Coumarin 6 Research Articles

Differences in the permeation of Licoricchalcone A-polysaccharide self-assembled nanoparticles on healthy and DNCB-induced atopic dermatitis in Balb/c mice

Nanoformulation have been widely used in skin and transdermal drug delivery. However, the differences in integral nanoparticles absorption in healthy and diseased skin have not yet fully analyzed. The present study attempted to explore the percutaneous absorption of drugs via lesional skin by using atopic dermatitis (AD) as a model, dinitrochlorobenzene (DNCB) induced AD-like skin. In here, the small molecules of insoluble Licoricchalcone A (LA) and macromolecules glycyrrhizin polysaccharide were used to prepare LA-polysaccharide self-assembled nanoparticles (GPA-SANs) by micro-precipitation. An environment-responsive dye, P4, was loaded into SAN to track the transdermal translocation of the nanoparticles, while the drug marked with coumarin 6 (C6). Compared to healthy skin, the permeability of GPA-SANs on AD-like skin is stronger, which may be due to damage to the stratum corneum of the AD-like skin and increased intercellular spaces, resulting in an increased permeability coefficient. Therefore, the storage of nanoparticles and their diffusion at the lesion site also increased accordingly. CLSM shown that the fluorescence of P4 and C6 is observed to concentrate around the hair follicles and disseminate in the surrounding area in both AD-affected and healthy skin.It can be clearly seen that fluorescence signal of C6 in the intercellular spaces of the dermis and epidermis of AD-like skin, indicating that nano-drug on the disease skin can penetrate through the intercellular pathway to achieve therapeutic. The focus of the present study is to assess the permeability of healthy and disease skin, discuss their characteristics and discrepancy, aiming to provide a reference for the further study of nano-formulations in transdermal delivery.

Preparation, optimisation, and properties of O-carboxymethyl chitosan-g-cholesterol succinic acid monoester polymer nanomicelles

Polymer nanomicelles have the advantages of small particle size, improved drug solubility, retention effect and enhanced permeability, so they can be used in the treatment of tumour diseases. The aim of this study was to prepare and optimise a nanomicelle which can improve the solubility of insoluble drugs. Firstly, the carboxyl group of cholesterol succinic acid monoester was grafted with the side chain amino group of O-carboxymethyl chitosan-g-cholesterol succinic acid monoester (CCMC), and its structure was characterized by fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR). Particle size has an important impact on tissue distribution, cell uptake, permeability and inhibition of tumour tissue. In this study, particle size and polydispersity index (PDI) were selected as indexes to optimise the preparation process of CCMC nanomicelles through single factor experiment, Plackett-Burman experiment, the steepest climbing experiment and response surface design experiment. The optimised CCMC nanomicelles showed an average particle size of 173.9 ± 2.3 nm and a PDI of 0.170 ± 0.053. The Cell Counting Kit-8 assay showed no significant effect on cell viability in the range of 0-1000 μg ml-1concentration. Coumarin-6 (C6) was used as a fluorescent probe to investigate the drug-carrying ability of CCMC nanomicelles. C6-CCMC showed 86.35 ± 0.56% encapsulation efficiency with a drug loading of 9.18 ± 0.32%. Both CCMC and C6-CCMC demonstrated excellent stability in different media. Moreover, under the same conditions, the absorption effect of C6 in C6-CCMC nanomicelles was significantly higher than that of free C6 while also exhibiting good sustained-release properties. Therefore, this study demonstrates CCMC nanomicelles as a promising new drug carrier that can significantly improve insoluble drug absorption.

Humidity-sensitive luminescent dye-doped polyelectrolyte films: Fabrication, characterization, and potential application as colorimetric moisture sensor

A novel type of luminescent dye-doped polyelectrolyte films, which change their light absorption and photoluminescent properties upon changing relative humidity (RH) is reported. A polyelectrolyte – poly(4-styrene sulfonic acid) (PSSA) was chosen as a matrix, while Coumarin 6 (C6) was used as a luminescent dye. The films were prepared using a dip-coating technique. Coatings with a refractive index (RI) of around 1.49 and various thicknesses in a submicrometric range were obtained by changing the withdrawal speed or concentration of the polyelectrolyte. It was found that depending on the RH, C6 in the polyelectrolyte films may exist in two equilibrium forms – monocationic and dicationic. Significant differences between these two forms upon RH level variations were observed and investigated using FT-IR and UV–Vis spectroscopic techniques. FT-IR spectroscopy confirmed the distortion of the double bond conjugation in the benzothiazole unit of the dicationic form of the dye in the dry state. The dependences of the UV–Vis absorption and luminescent properties on RH were determined. The distinct color changes of the films, ranging from faint yellow to intense pink-red, enabled the estimation of the RH level through visual inspection. Taking advantage of a straightforward preparation protocol for this newly developed material, we believe that it may be used as a humidity-sensitive coating.

Photochemical optimization of fluorescent dye-doped PDMS for enhanced luminescent solar concentrator performance

Luminescent solar concentrators (LSCs) that incorporate organic dyes face challenges such as self-absorption loss and aggregation-caused quenching (ACQ) as doping concentration increases, limiting the dye loading capacity. Particularly for dyes with a small Stokes shift, losses due to self-absorption or quenching are prominent even at low concentrations, hindering the attainment of high power conversion efficiency (PCE) in LSCs. Additionally, exposure of the dye-impregnated polymer matrix to oxygen, moisture, UV light, and other factors leads to a decrease in luminescence efficiency and stability due to the photooxidation reaction of the phosphor. This study presents a facile approach for enhancement of the efficiency and environmental stability of coumarin 6 (C6) dye-doped polydimethylsiloxane (PDMS) LSC through ultraviolet ozone (UVO) treatment. Photocleavage of the C6 dimer into a C6 monomer through UVO treatment leads to a significant enhancement in luminescence. Additionally, thin SiOx layers formed on both sides of the LSC not only assist in capturing luminescent light more efficiently but also block the penetration of oxygen and moisture into the LSC, resulting improved device stability. UVO-treated LSC shows approximately 32 % improvement in PCE compared to bare LSCs and exhibits significantly better stability during the 30-day long-term performance test.

Impact of binary inorganic salt on micellization of pluronic block copolymers: A photophysical analysis

The impact of binary inorganic salt zinc chloride (ZnCl2) on the micellization behavior of triblock pluronic copolymer, F108 was investigated by various spectroscopic methods in the presence of Coumarin-6 (C6) as a fluorescent probe. Ground and excited state photophysical properties revealed that the microenvironment around the C6 molecule changes in the presence of ZnCl2 compared to that in a salt-free solution. The addition of salt to the medium increases the hydrophobicity and microviscosity of the micelle core. Due to the presence of ZnCl2, the central PPO core experiences dehydration, reduces the interaction between water molecules and PEO groups, and enhances the hydrophobic interaction between C6 and hydrophobic PPO parts in the micelle with more solubility of C6. This study helps to develop the property of copolymers as drug carriers in various pharmaceutical applications and drug delivery systems.

Microviscosity-Assisted Disaggregation of a Model Ophthalmic Drug and FRET-Controlled Singlet Oxygen Generation in Lyotropic Liquid Crystals.

Different phases of lyotropic liquid crystals (LLCs), made up of mesogen-like sodium dodecyl sulfate (SDS), mainly bestow different bulk viscosities. Along with this, the role of microviscosities of the individual LLC phases is of immense interest because a minute change in it due to guest incorporation can cause significant alteration in their property as a potential energy transfer scaffold. Recently, LLCs have been identified as plausible drug delivery agents for ocular treatments. In this direction, the present work illustrates photophysical modulations of an important laser dye as well as an ophthalmic medicine, coumarin 6 (C6), inside different LLC phases in an aqueous medium. C6 molecules spontaneously accumulate in water, leading to aggregation-caused quenching (ACQ) of fluorescence. However, the different phases of the LLCs prepared from SDS and water helped in disintegrating the C6 colonies to various extents depending upon the microviscosity. The heterogeneity in the LLC phases, in turn, could modulate the Förster resonance energy transfer (FRET) between C6 and the LLC incorporated with N-doped carbon nanoparticles (N-CNPs). The N-CNPs act as potential photosensitizers and generate singlet oxygen (1O2), a reactive oxygen species (ROS), to different extents. Microviscosities of the prepared LLCs were calculated by using fluorescence correlation spectroscopy (FCS). The different phases of the LLCs, viz., lamellar and hexagonal, with different microviscosities controlled the extent of C6 disaggregation and hence the FRET and the ROS generation. The results are encouraging since ROS generation has a significant role in the vision mechanism and PDT-based applications. LLC-based drug administration with potential FRET to control ROS generation may become handy in ophthalmology. The LLC phases used in this experiment not only served the purpose of drug delivery but also the photophysical events therein are compatible with the ocular environment.

α-Tocopherol-loaded multi-layer nanoemulsion using chitosan, and dextran sulfate: Cellular uptake, antioxidant activity, and in vitro bioaccessibility

The potential of multi-layer nanoemulsions (NEs) for improving the cellular uptake, antioxidant activity, and in vitro bioaccessibility of α-tocopherol (ToC) was examined. ToC-loaded multi-layer NEs were prepared using lecithin (primary-NEs, P-NEs), chitosan (secondary-NEs, S-NEs), and dextran sulfate (tertiary-NEs, T-NEs) as wall materials. The bioadhesion, cellular permeability, and uptake of the multi-layer NEs were significantly higher than that of the free coumarin 6 (C6). As a result of cellular uptake, the mean fluorescence intensity of T-NEs was the highest among the three types of multi-layer NEs and was 9.8-fold higher than that of free C6. The cellular antioxidant abilities of P-NEs, S-NEs, and T-NEs were 40, 45, and 50 %, respectively. Multi-layer nanoencapsulation sustains free fatty acid release after digestion. Moreover, the bioavailability of T-NEs exhibited a two-fold increase compared with that of the free ToC. These findings indicate that by multi-layer NEs using a layer-by-layer method, the cellular uptake, in vitro bioaccessibility, and antioxidant activity of ToC can be improved. Furthermore, T-NEs using chitosan and dextran sulfate can potentially enhance the cellular uptake, in vitro bioaccessibility, and antioxidant activity of ToC. These findings would facilitate the application of multi-layer NEs for lipophilic bioactive compounds using biopolymers.

Fluorescent composite based on peptide nanotubes activating coumarin 6 for sensitive detection of new coccine in food samples

New coccine (NC), as a kind of common colorant, has been frequently used in our daily life. Herein, the fluorescent composite (PNTs@C6) prepared by the hydrophobic non-covalent interaction between peptide nanotubes and coumarin 6 (C6) was designed for the determination of NC. Due to the activation of C6 by peptide nanotubes, the composite exhibits strong green fluorescence emission, which can be selectively quenched by NC through the inner filter effect. Therefore, a new fluorescent method based on the PNTs@C6 composite for NC detection was constructed. Under optimal conditions, the fluorescence quenching of the sensor exhibits a good linear relationship with the concentration of NC in the range of 0.01–10 μM and the limit of detection is 3.6 nM. Furthermore, the strategy shows simplicity, rapid response and high selectivity and has been successfully applied to the detection of NC in food samples.

Procedurally Targeted Delivery of Antitumor Drugs Using FAPα-Responsive TPGS Dimer-Based Flower-like Polymeric Micelles.

To overcome the intestinal epithelium barrier and achieve a better antitumor effect, the procedurally targeting flower-like nanomicelles for oral delivery of antitumor drugs were designed based on FAPα-responsive TPGS1000 dimer (TPGS-Gly-Pro-TPGS) and L-carnitine linked poly(2-ethyl-2-oxazoline)-b-poly(D, l-lactide) (Car-PEOz-b-PLA). As expected, compared with unmodified polymeric micelles (TT-PMs) composed of TPGS-Gly-Pro-TPGS, L-carnitine conjugated polymeric micelles (CTT-PMs) formed from both TPGS-Gly-Pro-TPGS and Car-PEOz-b-PLA with favorable stability in simulated gastrointestinal fluid and FAPα-dependent release capability exhibited remarkably enhanced cellular uptake and transmembrane transport through OCTN2 mediation confirmed by fluorescence immunoassay, which was intuitively evidenced by stronger fluorescence within epithelial cells, and the basal side of small intestinal epithelium of mice being given intragastric administration of DiI-labeled micelles. The transport of CTT-PMs across the intestinal epithelium in an intact form was mediated by clathrin along the intracellular transport pathway of endosome-lysosome-ER-Golgi apparatus. Furthermore, both the increased uptake by FAPα-positive U87MG cells and unchangeable uptake by FAPα-negative C6 cells for coumarin-6 (C-6)/CTT-PMs compared with C-6/TT-PMs evidenced the targeting ability of CTT-PMs to FAPα-positive tumor cells. Both OCTN2-mediation and FAPα-responsiveness were beneficial for polymeric micelles to improve the delivery and therapeutic efficiency of antitumor agents, which was further supported by the remarkable enhancement in in vivo antitumor efficacy via promoting apoptosis of tumor cells for paclitaxel (PTX)-loaded CTT-PMs (PTX/CTT-PMs) with low toxicity compared with PTX/TT-PMs. Our findings offered an alternative design strategy for procedurally targeted delivery of chemotherapeutics by an oral route.

Surface engineering of chitosan nanosystems and the impact of functionalized groups on the permeability of model drug across intestinal tissue

Surface attributes of nanocarriers are crucial to determine their fate in the gastrointestinal (GI) tract. Herein, we have functionalized chitosan with biochemical moieties including rhamnolipid (RL), curcumin (Cur) and mannose (M). FTIR spectra of functionalized chitosan nanocarriers (FCNCs) demonstrated successful conjugation of M, Cur and RL. The functional moieties influenced the entrapment of model drug i.e., coumarin-6 (C6) in FCNCs with payload-hosting and non-leaching behavior i.e., >91 ± 2.5 % with negligible cumulative release of <2 % for 5 h in KREB, which was further verified in the simulated gastric and intestinal fluids. Consequently, substantial difference in the size and zeta potential was observed for FCNCs with different biochemical moieties. Scanning electron microscopy and atomic force microscopy of FCNCs displayed well-dispersed and spherical morphology. In addition, in vitro cytotoxicity results of FCNCs confirmed their hemocompatibility. In the ex-vivo rat intestinal models, FCNCs displayed a time-dependent-phenomenon in cellular-uptake and adherence. However, apparent-permeability-coefficient and flux values were in the order of C6-RL-FCNCs > C6-M-FCNCs > C6-Cur-FCNCs = C6-CNCs > Free-C6. Furthermore, the transepithelial electrical resistance revealed the FCNCs mediated recovery of membrane-integrity with reversible tight junctions opening. Thus, FCNCs have the potential to overcome the poor solubility and/or permeability issues of active pharmaceutical ingredients and transform the impact of functionalized-nanomedicines in the biomedical industry.

Distinguishing nanoparticle drug release mechanisms by asymmetric flow field-flow fractionation.

This research demonstrates the development, application, and mechanistic value of a multi-detector asymmetric flow field-flow fractionation (AF4) approach to acquire size-resolved drug loading and release profiles from polymeric nanoparticles (NPs). AF4 was hyphenated with multiple online detectors, including dynamic and multi-angle light scattering for NP size and shape factor analysis, fluorescence for drug detection, and total organic carbon (TOC) to quantify the NPs and dissolved polymer in nanoformulations. The method was demonstrated on poly(lactic-co-glycolic acid) (PLGA) NPs loaded with coumarin 6 (C6) as a lipophilic drug surrogate. The bulk C6 release profile using AF4 was validated against conventional analysis of drug extracted from the NPs and complemented with high performance liquid chromatography - quadrupole time-of-flight (HPLC-QTOF) mass spectrometry analysis of oligomeric PLGA species. Interpretation of the bulk drug release profile was ambiguous, with several release models yielding reasonable fits. In contrast, the size-resolved release profiles from AF4 provided critical information to confidently establish the release mechanism. Specifically, the C6-loaded NPs exhibited size-independent release rate constants and no significant NP size or shape transformations, suggesting surface desorption rather than diffusion through the PLGA matrix or erosion. This conclusion was supported through comparative experimental evaluation of PLGA NPs carrying a fully entrapped drug, enrofloxacin, which showed size-dependent diffusive release, along with density functional theory (DFT) calculations indicating a higher adsorption affinity of C6 onto PLGA. In summary, the development of the size-resolved AF4 method and data analysis framework fulfills salient analytical gaps to determine drug localization and release mechanisms from nanomedicines.

Solute dynamics in a block copolymer: effect of additives and temperature

The solute dynamics in a symmetrical poly (ethylene oxide)-poly (propylene oxide)-poly (ethylene oxide) (PEO-PPO-PEO) triblock copolymer, P-123 were studied in aqueous and saline solutions as a function of additives, temperature using spectroscopic techniques. We have chosen a hydrophobic solute Coumarin-6 (C-6) as probe to study the photophysics and rotational dynamics in the above systems. We found that the rotational dynamics of C-6 is hindered in saline solution compared to that in aqueous solution of P-123. Therefore, in the saline solution of P-123, C-6 faced more restricted environment compared to the aqueous solution of P-123. In the absence of saline, at a temperature higher than cmt, we observed that addition of 0.02 M n-hexanol decreases the rotational relaxation time compared to that in P-123. Whereas, addition of 0.02 M n-hexylamine the rotational relaxation remains almost same compared to that in P-123. Therefore, n-hexanol affect more on the solute dynamics compared to n-hexylamine because of its preferential partitioning in the micellar phase owing to its greater hydrophobic ranking compared to n-hexylamine. In the saline solution we observed that addition of 0.02 M n-hexanol on P-123 solution affect more on the rotational dynamics of C-6 compared to the addition of 0.02 M n-hexylamine.

Coemissive luminescent nanoparticles combining aggregation-induced emission and quenching dyes prepared in continuous flow

Achieving an ideal light-harvesting system at a low cost remains a challenge. Herein, we report the synthesis of a hybrid dye system based on tetraphenylene (TPE) encapsulated organic dyes in a continuous flow microreactor. The composite dye nanoparticles (NPs) are synthesized based on supramolecular self-assembly to achieve the co-emission of aggregation-induced emission dyes and aggregation-caused quenching dyes (CEAA). Numerical simulations and molecular spectroscopy were used to investigate the synthesis mechanism of the CEAA dyes. Nanoparticles of CEAA dyes provide a platform for efficient cascade Förster resonance energy transfer (FRET). Composite dye nanoparticles of TPE and Nile red (NiR) are synthesized for an ideal light-harvesting system using coumarin 6 (C-6) as an energy intermediate. The light-harvesting system has a considerable red-shift distance (~126 nm), high energy-transfer efficiency (ΦET) of 99.37%, and an antenna effect of 26.23. Finally, the versatility of the preparation method and the diversity of CEAA dyes are demonstrated.

Sorafenib-Entrapped, Self-Assembled Pullulan–Stearic Acid Biopolymer-Derived Drug Delivery System to PLC/PRF/5 Hepatocellular Carcinoma Model

This study aimed to design a prototypic drug delivery system (DDS) made of an amphiphilic, pullulan (Pull)-derived biodegradable polymer for targeting the asialoglycoprotein receptor (ASGPR) overexpressed in HCC. Stearic acid (SA) was conjugated to increase the hydrophobicity of pullulan (Pull-SA). Pullulan (Pull) was linked to stearic acid (SA) after functional group modifications via EDC/NHS chemistry and characterized. Sorafenib tosylate (SRFT) was entrapped in pullulan-stearic acid nanoparticles (Pull-SA-SRFT) and its particle size, zeta potential, entrapment efficiency (EE), loading capacity (LC), and release efficiency was measured. The competence of Pull-SA-SRFT over SRFT in vitro was assessed using the ASGPR over-expressing PLC/PRF/5 hepatocellular carcinoma (HCC) cell line. This was done by studying cytotoxicity by MTT assay and chromosome condensation assay, early apoptosis by annexin-Pi staining, and late apoptosis by live-dead assay. The cellular uptake study was performed by incorporating coumarin-6 (C6) fluorophore in place of SRFT in Pull-SA conjugates. A biodistribution study was conducted in Swiss-albino mice to assess the biocompatibility and targeting properties of SRFT and Pull-SA-SRFT to the liver and other organs at 1, 6, 24, and 48 h. The characterization studies of the copolymer confirmed the successful conjugation of Pull-SA. The self-assembled amphiphilic nanocarrier could proficiently entrap the hydrophobic drug SRFT to obtain an entrapment efficiency of 95.6% (Pull-SA-SRFT). Characterization of the synthesized nanoparticles exhibited highly desirable nanoparticle characteristics. In vitro, apoptotic studies urged that Pull-SA-SRFT nanoparticle was delivered more efficiently to HCC than SRFT. The cellular uptake study performed, gave propitious results in 4 hrs. The biodistribution study conducted in immunocompetent mice suggested that Pull-SA-SRFT was delivered more than SRFT to the liver when compared to other organs, and that the system was biocompatible. Pull-SA-SRFT is a promisingly safe, biodegradable, cell-specific nanocarrier and a potential candidate to target hydrophobic drugs to HCC.

Evaluating the integrity of polymersomes by FRET for optimization of the lyophilization parameters

Polymersomes (polymeric vesicles) are non-viral delivery vehicles self-assembled from block copolymers (BCPs), holding promising potential in biomedical applications. Despite the higher chemical stabilities of the BCPs, lyophilization is still required for the long-term preservation of the polymersomes and their encapsulated drugs. However, formulation and processing parameters can affect the efficiency of the lyophilization. In this work, we present an approach to evaluate the integrity of polymersomes based on Fluorescence Resonance Energy Transfer (FRET) for rapid optimization of the lyophilization parameters. Specifically, Coumarin 6 (C6) and Nile red (NR)-encapsulated polymersomes were fabricated separately and mixed together for lyophilization. Upon reconstitution, FRET was detected for polymersomes which lost integrity during the lyophilization or reconstitution. The evaluation was carried out for poly(ethylene glycol)-b-poly(lactic acid) (PEG-b-PLA) polymersomes lyophilized with eight different excipients, and the results showed that the best polymersomes integrity could be achieved with the addition of hydroxypropyl-beta-cyclodextrin (HP-β-CD). We believe the approach described here would greatly facilitate the optimization of the polymersomes lyophilization, accelerating the translation of polymersomes to practical applications.

Structural and Optical Properties of Nanocrystalline 3-(2-Benzothiazolyl)-7-(diethylamino) Coumarin (C6) Thin Films for Optoelectronic Application

In the current work, the structural and optical properties of thermally evaporated 3-(2-Benzothiazolyl)-7-(diethylamino) coumarin [Coumarin 6 (C6)] thin films on a pre-cleaned quartz substrate were studied as a function of the annealing temperature. The influence of annealing on the structural, morphological, and molecular structures was investigated by x-ray diffraction (XRD), atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectroscopy, respectively. The XRD and AFM results confirmed that the as-deposited and annealed films have nanostructural features (30.96–45.34 nm). Also, the increase in roughness of the C6 thin film surface resulted from particle agglomeration and coalescence. Optical constants of C6 thin films were derived from the transmittance T(λ) and reflectance, R(λ) measurements in the spectral range of 200–2500 nm. Analysis of the optical absorption coefficient data indicates that the type of electronic transition in these films is an indirect allowed transition. The estimated optical band gap was decreased from 2.12 eV to 2.01 eV as the annealing temperature was increased. Dispersion and dielectric parameters were determined as functions of the annealing temperature. Lastly, nonlinear optical parameters such as the third-order nonlinear susceptibility, χ(3) and nonlinear refractive index, n(2) were estimated and influenced by annealing temperature. The optical properties of C6 thin films were showed that C6 thin films would be used in a wide range of photonic applicationsGraphical

N-acetylcysteine functionalized chitosan oligosaccharide-palmitic acid conjugate enhances ophthalmic delivery of flurbiprofen and its mechanisms

An N-acetylcysteine functionalized chitosan oligosaccharide-palmitic acid conjugate (NAC-COS-PA) with bioadhesive and permeation promoting properties was synthesized to enhance transocular drug delivery. Flurbiprofen (FB) loaded self-assembled NAC-COS-PA nanomicelles (NAC-COS-PA-FB) were prepared and the drug loading was 7.35 ± 0.32%. Human immortalized corneal epithelial (HCE-T) cell cytotoxicity and hen's egg test-chorioallantoic membrane assays confirmed that the conjugate had good biocompatibility. The transportation efficiency of coumarin-6 (C6) loaded nanomicelles in the HCE-T cell monolayer was approximately 1.97 times higher than that of free C6. Decreased intracellular Ca2+ concentration and cell membrane potential, increased cell membrane fluidity, and reversible changes in the F-actin cytoskeleton are presumed to be responsible for the enhanced drug permeation. NAC-COS-PA exhibited strong binding capacity with mucin and rabbit eyeball. In vivo pharmacokinetics indicated that the area under the curve (AUC0–6 h) and the maximum concentration (Cmax) of NAC-COS-PA-FB were approximately 1.92 and 2.44 times that of the FB solution, respectively. NAC-COS-PA-FB demonstrated the best in vivo anti-inflammatory efficacy compared to unfunctionalized nanomicelles (COS-PA-FB) and FB solution. Consequently, NAC-COS-PA appears to be a promising bioadhesive carrier for ophthalmic delivery.

Sorafenib-Loaded PLGA-TPGS Nanosystems Enhance Hepatocellular Carcinoma Therapy Through Reversing P-Glycoprotein-Mediated Multidrug Resistance.

Multidrug resistance (MDR) is a key determinant for hepatocellular carcinoma chemotherapy failure. P-glycoprotein is one of the main causes of MDR by causing drug efflux in tumor cells. In order to solve this thorny problem, we prepared a sorafenib-loaded polylactic acid-glycolic acid (PLGA) - D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (SPTNs). SPTNs were successfully synthesized through an ultrasonic emulsion solvent evaporation method with a favourable encapsulation efficiency of 90.35%. SPTNs were almost spherical in shape with uniform particle size (215.70 ± 0.36 nm), narrow polydispersity index (0.27 ± 0.02) and negative surface charge (-26.01 ± 0.65 mV). In the cellular uptake assay, the intracellular coumarin-6 (C6) fluorescence of TPGS component-based PLGA nanoparticles (C6-PTNs) was 1.63-fold higher relative to that of PVA component-based PLGA nanoparticles (C6-PVNs). The half-maximal inhibitory concentration and apoptosis ratio of SPTNs against HepG2/MDR cells were 3.90 μM and 75.62%, respectively, which were notably higher than free SF and sorafenib-PLGA-PVA nanoparticles (SPVNs). The anti-drug efflux activities of SPTNs were assessed by the intracellular trafficking assay using verapamil as a P-gp inhibitor. SPTNs could effectively inhibit the drug efflux in tumor cells detected by flow cytometry, and suppressed relative MDR1 gene as well as P-glycoprotein expression in tumor cells. Attributed to the MDR reversion effect of SPTNs, the in vivo antitumor efficacy experiment showed that SPTNs significantly inhibited the tumor growth of HepG2/MDR xenograft-bearing nude mice, and obviously reduced the toxicity against liver and kidney compared with SF treatment. In summary, SPTNs, as highly efficient and safe antitumor nano delivery systems, showed promising potential for hepatocellular carcinoma therapy through reversing P-glycoprotein-mediated MDR. Graphical Abstract.

Hyaluronidase and pH Dual-Responsive Nanoparticles for Targeted Breast Cancer Stem Cells.

pH-responsive and CD44 receptor-mediated targeted nanoparticles for eliminating cancer stem cells (CSCs) were developed based on complexes of PEG-poly(β-amino ester) (PEG-PBAE) micelles (PPM) coated with hyaluronic acid (HA) (HA-coated PPM complex, or HPPMc). Thioridazine (Thz) was loaded into HPPMc with a decent drug loading content. The release results of the drug in vitro showed that Thz was released from the HPPMc, which was stimulated by both the acidic pH and specific enzymes. Cytotoxicity studies on mammospheres (MS) revealed that the toxicity potential of Thz-loaded HPPMc (Thz–HPPMc) at pH 5.5 was better than drug solutions. Compared with that at pH 7.4, a higher cellular uptake of a coumarin-6 (C6)-labeled complex at pH 5.5 was observed, which demonstrated that complexes were efficiently taken up in MS. Meanwhile, free HA competitively inhibited the cellular uptake of HPPMc, which revealed that the uptake mechanism was CD44 receptor-mediated endocytosis. Within the acidic endolysosomal environment, the protonation of PBAE facilitated the escape of the complex from the lysosome and releases the drug. The results of in vivo distribution studies and tumor suppression experiments showed that HPMMc could stay in the tumor site of BALB/c nude mice for a longer period of time, and Thz–HPPMc could significantly improve the tumor-suppressing effect. All these results demonstrated the great potential of the multifunctional nanoparticle system for eliminating CSCs.

Study on Anti-Acute Mononuclear Leukemia Activity and Mechanism of Lentinus Edodes Derived β-Glucan/ Selenium Nanoparticles Composites

Objective: Acute monocytic leukemia (AMoL) is the M5 subtype of acute myeloid leukemia (AML) which has the characteristics of high degree of malignancy, prone to extramedullary infiltration, poor efficacy of conventional chemotherapy, easy recurrence and so on. Besides, chemotherapy has large side effects and high cost. Therefore, it is urgent to find natural, non-toxic and cheap drugs for the treatment of acute monocytic leukemia. We evaluated the anti-acute mononuclear leukemia activities of selenium nanoparticles embedded in lentinan in vivo and in vitro, and explored the mechanism of how AMoL cells react to it. It is expected to provide a new method and basis for the treatment of acute mononuclear leukemia.Methods: Utilizing the aggregation and assembly behavior of Lentinus edodes extracted rigid tri-helical β-glucan (Lentinan, LNT) in aqueous solution, cooperative research group prepared Lentinus β-glucan/Selenium nanoparticle complex called LNT-Se by encapsulating selenium nanoparticles (SeNPs) in the cavity of LNT. CCK-8 and flow cytometry were used to detect cytotoxicity, apoptosis rate and cell cycle changes after LNT-Se treatment. Single cell microfluidics chip was used to observe the fluorescence intensity of green fluorescent protein (GFP) of single cell treated by drug. Transmission electron microscopy (TEM) was used to detect ultrastructural changes of THP-1. Coumarin 6 (C6) was used to modify LNT-Se, flow cytometry and confocal microscopy were used to detect drug uptake and primary targeting organelles in AML-M5 cells treated with C6-LNT-Se. The changes of reactive oxygen species (ROS) levels in AML-M5 cells after LNT-Se treatment were detected by flow cytometry. Oxidation-related indexes were further detected, such as malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px). The RNA extracted from untreated and LNT-Se-treated THP-1 cells was sequenced by mRNA-seq. AML-M5 patient-derived tumor xenograft (PDX) leukemia mouse model was established to evaluate the efficacy of LNT-Se in vivo. Serum was collected for detecting liver and kidney functions. Tissue sections were stained by hematoxylin-eosin staining (HE). Specific molecules on the surface of human leukemia cells were detected by immunohistochemistry (IHC) to investigate the efficacy of LNT-Se.Results: SeNPs were successfully embedded into LNT hollow nanotubes and were stably dispersed in water. LNT-Se could significantly inhibit the proliferation of AML-M5 cell lines and had no obvious toxic effect on normal cell lines. LNT-Se could promote the apoptosis of AML-M5 cells and block the cell cycle in the G2/M phase. 50μg/ mL LNT-Se could promote more than 40% apoptosis rate in AML-M5 patient cells, while only about 10% in healthy volunteer cells. At the single cell microfluidic level, the green fluorescence of THP-1 GFP + cells decreased rapidly after 2mg/mL LNT-Se treatment for 2h. After LNT-Se treatment, THP-1 cells showed obvious apoptotic vacuolation, nuclear condensation, chromatin agglutination under TEM. AML-M5 cells could take up C6-LNT-Se and reached the highest uptake at 2h, and C6 fluorescence sites mainly overlapped with lysosomal fluorescence. LNT-Se could decrease intracellular ROS level and MDA content, and increase the activity of GPX in supernatant, but the MDA content and SOD activity in supernatant had no significant changes. Differential gene analysis of transcriptome showed that the first 12 genes were all mitochondrial coding genes. Enrichment analysis showed that TNF, MAPK and NF-κB pathways were up-regulated and oxidative phosphorylation pathways were down-regulated. The experimental results of leukemia PDX animal model showed that the weight loss of mice was slowed down after LNT-Se treatment, and the tumor burden was reduced. Compared with normal mice, there was no significant difference in liver and kidney function after LNT-Se administration, and no pathological changes were observed in viscera.Conclusions: LNT-Se had a good anti-acute mononuclear leukemia effect in vitro and in vivo, and could be absorbed by cells, and the primary target organelle was lysosome. Both in vivo and in vitro experiments suggested that LNT-Se was less toxic. LNT-Se had antioxidant activity and might exert anti-AML-M5 activity through TNF, MAPK and NF-κB pathways. These results indicated that LNT-Se could be used as an effective anti-AML-M5 drug. DisclosuresNo relevant conflicts of interest to declare.