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Radiotherapy (RT) involves delivering X-ray beams to the tumor site to trigger DNA damage. In this approach, it is fundamental to preserve healthy cells and to confine the X-ray beam only to the malignant cells. The integration of gold nanoparticles (AuNPs) in the X-ray methodology could be considered a powerful tool to improve the efficacy of RT. Indeed, AuNPs have proven to be excellent allies in contrasting tumor pathology upon RT due to their high photoelectric absorption coefficient and unique physiochemical properties. However, an analysis of their physical and morphological reaction to X-ray exposure is necessary to fully understand the AuNPs' behavior upon irradiation before treating the cells, since there are currently no studies on the evaluation of potential NP morphological changes upon specific irradiations. In this work, we synthesized two differently shaped AuNPs adopting two different techniques to achieve either spherical or star-shaped AuNPs. The spherical AuNPs were obtained with the Turkevich–Frens method, while the star-shaped AuNPs (AuNSs) involved a seed-mediated approach. We then characterized all AuNPs with Transmission Electron Microscopy (TEM), Uv-Vis spectroscopy, Dynamic Light Scattering (DLS), zeta potential and Fourier Transform Infrared (FTIR) spectroscopy. The next step involved the treatment of AuNPs with two different doses of X-radiation commonly used in RT, namely 1.8 Gy and 2 Gy, respectively. Following the X-rays' exposure, the AuNPs were further characterized to investigate their possible physicochemical and morphological alterations induced with the X-rays. We found that AuNPs do not undergo any alteration, concluding that they can be safely used in RT treatments. Lastly, the actin rearrangements of THP-1 monocytes treated with AuNPs were also assessed in terms of coherency. This is a key proof to evaluate the possible activation of an immune response, which still represents a big limitation for the clinical translation of NPs. [ABSTRACT FROM AUTHOR]

Facile synthesis of metal nanoparticles with controlled physicochemical properties using environment-friendly reagents can open new avenues in biomedical applications. Nanomaterials with controlled physicochemical properties have opened new prospects for a variety of applications. In the present study, we report a single-step photochemical synthesis of ~5 nm-sized silver (Ag) and gold (Au) nanoparticles (NPs), and Ag–Au alloy nanoparticles using L-tyrosine. The physicochemical and surface properties of both monometallic and bimetallic NPs were investigated by analytical, spectroscopic, and microscopic techniques. Our results also displayed an interaction between L-tyrosine and surface atoms that leads to the formation of AgAu NPs by preventing the growth and aggregation of the NPs. This method efficiently produced monodispersed NPs, with a narrow-sized distribution and good stability in an aqueous solution. The cytotoxicity assessment performed on breast cancer cell lines (MCF-7) revealed that the biofriendly L-tyrosine-capped AgNPs, AuNPs, and bimetallic AgAu NPs were biocompatible. Interestingly, AgAu NPs have also unveiled controlled cytotoxicity, cell viability, and in vitro peroxidase nanozyme activity reliant on metal composition and surface coating. [ABSTRACT FROM AUTHOR]

The conventional methods of cancer treatment and diagnosis, such as radiotherapy, chemotherapy, and computed tomography, have developed a great deal. However, the effectiveness of such methods is limited to the possible failure or collateral effects on the patients. In recent years, nanoscale materials have been studied in the field of medical physics to develop increasingly efficient methods to treat diseases. Gold nanoparticles (AuNPs), thanks to their unique physicochemical and optical properties, were introduced to medicine to promote highly effective treatments. Several studies have confirmed the advantages of AuNPs such as their biocompatibility and the possibility to tune their shapes and sizes or modify their surfaces using different chemical compounds. In this review, the main properties of AuNPs are analyzed, with particular focus on star-shaped AuNPs. In addition, the main methods of tumor treatment and diagnosis involving AuNPs are reviewed. [ABSTRACT FROM AUTHOR]

The SARS-CoV-2 outbreaks highlighted the need for effective, reliable, fast, easy-to-do and cheap diagnostics procedures. We pragmatically experienced that an early positive-case detection, inevitably coupled with a mass vaccination campaign, is a milestone to control the COVID-19 pandemic. Gold nanoparticles (AuNPs) can indeed play a crucial role in this context, as their physicochemical, optics and electronics properties are being extensively used in photothermal therapy (PTT), radiation therapy (RT), drug delivery and diagnostic. AuNPs can be synthesized by several approaches to obtain different sizes and shapes that can be easily functionalized with many kinds of molecules such as antibodies, proteins, probes, and lipids. In addition, AuNPs showed high biocompatibility making them useful tool in medicine field. We thus reviewed here the most relevant evidence on AuNPs as effective way to detect the presence of SARS-CoV-2 antigens. We trust future diagnostic efforts must take this 'old-fashioned' nanotechnology tool into consideration for the development and commercialization of reliable and feasible detection ki [ABSTRACT FROM AUTHOR]

The quest for novel nanoscale materials for different applications necessitates that they are easy to obtain and have excellent physical properties and low toxicity. Moreover, considering the ongoing environmental impact of noxious chemical waste products, it is important to adopt eco-friendly approaches for nanoparticle synthesis. In this work, a natural polymer (medium molecular weight chitosan) derived from chitin was employed as a reducing agent to obtain gold nanoparticles (AuNPs) with a chitosan shell (AuNPs@CS) by a microwave oven. The chitosan is economically viable and cost-competitive in the market showing also nontoxic behavior in the environment and living organisms. The synthesized AuNPs@CS-FITC NPs were fully characterized by spectroscopic and microscopic characterization techniques. The size distribution of NPs was about 15 nm, which is a suitable dimension to use in biomedical applications due to their high tissue penetration, great circulation in blood, and optimal clearance as well as low toxicity. The prepared polymer-capped NPs were further functionalized with a fluorescent molecule, i.e., Fluorescein-5-isothiocyanate (FITC), to perform imaging in the cell. The results highlighted the goodness of the synthesis procedure, as well as the high internalization rate that resulted in an optimal fluorescence intensity. Thus, this work presents a good sustainable/green approach-mediated polymer nanocomposite for various applications in the field of diagnostic imaging. [ABSTRACT FROM AUTHOR]

Green synthesis from plant waste involves the generation of functional nanoparticles (NPs), offering significant potential for a wide range of applications. Numerous studies have focused on the use of plant extracts to produce AuNPs suitable for various applications in the medical field, particularly in photothermal therapy and cancer therapy, owing to their plasmonic properties. Moreover, NP-mediated immunostimulation and immunosuppression is an intriguing field of research, focusing on how manipulation of NP physicochemical properties can influence their inter-action with immune cells and immune modulation. However, to date, few investigations have been conducted on the modulation of the inflammatory response mediated by green-synthesized nanostructures. To this aim, we synthesized AuNPs using extracts of Laurus nobilis , which exhibit high crystallinity and are inherently coated by a dense network of polyphenols, thus maintaining stability on their surface through the green synthesis approach. Then, in order to explore how these green-synthesized nanostructures can enhance or suppress the inflammatory cellular responses, we investigated the response of free polyphenols and AuNPs@polyphenols in murine bone marrow derived dendritic cells (BMDCs), by means of morphomechanical analysis and biochemical assays. Our findings demonstrated that DCs exposed to both free polyphenol extract and AuNPs@polyphenols were able to inhibit the secretion of crucial inflammatory mediators in response to lipopolysaccharide (LPS) administration. Therefore, polyphenols immobilized on Au surface were more effective in the inflammation suppression. These evidence paving the way for a powerful strategy to develop edible anti-inflammatory adjuvants, overcoming the limitations associated with the use of free polyphenols in clinical practice. [Display omitted] • free polyphenols and AuNPs@polyphenols in BMDCs were investigated by morphomechanical analysis and biochemical assays. • BMDCs exposed to both free polyphenols extract and AuNPs@polyphenols are able to suppress the secretion of crucial inflammatory mediators. • AuNPs@polyphenols are powerful tools to develop edible anti-inflammatory adjuvants and overcome the limitations associated to free polyphenols in clinical practice. [ABSTRACT FROM AUTHOR]

References 1 De Matteis V., Cascione M., Toma C.C., Pellegrino P., Rizzello L., Rinaldi R. Tailoring Cell Morphomechanical Perturbations Through Metal Oxide Nanoparticles. In addition, the cell viability assessment confirmed the negligible toxicity of these materials in cells. The increasingly widespread use of engineered nanomaterials in many applications increases the need to understand the mechanisms behind their toxicity. [Extracted from the article]