Dye Carriers Research Articles

Two-photon Dye-Based Fluorogenic Organic Nanoparticles as Intracellular Thiols Sensors.

Optical bioimaging is an ever-growing field that benefits both from the fast progress of optical instrumentation and modalities, and from the development of light-emitting probes. The efficacy of molecular fluorescent dyes is crucial, yet hindered by limited brightness and hydrophilicity. Addressing these challenges, self-stabilized fluorogenic organic nanoparticles only made of pure dyes (dFONs) are introduced in this work. Comprising thiol-sensitive fluorogenic chromophores, these dFONs exhibit enhanced brightness exclusively in the presence of biological thiols, notably glutathione, overcoming the need for water-solubilizing moieties. Importantly, these nanoparticles demonstrate large fluorescence and one- and two-photon brightness, enabling sensitive bioimaging of intracellular thiols at micromolar concentrations. Notably, only the pristine fluorogenic nanoparticles can penetrate the cells and does not require to wash the cells before imaging, emphasizing their unique role as dye carriers, fluorogenic probes and ease of use. This work highlights the transformative potential of dFONs in advancing optical bioimaging, paving the way for the use of dFONs not just as tracers, but also now as biosensors and ultimately in the future as biomarkers.

Improving the coloration depth and fastness of poly(ethylene‐vinyl acetate) foam dyed with disperse dye by carrier dyeing and film formation

AbstractIn order to solve the problems of poor dyeing properties and the colour fastness to ageing of poly(ethylene‐vinyl acetate) (EVA) foam, good dyeing performance was obtained by disperse dye carrier dyeing method, and the colour fastness to ageing was improved by surface film forming. The effect of dyeing process on dyeing properties was investigated by the single factor variable method. The effect of film formation on colour fastness to ageing was also studied. The results showed that disperse dye carrier dyeing could significantly improve the dyeing depth of EVA foam. Addition of carrier and prolongation of dyeing time could significantly improve the colour strength (K/S) values and dye penetration. However, the increase of the dosage of dyes and the concentration of the carrier could lead to a serious decrease of the colour fastness to ageing of EVA. The colour fastness to ageing of EVA could be obviously improved by film forming on the surface. Waterborne polyurethane film‐forming agent could improve the colour fastness to ageing by 1.5 grades, but the rubbing fastness was poor. When waterborne polyurethane and acrylate film‐forming agent were compounded, the colour fastness to ageing and the colour fastness to rubbing could be improved.

Reverse Micellar Dyeing of Cotton Fabric with Reactive Dye Using Biodegradable Non-Ionic Surfactant as Nanoscale Carrier: An Optimisation Study by One-Factor-at-One-Time Approach.

This study investigates the feasibility of using biodegradable secondary alcohol ethoxylate (SAE) non-ionic surfactant as a building block for the formation of reverse micelles, functioning as reactive dye carriers for the dyeing of cotton fabric in non-aqueous octane medium. Ten dyeing parameters were optimised, by a one-factor-at-a-time approach, namely: (i) effect of colour fixation agent; (ii) surfactant-to-water mole ratio; (iii) surfactant-to-co-surfactant mole ratio; (iv) volume of soda ash; (v) volume of dye; (vi) solvent-to-cotton ratio; (vii) dyeing temperature; (viii) dyeing time; (ix) fixation time; (x) soda-ash-to-cotton ratio. The colour properties, fastness properties and physical properties of SAE-dyed samples were experimentally compared with the conventional water-dyed samples. The optimised condition was found when SAE samples were dyed as follows: (a) 1:20 surfactant-to-water ratio; (b) 1:8 surfactant-to-co-surfactant ratio; (c) 10:1 solvent ratio; (d) 40 min dyeing time; (e) 60 min fixation time; and (f) 70 °C dyeing and fixation temperature. The results showed that SAE-dyed samples have better colour strength, lower reflectance percentage and comparable levelness, fastness and physical properties than that of water-dyed samples. SEM images revealed that the dyed cotton fibres had no severe surface damage caused by an SAE-based reverse micellar dyeing system. The TEM image depicts that the reverse micelle was of nanoscale, spherical-shaped and had a core-shell structure, validating the presence of reverse micelle as a reactive dye carrier and the potential of an SAE-based reverse micellar system for dyeing of cotton fabrics.

Enhancing near-infrared fluorescence intensity and stability of PLGA-b-PEG micelles by introducing Gd-DOTA at the core boundary.

Micelles have been extensively used in biomedicine as potential carriers of hydrophobic fluorescent dyes. Their small diameters can potentially enable them to evade recognition by the reticuloendothelial system, resulting in prolonged circulation. Nevertheless, their lack of stability in physiological environments limits the imaging utility of micelles. In particular, when a dye sensitive to water, such as IR-1061, is encapsulated in the micelle core, the destabilized structure leads to interactions between water and dye, degrading the fluorescence. In this study, we investigated a method to improve micelle stability utilizing the electrical effect of gadolinium (Gd3+ ) and tetraazacyclododecane tetraacetic acid (DOTA), introduced into the micelles. Three micellar structures, one containing a poly(lactic-co-glycolic acid)-block-poly(ethylene glycol) (PLGA-b-PEG) block copolymer, and two other structures, including PLGA-b-PEG with DOTA or Gd-DOTA introduced at the boundary of PLGA and PEG, were prepared with IR-1061 in the core. Structures that contained DOTA at the border of the PLGA core and PEG shell exhibited much higher fluorescence intensity than probes without DOTA. With Gd3+ ions at the DOTA center, fluorescence stability was enhanced remarkably in physiological environments. Most interesting is the finding that fluorescence is enhanced with increased Gd-DOTA concentrations. In conclusion, we found that overall fluorescence and stability are improved by introducing Gd-DOTA at the boundary of the PLGA core and PEG shell. Improving micelle stability is crucial for further biomedical applications of micellar probes such as bimodal fluorescence and magnetic resonance imaging.

Bacterial outer membrane vesicles as cationic dye carriers for optoacoustics-guided phototherapy of cancer

BackgroundCationic dyes are widely used as biomarkers for optical imaging. However, most of these are hydrophobic and cannot be employed in vivo without chemical conjugation or modification. Herein, we report for the first time the use of bacterial outer membrane vesicles (OMVs) as nanocarriers of cationic dyes for cancer theranostics.ResultsWe demonstrate that cationic dyes (IR780, Cy7, and Cy7.5) form stable complexes with negatively charged bacterial-OMVs, improving the dyes’ in vivo circulation and optoacoustic properties. Such OMV-Dye complexes are biodegradable and safe for in vivo applications. Importantly, this method of cationic dye loading is faster and easier than synthetic chemistry approaches, and the efficient tumor accumulation of OMV-Dyes enables sensitive tumor detection using optoacoustic technology. As a proof-of-concept, we generated OMV-IR780 for optoacoustics-guided in vivo tumor phototherapy in a mouse model.ConclusionsOur results demonstrate cationic dye-bound OMVs as promising novel nanoagents for tumor theranostics.

Simulation of an industrial scale scCO2 beam dyeing process

An industrial dyeing process in supercritical carbon dioxide has been modelled with computational fluid dynamics using Ansys Fluent software. In order to investigate the distribution of the dye carrier fluid, the flow resistance of the fabric has been accurately characterised. For this purpose, in the first part of the work a plain-woven fabric geometry was created in the open software Tex-Gen and modelled in Ansys Fluent to predict the permeation of fluid through the pores of the fabric material and to estimate the relationship between local fluid velocity and pressure drop. The second part of the study focused on evaluating the influence of beam structure, inlet flow rate, fabric height on the fluid flow through the fabric, which must be uniform to achieve a homogeneous level of dyeing. From the simulations the main obstacle to achieving a uniform flow velocity in the fabric is the pressure rise that occurs in the beam and creates a slight difference in permeation velocity between the two axial ends of the fabric; other disturbances, such as the effect of the perforated structure of the beam, are usually minor. Due to the low viscosity of supercritical carbon dioxide, inertial losses predominate over viscous losses in the porous medium. This means that approaches based only on the permeability of the fabric and the application of Darcy's law are inadequate to correctly predict the response of a dyeing unit when using carbon dioxide.

Self-organised surfactant assemblies as nanostructured dye carriers: a mixed micellar comparative approach for enhanced dye solubilisation

ABSTRACT The reported work is focused on the solubility of Rhodamine B (cationic dye), as an important methodology to investigate the extent of incorporation or penetration of dye inside the micelles spectroscopically, so the solubilised dye can be filtered via Micellar-enhanced ultrafiltration process to keep our environment safe from toxic effects of industrial effluent. Solutions were prepared by using micellar media of anionic surfactants i.e. Sodium dodecyl sulphate (SDS), Sodium Oleate (SO) as well as mixed micellar media of said anionics with non-ionic surfactant i.e. Triton X-100 (TX-100). The extent of solubilisation has been, quantitatively, calculated using data of differential spectroscopy, in terms of partition coefficient Kx and Gibbs energy of partition, ∆Gp. It has been observed that mixed micellar media has better solubilisation capacity than micellar solution of individual surfactants. A better micellar solubilisation and ultimately the high Gibbs energy of partition, ∆Gp with SO/TX-100 system i.e. −40.89 as compared to SDS/TX-100 system (−37.03) has been observed due to the presence of long carbon chain in SO.

Dyeing of Cotton Fabric in Decamethylcyclopentasiloxane Using Alkyl Polyglucoside-based Reverse Micelle as Reactive Dye Carrier

Dyeing of Cotton Fabric in Decamethylcyclopentasiloxane Using Alkyl Polyglucoside-based Reverse Micelle as Reactive Dye Carrier

Cyanine Dyes for Photo-Thermal Therapy: A Comparison of Synthetic Liposomes and Natural Erythrocyte-Based Carriers

Cyanine fluorescent dyes are attractive diagnostic or therapeutic agents due to their excellent optical properties. However, in free form, their use in biological applications is limited due to the short circulation time, instability, and toxicity. Therefore, their encapsulation into nano-carriers might help overcome the above-mentioned issues. In addition to indocyanine green (ICG), which is clinically approved and therefore the most widely used fluorescent dye, we tested the structurally similar and cheaper alternative called IR-820. Both dyes were encapsulated into liposomes. However, due to the synthetic origin of liposomes, they can induce an immunogenic response. To address this challenge, we proposed to use erythrocyte membrane vesicles (EMVs) as “new era” nano-carriers for cyanine dyes. The optical properties of both dyes were investigated in different biological relevant media. Then, the temperature stability and photo-stability of dyes in free form and encapsulated into liposomes and EMVs were evaluated. Nano-carriers efficiently protected dyes from thermal degradation, as well as from photo-induced degradation. Finally, a hemotoxicity study revealed that EMVs seem less hemotoxic dye carriers than clinically approved liposomes. Herein, we showed that EMVs exhibit great potential as nano-carriers for dyes with improved stability and hemocompatibility without losing excellent optical properties.

Application of cationic-nonionic surfactant based nanostructured dye carriers: Mixed micellar solubilization

Most of organic compounds being hydrophobic in nature are insoluble or sparingly soluble in water. The improvement in solubility is one of the major challenges in their industrial applications. Said issue can be addressed using micellar solutions of surfactants. Surfactants, owing to their inherent amphiphilic nature, have invited the interest of many researchers. It has, however, been observed that the stability and solubilizing capability of a single surfactant-based colloidal system is not up to the mark. To overcome this problem, we have formulated and applied composite micelles of CTAB/TX-100 and CPC/TX-100 as carriers of direct red 28 molecules to aid dispersion, solubility and stability of the dye in aqueous medium. Herein, thermodynamics of micellization and degree of the dye partitioning have been quantified conductometrically and spectroscopically. Results suggest that blend of different surfactants act synergistically to augment the dye partitioning. Furthermore, it has also been noted that micellization of surfactants, counterion binding and the dye partitioning are spontaneous processes.

Single-use surgical face masks, as a potential source of microplastics: Do they act as pollutant carriers?

Millions of people are using face coverings (including single-use surgical face masks) as a result of the COVID-19 pandemic and a large number of used masks, particularly single-use masks enter uncontrolled the environment since most of the users have little information on how to dispose of them safely. This new important waste is a potential source of microplastics, which is found nowadays in many parks, streets, and coastlines. Discarded masks will be finally drained to the ocean polluting the marine environment and threatening marine life. This short communication examines the role of face masks and subsequently mask-derived microplastics as pollutant carriers in environmental compartments (e.g. hydrosphere, biosphere, etc.) by investigating their sorption characteristics regarding dye molecules. In this context, batch-type equilibrium experiments were performed and the effect of different sorption parameters has been explored (i.e. contact time and temperature). The results show that single-use surgical face masks can act as dye carriers (Methylene Blue, Crystal Violet and Malachite Green) in the aquatic environment. In addition, preliminary experiments on the thermal treatment of face masks and the use of the resulting carbonaceous material as efficient adsorbent have been performed, pointing out a possibility for used mask disinfection and recycling.

Dye-Loaded Nanoemulsions: Biomimetic Fluorescent Nanocarriers for Bioimaging and Nanomedicine.

Lipid nanoemulsions (NEs), owing to their controllable size (20 to 500nm), stability and biocompatibility, are now frequently used in various fields, such as food, cosmetics, pharmaceuticals, drug delivery, and even as nanoreactors for chemical synthesis. Moreover, being composed of components generally recognized as safe (GRAS), they can be considered as "green" nanoparticles that mimic closely lipoproteins and intracellular lipid droplets. Therefore, they attracted attention as carriers of drugs and fluorescent dyes for both bioimaging and studying the fate of nanoemulsions in cells and small animals. In this review, the composition of dye-loaded NEs, methods for their preparation, and emerging biological applications are described. The design of bright fluorescent NEs with high dye loading and minimal aggregation-caused quenching (ACQ) is focused on. Common issues including dye leakage and NEs stability are discussed, highlighting advanced techniques for their characterization, such as Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS). Attempts to functionalize NEs surface are also discussed. Thereafter, biological applications for bioimaging and single-particle tracking in cells and small animals as well as biomedical applications for photodynamic therapy are described. Finally, challenges and future perspectives of fluorescent NEs are discussed.

Making polymers colored and stiffer by dyed regenerated cellulose employing Pickering emulsions

We demonstrate the successful use of Pickering emulsions utilizing regenerated cellulose that carry covalently immobilized dye molecules as emulsifiers to color PMMA and enhance its mechanical performance. Due to the use of this biobased dye carrier, the materials we describe exhibit enhanced “green” character. First we show that oil-in-water Pickering emulsions of PMMA can be effectively stabilized by dyed regenerated cellulose. We describe how uniformly colored PMMA-cellulose composites with high transparency in the visible range can be obtained. We provide detailed characterization of the resulting composites. Thermogravimetric analysis shows an increase of onset of degradation temperature, thus indicates improved thermal stability. Also the mechanical properties become improved, as indicated by flexural strength enhancement. The Pickering emulsion-based procedure is simple and cost effective, and could be easily adopted to prepare other polymer-nanocomposite systems.

Thirteen-week inhalation toxicity study of 1-methylnaphthalene in F344 rats.

1-Methylnaphthalene is generally utilized in solvents, as an intermediate in organic synthesis, a dye carrier, in resins, and others. There are some toxicological studies of 1-methylnaphthalene; however, inhalation toxicity studies are rare. Each of 10 male and female F344 rats was exposed to vapors of 1-methylnaphthalene for 13weeks (6h a day, 5days per week) at concentrations of 0, 0.5, 4, and 30ppm in a whole-body inhalation chamber system. The exposure concentrations were 0.52 ± 0.05, 4.08 ± 0.25, and 30.83 ± 1.28ppm for the low-, middle-, and high-dose group, respectively. Body weight changes were not affected by exposure to 1-methylnaphthalene. Blood prothrombin time was delayed at 30ppm in male and female groups, and activated partial thromboplastin time was also delayed at 30ppm in the male group. Values of alanine aminotransferase in the serum were decreased and those of albumin were increased at 30ppm in the male group. Differential cell counts and levels of lactate dehydrogenase in the bronchoalveolar lavage fluid were not affected. However, mucous cell hyperplasia in the nasopharyngeal tissues was found and the severity was correlated to exposure concentrations. In conclusion, 1-methylnaphthalene mainly affects the upper respiratory system and the no-observed-adverse-effect levelis suggested to be 4ppm on the basis of histopathological findings.

Solid silica nanoparticles as carriers of fluorescent squaraine dyes in aqueous media: Toward a molecular engineering approach

Hybrid squaraine-SiO2 nanoparticles extremely homogeneous in size (50 ± 2 nm), and with photoluminescent emission in the optical tissue window, were prepare by using the reverse microemulsion technique. Three different high quantum-yield squaraine dyes were used and the photophysical behavior of the prepared samples were qualitatively and quantitatively studied, by steady state and time-resolved photoluminescence, in order to establish structure-property relationships useful for the optimization of the preparation method. These squaraine dyes are insoluble in water and suffer a severe decrease of quantum yield if derivatized with polar groups. The role of the hydrophilicity of the dye-APTS adduct in ruling its dispersion in the nascent silica matrix was confirmed, and the possibility to improve the tuning of the process by properly administration of the adduct with the co-surfactant was demonstrated.

Películas y recubrimientos comestibles funcionalizados

Debido a las pérdidas en productos hortofrutícolas por plagas y manejo postcosecha inadecuado, en los últimos años se ha buscado el desarrollo y la producción de películas comestibles biodegradables como una forma de protección. Estas películas comestibles están hechas con materiales como carbohidratos, proteínas o lípidos, con características físicas y mecánicas similares a los envases no degradables, pero con la ventaja de funcionar como barreras bioactivas, ya que, mediante la adición de extractos vegetales, pueden presentar actividad antimicrobiana, protección contra la luz UV y visible, servir como acarreadores de antioxidantes y/o colorantes, mejorando con esto las características visuales del producto. Debido a estos atributos, han sido denominadas "películas inteligentes", ya que se ha observado un progreso considerable en su elaboración, como la presencia de sensores coloridos capaces de detectar cambios químicos y la presencia de microorganismos en los alimentos, mostrando si son o no, óptimos para el consumo. El objetivo de este trabajo es hacer una síntesis de diversas investigaciones, así como las tendencias recientes en el estudio y desarrollo de películas y recubrimientos comestibles, con énfasis en su aplicación a la cadena hortofrutícola y su efecto sobre productos frescos y mínimamente procesados.

Interpenetrating polymer networks in polyvinyl alcohol/cellulose nanocrystals hydrogels to develop absorbent materials

Polyvinyl alcohol/cellulose nanocrystals/poly(2-Hydroxyethyl methacrylate) (PVA/CNC/polyHEMA) and PVA/CNC/poly(N'-methylenebisacrylamide) (PVA/CNC/polyMBA) hydrogels were prepared by photo-crosslinking followed by freezing/thawing (F-T) cycle and this novel preparation method was reported. The formation of interpenetrating polymer networks (IPN) resulted from the addition of crosslinking HEMA or MBA monomers displayed improved interfacial adhesion. The produced hydrogels were measured by scanning electron microscopy (SEM), real-time fourier transform infrared (RTIR), thermogravimetric analysis (TGA), mechanical, swelling and adsorption tests. The results showed both PVA/CNC/polyHEMA with semi-IPN and PVA/CNC/polyMBA with dual network (DN) hydrogels had higher thermal stability, lower water loss rate and better swelling and reswelling and mechanical properties, comparing to PVA and PVA/CNC hydrogels. The adsorption behaviors of hydrogels using xylenol orange (XO) and methylene blue (MB) as model dyes were evaluated, indicating that PVA/CNC/polyHEMA and PVA/CNC/polyMBA hydrogels could hold some dyes. Overall, this work provided a good way for increasing mechanical, swelling, reswelling, thermal, and adsorption properties of PVA/CNC, which will be a promising water-manageable material for agriculture application and a candidate for dye carrier.

Synthesis of triblock copolymeric micelle based on poly (ethylene glycol) and poly (vinyl acetate) through reversible addition–fragmentation chain transfer polymerization

HypothesisPolymeric micelles are fabricated by the self-aggregation of amphiphilic polymers in aqueous medium. Amphiphilic block copolymers consist of hydrophobic and hydrophilic blocks. The hydrophilic blocks form corona, while hydrophobic blocks produce core of the micelle. ExperimentsIn the present manuscript, a triblock copolymer derived from poly (ethylene glycol) and poly (vinyl acetate) (PVAc-b-PEG200-b-PVAc) has been prepared via reversible addition–fragmentation chain transfer polymerization. Its structural properties as well as micellar stability have been studied and application as dye carrier has been discussed in details. FindingsThe GPC analysis shows the low polydispersity of the developed copolymer that signifies the controlled nature of polymerization. The copolymer demonstrates long-term micellar stability, which has been determined by dynamic light scattering (DLS) analysis. The block copolymer reveals excellent pH-triggered release behavior of loaded Nile red, which ascertained the dye carrier feature of PVAc-b-PEG200-b-PVAc.

Tailoring Nanocrystalline Metal-Organic Frameworks as Fluorescent Dye Carriers for Bioimaging.

Challenges exist in taking advantage of dye molecules for reliable and reproducible molecular probes in biomedical applications. In this study, we show how to utilize the dye molecules for bioimaging within protective carriers of nanocrystalline metal-organic frameworks (nMOFs) particles. Specifically, Resorufin and Rhodamine-6G having different molecular sizes were encapsulated within close-fitting pores of nMOF-801 and nUiO-67 particles, respectively. The resulting nanocrystalline particles have high crystallinity, uniform size, and morphology and preserve enhanced photoluminescence properties with exceptional stabilities in biomedical environment. The samples are further functionalized with a targeting agent and successfully work for fluorescence imaging of FL83B (human hepatocyte cell) and HepG2 (human hepatocellular carcinoma) without cytotoxicity.

Hyaluronic acid in complexes with surfactants: The efficient tool for reduction of the cytotoxic effect of surfactants on human cell types

The cationic surfactants carbethoxypendecinium bromide (Septonex) and cetyltrimethylammonium bromide (CTAB) are known to be harmful for certain cell types (bacteria, fungi, mammal cells, etc.). Colloidal complexes of these surfactants with negatively-charged hyaluronic acid (HyA) were prepared for potential drug and/or universal delivery applications. The complexes were tested for their cytotoxic effect on different human cell types – osteoblasts, keratinocytes and fibroblasts. Both the CTAB-HyA and Septonex-HyA complexes were found to reduce the cytotoxicity induced by surfactants alone concerning all the tested concentrations. Moreover, we suggested the limits of HyA protection provided by the surfactant-HyA complexes, e.g. the importance of the amount of HyA applied. We also determined the specific sensitivity of different cell types to surfactant treatment. Keratinocytes were more sensitive to CTAB, while osteoblasts and fibroblasts were more sensitive to Septonex. Moreover, it was indirectly shown that CTAB combines lethal toxicity with cell metabolism induction, while Septonex predominantly causes lethal toxicity concerning fibroblasts. This comprehensive study of the effect of surfactant-HyA complexes on various human cell types revealed that HyA represents a useful CTAB or Septonex cytotoxic effect modulator at diverse levels. Potential applications for these complexes include drug and/or nucleic acid delivery systems, diagnostic dye carriers and cosmetics production.