The Discovery of New Inhibitors of Insulin-Regulated Aminopeptidase by a High-Throughput Screening of 400,000 Drug-like Compounds.

With the ambition to identify novel chemical starting points that can be further optimized into small drug-like inhibitors of insulin-regulated aminopeptidase (IRAP) and serve as potential future cognitive enhancers in the clinic, we conducted an ultra-high-throughput screening campaign of a chemically diverse compound library of approximately 400,000 drug-like small molecules. Three biochemical and one biophysical assays were developed to enable large-scale screening and hit triaging. The screening funnel, designed to be compatible with high-density microplates, was established with two enzyme inhibition assays employing either fluorescent or absorbance readouts. As IRAP is a zinc-dependent enzyme, the remaining active compounds were further evaluated in the primary assay, albeit with the addition of zinc ions. Rescreening with zinc confirmed the inhibitory activity for most compounds, emphasizing a zinc-independent mechanism of action. Additionally, target engagement was confirmed using a complementary biophysical thermal shift assay where compounds causing positive/negative thermal shifts were considered genuine binders. Triaging based on biochemical activity, target engagement, and drug-likeness resulted in the selection of 50 qualified hits, of which the IC50 of 32 compounds was below 3.5 µM. Despite hydroxamic acid dominance, diverse chemotypes with biochemical activity and target engagement were discovered, including non-hydroxamic acid compounds. The most potent compound (QHL1) was resynthesized with a confirmed inhibitory IC50 of 320 nM. Amongst these compounds, 20 new compound structure classes were identified, providing many new starting points for the development of unique IRAP inhibitors. Detailed characterization and optimization of lead compounds, considering both hydroxamic acids and other diverse structures, are in progress for further exploration.

Effects of different primers and colouring solutions on orthodontic bonding: shear bond strength and colour change.

OBJECTIVES: This in vitro study evaluated the effect of different colouring solutions and primer systems used in the bonding of brackets on enamel colour change and bond strength. MATERIALS AND METHODS: 120 premolar teeth were divided into four main groups; brackets were bonded with 37% orthophosphoric acid + Transbond XT Primer in Group 1, 3 M Single Bond Universal in Group 2, Transbond Plus SEP in Group 3, and G-Premio Bond in Group 4. Each group was divided into three subgroups, and the teeth were placed in a cup containing coffee and tea mixture, in a cup containing cola and in distilled water. A bond strength test was applied to all teeth. Colour measurements of all teeth were performed at 2 different times: before bonding and after the bond strength test. RESULTS: The average bond strength of the 37% orthophosphoric acid group was higher than that of the other groups. The effect of primer and solution groups on colour change was statistically significant (p = 0.001 and p = 0.023, respectively). CONCLUSIONS: In this study, the bond strength was clinically sufficient in all primer groups. The highest colour change was observed when the tea-coffee solution and Transbond Plus SEP primer were used. CLINICAL RELEVANCE: This study has identified enamel discoloration and bond strength from different colouring solutions and primer systems used for bonding braces, which can be used to inform clinicians and patients to achieve better treatment results.

Indocyanine green-enhanced transpupillary thermotherapy for juxtapapillary retinal capillary hemangioblastoma.

PURPOSE: To study the clinical presentation and treatment outcomes of indocyanine green-enhanced transpupillary thermotherapy (ICG-TTT) for treatment-naïve juxtapapillary retinal capillary hemangioblastoma (JRCH). METHODS: A prospective interventional case series. The technique involved ICG dye infusion 45 seconds prior to application of TTT. The main study outcomes were local tumor control, resolution of subretinal fluid (SRF), and improvement in best-corrected visual acuity (BCVA). RESULTS: Eight eyes of seven patients (5 males and 2 females) were included. The mean age was 26 years (range: 5-56 years). Systemic evaluation revealed von-Hippel Lindau (VHL) disease in five patients. The most common location was the temporal aspect of the optic disc (5 eyes). The mean basal diameter was 2.9 mm (range: 1-8 mm), and tumor thickness was 1.4 mm (range: 1-4 mm). All eight eyes were treated with multiple sessions of ICG-TTT (mean: 3 sessions). Six eyes received adjuvant intravitreal injection of dexamethasone implant (4 eyes) and/or bevacizumab (4 eyes). Post treatment, six eyes (75%) had tumor regression with reduction of SRF. One eye had a partial response with persisting SRF, and one eye showed poor response to TTT for which external beam radiotherapy was performed. At the last follow-up (median: 11 months; range: 6-29 months), the BCVA remained stable in seven eyes and improved in one eye (hand motion to 20/40). CONCLUSION: Multiple ICG-TTT sessions can be considered as an alternative treatment option for JRCH with effective local tumor control and SRF resolution.

Click Reaction-Mediated Fluorescent Immunosensor Based on Cu-MOF Nanoparticles for Ultrasensitive and High-Throughput Detection of Aflatoxin B1 in Food Samples.

Due to the high toxicity of aflatoxin B1 and its risks to human health, we developed a click reaction-mediated automated fluorescent immunosensor (CAFI) for sensitive detection of aflatoxin B1 based on the Cu(I)-catalyzed click reaction. With its large specific surface area, a copper-based metal-organic framework (Cu-MOF) was synthesized to adsorb and enrich the copper ion (Cu(II)) and then load the complete antigen (BSA-AFB1). After the immunoreaction, Cu(II) inside the Cu-MOF-Antigen conjugate would be reduced to Cu(I) in the presence of sodium ascorbate, which triggered the click reaction between the fluorescent donor-modified DNA and the receptor-modified complementary DNA to lead to a fluorescence signal readout. The whole reaction steps were finished by the self-developed automated immunoreaction device. This CAFI method showed a limit of detection (LOD) of 0.48 pg/mL as well as a 670-fold enhancement in sensitivity compared to conventional ELISA, revealing its great potential in practical applications and automated detection.

Chalcogen Atom-Modulated Croconaine for Efficient NIR-II Photothermal Theranostics.

Organic dye-based agents with near-infrared (NIR)-II absorption have great potential for cancer theranostics because of the deeper tissue penetration and good biocompatibility. However, proper design is required to develop NIR-II-absorbing dyes with good optical properties. We proposed to construct chalcogen atom-modulated croconaine for NIR-II light-triggered photothermal theranostics. By introducing different chalcogen atoms (O, S, Se, or Te) into the structure of croconaine, the light absorption of croconaine can be precisely regulated from the NIR-I to the NIR-II range due to the heavy-atom effect. Especially, Te-substituted croconaine (CRTe) and its nanoformulations exhibit superior NIR-II responsiveness, a high photothermal conversion efficiency (70.6%), and good photostability. With their favorable tumor accumulation, CRTe-NPs from tumor regions can be visualized by NIR-II optoacoustic systems with high resolution and high contrast; meanwhile, their superior photothermal performance also contributes to efficient cell killing and tumor elimination upon 1064 nm laser irradiation. Therefore, this work provides an efficient strategy for the molecular design of NIR-II organic photothermal agents.

Phenolic Determination in Proembryogenic Cell Complexes of Buckwheat Morphogenic Cell Culture with Osmium Tetroxide, Toluidine Blue O Dye, and Iron Chloride.

The study of the localization of secondary metabolites in both plants and the cell cultures on the intravital sections is hampered by the difficulty of obtaining thin, correctly oriented sections. Techniques for fixing tissues in resins allow these difficulties to be overcome. Properly selected tissue fixation techniques allow using different dyes to identify the compound of interest. In addition, some components of tissue fixation can act as fixatives and as a dye for identifying secondary metabolites. For example, osmium tetroxide, which fixes lipids in tissues, stains phenolic compounds black. This paper describes methods for the detection of phenolic compounds in morphogenic callus culture of buckwheat using osmium tetroxide, Toluidine Blue O dye, and ferric chloride as dyes in epoxy resin-embedded cell culture with double fixation of the material and when material fixed in Karnovsky's fixative.

Highly efficient catalytic degradation of organic dyes using iron nanoparticles synthesized with Vernonia Amygdalina leaf extract.

Today, nanoscience explores the potential of nanoparticles due to their extraordinary properties compared to bulk materials. The synthesis of metal nanoparticles using plant extracts is a very promising method for environmental remediation, which gets global attention due to pollution-led global warming. In the present study, iron nanoparticles (FeNPs) were successfully synthesized by the green method using Vernonia amygdalina plant leaf extract as a natural reducing and capping agent. Biosynthesized FeNPs were characterized with different analytical techniques such as UV-visible, FT-IR, XRD, and SEM. The analysis revealed the formation of amorphous FeNPs with an irregular morphology and non-uniform distribution in size and shape. The average particle size was approximately 2.31 µm. According to the catalytic degradation investigation, the FeNPs produced via the green approach are highly effective in breaking down both CV and MB into non-toxic products, with a maximum degradation efficiency of 97.47% and 94.22%, respectively, when the right conditions are met. The kinetics study exhibited a high correlation coefficient close to unity (0.999) and (0.995) for the degradation of MB and CV, respectively, for the zero-order pseudo-kinetics model, which describes the model as highly suitable for the degradation of both dyes by FeNPs compared to other models. The reusability and stability of biosynthesized nano-catalysts were studied and successfully used as efficient catalysts with a slight decrease in the degradation rate more than four times. The results from this study illustrate that green synthesized FeNPs offer a cost-effective, environmentally friendly, and efficient means for the catalytic degradation of organic dyes.

Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study.

AIM: The aim of the present study was to assess the stain removal ability and color stability of three distinct dentifrices on artificially stained enamel surface. MATERIALS AND METHODS: This study included 75 intact, healthy premolars free of dental caries that were extracted during orthodontic therapy. The samples were allowed to dry for 6 hours after being submerged in the prepared tea solution for roughly 18 hours every day. Then this procedure was repeated for seven successive days. All samples were randomly divided into three experimental groups with 25 samples in each group. Group I: control dentifrice, group II: dentifrice containing hydrogen peroxide, group III: dentifrice containing papain and bromelain. A specially designed toothbrushing simulator was used to brush every sample in the relevant group. Using a spectrophotometer and a measurement program, color measurement was evaluated after staining process after 4 weeks and 8 weeks of teeth cleaning. Using a profilometer, the surface roughness values (Ra) were assessed. RESULTS: After 8 weeks of brushing of stained samples, the color stability was better in dentifrice containing hydrogen peroxide (1.14 ± 0.11) followed by dentifrice containing papain and bromelain (1.22 ± 0.08) and control group (1.30 ± 0.09). And after 8 weeks of brushing of stained samples, the surface roughness was more in dentifrice containing hydrogen peroxide (0.237 ± 0.02) followed by dentifrice containing papain and bromelain (0.229 ± 0.13) and control group (0.207 ± 0.05). CONCLUSION: The present study concluded that the dentifrice containing hydrogen peroxide showed a superior whitening effect on the stained enamel surface than dentifrice containing papain and bromelain and control dentifrice. CLINICAL SIGNIFICANCE: The development of various dentifrice products has been greatly aided by the increased demand for an improved esthetic appearance. Teeth's natural color and any external stains that could accumulate on the tooth surface combine to determine a tooth's color. Additionally, the use of whitening dental pastes to remove external stains has grown in favor. With the development of these whitening toothpastes, dentifrices' ability to lessen or eliminate extrinsic dental stains has increased. How to cite this article: Mishra D, Kamath DG, Alagla M, et al. Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study. J Contemp Dent Pract 2024;25(1):68-71.

Rotor-based image-guided therapy of glioblastoma.

Glioblastoma (GBM), deep in the brain, is more challenging to diagnose and treat than other tumors. Such challenges have blocked the development of high-impact therapeutic approaches that combine reliable diagnosis with targeted therapy. Herein, effective cyanine dyes (IRLy) with the near-infrared two region (NIR-II) adsorption and aggregation-induced emission (AIE) have been developed via an "extended conjugation & molecular rotor" strategy for multimodal imaging and phototherapy of deep orthotopic GBM. IRLy was synthesized successfully through a rational molecular rotor modification with stronger penetration, higher signal-to-noise ratio, and a high photothermal conversion efficiency (PCE) up to ∼60%, which can achieve efficient NIR-II photo-response. The multifunctional nanoparticles (Tf-IRLy NPs) were further fabricated to cross the blood-brain barrier (BBB) introducing transferrin (Tf) as a targeting ligand. Tf-IRLy NPs showed high biosafety and good tumor enrichment for GBM in vitro and in vivo, and thus enabled accurate, efficient, and less invasive NIR-II multimodal imaging and photothermal therapy. This versatile Tf-IRLy nanosystem can provide a reference for the efficient, precise and low-invasive multi-synergistic brain targeted photo-theranostics. In addition, the "extended conjugation & molecular rotor" strategy can be used to guide the design of other photothermal agents.

Tecoma stans floral extract-mediated synthesis of MgFe2O4/ZnO nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue dye.

Toxic organic dyes-containing wastewater treatment by adsorption and photocatalytic techniques is widely applied, but adsorbents and photocatalysts are often synthesized through chemical methods, leading to secondary pollution by released chemicals. Here, we report a benign method using Tecoma stans floral extract to produce MgFe2O4/ZnO (MGFOZ) nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue (CBB) dye. Green MGFOZ owned a surface area of 9.65 m2/g and an average grain size of 54 nm. This bio-based nanomaterial showed higher removal percentage and better recyclability (up to five cycles) than green MgFe2O4 and ZnO nanoparticles. CBB adsorption by MGFOZ was examined by kinetic and isotherm models with better fittings of Bangham and Langmuir or Temkin. RSM-based optimization was conducted to reach an actual adsorption capacity of 147.68 mg/g. Moreover, MGFOZ/visible light system showed a degradation efficiency of 89% CBB dye after 120 min. CBB adsorption can be controlled by both physisorption and chemisorption while •O2- and •OH radicals are responsible for photo-degradation of CBB dye. This study suggested that MGFOZ can be a promising adsorbent and catalyst for removal of organic dyes in water.

Amino acid-based metallo-supramolecular nanoassemblies capable of regulating cellular redox homeostasis for tumoricidal chemo-/photo-/catalytic combination therapy.

Nanozymes, as nanomaterials with natural enzyme activities, have been widely applied to deliver various therapeutic agents to synergistically combat the progression of malignant tumors. However, currently common inorganic nanozyme-based drug delivery systems still face challenges such as suboptimal biosafety, inadequate stability, and inferior tumor selectivity. Herein, a super-stable amino acid-based metallo-supramolecular nanoassembly (FPIC NPs) with peroxidase (POD)- and glutathione oxidase (GSHOx)-like activities was fabricated via Pt4+-driven coordination co-assembly of l-cysteine derivatives, the chemotherapeutic drug curcumin (Cur), and the photosensitizer indocyanine green (ICG). The superior POD- and GSHOx-like activities could not only catalyze the decomposition of endogenous hydrogen peroxide into massive hydroxyl radicals, but also deplete the overproduced glutathione (GSH) in cancer cells to weaken intracellular antioxidant defenses. Meanwhile, FPIC NPs would undergo degradation in response to GSH to specifically release Cur, causing efficient mitochondrial damage. In addition, FPIC NPs intrinsically enable fluorescence/photoacoustic imaging to visualize tumor accumulation of encapsulated ICG in real time, thereby determining an appropriate treatment time point for tumoricidal photothermal (PTT)/photodynamic therapy (PDT). In vitro and in vivo findings demonstrated the quadruple orchestration of catalytic therapy, chemotherapeutics, PTT, and PDT offers conspicuous antineoplastic effects with minimal side reactions. This work may provide novel ideas for designing supramolecular nanoassemblies with multiple enzymatic activities and therapeutic functions, allowing for wider applications of nanozymes and nanoassemblies in biomedicine.

Cationized orthogonal triad as a photosensitizer with enhanced synergistic antimicrobial activity.

Single-molecule-based synergistic phototherapy holds great potential for antimicrobial treatment. Herein, we report an orthogonal molecular cationization strategy to improve the reactive oxygen species (ROS) and hyperthermia generation of heptamethine cyanine (Cy7) for photodynamic and photothermal treatments of bacterial infections. Cationic pyridine (Py) is introduced at the meso­position of the asymmetric Cy7 with intramolecular charge transfer (ICT) to construct an atypical electron-transfer triad, which reduces ΔES1-S0, circumvents rapid charge recombination, and simultaneously enhances intersystem crossing (ISC) based on spin-orbit charge-transfer ISC (SOCT-ISC) mechanism. This unique molecular construction produces anti-Stokes luminescence (ASL) because the rotatable CN bond enriched in high vibrational-rotational energy levels improves hot-band absorption (HBA) efficiency. The obtained triad exhibits higher singlet oxygen quantum yield and photothermal conversion efficiency compared to indocyanine green (ICG) under irradiation above 800 nm. Cationization with Py enables the triad to target bacteria via intense electrostatic attractions, as well as biocidal property against a broad spectrum of bacteria in the dark. Moreover, the triad under irradiation can enhance biofilm eradication performance in vitro and statistically improve healing efficacy of MRSA-infected wound in mice. Thus, this work provides a simple but effective strategy to design small-molecule photosensitizers for synergistic phototherapy of bacterial infections. STATEMENT OF SIGNIFICANCE: We developed an orthogonal molecular cationization strategy to enhance the reactive oxygen species and thermal effects of heptamethine cyanine (Cy7) for photodynamic and photothermal treatments of bacterial infections. Specifically, cationic pyridine (Py) was introduced at the meso­position of the asymmetric Cy7 to construct an atypical electron-transfer triad, which reduced ΔES1-S0, circumvented rapid charge recombination, and simultaneously enhanced intersystem crossing (ISC). This triad, with a rotatable CN bond, produced anti-Stokes luminescence due to hot-band absorption. The triad enhanced antimicrobial performance and statistically improved the healing efficacy of MRSA-infected wounds in mice. This site-specific cationization strategy may provide insights into the design of small molecule-based photosensitizers for synergistic phototherapy of bacterial infections.

Recent advancements in sustainable synthesis of zinc oxide nanoparticles using various plant extracts for environmental remediation.

The sustainable synthesis of zinc oxide nanoparticles (ZnO-NPs) using plant extracts has gained significant attention in recent years due to its eco-friendly nature and potential applications in numerous fields. This synthetic approach reduces the reliance on non-renewable resources and eliminates the need for hazardous chemicals, minimizing environmental pollution and human health risks. These ZnO-NPs can be used in environmental remediation applications, such as wastewater treatment or soil remediation, effectively removing pollutants and improving overall ecosystem health. These NPs possess a high surface area and band gap of 3.2 eV, can produce both OH° (hydroxide) and O2-° (superoxide) radicals for the generation of holes (h+) and electrons (e-), resulting in oxidation and reduction of the pollutants in their valence band (VB) and conduction band (CB) resulting in degradation of dyes (95-100% degradation of MB, MO, and RhB dyes), reduction and removal of heavy metal ions (Cu2+, Pb2+, Cr6+, etc.), degradation of pharmaceutical compounds (paracetamol, urea, fluoroquinolone (ciprofloxacin)) using photocatalysis. Here, we review an overview of various plant extracts used for the green synthesis of ZnO NPs and their potential applications in environmental remediation including photocatalysis, adsorption, and heavy metal remediation. This review summarizes the most recent studies and further research perspectives to explore their applications in various fields.

Physicochemical and photocatalytic properties of biogenic ZnO and its chitosan nanocomposites for UV-protection and antibacterial activity on coated textiles.

The textiles for medical use and the purification of textile factory effluents have become the most crucial part of the human healthcare sector. In this study bioactive compounds produced by four distinct plant extracts were used for the synthesis of zinc oxide nanoparticles. The four different ZnO nanoparticles were comprehensively characterized by different analytical techniques. XRD analysis revealed the crystalline nature and phase purity of the ZnO nanoparticles. FTIR spectra provided information on the function of plant extracts in the stabilization or capping process. The size distribution and morphological diversity of the nanoparticles were further clarified by SEM and TEM images. The photocatalytic degradation activity of the four ZnO nanoparticles on two different dyes showed that ZnO nanoparticles prepared from A. indica were most effective for the degradation of 98 % and 91 % of Rhodamine B and Alizarin red dye respectively. The selected ZnO nanoparticles from A. indica were used to prepare ZnO-chitosan nanocomposites before coating on cotton fabrics. The hydrophobicity, UV protection factor, and antibacterial activity of ZnO-chitosan nanocomposites, when coated on cotton fabrics, were also examined. The overall results demonstrated the ZnO and ZnO-chitosan nanocomposite prepared in the present study as a promising material for environmental remediation application.

Gardenia yellow pigment: Extraction methods, biological activities, current trends, and future prospects.

Food coloring plays a vital role in influencing consumers' food choices, imparting vibrant and appealing colors to various food and beverage products. Synthetic food colorants have been the most commonly used coloring agents in the food industry. However, concerns about potential health issues related to synthetic colorants, coupled with increasing consumer demands for food safety and health, have led food manufacturers to explore natural alternatives. Natural pigments not only offer a wide range of colors to food products but also exhibit beneficial bioactive properties. Gardenia yellow pigment is a water-soluble natural pigment with various biological activities, widely present in gardenia fruits. Therefore, this paper aims to delve into Gardenia Yellow Pigment, highlighting its significance as a food colorant. Firstly, a thorough understanding and exploration of various methods for obtaining gardenia yellow pigment. Subsequently, the potential functionality of gardenia yellow pigment was elaborated, especially its excellent antioxidant and neuroprotective properties. Finally, the widespread application trend of gardenia yellow pigment in the food industry was explored, as well as the challenges faced by the future development of gardenia yellow pigment in the field of food and health. Some feasible solutions were proposed, providing valuable references and insights for researchers, food industry professionals, and policy makers.

Fluorescent microscopy evaluation of diode laser effect on the penetration depth of turmeric (Curcuma longa) extract cream on skin tissues of Wistar rats.

The study investigates the effect of diode laser exposure on curcumin's skin penetration, using turmeric extraction as a light-sensitive chemical and various laser light sources. It uses an in vivo skin analysis method on Wistar strain mice. The lasers are utilized at wavelengths of 403 nm, 523 nm, 661 nm, and 979 nm. The energy densities of the lasers are 20.566 J/cm2, 20.572 J/cm2, 21.162 J/cm2, and 21.298 J/cm2, which are comparable to one another. The experimental animals were divided into three groups: base cream (BC), turmeric extract cream (TEC), and the combination laser (L), BC, and TEC treatment group. Combination light source (LS) with cream (C) was performed with 8 combinations namely 523 nm ((L1 + BC) and (L1 + TEC)), 661 nm ((L2 + BC) and (L2 + TEC)), 403 nm ((L3 + BC) and (L3 + TEC)), and 979 nm ((L4 + BC) and (L4 + TEC)). The study involved applying four laser types to cream-covered and turmeric extract-coated rat skin, with samples scored for analysis. The study found that both base cream and curcumin cream had consistent pH values of 7-8, within the skin's range, and curcumin extract cream had lower viscosity. The results of the statistical analysis of Kruskal-Wallis showed a significant value (p < 0.05), which means that there are at least two different laser treatments. The results of the post hoc analysis with Mann-Whitney showed that there was no significant difference in the LS treatment with the addition of BC or TEC when compared to the BC or TEC treatment alone (p > 0.05), while the treatment using BC and TEC showed a significant difference (p < 0.05). Laser treatment affects the penetration of the turmeric extract cream into the rat skin tissue.

Tuning Shortwave-Infrared J-aggregates of Aromatic Ring-Fused Aza-BODIPYs by Peripheral Substituents for Combined Photothermal and Photodynamic Therapies at Ultralow Laser Power.

Achieving photothermal therapy (PTT) at ultralow laser power density is crucial for minimizing photo-damage and allowing for higher maximum permissible skin exposure. However, this requires photothermal agents to possess not just superior photothermal conversion efficiency (PCE), but also exceptional near-infrared (NIR) absorptivity. J-aggregates, exhibit a significant redshift and narrower absorption peak with a higher extinction coefficient. Nevertheless, achieving predictable J-aggregates through molecular design remains a challenge. In this study, we successfully induced desirable J-aggregation (λabs max : 968 nm, ϵ: 2.96×105  M-1 cm-1 , λem max : 972 nm, ΦFL : 6.2 %) by tuning electrostatic interactions between π-conjugated molecular planes through manipulating molecular surface electrostatic potential of aromatic ring-fused aza-BODIPY dyes. Notably, by controlling the preparation method for encapsulating dyes into F-127 polymer, we were able to selectively generate H-/J-aggregates, respectively. Furthermore, the J-aggregates exhibited two controllable morphologies: nanospheres and nanowires. Importantly, the shortwave-infrared J-aggregated nanoparticles with impressive PCE of 72.9 % effectively destroyed cancer cells and mice-tumors at an ultralow power density of 0.27 W cm-2 (915 nm). This phototherapeutic nano-platform, which generates predictable J-aggregation behavior, and can controllably form J-/H-aggregates and selectable J-aggregate morphology, is a valuable paradigm for developing photothermal agents for tumor-treatment at ultralow laser power density.

A universal dual-mode hydrogel array based on phage-DNA probe for simultaneous rapid screening and precisely quantitative detection of Escherichia coli O157:H7 in foods by the fluorescent/microfluidic chip electrophoresis methods.

Rapid and specific detection of virulent bacterial strains is a great challenge for food safety regarding large amounts of contaminated samples. Herein, a dual-mode hydrogel array biosensor was constructed to simultaneously rapidly screen and precisely quantitatively detect virulent Escherichia coli O157:H7 (E. coli O157:H7) based on a novel DNA-modified phage probe. First, E. coli O157:H7 was incubated with alginate to form the E. coli O157:H7/hydrogel premix complex. Subsequently, hydrogel formation by cross-linking upon the addition of calcium ions and phages for E. coli O157:H7 modified with a DNA primer (phage-DNA) was added to the alginate hydrogel. The DNA on the complex could trigger rolling circle amplification (RCA) to form a phage probe containing a long-chain DNA skeleton (phage@RCA-DNA). The RCA-DNA was then hybridized with the complementary DNA (cDNA) to form double-stranded DNA fragments (phage@RCA-dsDNA), which could be stained by the SYBR Green dye to emit visual green fluorescence (FL) and determined by a smartphone for rapid screening. Meanwhile, the unreacted cDNA in the supernatant could be quantitatively detected by microfluidic chip electrophoresis (MCE). The signal decrement was also proportional to the bacterial concentration. The detection limit values of E. coli O157:H7 were 50 CFU mL-1 by the FL signal and 6 CFU mL-1 by the MCE signal. The two results could be mutually corrected to decrease the false-positive results. This assay was also employed to detect virulent Salmonella Typhimurium (S. Typhimurium) using the corresponding S. Typhimurium phage@RCA-DNA probe. All these results demonstrated that the universal bioassay was suitable for simultaneous rapid screening and precisely quantitative detection of virulent bacterial strains.

3, 5-Dihydroxy 4', 7-dimethoxyflavone-DNA interaction study for nucleic acid detection and differential cell staining.

The present study is focused on application of a natural compound, 3, 5-dihydroxy 4', 7-dimethoxyflavone (DHDM) from a medicinal plant Alpinia nigra for nucleic acid detection and differential cell staining. DHDM was found to interact with nucleic acid and forms complex, which was investigated for various applications. It was successfully utilized to visualize plasmid, genomic, and ds-linear DNA in agarose gel electrophoresis without affecting the DNA mobility in the gel. Fluorescence of DHDM increased several fold upon binding to dsDNA. Photostability of the compound was assessed and showed photobleaching effect that decreased gradually over time. Application of the compound was further extended to differential cell staining. When observed in fluorescence microscope, DHDM stained the dead cells and differentiated them from live cells in the case of bacterial, yeast, and mammalian cells. Higher concentration of the compound was found to be less cytotoxic to cancerous cells. Nucleic acid staining dyes like Ethidium bromide (EtBr), Propidium iodide (PI), etc. are carcinogens and environmental pollutants and therefore DHDM a natural compound, is a major benefit and thus can serve as an alternative to the current dyes.

Influence of photoactivation on tissue response to different dyes used in photodynamic therapy and laser ablation therapy.

Laser ablation therapy (LA) uses Indocyanine Green dye (ICG) which efficiently absorbs laser energy and the increased temperature results in an instantaneous flame that chars tissue and microbes. Photodynamic therapy (PDT) uses different dyes that are activated by light to kill bacteria. This study evaluated the biocompatibility of the dye Curcumin (CUR), Methylene Blue (MB), and Indocyanine Green (ICG) before and after laser activation (ACT). Polyethylene tubes containing one of the dyes were implanted in the subcutaneous tissue of 32 rats (4 tubes per rat) which were divided into 8 groups: C - control (saline solution); C + ACT (Red Laser 660 nm); CUR; CUR + ACT (480 nm blue LED); MB; MB + ACT (Red Laser 660 nm); ICG; ICG + ACT (810 nm Infrared Laser). After 7 and 30 days (n = 8/time), the rats were euthanized and the tubes with the surrounding tissue were removed and processed for histological analysis of inflammation using H&E stain, and collagen fiber maturation using picrosirius red (PSR). A two-way analysis of variance statistical test was applied (p < 0.05). At 7 days, regardless of laser activation, the CUR group showed a greater inflammatory infiltrate compared to the ICG and control groups, and the MB group had a greater inflammation only in relation to the control (p < 0.05). At 30 days, CUR and MB groups showed a greater inflammatory infiltrate than the control (p < 0.05). ICG group was equal to the control in both periods, regardless of the laser activation (p > 0.05). Laser activation induced the proliferation of collagen immature fibers at 7 days, regardless of the dye (p < 0.05). The CUR group showed a lower percentage of immature and mature fibers at 7 days, compared to ICG and control (p < 0.05) and, at 30 days, compared to control (p < 0.05). Regardless of laser activation, the ICG showed the results of collagen maturation closest to the control (p > 0.05). It was concluded that all dyes are biocompatible and that laser activation did not interfere with biocompatibility. In addition, the maturity of collagen was adequate before and after the laser activation. These results demonstrate that the clinical use of dyes is safe even when activated with a laser.