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The use of alpha-particle (α-particle) radionuclides, especially [223Ra]RaCl2 (radium dichloride), for targeted alpha therapy is steadily increasing. Despite the positive clinical outcomes of this therapy, very little data are available about the effect on the ultrastructure of cells. The purpose of this study was to evaluate the nanomechanical and ultrastructure effect of [223Ra] RaCl2 on cancer cells. To analyze the effect of [223Ra]RaCl2 on tumor cells, human breast cancer cells (lineage MDA-MB-231) were cultured and treated with the radiopharmaceutical at doses of 2 µCi and 0.9 µCi. The effect was evaluated using atomic force microscopy (AFM) and transmission electron microscopy (TEM) combined with Raman spectroscopy. The results showed massive destruction of the cell membrane but preservation of the nucleus membrane. No evidence of DNA alteration was observed. The data demonstrated the formation of lysosomes and phagosomes. These findings help elucidate the main mechanism involved in cell death during α-particle therapy. [ABSTRACT FROM AUTHOR]

Alpha and beta particulate radiation are used for non-treated neoplasia, due to their ability to reach and remain in tumor sites. Radium-223 (223Ra), an alpha emitter, promotes localized cytotoxic effects, while radioactive gold (198Au), beta-type energy, reduces radiation in the surrounding tissues. Nanotechnology, including several radioactive nanoparticles, can be safely and effectively used in cancer treatment. In this context, this study aims to analyze the antitumoral effects of [223Ra]Ra nanomicelles co-loaded with radioactive gold nanoparticles ([198Au]AuNPs). For this, we synthesize and characterize nanomicelles, as well as analyze some parameters, such as particle size, radioactivity emission, dynamic light scattering, and microscopic atomic force. [223Ra]Ra nanomicelles co-loaded with [198Au]AuNPs, with simultaneous alpha and beta emission, showed no instability, a mean particle size of 296 nm, and a PDI of 0.201 (±0.096). Furthermore, nanomicelles were tested in an in vitro cytotoxicity assay. We observed a significant increase in tumor cell death using combined alpha and beta therapy in the same formulation, compared with these components used alone. Together, these results show, for the first time, an efficient association between alpha and beta therapies, which could become a promising tool in the control of tumor progression. [ABSTRACT FROM AUTHOR]

Photoelectrochemical systems based on half-photoelectrochemical cells have been widely exploited in the development of analytical methods. However, the development of self-powered systems based on dual-photoelectrode photoelectrochemical cells for the determination of many species is still a challenger. In this work, a two-compartment photoelectrochemical cell has been developed to determine tannic acid exploiting the effects of the analyte on the photoelectrochemical response of a CdS/TiO2/FTO photoanode. The photoactivity of the photoanode was characterised by electrochemical impedance spectroscopy (EIS) and measurements of the photocurrent. The spectroscopic characteristics of the photoanode were evaluated by Raman and Fourier-transform infrared spectroscopy (FT-IR) measurements, the structural characteristics were evaluated by powder X-ray diffraction (PXRD) measurements, the morphology of the surface was evaluated by scanning electron microscopy, and the composition analysis was evaluated by energy-dispersive X-ray spectroscopy. Electrochemical impedance measurements were performed under the incidence and absence of light to investigate the effects of photons on the charge transfer resistance of the photoanode. The nature of the semiconductor and the flat band potential of the photoanode were evaluated by Mott-Schottky analysis. The influence of the TA on the photoelectrochemical response of the CdS/TiO2/FTO electrode was evaluated by measuring the photocurrent of the system. The PEC platform presented a linear response range for TA from 10 to 500 μmol L−1. The PEC was successfully applied to the determination of the TA in orange juice samples with a mean recovery percentage of about 99%. [ABSTRACT FROM AUTHOR]

Breast cancer is women's most common type of cancer, with a global rate of over 522,000 deaths per year. One of the main problems related to breast cancer relies in the early detection, as the specialized treatment. In this direction was developed, characterized and tested in vivo a smart delivery system, based on radiolabelled magnetic core mesoporous silica doped with trastuzumab as intralesional nanodrug for breast cancer imaging and possible therapy. The results showed that nanoparticles had a size of 58.9 ± 8.1 nm, with specific surface area of 872 m2/g and pore volume of 0.85 cm3/g with a pore diameter of 3.15 nm. The magnetic core mesoporous silica was efficiently labelled with 99mTc (97.5% ±0.8) and doped >98%. The cytotoxicity assay, demonstrated they are safe to use. The data were corroborated with the IC50 result of: 829.6 µg ± 43.2. The biodistribution showed an uptake by the tumour of 7.5% (systemic via) and 97.37% (intralesional) with less than 3% of these nanoparticles absorbed by healthy tissues. In a period 6-h post-injection, no barrier delimited by the tumour was crossed, corroborating the use as intralesional nanodrug. [ABSTRACT FROM AUTHOR]

Nanodrugs have in recent years been a subject of great debate. In 2017 alone, almost 50 nanodrugs were approved for clinical use worldwide. Despite the advantages related to nanodrugs/nanomedicine, there is still a lack of information regarding the biological safety, as the real behavior of these nanodrugs in the body. In order to better understand these aspects, in this study, we evaluated the effect of polylactic acid (PLA) nanoparticles (NPs) and magnetic core mesoporous silica nanoparticles (MMSN), of 1000 nm and 50 nm, respectively, on human cells. In this direction we evaluated the cell cycle, cytochemistry, proliferation and tubulogenesis on tumor cells lines: from melanoma (MV3), breast cancer (MCF-7, MDA-MB-213), glioma (U373MG), prostate (PC3), gastric (AGS) and colon adenocarcinoma (HT-29) and non-tumor cell lines: from human melanocyte (NGM), fibroblast (FGH) and endothelial (HUVEC), respectively. The data showed that an acute exposure to both, polymeric nanoparticles or MMSN, did not show any relevant toxic effects on neither tumor cells nor non-tumor cells, suggesting that although nanodrugs may present unrevealed aspects, under acute exposition to human cells they are harmless. [ABSTRACT FROM AUTHOR]

This study investigates the enhancement of benzylpenicillin's antibacterial properties using nanomedicine, specifically by developing benzylpenicillin nanoemulsions. To address the escalating issue of bacterial resistance, we employed the advanced techniques Raman spectroscopy and atomic force microscopy to analyze the nanoemulsions' molecular structure and characteristics. We then evaluated the impact of these nanoemulsions on nitric oxide production by macrophages to deternine their potential to modulate inflammatory responses. We further assessed the antibacterial effectiveness of the nanoparticles against the pathogens Streptococcus pyogenes (Group A Streptococcus) and Streptococcus agalactiae (Group B Streptococcus). The results of antibiograms showed significant efficacy against Gram-positive bacteria, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, confirming their bactericidal potential. The investigation into the mechanism of action suggested substantial disruption to bacterial membrane integrity, underscoring a possible mode of antibacterial activity. Overall, the study provides valuable insights into the synergistic relationship between antibiotics and nanoparticles. In particular, it demonstrates the potential of benzylpenicillin nanoparticles to enhance the antimicrobial efficacy and influence inflammatory responses obtained by evaluating nitrite, IL-6 and TNF-α, offering promising avenues for future clinical applications and strategies to combat bacterial resistance., (Copyright © 2024. Published by Elsevier Masson SAS.)

Diabetes Mellitus (DM) is a disease characterized by high blood glucose levels, known as hyperglycemia. Diabetes represents a risk factor for the development of neurodegenerative diseases, such as Alzheimer's Disease (AD), one of the most prevalent neurodegenerative diseases worldwide, which leads to progressive mental, behavioral, and functional decline, affecting many brain structures, especially the hippocampus. Here, we aim to characterize the ultrastructural, nanomechanical, and vibrational changes in hyperglycemic hippocampal tissue using atomic force microscopy (AFM) and Raman spectroscopy. DM was induced in rats by streptozotocin injection (type 1) or dietary intervention (type 2). Cryosections of the hippocampus were prepared and analyzed on an MM8 AFM (Bruker) in Peak Force Quantitative Nanomechanics mode, performing 25 μm 2 scans in 9 regions of 3 samples from each group. Ultrastructural and nanomechanical data such as surface roughness, area, volume, Young's modulus, and adhesion were evaluated. The hippocampal samples were also analyzed on a T64000 Spectrometer (Horiba), using a laser λ = 632.8 nm, and for each sample, four spectra were obtained in different regions. AFM analyses show changes on the ultrastructural scale since diabetic animals had hippocampal tissue with greater roughness and volume. Meanwhile, diabetic tissues had decreased adhesion and Young's modulus compared to control tissues. These were corroboratedby Raman data that shows changes in the molecular composition of diabetic tissues. The individual spectra show that the most significant changes are in the amide, cholesterol, and lipid bands. Overall, the data presented here show that hyperglycemia induces biophysical alterations in the hippocampal tissue of diabetic rats, providing novel biophysical and vibrational cues on the relationship between hyperglycemia and dementia., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)