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A cell's mechanical properties have been linked to cancer development, motility and metastasis and are therefore an attractive target as a universal, reliable cancer marker. For example, it has been widely published that cancer cells show a lower Young's modulus than their non-cancerous counterparts. Furthermore, the effect of anti-cancer drugs on cellular mechanics may offer a new insight into secondary mechanisms of action and drug efficiency. Scanning ion conductance microscopy (SICM) offers a nanoscale resolution, non-contact method of nanomechanical data acquisition. In this study, we used SICM to measure the nanomechanical properties of melanoma cell lines from different stages with increasing metastatic ability. Young's modulus changes following treatment with the anti-cancer drugs paclitaxel, cisplatin and dacarbazine were also measured, offering a novel perspective through the use of continuous scan mode SICM. We found that Young's modulus was inversely correlated to metastatic ability in melanoma cell lines from radial growth, vertical growth and metastatic phases. However, Young's modulus was found to be highly variable between cells and cell lines. For example, the highly metastatic cell line A375M was found to have a significantly higher Young's modulus, and this was attributed to a higher level of F-actin. Furthermore, our data following nanomechanical changes after 24 hour anti-cancer drug treatment showed that paclitaxel and cisplatin treatment significantly increased Young's modulus, attributed to an increase in microtubules. Treatment with dacarbazine saw a decrease in Young's modulus with a significantly lower F-actin corrected total cell fluorescence. Our data offer a new perspective on nanomechanical changes following drug treatment, which may be an overlooked effect. This work also highlights variations in cell nanomechanical properties between previous studies, cancer cell lines and cancer types and questions the usefulness of using nanomechanics as a diagnostic or prognostic tool. [ABSTRACT FROM AUTHOR]

Clathrin‐mediated endocytosis (CME) is an essential cell physiological process of broad biomedical relevance. Since the recent introduction of Pitstop‐2 as a potent CME inhibitor, we and others have reported on substantial clathrin‐independent inhibitory effects. Herein, we developed and experimentally validated a novel fluorescent derivative of Pitstop‐2, termed RVD‐127, to clarify Pitstop‐2 diverse effects. Using RVD‐127, we were able to trace additional protein targets of Pitstop‐2. Besides inhibiting CME, Pitstop‐2 and RVD‐127 proved to directly and reversibly bind to at least two members of the small GTPase superfamily Ran and Rac1 with particularly high efficacy. Binding locks the GTPases in a guanosine diphosphate (GDP)‐like conformation disabling their interaction with their downstream effectors. Consequently, overall cell motility, mechanics and nucleocytoplasmic transport integrity are rapidly disrupted at inhibitor concentrations well below those required to significantly reduce CME. We conclude that Pitstop‐2 is a highly potent, reversible inhibitor of small GTPases. The inhibition of these molecular switches of diverse crucial signaling pathways, including nucleocytoplasmic transport and overall cell dynamics and motility, clarifies the diversity of Pitstop‐2 activities. Moreover, considering the fundamental importance and broad implications of small GTPases in physiology, pathophysiology and drug development, Pitstop‐2 and RVD‐127 open up novel avenues. [ABSTRACT FROM AUTHOR]

Magnetite–gold dumbbell nanoparticles are essential for biomedical applications due to the presence of two surfaces with different chemical natures and the potential combination of magnetic and plasmonic properties. Here, the remote actuation of Fe3O4-Au hybrid particles in a rotating (1 Hz, 7 mT), static (7 mT) or pulsed low-frequency (31 Hz, 175 mT, 30 s pulse/30 s pause) magnetic field was studied. The particles were synthesized by a high-temperature wet chemistry protocol and exhibited superparamagnetic properties with the saturation magnetization of 67.9 ± 3.0 Am2 kg−1. We showcased the nanoparticles' controlled aggregation in chains (rotating/static magnetic field) in an aqueous solution and their disaggregation when the field was removed. The investigation of nanoparticle uptake by LNCaP and PC-3 cancer cells demonstrated that Fe3O4-Au hybrids mainly escaped endosomes and accumulated in the cytoplasm. A significant fraction of them still responded to a rotating magnetic field, forming short chains. The particles were not toxic to cells at concentrations up to 210 μg (Fe3O4) mL−1. However, cell viability decrease after incubation with the nanoparticles (≥70 μg mL−1) and exposure to a pulsed low-frequency magnetic field was found. We ascribe this effect to mechanically induced cell destruction. Overall, this makes Fe3O4-Au nanostructures promising candidates for intracellular actuation for future magneto-mechanical cancer therapies. [ABSTRACT FROM AUTHOR]

Novel derivatives of Mycosidine (3,5-substituted thiazolidine-2,4-diones) are synthesized by Knoevenagel condensation and reactions of thiazolidines with chloroformates or halo-acetic acid esters. Furthermore, 5-Arylidene-2,4-thiazolidinediones and their 2-thioxo analogs containing halogen and hydroxy groups or di(benzyloxy) substituents in 5-benzylidene moiety are tested for antifungal activity in vitro. Some of the synthesized compounds exhibit high antifungal activity, both fungistatic and fungicidal, and lead to morphological changes in the Candida yeast cell wall. Based on the use of limited proteomic screening and toxicity analysis in mutants, we show that Mycosidine activity is associated with glucose transport. This suggests that this first-in-class antifungal drug has a novel mechanism of action that deserves further study. [ABSTRACT FROM AUTHOR]

We have developed a model for evaluating the integral intercellular interactions in the "endotheliocyte‐neutrophil" system and have shown the high variability of adhesion contacts in different donors associated with different expression profiles of neutrophils. Two methods (forсe spectroscopy‐spectroscopy and scanning ion‐conductance microscopy) showed a decrease in the rigidity of the membrane‐cytoskeletal complex of neutrophils under the influence of Staphylococcus aureus 2879 M. Adding this strain to the "endotheliocyte‐neutrophil" system caused a statistically significant decrease in the adhesion force and adhesion work, which indicates a change in the expression profile and physicochemical properties of membranes of both types of interacting cells (neutrophils and endotheliocytes). [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles (MNPs) are widely considered for cancer treatment, in particular for magnetic hyperthermia (MHT). Thereby, MNPs are still being optimized for lowest possible toxicity on organisms while the magnetic properties are matched for best heating capabilities. In this study, the biocompatibility of 12 nm cobalt ferrite MNPs, functionalized with citrate ions, in different dosages on mice and rats of both sexes was investigated for 30 days after intraperitoneal injection. The animals' weight, behavior, and blood cells changes, as well as blood biochemical parameters are correlated to histological examination of organs revealing that cobalt ferrite MNPs do not have toxic effects at concentrations close to those used previously for efficient MHT. Moreover, these MNPs demonstrated high specific loss power (SLP) of about 400 W g−1. Importantly the MNPs retained their magnetic properties inside tumor tissue after intratumoral administration for several MHT cycles within three days. Thus, cobalt ferrite MNPs represent a perspective platform for tumor therapy by MHT due to their ability to provide effective heating without exerting a toxic effect on the organism. This opens up new avenues for smaller MNPs sizes while their heating efficiency is maintained. [ABSTRACT FROM AUTHOR]

Inflammatory eye diseases remain the most common clinical problem in ophthalmology. The secondary processes associated with inflammation, such as overproduction of reactive oxygen species (ROS) and exhaustion of the endogenous antioxidant system, frequently lead to tissue degeneration, vision blurring, and even blindness. Antioxidant enzymes, such as copper–zinc superoxide dismutase (SOD1), could serve as potent scavengers of ROS. However, their delivery into the eye compartments represents a major challenge due to the limited ocular penetration. This work presents a new therapeutic modality specifically formulated for the eye on the basis of multilayer polyion complex nanoparticles of SOD1 (Nano-SOD1), which is characterized by appropriate storage stability and pronounced therapeutic effect without side reactions such as eye irritation; acute, chronic, and reproductive toxicity; allergenicity; immunogenicity; mutagenicity even at high doses. The ability of Nano-SOD1 to reduce inflammatory processes in the eye was examined in vivo in rabbits with a model immunogenic uveitis—the inflammation of the inner vascular tract of the eye. It was shown during preclinical studies that topical instillations of Nano-SOD1 were much more effective compared to the free enzyme in decreasing uveitis manifestations. In particular, we noted statistically significant differences in such inflammatory signs in the eye as corneal and conjunctival edema, iris hyperemia, and fibrin clots. Moreover, Nano-SOD1 penetrates into interior eye structures more effectively than SOD itself and retains enzyme activity in the eye for a much longer period of time, decreasing inflammation and restoring antioxidant activity in the eye. Thus, the presented Nano-SOD1 can be considered as a potentially useful therapeutic agent for the treatment of ocular inflammatory disorders. [ABSTRACT FROM AUTHOR]