 9% w/w of Ta, and its amount increase as Ta concentration increases. Volumetric density is reduced (from 8.78 ± 0.06 to 8.56 ± 0.09 g/cm3 ) as Ta concentration increases (from 0% to 9% w/w) mainly due to the lower density of the tantalum compared to the tungsten metal. On the other hand, the TaCo2 phase contributes to the increase of Vickers's hardness by ~17.6% for the alloy with 9% Ta (394.7 ± 8.1 HV) compared with Co63 Cr28 W9 (336 ± 5 HV). The topographic analysis showed increased roughness and adhesion due to the nucleation of Ta1.1 O1.05 and Ca2 Ta2 O7 crystals after surface thermochemical treatment. The roughness and adhesion increase from 16.9 ± 0.6 nm and 8.3 ± 1.8 nN (untreated surface) to 255.7 ± 17.7 nm and 24.1 ± 12.6 nN (treated surface), respectively, for the Co63 Cr28 Ta9 alloy. These results suggest that thermochemical treatment provides surface conditions favorable to hydroxyapatite (HA) nucleation. The SEM and EDS data showed the nucleation of spongy structures, consistent with HA, composed mainly of Ca and P, indicating that oxides tantalum promoted a bioactive response on the sample's surface. The biological assay corroborated the alloy's safety and applicability, highlighting its potential in biomedical application since no harmful effects were observed.

Chitosan-graphene quantum dot based active film as smart wound dressing.

Graphene quantum dots (GQDs), are biocompatible materials, with mechanical strength and stability. Chitosan, has antibacterial and anti-inflammatory properties, and biocompatibility. Wound healing is a challenging process especially in chronic diseases and infection. In this study, films consisting of chitosan and graphene quantum dots were developed for application in infected wounds. The chitosan-graphene films were prepared in the acidic solution followed by slow solvent evaporation and drying. The chitosan-graphene films were characterized by the scanning electron microscopy, x-ray diffraction, atomic force microscopy, Raman spectroscopy and thermogravimetric analysis. The films' was evaluated by the wound healing assays, hemolytic potential, and nitrite production, cytokine production and swelling potential. The obtained films were flexible and well-structured, promoting cell migration, greater antibacterial activity, lower hemolytic activity, and maintaining wound moisture. Our data suggested that the use of graphene quantum dot-containing chitosan films would be an efficient and promising way in combating wounds.

Folic acid-functionalized graphene quantum dots: Synthesis, characterization, radiolabeling with radium-223 and antiviral effect against Zika virus infection.

The use of graphene quantum dots as biomedical devices and drug delivery systems has been increasing. The nano-platform of pure carbon has shown unique properties and is approved to be safe for human use. In this study, we successfully produced and characterized folic acid-functionalized graphene quantum dots (GQD-FA) to evaluate their antiviral activity against Zika virus (ZIKV) infection in vitro, and for radiolabeling with the alpha-particle emitting radionuclide radium-223. The in vitro results exhibited the low cytotoxicity of the nanoprobe GQD-FA in Vero E6 cells and the antiviral effect against replication of the ZIKV infection. In addition, our findings demonstrated that functionalization with folic acid doesn't improve the antiviral effect of graphene quantum dots against ZIVK replication in vitro. On the other hand, the radiolabeled nanoprobe 223Ra@GQD-FA was also produced as confirmed by the Energy Dispersive X-Ray Spectroscopy analysis. 223Ra@GQD-FA might expand the application of alpha targeted therapy using radium-223 in folate receptor-overexpressing tumors.

Graphene quantum dots unraveling: Green synthesis, characterization, radiolabeling with 99mTc, in vivo behavior and mutagenicity.

Graphene is one of the crystalline forms of carbon, along with diamond, graphite, carbon nanotubes, and fullerenes, and is considered as a revolutionary and innovating product. The use of a graphene-based nanolabels is one of the latest and most prominent application of graphene, especially in the field of diagnosis and, recently, in loco radiotherapy when coupled with radioisotopes. However, its biological behavior and mutagenicity in different cell or animal models, as well as the in vivo functional activities, are still unrevealed. In this study we have developed by a green route of synthesizing graphene quantum dots (GQDs) and characterized them. We have also developed a methodology for direct radiolabeling of GQDs with radioisotopes.Finally; we have evaluated in vivo biological behavior of GQDs using two different mice models and tested in vitro mutagenicity of GQDs. The results have shown that GQDs were formed with a size range of 160-280 nm, which was confirmed by DRX and Raman spectroscopy analysis, corroborating that the green synthesis is an alternative, environmentally friendly way to produce graphene. The radiolabeling test has shown that stable radiolabeled GQDs can be produced with a high yield (>90%). The in vivo test has demonstrated a ubiquitous behavior when administered to healthy animals, with a high uptake by liver (>26%) and small intestine (>25%). Otherwise, in an inflammation/VEGF hyperexpression animal model (endometriosis), a very peculiar behavior of GQDs was observed, with a high uptake by kidneys (over 85%). The mutagenicity test has demonstrated A:T to G:C substitutions suggesting that GQDs exhibits mutagenic activity.