Silver nanoparticles (Ag NPs) exhibit antibacterial activity and are extensively used in numerous applications. The aim of this study was to examine the toxic effect of Ag NPs on the marine microalga, Chlorella vulgaris. The microalgae, at the exponential growth phase, were treated with different concentrations of Ag NPs (50 and 100 nm) for 96 h. X-Ray diffraction (XRD) results indicated that the used NPs are single and pure Ag phase with a mean crystallite size of 21 and 32 nm. Ag NPs were found to have a negative effect on viable cell concentration, a variable effect on chlorophyll a concentration, and increased ROS formation. Transmission electron microscopy (TEM) analysis revealed that Ag NPs were present inside the microalgae cells and formed large aggregates in the culture medium. Ag⁺ ions, in the form of AgNO₃, were also assessed at higher concentrations and found to cause inhibitory effects.

The need for new therapeutic approaches in the treatment of challenging diseases such as cancer, which often consists of a highly heterogeneous and complex population of cells, brought up the idea of analyzing single cells. The development of novel techniques to analyze single cells has been intensively studied to fully understand specific alternations inducing abnormalities in cellular function. One of the techniques used for single cell analysis is surface-enhanced Raman spectroscopy (SERS) in which a noble metal nanoparticle is used to enhance Raman scattering. Due to its low toxicity and biocompatibility, gold nanoparticles (AuNPs) are commonly preferred as SERS substrates in single cell analysis. The intracellular uptake, localization and toxicity issues of AuNPs are the critical points for interpretation of data since the obtained SERS signals originate from molecules in close vicinity to AuNPs that are taken up by the cells. In this review, the AuNP–living cell interactions, cellular uptake and toxicity of AuNPs in relation to their physicochemical properties, and surface-enhanced Raman scattering from single cells are discussed.

The continuous production and widespread applications of synthetic plastics and their waste present immense environmental challenges and damage living systems. Microplastics (MPs) have become of great concern in various ecosystems due to their high stability and decomposition into smaller fragments such as nano-plastics (NPs). Nevertheless, MPs and NPs can be removed from the environment using several physical, chemical, and microbiological methods. This study presents a comprehensive narrative literature review, which aims to explore the various types of MPs and NPs, their sources, fate, toxicity, and impact on human health and environment. To achieve this aim, the study employed a comprehensive literature review methodology. In addition, it summarizes various methods of sample collection and analysis techniques. Remediation strategies for MPs and NPs removal are assessed and compared. Furthermore, it highlights interlinkages between the sustainable development goals (SDGs)—specifically SDG 14—and plastic pollution. Overall, priority for research and development in the field of MPs and NPs impacts on ecological ecosystems is a must as this will enable the development of scientific polices driven by global collaboration and governance which in turn will develop tools and methodologies that measure the impacts and risk of plastic pollution.

X-ray crystallography is a robust and powerful structural biology technique that provides high-resolution atomic structures of biomacromolecules. Scientists use this technique to unravel mechanistic and structural details of biological macromolecules (e.g., proteins, nucleic acids, protein complexes, protein-nucleic acid complexes, or large biological compartments). Since its inception, single-crystal cryocrystallography has never been performed in Türkiye due to the lack of a single-crystal X-ray diffractometer. The X-ray diffraction facility recently established at the University of Health Sciences, İstanbul, Türkiye will enable Turkish and international researchers to easily perform high-resolution structural analysis of biomacromolecules from single crystals. Here, we describe the technical and practical outlook of a state-of-the-art home-source X-ray, using lysozyme as a model protein. The methods and practice described in this article can be applied to any biological sample for structural studies. Therefore, this article will be a valuable practical guide from sample preparation to data analysis.

Titanium dioxide nanoparticles (TiO₂ NPs) are widely used in sunscreens, cosmetics and body implants, and this raises toxicity concerns. Although a large number of reports claim that they are safe to use, others claim that they induce reactive oxygen species formation and can be carcinogenic. In this study, the origins of toxic response to TiO₂ NPs were investigated by using Surface-enhanced Raman spectroscopy (SERS) which provides multidimensional information on the cellular dynamics at single cell level without any requirement for cell fixation. Three cell lines of vein (HUVEC), lung carcinoma (A549) and skin (L929) origin were tested for their toxic response upon exposure to 20, 40, 80 and 160 µg/mL anatase-TiO₂ NPs for 24 h. It was demonstrated that the level of toxic response is both cell line and dose-dependent. L929 fibroblasts were the most resistant cell line to oxidative stress whereas in HUVEC and A549, cell lines collagen and lipid deformation were observed, respectively.

Gold nanoparticles (AuNPs) can cross the blood brain barrier, thus can be used as nanocarriers in brain drug delivery. However, the effect of bare and polyethylene glycol-modified (PEGylated) AuNPs on normal neural function has not been extensively investigated. In this study, bioelectrical properties of neuronal functions of male BALB/c mice were explored ex vivo and in vivo by using 5 nm bare AuNPs and PEGylated AuNPs. Electrophysiological properties of neurons from hippocampal CA1 region sections were recorded by patch clamp method. Ex vivo, firing rate of action and membrane potentials in response to negative current stimuli significantly altered only after bare AuNP exposure compared to control (p < 0.05). After in vivo injections, anxiety levels of animals were similar. Amplitude of action potentials reduced only in bare AuNP group (p < 0.05). In conclusion, excitability of hippocampal neurons is increasing with bare AuNP exposure, and PEGylation might be more biocompatible for medical applications.