Ligand Regulation Strategy to Modulate ROS Nature in a Rhodamine-Iridium(III) Hybrid System for Phototherapy.

The efficacy of photodynamic therapy (PDT) is highly dependent on the photosensitizer features. The reactive oxygen species (ROS) generated by photosensitizers is proven to be associated with immunotherapy by triggering immunogenic cell death (ICD) as well. In this work, we establish a rhodamine-iridium(III) hybrid model functioning as a photosensitizer to comprehensively understand its performance and potential applications in photodynamic immunotherapy. Especially, the correlation between the ROS generation efficiency and the energy level of the Ir(III)-based excited state (T1'), modulated by the cyclometalating (C∧N) ligand, is systematically investigated and correlated. We prove that in addition to the direct population of the rhodamine triplet state (T1) formed through the intersystem crossing process with the assistance of a heavy Ir(III) metal center, the fine-tuned T1' state could act as a relay to provide an additional pathway for promoting the cascade energy transfer process that leads to enhanced ROS generation ability. Moreover, type I ROS can be effectively produced by introducing sulfur-containing thiophene units in C∧N ligands, providing a stronger M1 macrophage-activation efficiency under hypoxia to evoke in vivo antitumor immunity. Overall, our work provides a fundamental guideline for the molecular design and exploration of advanced transition-metal-based photosensitizers for biomedical applications.

ZnO/black phosphorus/C3N4 composite: An effective photocatalyst for Cr (VI) reduction and degradation of rhodamine B.

The utilization of photocatalysts offers a promising approach for the removal of Cr (VI) and rhodamine dyes. Through the generation of reactive species and subsequent degradation reactions, photocatalysis provides an efficient and environmentally friendly method for the remediation of wastewater. In this study, we have synthesized an n-p-n heterojunction of carbon nitride (C3N4), zinc oxide (ZnO), and black phosphorus (BP) through the sonication-stirring method. The photocatalytic ability of this composite was examined for the decomposition rhodamine B (RhB) and detoxification of hexavalent chromium ion (up to 97% during 80 min) under Xenon irradiation. The results of trapper experiments indicated that the active species were hydroxyl radical (˙OH), electron (e-), and superoxide anion radical (˙O2-). Based on the obtained potential of the lowest unoccupied molecular orbitals (LUMO) and the highest occupied molecular orbital (HOMO) for the mentioned semiconductors, through Mutt-Schottky results, the double Z-scheme mechanism was proposed for the studied process. The electrochemical impedance spectroscopy data exhibited good charge transfer for the evaluated composite versus the pure compounds. The impressive separation of holes and electrons along with the low recombination were confirmed by the responses of photocurrent and quenching the photoluminescence (pl) intensity for the composite, respectively. The current density of the composite recorded 66.6%, 87.3%, and 92% higher than those of BP, C3N4, and ZnO, indicating an excellent electron-hole separation for the ternary composite compared to the pure semiconductors. Diffuse reflectance spectra (DRS) data revealed 2.9, 3.17, 1.15, and 2.63 eV as the band gap values for C3N4, ZnO, BP, and composite. The rate constant of the new composite to remove RhB and reduce hexavalent chromium were about 4.79 and 2.64 times higher than that of C3N4, respectively.

Combinatorial drug-loaded quality by design adapted transliposome gel formulation for dermal delivery: In vitro and dermatokinetic study.

BACKGROUND: Ursolic acid is a powerful drug that possesses many therapeutic properties, such as hepatoprotection, immunomodulation, anti-inflammatory, antidiabetic, antibacterial, antiviral, antiulcer, and anticancer activity. Centella asiatica (L.) Urban (Umbelliferae) contains a triterpene called asiatic acid, which has been used effectively in traditional Chinese and Indian medicine system for centuries. Anticancer, anti-inflammatory, and neuroprotective properties are only some of the many pharmacological actions previously attributed to asiatic acid . AIM: The present work developed an optimized combinatorial drug-loaded nano-formulation by Quality by design approach. MATERIALS AND METHODS: The optimize transliposome for accentuated dermal delivery of dual drug. The optimization of drug-loaded transliposome was done using the "Box-Behnken design." The optimized formulation was characterized for vesicles size, entrapment efficiency (%), and in vitro drug release. Additionally, transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), and dermatokinetic study were performed for further evaluation of drug-loaded optimized transliposome formulation. RESULTS: The optimized combinatorial drug-loaded transliposome formulation showed a particle size of 86.36 ± 2.54 nm, polydispersity index (PDI) 0.230 ± 0.008, and an entrapment efficiency of 87.43 ± 2.66% which depicted good entrapment efficiency. In vitro drug release of ursolic acid and asiatic acid transliposomes was found to be 85.12 ± 2.54% and 80.23 ± 3.23%, respectively, as compared to optimized ursolic acid and asiatic acid transliposome gel drug release that was 67.18 ± 2.85% and 60.28 ± 4.12%, respectively. The skin permeation study of ursolic and asiatic acid conventional formulation was only 32.48 ± 2.42%, compared with optimized combinatorial drug-loaded transliposome gel (79.83 ± 4.52%) at 12 h. After applying combinatorial drug-loaded transliposome gel, rhodamine was able to more easily cross rat skin, as observed by confocal laser scanning microscopy, in comparison with when the rhodamine control solution was used. DISCUSSION: The UA_AA-TL gel formulation absorbed more ursolic acid and asiatic acid than the UA_AA-CF gel formulation, as per dermatokinetic study. Even after being incorporated into transliposome vesicles, the antioxidant effects of ursolic and asiatic acid were still detectable. In most cases, transliposomes vesicular systems generate depots in the skin's deeper layers and gradually release the medicine over time, allowing for fewer applications. CONCLUSION: In overall our studies, it may be concluded that developed dual drug-loaded transliposomal formulation has great potential for effective topical drug delivery for skin cancer.

A new Fe3+-selective, sensitive, and dual-channel turn-on probe based on rhodamine carrying thiophenecarboxaldehyde: Smartphone application and imaging in living cells.

A new dual-channel probe based on rhodamine B derivative (MSB) was successfully designed, synthesized, characterized by Nuclear Magnetic Resonance (NMR) Spectroscopy, Fourier Transform Infrared Spectrophotometer (FTIR), Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS), X-ray Photoelectron Spectroscopy (XPS), and Single Crystal X-rayDiffraction, and the sensing abilities toward Fe3+ cation have been demonstrated and the probe was successfully utilized for fluorescence imaging of Fe3+ in living cells. The probe demonstrated quite fast, sensitive, and selective response to Fe3+ by causing an extreme enhancement in UV-vis and fluorescence spectroscopy techniques in the buffered aqueous media which makes MSB a dual-channel probe. While the color of MSB solution was initially light yellow, it turned pink in the presence of Fe3+, which provided highly selective naked-eye determination among several ions as alkaline, alkaline-earth, and transition metal ions. After that, the probe was easily applied to paper strips and real samples such as drinking waters and supplementary iron tablets for sensing Fe3+ in an aqueous solution. The detection limit (LOD) and the response time of the probe were determined as 4.85x10-9 M and 4 min, respectively, which are quite lower compared with other rhodamine based Fe3+ sensors in the literature. According to Job's plot, 1H NMR titration, MALDI-TOF MS, XPS, and DFT study techniques, the complexation ratio between MSB and Fe3+ was found as 1:1. Moreover, the spectral response was reversible with alternately addition of Fe3+ or Na2EDTA to the MSB solution. In addition, fluorescence imaging in NIH/3T3 mouse fibroblast cells and studies in real samples with a quite high recovery rate exhibited that the probe is qualified for detection of Fe3+ ion with multiple practical usages.

Degradation of rhodamine B by persulfate activated with green tea iron nanoparticles.

Green iron tea nanoparticles (GT-Fe NPs) were used as persulfate(PS) activators to oxidize rhodamine B (RhB) in this study. Optimized oxidative degradation condition was 0.033 mM Fe, 5 mM PS at pH 3.0 and 298 K with an initial RhB content of 50 mg/L. After 120 min of RhB degradation utilizing GT-Fe NPs activated PS, 99% of RhB reduction was achieved, while 98% RhB reduction with PS activated by citric acid-Fe2+(CA-Fe) with the same amount of Fe2+. This RhB reduction was due to the delayed release of Fe(II) in the GT-Fe NPs. The addition of GT-Fe NPs enhanced the synthesis of OH· and SO4-· while inhibiting the formation of O2-·. A possible RhB degradation pathway was the chromophore destruction and ring-opening processes using GT-Fe NPs/PS, which produced a range of low molecular weight carboxylic acids (oxalic acid, lactic acid, acetic acid, and formic acid). GT-Fe NPs seem to be a promising persulfate activator in comparison to common activators such as CA-Fe.

Excitation-Wavelength-Dependent Functionalities of Temporally Controlled Sensing and Generation of Singlet Oxygen by a Photoexcited State Engineered Rhodamine 6G-Anthracene Conjugate.

The present study provides design guidance for unique multipotent molecules that sense and generate singlet oxygen (1 O2 ). A rhodamine 6G-aminomethylanthracene-linked donor-acceptor molecule (RA) is designed and synthesized for demonstrating wavelength-dependent functionalities as follows; (i) RA acts as a conventional fluorogenic 1 O2 sensor molecule like the commercially available reagent, singlet oxygen sensor green (SOSG), when it absorbs ultraviolet (UV)-visible light and reacts with 1 O2 . (ii) RA acts as a temporally controlled 1 O2 sensing reagent under the longer wavelength (∼700 nm) photosensitization. RA enters an intermediate state after capturing 1 O2 and does not become strongly fluorescent until it is exposed to UV, blue, or green light. (iii) RA acts as an efficient photosensitizer to generate 1 O2 under green light illumination. The spin-orbit charge transfer mediated intersystem crossing (SOCT-ISC) process achieves this function, and RA shows a potential cancer-killing effect on pancreatic cancer cells. The wavelength-switchable functionalities in RA offer to promise molecular tools to apply 1 O2 in a spatiotemporal manner.

Triterpenes from Momordica balsamina (African pumpkin): ABCB1 inhibition and synergistic interaction with doxorubicin in resistant cancer cells.

Aiming at overcoming multidrug resistance (MDR) in cancer, we have been studying Momordica balsamina, a vegetable known as African pumpkin. Five undescribed cucurbitane-type triterpenoids (balsaminaepoxide, balsaminatriol, balsaminoic acid, balsaminal, and balsaminol G) along with five known cucurbitacins were isolated from the methanol extract of Momordica balsamina aerial parts, whose structures were elucidated by spectroscopic data, mainly 1D and 2D NMR experiments. Compounds were evaluated for their ability as P-glycoprotein (P-gp/ABCB1) inhibitors in multidrug resistant human ABCB1-transfected mouse lymphoma cells (L5178Y, MDR) and resistant human colon adenocarcinoma cells (COLO 320), using the rhodamine-123 exclusion test, by flow cytometry. Several compounds, which were found to be non-cytotoxic, strongly inhibited P-gp efflux activity in a dose-dependent manner in both cell models. In MRD mouse lymphoma cells, balsaminol G and karavilagenin B were the most active, while in resistant colon adenocarcinoma cells, the strongest inhibitory activity was found for balsaminaepoxide, balsaminatriol and karavilagenin C, being several-fold more active than the positive control verapamil. In chemosensitivity assays, in a model of combination chemotherapy, selected compounds showed to interact synergistically with doxorubicin, thus substantiating their potential as MDR reversers. The strongest synergistic interaction was found for balsaminal and balsaminol G.

Mg-Fe-Al-O spinel: Preparation and application as a heterogeneous photo-Fenton catalyst for degrading Rhodamine B.

It is an urgent need to develop new environmentally friendly spinel ferrites with high catalytic efficiency. In this work, a series of Mg-Fe-Al-O spinels with different ratios of Mg/Al were successfully synthesized by the reaction sintering method and were used as a heterogeneous photo-Fenton catalyst for degradation of Rhodamine B (RhB). The effect of different ratios of Mg/Al on the properties of Mg-Fe-Al-O spinel was characterized and analyzed through a range of advanced characterization techniques and DFT calculations. The influence factors on the photo-Fenton reaction catalyzed by Mg-Fe-Al-O spinels were systematically investigated. The results showed that the prepared Mg-Fe-Al-O spinels had larger lattice parameters, wider bandgap, and stronger magnetism, with the Mg content increased. Among them, Mg-9 (Mg0.88Fe1.88Al0.23O4) had the best catalytic performance in the photo-Fenton reaction. The degradation efficiency of RhB reached 98.45%, and the TOC removal efficiency was 83.47%. The elemental valence and PDOS of Mg-9 (Mg0.88Fe1.88Al0.23O4) spinels were closer to MgFe2O4. The photo-generated holes could directly oxidize water and hydroxyl to generate reactive oxygen species ·OH, improving the catalytic activity.

Physiological synaptic activity and recognition memory require astroglial glutamine.

Presynaptic glutamate replenishment is fundamental to brain function. In high activity regimes, such as epileptic episodes, this process is thought to rely on the glutamate-glutamine cycle between neurons and astrocytes. However the presence of an astroglial glutamine supply, as well as its functional relevance in vivo in the healthy brain remain controversial, partly due to a lack of tools that can directly examine glutamine transfer. Here, we generated a fluorescent probe that tracks glutamine in live cells, which provides direct visual evidence of an activity-dependent glutamine supply from astroglial networks to presynaptic structures under physiological conditions. This mobilization is mediated by connexin43, an astroglial protein with both gap-junction and hemichannel functions, and is essential for synaptic transmission and object recognition memory. Our findings uncover an indispensable recruitment of astroglial glutamine in physiological synaptic activity and memory via an unconventional pathway, thus providing an astrocyte basis for cognitive processes.

Blinking Fluorescent Probes for Tubulin Nanoscopy in Living and Fixed Cells.

Here we report a small molecule tubulin probe for single-molecule localization microscopy (SMLM), stimulated emission depletion (STED) microscopy and MINFLUX nanoscopy, which can be used in living and fixed cells. We explored a series of taxane derivatives containing spontaneously blinking far-red dye hydroxymethyl silicon-rhodamine (HMSiR) and found that the linker length profoundly affects the probe permeability and off-targeting in living cells. The best performing probe, HMSiR-tubulin, is composed of cabazitaxel and the 6'-regioisomer of HMSiR bridged by a C6 linker. Microtubule diameter of ≤50 nm was routinely measured in SMLM experiments on living and fixed cells. HMSiR-tubulin allows a complementary use of different nanoscopy techniques for investigating microtubule functions and developing imaging methods. For the first time, we resolved the inner microtubule diameter of 16 ± 5 nm by optical nanoscopy and thereby demonstrated the utility of a self-blinking dye for MINFLUX imaging.

Photothermal-Enhanced Fenton-like Catalytic Activity of Oxygen-Deficient Nanotitania for Efficient and Safe Tooth Whitening.

The growing demand for charming smiles has led to the popularization of tooth bleaching procedures. Current tooth bleaching products with high-concentration hydrogen peroxide (HP, 30-40%) are effective but detrimental due to the increased risk of enamel destruction, tooth sensitivity, and gingival irritation. Herein, we reported a less-destructive and efficient tooth whitening strategy with a low-concentration HP, which was realized by the remarkably enhanced Fenton-like catalytic activity of oxygen-deficient TiO2 (TiO2-x). TiO2-x nanoparticles were synthesized with a modified solid-state chemical reduction approach with NaBH4. The Fenton-like activity of TiO2-x was optimized by manipulating oxygen vacancy (OV) concentration and further promoted by the near-infrared (NIR)-induced photothermal effect of TiO2-x. The TiO2-x sample named BT45 was chosen due to the highest methylene blue (MB) adsorption ability and Fenton-like activity among acquired samples. The photothermal property of BT45 under 808 nm NIR irradiation was verified and its enhancement on Fenton-like activity was also studied. The BT45/HP + NIR group performed significantly better in tooth whitening than the HP + NIR group on various discolored teeth (stained by Orange II, tea, or rhodamine B). Excitingly, the same tooth whitening performance as the Opalescence Boost, a tooth bleaching product containing 40% HP, was obtained by a self-produced bleaching gel based on this novel system containing 12% HP. Besides, negligible enamel destruction, safe temperature range, and good cytocompatibility of TiO2-x nanoparticles also demonstrated the safety of this tooth bleaching strategy. This work indicated that the photothermal-enhanced Fenton-like performance of the TiO2-x-based system is highly promising in tooth bleaching application and can also be extended to other biomedical applications.

New TiO2-doped Cu-Mg spinel-ferrite-based photocatalyst for degrading highly toxic rhodamine B dye in wastewater.

The quest for finding an effective photocatalyst for environmental remediation and treatment strategies is attracting considerable attentions from scientists. In this study, a new hybrid material, Cu0.5Mg0.5Fe2O4-TiO2, was designed and fabricated using coprecipitation and sol-gel approaches for degrading organic dyes in wastewater. The prepared hybrid materials were fully characterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results revealed that the Cu0.5Mg0.5Fe2O4-TiO2 hybrid material was successfully synthesized with average particle sizes of 40.09 nm for TiO2 and 27.9 nm for Cu0.5Mg0.5Fe2O4. As the calculated bandgap energy of the hybrid material was approximately 2.86 eV, it could harvest photon energy in the visible region. Results indicate that the Cu0.5Mg0.5Fe2O4-TiO2 also had reasonable magnetic properties with a saturation magnetization value of 11.2 emu/g, which is a level of making easy separation from the solution by an external magnet. The resultant Cu0.5Mg0.5Fe2O4-TiO2 hybrid material revealed better photocatalytic performance for rhodamine B dye (consistent removal rate in the 13.96 × 10-3 min-1) compared with free-standing Cu0.5Mg0.5Fe2O4 and TiO2 materials. The recyclability and photocatalytic mechanism of Cu0.5Mg0.5Fe2O4-TiO2 are also well discussed.

Pure and Ce-doped spinel CuFe2O4 photocatalysts for efficient rhodamine B degradation.

Wastewater management is becoming a serious issue worldwide. To enhance the reuse of wastewater, one has to remove toxic pollutants present in it. High amount of dye is present in wastewater, and to remove these dyes is the large scope of this research. Herein, we report production of pure and Ce-doped copper ferrite via hydrothermal route. The synthesized nanoparticles were collected and analyzed by basic characterization techniques. The bandgap energy calculated for pure, 1% Ce, and 2% Ce-doped CuFe2O4 was found to be 2.77, 2.57, and 2.36eV, respectively. Reduction in bandgap was attributed to the doping element. The shape and size of pure and Ce-doped products were investigated using a scanning electron microscope. Agglomeration was observed in the pure copper ferrite sample. In the Ce-doped sample, agglomeration was clearly reduced and the 2% Ce-doped CuFe2O4 sample showed growth of small nanoparticles. They showed complete growth and were arranged in a uniform manner without agglomeration. The surface area of the 2% Ce-CuFe2O4 sample was found to be 65.89 m2/g with 7.02 nm pore diameter. The photocatalytic activity of the prepared material was observed for rhodamine B degradation. The pure and catalyst-added dye was exposed under visible light. The samples were tested for UV. The efficiency obtained for pure dye solution, pristine CuFe2O4-added, and 1% Ce and 2% Ce-doped CuFe2O4-added dye solutions were 48%, 50%, 66%, and 88% within 2 h of irradiation. The 2% Ce-doped CuFe2O4 sample showed excellent photocatalytic activity as the bandgap and morphology were enhanced by doping an appropriate ratio of Ce ions.

A novel bimetallic (Fe/Bi)-povidone-iodine micro-flowers composite for photocatalytic and antibacterial applications.

The present work describes the synthesis of polyvinylpyrrolidone (PVP) assisted Fe-BiOI based Fe/Bi-povidone­iodine (Fe/Bi-P-I) micro-flowers based composite and its photocatalytic and antibacterial applications. The Fe/Bi-P-I micro-flowers-based composite material was synthesized using a simple co-precipitation method. The prepared Fe/Bi-P-I micro-flowers-based composite materials were characterized using various characterization techniques and tested against photocatalytic degradation of rhodamine B (RhB) dye and antibacterial analysis. The PVP or povidone­iodine provides more exposure of reactive sites and oxygen vacancies, which leads to a high separation rate of photoinduced charge carriers, and migration, thereby 100% of photodegradation efficiency at 1 mg/L initial concentration of RhB dye towards the synthesized P-Fe-BiOI based micro-flowers composite. Interestingly, Povidone-Iodine in Fe/Bi-P-I micro-flowers-based composite might be advantageous for antimicrobial activity against both gram-negative (E. coli), and gram-positive (S. aureus) bacterial strains. Therefore, the prepared Fe/Bi-P-I micro-flowers-based composite improved both photocatalytic degradation of organic pollutants as well as high antimicrobial activity. The method of synthesizing the Bi/Fe-P-I micro flower composite in the present study is novel, facile, and economically viable.

Preparation of immunomagnetic beads coupled with a rhodamine hydrazine immunosensor for the detection of Mycobacterium avium subspecies paratuberculosis in bovine feces, milk, and colostrum.

The aim of this study was to develop and evaluate a method for detecting Mycobacterium avium ssp. paratuberculosis (MAP) bacteria in bovine fecal, milk, and colostrum samples using immunomagnetic beads (IMB) and a rhodamine hydrazone immunosensor. Immunomagnetic beads were prepared by using purified antibodies from hyperimmunized sera that were coupled to Fe nanoparticles with diethylene triamine pentaacetic acid (DTPA) or ethyl (dimethyl aminopropyl) carbodiimide (EDC)-N-hydroxy succinimide (NHS) as linkers. Rhodamine hydrazone particles were synthesized and coupled to IgY anti-MAP antibodies using DTPA or EDC-NHS linkers. Separation efficiency of the IMB was tested on bovine fecal, milk, and colostrum samples experimentally contaminated with MAP. The studied methods were evaluated on their ability to detect MAP and separate bacteria in complex mediums. The ELISA results indicated 95% efficacy in antibody coupling to IMB, with the DTPA-IMB method being more efficient than the EDC-NHS-IMB method. By using the DTPA-IMB method, MAP bacteria were successfully recovered from fecal, milk, and colostrum samples. The DTPA-IMB method used in combination with the rhodamine hydrazone immunosensor had a limit of detection equal to 30 and 30,000 MAP cells/mL using chromogenic and fluorescent properties, respectively. Combining the DTPA-IMB separation method with the rhodamine hydrazone immunosensor provides a fast, sensitive, and cost-beneficial method for detecting MAP in bovine feces, milk, and colostrum.

Oligonucleotide-capped nanoporous anodic alumina biosensor as diagnostic tool for rapid and accurate detection of Candida auris in clinical samples.

Candida auris has arisen as an important multidrug-resistant fungus because of several nosocomial outbreaks and elevated rates of mortality. Accurate and rapid diagnosis of C. auris is highly desired; nevertheless, current methods often present severe limitations and produce misidentification. Herein a sensitive, selective, and time-competitive biosensor based on oligonucleotide-gated nanomaterials for effective detection of C. auris is presented. In the proposed design, a nanoporous anodic alumina scaffold is filled with the fluorescent indicator rhodamine B and the pores blocked with different oligonucleotides capable of specifically recognize C. auris genomic DNA. Gate opening modulation and cargo delivery is controlled by successful DNA recognition. C. auris is detected at a concentration as low as 6 CFU/mL allowing obtaining a diagnostic result in clinical samples in one hour with no prior DNA extraction or amplification steps.

Mechanistic investigations of antitumor activity of a Rhodamine B­oleanolic acid derivative bioconjugate.

Cancer remains a major health problem worldwide due to its high mortality rate. New therapeutic options highlight the importance of discovering new compounds that target the tumor microenvironment, interrupt angiogenesis and act selectively. The present study assessed the antitumor effect and investigated the mechanism of action of a rhodamine B­conjugated oleanolic acid derivative (RhodOA). Consequently, the compound was tested on different human tumor cell lines (A375 melanoma, A549 lung adenocarcinoma and MDA­MB­231 breast adenocarcinoma) and on a non­tumor cell line HaCaT human keratinocyte. RhodOA produced a dose­dependent decrease in tumor cell viability especially in the melanoma cells while affecting the keratinocytes less. In melanoma cells, RhodOA reduced cell migration and produced condensation of cell nuclei and of actin fibers. Furthermore, an impairment in melanoma cell mitochondrial function was observed, while the mitochondrial function of keratinocytes was left intact. In the in ovo chorioallantoic membrane model, RhodOA elicited antiangiogenic effect, without showing irritation effect on the membrane. The study provides information on the selective antitumor effect of the derivative and its ability to inhibit cellular respiration, therefore RhodOA can be classified as 'MITOCAN'.

A versatile luminescent resonance energy transfer (LRET)-based ratiometric upconversion nanoprobe for intracellular miRNA biosensing.

Rational design and fabrication of bio-nanoprobes for intracellular miRNA biosensing are highly desired for early clinical diagnosis and prognosis. Herein, we have developed a versatile LRET-based ratiometric (LBRU) nanoprobe of NaYF4:Yb,Er@NaYF4@NH2-mSiO2/rhodamine B/C-DNA sandwich-structured nanocomposites for intracellular miRNA biosensing. The nanoprobe was composed of NaYF4:Yb,Er@NaYF4 upconversion nanoparticles (energy donor) with an amino functionalized mesoporous silica shell (NH2-mSiO2), rhodamine B (acceptor) loaded into the mesopores of NH2-mSiO2, and the complementary sequences of target miRNA (denoted as C-DNA) acting as recognition species wrapped on the nanocomposite. Due to the LRET behavior between donors and acceptors, the loaded rhodamine B can quench the green upconversion emission of NaYF4:Yb,Er@NaYF4 at 540 nm completely. Moreover, it can be released from the nanocomposite in the presence of target miRNA, which blocked the LRET behavior to "turn on" the green upconversion luminescence. Besides, as the unaffected red upconversion luminescence (at 660 nm) can be used as an internal standard to provide built-in correction for environmental effects, the intensity ratio of upconversion luminescence at 540 and 660 nm (I540/I660) was employed as the output signal to afford an accurate detection of target miRNA. Due to the biocompatibility, high photostability and low auto-fluorescence background, the nanoprobe was successfully utilized to diagnose the intracellular miRNA-21 expression in MCF-7 cells via upconversion fluorescence imaging. We envision that the proposed LBRU nanoprobe has great potential applications in early cancer diagnosis.

Developmental stages of zebrafish (Danio rerio) embryos and toxicological studies using foldscope microscope.

Zebrafish (Danio rerio), is a well-established vertebrate animal model widely used in developmental biology and toxicological research. In the present study, foldscope is used as an innovative tool to study the developmental stages and toxicological analysis of the zebrafish embryos. Briefly, the developmental stages, such as zygote, cleavage, blastula, gastrula, segmentation, and pharyngula formation are observed and documented using simple foldscope. Toxicological parameters upon exposure to different concentration of ethanol extract of Curcuma longa and its lead compound, ar-turmerone along with rhodamine B (bio-coupler) on zebrafish embryos are analyzed upto 72 hr using foldscopes in live condition. The lethal endpoints, such as coagulation, lack of somite formation, non-detachment of tail, and lack of heartbeat are clearly monitored and documented using foldscope. Bio-evaluation of test compounds with the aid of foldscope confirms that the toxicity is directly proportional to the concentration. Our results conclude that, ethanol extract of C. longa, ar-turmerone and rhodamine B exposed embryos remains healthy up to 96, 48, and 24 µg concentrations, respectively. Embryos exposed to higher concentrations become coagulated, however normal physiological active movement of tail lashing and heartbeat are evident in lower concentration exposed embryos. Except coagulation, no other abnormalities are observed and interestingly, the hatching ability is not delayed, when compared with the control embryos. It is confirmed that the test compounds are not highly toxic to zebrafish embryos. Hence it can be used for further analysis, especially for studying the neural-regeneration and its neuronal development in zebrafish embryos.

Reproducible and Bendable SERS Substrates with Tailored Wettability Using Block Copolymers and Anodic Aluminum Oxide Templates.

Surface properties are essential for substrates exhibiting high sensitivity in surface-enhanced Raman scattering (SERS) applications. In this work, novel SERS hybrid substrates using polystyrene-block-poly(methyl methacrylate) and anodic aluminum oxide templates is presented. The hybrid substrates not only possess hierarchical porous nanostructures but also exhibit superhydrophilic surface properties with the water contact angle ≈0°. Such surfaces play an important role in providing uniform enhanced intensities over large areas (relative standard deviation ≈10%); moreover, these substrates are found to be highly sensitive (limit of detection ≈10-12 m for rhodamine 6G (R6G)). The results show that the hybrid SERS substrates can achieve the simultaneous detection of multicomponent mixtures of different target molecules, such as R6G, crystal violet, and methylene blue. Furthermore, the bending experiments show that about 70% of the SERS intensities are maintained after bending from ≈30° to 150°.