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Nanoparticles (NPs) have been used in drug delivery therapies, medical diagnostic strategies, and as current Covid-19 vaccine carriers. Many microscope-based imaging systems have been introduced to facilitate detection and visualization of NPs. Unfortunately, none can differentiate the core and the shell of NPs. Spectral imaging has been used to distinguish a drug molecule and its metabolite. We have recently integrated this technology to a resolution of 9 nm by using artificial intelligence-driven analyses. Such a resolution allowed us to collect many robust datapoints for each pixel of an image. Our analyses could recognize 45 spectral points within a pixel to detect unlabeled Ag-NPs and Au-NPs in single live cells and tissues (liver, heart, spleen and kidneys). The improved resolution and software provided a more specific fingerprinting for each single molecule, allowing simultaneous analyses of 990 complex interactions from the 45 points for each molecule within a pixel of an image. This in turn allowed us to detect surface-functionalization of Ag-NPs to distinguish the core from the shell of Ag-NPs for the first time. Our studies were validated using various laborious and time-consuming conventional techniques. We propose that spectral imaging has tremendous potential to study NP localization and identification in biological samples at a high temporal and spatial resolution, based primarily on spectral identity information.

In recent days, vanadium complexes and nanoparticles have received sustainable attention owing to their vast applications in different fields. In the present study, we report a facile approach for the synthesis of irregular dumbbell shaped vanadium pentoxide nanoparticles (V2O5 NPs: 30-60 nm) via the polyol-induced microwave irradiation process along with calcination. The as-synthesized nanoparticles were characterized using various physico-chemical techniques (e.g. XRD, TEM, FT-IR, DLS and XPS). The cell viability assay showed that V2O5 NPs could efficiently inhibit the proliferation of different cancer cells (B16F10, A549, and PANC1), depicting their anti-proliferative activity. However, V2O5 NPs did not exert significant cytotoxicity to the normal cells (CHO, HEK-293 and NRK-49F), suggesting their biocompatible nature. Interestingly, these nanoparticles inhibited the proliferation and migration of the endothelial cells (HUVECs and EA.hy926) and disrupted the blood vasculature in a chick embryo model, indicating their anti-angiogenic properties. The mechanistic study revealed that the effective internalization of V2O5 NPs generated intracellular reactive oxygen species (ROS) which in turn up-regulated p53 protein and down-regulated survivin protein in cancer cells, leading to the apoptosis process. Furthermore, the administration of V2O5 NPs to melanoma bearing C57BL6/J mice significantly increased their survivability as compared to the control untreated tumor bearing mice, exhibiting the therapeutic potential of the nanoparticles against melanoma. Additionally, the in vivo toxicity study demonstrated no toxic effect in mice upon sub-chronic exposure to V2O5 NPs. Altogether, we strongly believe that V2O5 NPs could intrinsically provide a new direction for alternative therapeutic treatment strategies for melanoma and other cancers by employing their anti-angiogenic properties in the future.

Angiogenesis, a process involving the growth of new blood vessels from the pre-existing vasculature, plays a crucial role in various pathophysiological conditions. We have previously demonstrated that europium hydroxide [Eu(III)(OH)3] nanorods (EHNs) exhibit pro-angiogenic properties through the generation of reactive oxygen species (ROS) and mitogen activated protein kinase (MAPK) activation. Considering the enormous implication of angiogenesis in cardiovascular diseases (CVDs) and cancer, it is essential to understand in-depth molecular mechanisms and signaling pathways in order to develop the most efficient and effective alternative treatment strategy for CVDs. However, the exact underlying mechanism and cascade signaling pathways behind the pro-angiogenic properties exhibited by EHNs still remain unclear. Herein, we report for the first time that the hydrogen peroxide (H2O2), a redox signaling molecule, generated by these EHNs activates the endothelial nitric oxide synthase (eNOS) that promotes the nitric oxide (NO) production in a PI3K (phosphoinositide 3-kinase)/Akt dependent manner, eventually triggering angiogenesis. We intensely believe that the investigation and understanding of the in-depth molecular mechanism and signaling pathways of EHNs induced angiogenesis will help us in developing an effective alternative treatment strategy for cardiovascular related and ischemic diseases where angiogenesis plays an important role.

Reduced graphene oxide (rGO) generates reactive oxygen species (ROS) under visible light in air via a singlet oxygen–superoxide anion radical pathway which readily kills Enterobacter sp. The rGO+ intermediate reacts with a hydroxyl ion to produce graphene oxide (GO) as a coating on the surface of rGO resulting in enhanced fluorescence and a slow down in photo-induced ROS formation. GO is not toxic but on ageing it gets a surface coating of rGO and shows toxicity.

The desirable properties of a matrix for tissue engineering applications appears to shift from a minimal model of supporting cell growth to a more inclusive role as a matrix to trigger the regeneration process. This requirement has propelled efforts towards bio-functionalization of matrices both by chemical and textural modification of most advanced materials, including silk. Amongst different biomaterials, silk fibroin (SF) has been extensively used for various tissue engineering applications, because of its low immunogenicity and good mechanical strength, although low biological activity and a poor biodegradability rate has remained its major limitation for use in regenerative medicine. In the present study, the physical as well as biological properties of SF have been improved by incorporation of honey, a natural healing agent. Honey-blended SF films (HSF) demonstrated increased mechanical strength together with enhanced wettability, swelling ability and degradability without hampering the original mechanical and biological properties of both honey and SF. In addition, parallel-aligned nanostructures were produced over native SF and HSF using soft lithography to form two-dimensional nano-patterned membranes. HSF films demonstrated enhanced surface roughness in flat membranes and even more so in nano-patterned membranes when compared with native SF membranes which are essential for cellular adhesion and proliferation. Furthermore, biocompatibility and cellular behavior such as adhesion, proliferation, spreading and interaction of 3T3 fibroblast cells were improved using HSF when compared with using native SF membranes. Thus, HSF membranes with enhanced bio-physical properties are a potential material for use in regenerative medicine and tissue engineering applications.

A rhodamine–naphthalimide dyad with multiple coordination sites displays Fe3+ and Cr3+ specific absorption and fluorescence emission profiles and permits specific detection of Fe3+ and Cr3+ ions present in aqueous samples, and live A549 and CHO cells in a chemoselective manner.

A series of meso-substituted thienyl BODIPY analogues (1, 1a–g) have been designed and synthesized. Among those, compounds 1c, 1d and 1e show biocompatibility towards endothelial cells whereas 1c and 1d show significant cytotoxicity towards cancerous cells. The formation of intracellular reactive oxygen species (ROS) and the activation of the apoptotic protein may be a plausible mechanism for the anti-proliferative nature of 1c and 1d. Additionally, compounds 1c, 1d, and 1e fluoresce inside the cancer cells. The combined results suggest the future theranostic (therapeutics + diagnostics) applications of 1c and 1d in cancer diseases.

Correction for ‘meso-Substituted BODIPY fluorescent probes for cellular bio-imaging and anticancer activity’ by Thumuganti Gayathri et al., RSC Adv., 2014, 4, 47409–47413.

A novel hybrid nanoporous material (LNH-1) bearing a tris(propyliminomethyl)-phloroglucinol fluorescent moiety in the framework has been designed and administration of an LNH-1 based drug delivery system containing doxorubicin to cancer cells showed inhibition of proliferation, suggesting its future potential theranostics application in cancer.

It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood vessels formation. Additionally, it helps to promote endothelial cell (EA.hy926 cells) migration in wound healing assays. Formation of reactive oxygen species (ROS), especially hydrogen peroxide (H(2)O(2))-a redox signaling molecule, might be the plausible mechanism for nanoflower-based angiogenesis. Angiogenesis by nanoflowers may provide the basis for the future development of new alternative therapeutic treatment strategies for cardiovascular and ischemic diseases, where angiogenesis plays a significant role.

A new approach, involving the anchoring-unanchoring of a fluorophore, has been developed for the detection of Au-species. The fluorescent probe was found to be highly selective for sensing gold species in the presence of several other metal ions. A successful application to bioimaging has also been demonstrated with A549 lung cancer cells.