Peak Absorption Wavelength Research Articles

Optimizing near infrared laser irradiation and photosensitizer accumulation period for indocyanine green-mediated photodynamic therapy in breast cancer xenografts: a focus on treatment and characterization.

Photodynamic therapy (PDT) is a promising cancer treatment approach. Indocyanine green (ICG) is a water-soluble tricarbocyanine dye with a peak absorption wavelength of around 800nm and possesses the capacity to produce reactive oxygen species. FTIR spectroscopy is rarely used and offers insights into molecular changes in cancer studies. MCF-7 cells were injected into Nude mouse. Once the tumor had grown to a size of 3-4mm, mice were randomized into the 12 PDT groups. After each mouse received 5mg/kg of ICG, they were photo-irradiated with a diode laser emitting light at 809nm, followed by waiting intervals of 0, 30, 60, and 90min. Laser irradiation parameters were 150, 250, 500 mW/cm2 and irradiation duration was 1200s. The tumor size was measured every day for four days. The FTIR spectroscopy was used to perform spectral analysis on tumor tissue samples. Four distinct regions (3600-2800cm-1, 1750-1550cm-1, 1540-1450cm-1, and 1700-1100cm-1) were analyzed, and Hierarchical Cluster study was carried out. A decrease in tumor volume was observed with all PDT applications, except, increases in tumor volume was observed at 150mW 90-minute group. PDT administered after 90min revealed variations in 150mW and 250mW laser powers in the 3600cm-1-2800cm-1 range. The 250mW and 500mW applications resulted in a considerable reduction in fibroadenoma and carcinoma tissues, according to an analysis comparing the A1695 / A1635 ratio. It is proposed that the ideal treatments for further investigation have a power output of 250 mW.

Molecular Mechanisms Underlying the Spectral Shift in Zebrafish Cone Opsins.

Visual pigments are essential for converting light into electrical signals during vision. Composed of an opsin protein and a retinal-based chromophore, pigments in vertebrate rods (Rh1) and cones (Rh2) have different spectral sensitivities, with distinct peak absorption wavelengths determined by the shape and composition of the chromophore binding pocket. Despite advances in understanding Rh1 pigments such as bovine rhodopsin, the molecular basis of spectral shifts in Rh2 cone opsins has been less studied, particularly the E122Q mutation, which accounts for about half of the observed spectral shift in these pigments. In this study, we employed molecular modeling and quantum mechanical techniques to investigate the molecular mechanisms behind the spectral difference in blue-shifted Rh2-1 (absorption peak = 467 nm, 122Q) and green-shifted Rh2-4 (absorption peak = 505 nm, 122E) zebrafish cone opsins. We modeled the pigments 3D structures based on their sequences and conducted all-atom molecular dynamics simulations totaling 2 microseconds. Distance analysis of the trajectories identified three key sites: E113, E181, and E122. The E122Q mutation, previously known, validates our findings, while E181 and E113 are newly identified contributors. Structural analysis revealed key features with differing values that explain the divergent spectral sensitivities of Rh2-1 and Rh2-4: 1) chromophore atom fluctuations and C5-C6 torsion angle, 2) binding pocket volume, 3) hydration patterns, and 4) E113-chromophore interaction stability. Quantum mechanics further confirms the critical role of residue E181 in Rh2-1 and E122 in Rh2-4 for their spectral behavior. Our study provides new insights into the molecular determinants of spectral shifts in cone opsins, and we anticipate that it will serve as a starting point for a broader understanding of the functional diversity of visual pigments.

Production of low-cost lactic acid from dairy wastes and dates wastewater and bioactive silver-poly (lactic acid) nanocomposite for biological applications

L-Lactic acid-producing Lactobacillus lactis and L. plantarum were isolated from date wastes. The fermentation process was optimized using a one-variable-at-a-time approach. Dairy wastewater and wastewater from the date industry were utilized as low-cost culture media to produce lactic acid. The selected two bacterial strains were co-cultured in wastewater medium to produce L-lactic acid and D-lactic acid. Lactic acid production was significantly improved by glucose (carbon source), yeast extract (nitrogen source), initial inoculum level, and polysorbate 80. A central composite design and response surface methodology were used to optimize the variables and their levels to improve lactic acid yield. The supplemented yeast extract, glucose, and polysorbate 80 improved lactic acid. The predicted variables and their levels for maximum lactic acid production were glucose (67.5 g/L), yeast extract (10.28 g/L), and polysorbate 80 (0.48 mL/L). The prepared nanocomposites exhibited antibacterial activity against foodborne bacterial pathogens. The structural properties of the silver-polylactic acid nano compost materials were determined. The characterized compost materials exhibited a peak absorption wavelength of 430 nm. The silver and poly(lactic acid) were characterized using X-ray diffraction analysis and were 30 to 50 nm in size.

Optimization of Laser Micro/Nano Processing of Silicon and Quartz

This research paper explores the application of three laser systems, namely the Nd:YAG laser, fiber laser, and CO2 laser, for the micro/nano machining of silicon and quartz materials. The experimental results demonstrate the successful formation of stable silicon nanoparticles with reduced dimensions. Additionally, a quartz sheet was utilized to create a microlens array. The laser microprocessing technique was enhanced through the implementation of design of experiments (DOE) analysis. A Box-Behnken design (BBD) software was employed to conduct 17 tests, investigating the influence of laser parameters on the microprocessing outcomes. The COMSOL software was utilized for theoretical calculations to determine the distribution of surface temperatures and subsurface temperatures of silicon and quartz. The maximum temperatures achieved were approximately 5700 K for silicon and 2630 K for quartz. Numerical optimization using DOE software improved the production of silicon nanoparticles and quartz microlens, producing silicon nanoparticles wavelength peak and absorption peak values of 318.2 nm and 0.39, respectively. Additionally, quartz microlens numerical aperture and surface roughness improved to 0.494 and 4.64 nm, respectively. Due to the precise control offered by the laser micro/nano machining process, the findings of this study hold potential for diverse applications in optoelectronics and biological imaging that can leverage the unique characteristics of silicon nanoparticles and microlens arrays.

Synthesis of NIR/SWIR Absorbing InSb Nanocrystals Using Indium(I) Halide and Aminostibine Precursors

AbstractColloidal InSb quantum dots (QDs) are a potential alternative to toxic Pb‐ and Hg‐chalcogenide QDs for covering the technologically important near‐infrared/shortwave infrared (NIR/SWIR) spectral range. However, appropriate Sb precursors are scarce and obtaining narrow size distributions is challenging. Tris(dimethylamido)antimony (Sb(NMe2)3) is an appealing choice due to its commercial availability and non‐pyrophoric character but implies the reduction of antimony from the +3 to the required –3 state. In reported works, strong reducing agents such as lithium triethylborohydride are used, which lead to the fast co‐reduction of both Sb3+ and In3+. The downsides of this approach are reproducibility issues and the risk of forming metal nanoparticles due to the different reduction kinetics of Sb3+ and In3+. Here, indium(I) halides are explored as simultaneous indium source and mild reducing agent for the antimony precursor. The wavelength of the excitonic absorption peak of the phase‐pure InSb QDs obtained with this approach can be tuned from 630 to 1890 nm, which corresponds to a size range of ≈2–7 nm. The synthesis can also be conducted in a heat‐up manner, which facilitates the scale‐up and paves the way for the use of InSb QDs in applications such as NIR/SWIR photodetectors, cameras, biological imaging, and telecommunications.

Evolution of rhodopsin in flatfishes (Pleuronectiformes) is associated with depth and migratory behavior.

Visual signals are involved in many fitness-related tasks and are therefore essential for survival in many species. Aquatic organisms are ideal systems to study visual evolution, as the high diversity of spectral properties in aquatic environments generates great potential for adaptation to different light conditions. Flatfishes are an economically important group, with over 800 described species distributed globally, including halibut, flounder, sole, and turbot. The diversity of flatfish species and wide array of environments they occupy provides an excellent opportunity to understand how this variation translates to molecular adaptation of vision genes. Using models of molecular evolution, we investigated how the light environments inhabited by different flatfish lineages have shaped evolution in the rhodopsin gene, which is responsible for mediating dim-light visual transduction. We found strong evidence for positive selection in rhodopsin, and this was correlated with both migratory behavior and several fundamental aspects of habitat, including depth and freshwater/marine evolutionary transitions. We also identified several mutations that likely affect the wavelength of peak absorbance of rhodopsin, and outline how these shifts in absorbance correlate with the response to the light spectrum present in different habitats. This is the first study of rhodopsin evolution in flatfishes that considers their extensive diversity, and our results highlight how ecologically-driven molecular adaptation has occurred across this group in response to transitions to novel light environments.

Development of a new class of temperature-sensitive paints operating in the green spectrum of light for aerodynamic flow applications

Temperature-sensitive paint (TSP) is widely used in aerodynamic measurements, such as detecting laminar to turbulent transition locations, heat transfer measurements, etc. Most conventional TSP luminophores are Ruthenium and Europium complexes, whose peak absorption wavelengths occur at UV or blue spectrum of light. A new class of TSP is developed based on eosin Y as a luminophore. Eosin Y has peak emission and absorption wavelength in the green spectrum, allowing employment of conventional (Nd-YAG) lasers and scientific cameras in aerodynamic applications. The paint achieved a temperature sensitivity of 0.9 % /K, comparable to Rhodamine B based TSP, which operates in the green spectrum. The performance of the TSP is compared with the temperature and its gradient measured using an infrared camera (serving as a reference). The capability of the TSP is tested in three configurations of increasing complexity. The paint successfully detects the laminar to turbulent transition location (third configuration), indicating its promise as an addition to the existing ones for aerodynamic applications.

Synthesis and characterization of sustainable blue dyes: Enhancing diffusion on nylon fabrics with supercritical CO2 for eco-friendly dyeing methods

A very convenient method was developed to synthesize five dispersed anthraquinone dyestuffs using the readily available starting material 1,4-diaminoanthroquinone. This dye was prepared for coloration on nylon fabrics with supercritical carbon dioxide (ScCO2). All the synthesized dyes were characterized by 1H NMR, 13C NMR, and HRMS techniques. The UV-Vis absorbance measurements for all the dyes were carried out, and the results indicated that the absorption peak wavelength of the dyes was approximately 570–641 nm in the blue region. Further, these dispersed dyes were dyed on nylon fabrics with supercritical CO2. After dyed fabrics were tested, the color strength of K/S value and color fastness were tested using like washing, crocking, and sunlight. Additionally, it determines the sweat fastness of dyed nylon fabrics under acidic and basic conditions. The dyes are readily involved in the nucleophilic addition of amino (-NH2, nylon) functional groups to nylon fabrics in an alkaline medium. Therefore, our results showed that these dyes are commercially the most satisfactory, environmentally efficient dyes and practically exhibit sufficient color uniformity.

Hybrid graphene-high-aspect ratio plasmonic nanograting systems

One-dimensional plasmonic nanogratings (1D-PNGs) with high aspect ratios and narrow grooves promise enhanced coupling for hybrid graphene systems with the localized surface plasmon of the metallic grating and graphene surface plasmons. However, both the fabrication of the 1D-PNG and the application of graphene to it are difficult. We developed 1D-PNGs with a high aspect ratio of 15 and narrow grooves of 100 nm in width using the tapered mold method and a dry graphene-transfer procedure. Raman spectroscopy measurements showed that monolayer graphene was successfully transferred onto the 1D-PNGs, and the graphene was strongly doped with Au in the 1D-PNGs. Graphene on narrow grooves (free-standing graphene) demonstrated an almost identical p-doping level to graphene on Au because the narrow groove width allowed sufficient doping by Au for graphene on grooves. Reflectance measurements showed that the 1D-PNGs exhibited polarization- and wavelength-selective absorption at infrared (IR) wavelengths, and the effect of graphene blue-shifted the absorption peak wavelength induced by the surface plasmon resonance of 1D-PNGs. Numerical calculations agree well with these experimental results and indicate that the electric field strongly localizes on graphene in the grooves. Moreover, the doping level tunes the absorption wavelength owing to the coupling with graphene plasmons and the surface plasmon resonance of 1D-PNGs. This could provide electrical tunability to the graphene plasmons. Our fabrication procedure produced hybrid graphene-1D-PNGs with high aspect ratios and narrow groove systems for IR wavelengths. This system can contribute to developing high-performance electrically tunable graphene-based IR photodetectors, tunable IR emitters/absorbers, and biological sensors.

Angular‐Dispersive Narrowband Absorption Induced by Quasi‐BIC in SiO2‐Au Metamaterial

Quasibound states in the continuum (BIC) have earned extensive attentions due to the capability to realize extremely high quality‐factor (Q‐factor) resonance. Here, a metamaterial composed of silicon dioxide (SiO2) with low refractive index (≈1.45) on gold (Au) reflection mirror is proposed to realize narrowband perfect absorption with the assistance of quasi‐BIC and surface lattice resonance. The proposed SiO2‐Au absorber based on SiO2 metamaterial is composed of two tilted SiO2 cubes into a unit cell and periodically arranged on Au reflection mirror. By optimizing the geometry parameters, the proposed absorber presents both accidental quasi‐BIC and symmetry‐protected quasi‐BIC modes with near‐perfect absorptivity and high Q‐factor of 2330 and 1438, respectively. The Q‐factor can be further improved to 104 by increasing the thickness of SiO2 cubes to micrometer level. Meanwhile, the wavelength of absorption peak shows linear sensitivity of 16.67 and 17.88 nm per degree to incident angles as the absorptivity is higher than 92% and 75% in the spectra range of 215.0–141.0 nm, respectively. These results open the avenue for the metamaterial absorber in emitter, imaging, and biosensing applications.

Ultraviolet (UV) light effect on the electrical potential of interfacial water

Water is one of the most essential elements of life. Despite many studies on the physical and chemical properties of water, many features are still not yet understood. Here, we consider the negative electrical potential in the water adjacent to the Nafion membrane. The electrical potential becomes more negative closer to the membrane, a feature that might arise from the special water structure (interfacial water) next to Nafion. Evidence has shown that the water was characterized by a UV absorbance at ∼270 nm. We hypothesized that such radiant energy might contribute to the electrical potential of the interfacial water. Here, the effect of exposure to light on this potential, at wavelengths of 275 nm, 370 nm and 650 nm was studied. The electrical potential became more negative under 275 nm wavelength UV light, while other two wavelengths had negligible effects. The result fits well with the ∼270 nm wavelength absorption peak reported in previous studies. Potentially, the absorbed UV energy helps fuel the ‘water battery’. The findings shed light on the mechanism underlying the character of interfacial water adjacent to hydrophilic surfaces.

Variability in spectral absorption within cryptophyte phycobiliprotein types.

Cryptophytes are known to vary widely in coloration among species. These differences in color arise primarily from the presence of phycobiliprotein accessory pigments. There are nine defined cryptophyte phycobiliprotein (Cr-PBP) types, named for their wavelength of maximal absorbance. Because Cr-PBP type has traditionally been regarded as a categorical trait, there is a paucity of information about how spectral absorption characteristics of Cr-PBPs vary among species. We investigated variability in primary and secondary peak absorbance wavelengths and full width at half max (FWHM) values of spectra of Cr-PBPs extracted from 75 cryptophyte strains (55 species) grown under full spectrum irradiance. We show that there may be substantial differences in spectral shapes within Cr-PBP types, with Cr-Phycoerythrin (Cr-PE) 545 showing the greatest variability with two, possibly three, subtypes, while Cr-PE 566 spectra were the least variable, with only ±1 nm of variance around the mean absorbance maximum of 565 nm. We provide additional criteria for classification in cases where the wavelength of maximum absorbance alone is not definitive. Variations in spectral characteristics among strains containing the same presumed Cr-PBP type may indicate differing chromophore composition and/or the presence of more than one Cr-PBP in a single cryptophyte species.

Photoacclimation in the kleptoplastidic ciliate Mesodinium rubrum and its cryptophyte prey Teleaulax amphioxeia: phenotypic variability and implications for red tide remote sensing

Abstract Mesodinium rubrum is a kleptoplastidic ciliate that sequesters the chloroplasts and nuclei of cryptophyte algae to perform photosynthesis. Blooms of M. rubrum can cause red tides in coastal oceans worldwide. Such red tides are detectable by remote sensing, and studying M. rubrum pigments and optical properties is a crucial step toward characterizing its blooms using satellite observation. Previous studies have shown that M. rubrum photoacclimates, modifying its pigment content depending on irradiance. Using cultures at different irradiance levels, we observed that photoacclimation in M. rubrum closely resembles that of its cryptophyte prey Teleaulax amphioxeia, leading to substantial phenotypic variability. In both species, phycoerythrin 545 cellular concentrations increased 3-fold between the highest and lowest irradiance, suggesting a major role in photoacclimation. Absorption cross-section decreased, and pigment-specific absorption coefficients increased with irradiance at the peak absorption wavelengths of chlorophyll a and phycoerythrin 545. After assessing the variability of absorption properties in M. rubrum, we combined field measurements and high-resolution Sentinel-2 satellite images to estimate chlorophyll a concentration of a coastal red tide and document small-scale spatio-temporal features. This work provides an overview of pigment photoacclimation in a peculiar phytoplankter and suggests guidelines for future studies of M. rubrum blooms.

Size Optimization of Spherical Silver Nanoparticles Synthesized with Baicalin and Sodium Dodecyl Sulfate Using Response Surface Methodology

This study aimed to optimize the synthesis of silver nanoparticles mediated by Baicalin and sodium dodecyl sulfonate using Single factor experiment method and response surface methodology, to optimize their process parameters so as to prepare spherical silver nanoparticles with smaller particle size, and to compare the particle size of silver nanoparticles prepared under different conditions by comparing the wavelength of the maximum absorption peak measured by UV-visible spectrophotometer. Thus, the best synthesis program was determined. The average particle size of the silver nanoparticles prepared under the optimal conditions was 32.25 nm with high sphericity, and the silver nanoparticles synthesized under the optimized conditions were characterized by SEM, FTIR, particle size distribution and UV-vis.

New Green and High-throughput Microwell Spectrophotometric Method for Quality Control of Pharmaceutical Formulations of Selective Serotonin Reuptake Inhibitors via Microscale Formation of their N-Vinylamino-naphthoquinone Derivatives

Background: Selective serotonin reuptake inhibitors (SSRIs) are mostly prescribed for the treatment of depression. This study describes the microscale in-microwell formation of blue-colored N-vinylamino-naphthoquinone derivatives of SSRIs upon their reaction with 2,3-dichloro-1,4- naphthoquinone (DCNQ) and acetaldehyde. The reaction was subsequently utilized as a basis for the development of a new simple and sensitive microwell spectrophotometric method (MW-SPM) for the quality control of pharmaceutical formulations of four SSRIs. These SSRIs are fluoxetine (FLU), sertraline (SER), paroxetine (PAR), and reboxetine (REB). Methods: The MW-SPM procedure was performed in 96-microwell transparent plates, and the microplate reader was employed to measure the absorbances of the reaction products at their peak absorbance wavelength of 580 nm. The best conditions for the method were determined. Results: The relations showed good linearity (correlation coefficients were ≥0.9992) in the concentration range of 5 – 600 μg/mL. The limits of detection ranged from 5.20 to 15.58 μg/mL. The precision was deemed acceptable since all cases' relative standard deviation (RSD) values remained below 2.21%. Recovery experiments were conducted to confirm the accuracy of the method, yielding recovery values of at least 97.8%. The MW-SPM method was effectively utilized to analyze SSRIs in both their bulk and pharmaceutical dosage forms, exhibiting acceptable accuracy and precision. The recovery values ranged from 99.4% to 101.0% (with a margin of error of ± 0.5% to 1.6%). The results were comparable with those of the pre-validated reported methods. Four different metric tools evaluated the greenness of the proposed method, and the results proved that the method fulfills the requirements of green analytical approaches. Furthermore, the ability to handle numerous microvolume samples simultaneously in the described method provides it with a high-throughput characteristic. Conclusion: The proposed MW-SPM represents a valuable tool for an efficient analysis of SSRIs in pharmaceutical quality control units.

Optimization with 2K factorial design in green synthesis of silver nanoparticles (AgNPs) using Porophyllum ruderale extract

In recent years, metal nanoparticles (MNPs) have garnered interest in scientific development due to their novel properties, among which are optical, electrical, and magnetic properties, along with absorption capacity and high surface. There are currently several synthesis methods for MNPs, but many are costly and generate toxic agents as byproducts into the environment. Therefore, in this work, a green, ecological, and affordable synthesis of silver nanoparticles (AgNPs) was carried out using Porophyllum Ruderale (P. Ruderale). The AgNPs obtained were characterized by Fourier transform infrared spectroscopy (FTIR) to observe the functional groups that intervene in the synthesis. UV-Vis spectroscopy was used to study the surface plasmon band, confirming the peak absorbance wavelength at 385 nm. The morphological analysis by scanning electron morphology (SEM) showed AgNPs measuring 70–500 nm and spherical shapes. The synthesis process was optimized using two factors: temperature, reducing agent and precursor agent ratio (extract:RA) (AgNO3–PA), and an output variable, which is the particle size evaluated by SEM. The optimal temperature for AgNP formation was found to be 90 ºC; it was a key parameter to form AgNPs. The work proved AgNPs can be obtained and potentially used as biosensors, antimicrobial agents, and herbicides, among others.

Synthesis, Characterization, and Antifungal Activity Test of Nanosilver in Body Lotion Preparation

Nanosilver is a nanoparticle known for its good antifungal ability. This study aims to determine the synthesis process and characterization of nanosilver produced and the antifungal activity of nanosilver in body lotion preparations. Body lotion in this study was made using a body lotion base which includes stearic acid, cetyl alcohol, TEA, glycerin, olive oil and distilled water. F1, F2, and F3 have nanosilver content of 10%, 15% and 20%, respectively. F4, as the positive control, contained methylparaben and F5 as a negative control. The body lotion produced in this study has a colour, aroma and texture that panellists prefer. The body lotion produced does not irritate the skin, is homogeneous, has good spreadability and has a pH value of 7. Nanosilver in this study was synthesized using a chemical reduction method with sodium citrate as a reducer and stabilizer. The synthesized nanosilver was characterized using a Transmission electron Microscope (TEM) and UV-Vis spectrophotometer to determine the nanosilver’s shape, size and stability. The nanosilver produced has a round shape with an average particle diameter of 34.793 nm and has good stability because it has a wavelength absorption peak that is not large. Namely, at week-0, nanosilver has an absorption peak at a wavelength of 415.20 nm, and week-8 has an absorption peak at a wavelength of 423 nm. The antifungal activity test using the direct microscope count (DMC) method was conducted for eight weeks. Until week 8, it showed that each formulation experienced an increase in fungal hyphae, reaching 34.4% for F1, 21.2% for F2, 19.8% for F3, 16.8% for F4 and 46% for F5. From the results of this study, it can be seen that nanosilver can suppress fungal activity in body lotion preparations.

Cell-Based Measurement of Mitochondrial Function in Human Airway Smooth Muscle Cells.

Cellular mitochondrial function can be assessed using high-resolution respirometry that measures the O2 consumption rate (OCR) across a number of cells. However, a direct measurement of cellular mitochondrial function provides valuable information and physiological insight. In the present study, we used a quantitative histochemical technique to measure the activity of succinate dehydrogenase (SDH), a key enzyme located in the inner mitochondrial membrane, which participates in both the tricarboxylic acid (TCA) cycle and electron transport chain (ETC) as Complex II. In this study, we determine the maximum velocity of the SDH reaction (SDHmax) in individual human airway smooth muscle (hASM) cells. To measure SDHmax, hASM cells were exposed to a solution containing 80 mM succinate and 1.5 mM nitroblue tetrazolium (NBT, reaction indicator). As the reaction proceeded, the change in optical density (OD) due to the reduction of NBT to its diformazan (peak absorbance wavelength of 570 nm) was measured using a confocal microscope with the pathlength for light absorbance tightly controlled. SDHmax was determined during the linear period of the SDH reaction and expressed as mmol fumarate/liter of cell/min. We determine that this technique is rigorous and reproducible, and reliable for the measurement of mitochondrial function in individual cells.

DFT/TD-DFT Study of D–?–A dyes explore the NLO properties

The molecular structures and optical properties of six different N.dimethylphenylendiamino dyes were analyzed using a combination of DFT functionals (B3LYP and Cam-B3LYP/6-311+G(p,d)). The six dyes are D1-D6. The various parameters of the solvated phase, such as the polarizabilities, hyperpolarizabilities, peak absorption wavelengths, and HOMO-LUMO energy gaps, were calculated and analyzed. The results of the study are in agreement with the results of the NLO activity order thiophene linker > pyrrole bridge. Compared to the dipyrrole versions, the designed dithiophene-linker dyes exhibit longer absorption wavelengths and smaller HOMO-LUMO gaps. The predicted first hyperpolarisability of dyes D1-D3 are higher than that of D4-D5. This is mainly due to its enhanced electron-withdraw ability and the long p-conjugating action of the thiophene moiety. Highly elevated total hyperpolarisability of the designed dyes, suggests its potential application in organic NLO devices, which is expected to be useful.

NIR-Triggered On-Demand Nitric Oxide Release for Enhanced Synergistic Phototherapy of Hypoxic Tumor.

Hypoxia of tumor microenvironments is a major factor restricting tumor treatment, which causes progression and metastasis of tumor. The hypoxic tumor microenvironment not only makes the traditional treatment method, such as chemotherapy, ineffective but also hinders the O2-dependent treatments, such as photodynamic therapy (PDT). Recently, stimuli-responsive nitric oxide (NO) donors have attracted extensive research interest in hypoxic tumor treatment because the NO release process is O2-independent. Besides, NO can distribute more uniformly than drug molecules and more widely than the PDT-generated active species due to its strong diffusion ability (200 μm in cells) and long lifetime (2 s in cells). Encouraged by these advantages, a near infrared light-triggered NO release polymeric nanoplatform (P1-CapNO NPs) was constructed by a thermally sensitive NO release unit, a photothermal unit, and a hydrophilic polyethylene glycol unit. P1-CapNO NPs possess strong absorption in the NIR region (the wavelength of maximal absorption peak was 790 nm with a molar absorption coefficient of 2.4 × 105 M-1 cm-1), great photothermal conversion efficiency (23.8%), and NO release ability (the released NO concentration can reach 1.3 μM) under 808 nm laser irradiation. Owing to these advantages, the great synergistic antitumor effect can be achieved in vitro and in vivo even under the hypoxic environment. The synergistic therapeutic strategy in this work could bypass the obstacles caused by hypoxia in tumor treatment and provide a reference for building a NO-involved therapeutic platform.