Fluorescence Intensity Of Pyrene Research Articles

Water-soluble pillar[6]arene bearing pyrene on alternating methylene bridges for direct spermine sensing.

This paper describes the design and synthesis of a conjugate, which is composed of a percarboxylated water-soluble pillar[6]arene and three fluorescent pyrene chromophores on alternating methylene bridges. The optical characteristics are investigated. This conjugate is capable of encapsulating polycationic guest spermine, which results in an enhancement in the fluorescence intensity of pyrene. This host-pyrene conjugate is used for direct sensing of spermine, which shows selectivity towards a variety of biological analytes. The detection of spermine is demonstrated in live cells.

Pyrene interaction with selected heavy metal ions in aqueous sodium dodecyl sulphate (SDS)

Pyrene interaction with Fe3+, Cu2+, Cr3+, Ni2+, Pb2+ was studied in 0.02 mol L-1 SDS. All the studied heavy metal ions quenched the fluorescence intensity of pyrene though variations were found in the level of quenching. Stern-Volmer equation fitted the pyrene quenching by heavy metal ions. Stern-Volmer constants (KSV) were obtained with the fitting of the quenching data with the Stern-Volmer equation. KSV shows the level of quenching and the sensitivity of the method. Greater the KSV larger will be the detection and quantification limit and vice versa. KSV, detection limit (DL) and quantification limit (QL) varied from 9.26 × 103 mol L-1 to 4.13 × 103 mol L-1, 1.61 × 10-6 mol L-1 to 5.85 × 10-6 mol L-1 and 5.38 × 10-6 mol L-1 to 19.49 × 10-6 mol L-1 respectively. The overall sensitivity, DL and QL were observed in the order Fe3+ > Cu2+ > Cr3+ > Ni2+ > Pb2+. Pyrene fluorescence quenching by the studied heavy metal ions is a fruitful method for their determination in environmental samples.

Pyrene Interaction with Selected Amines in Aqueous Sodium Dodecyl Sulphate (SDS).

Pyrene interaction with a group of selected amines such as i.e. benzylamine, phenethylamine, trimethylamine, 1-phenylethylamine was studied in aqueous sodium dodecyl sulfate. All the four amines quenched the fluorescence intensity of pyrene in aqueous SDS. Pyrene acts as a sensitive and selective sensor for the detection of amines in environmental samples. Two different SDS concentrations (0.05mol L- 1 and 0.1mol L- 1) were used to get the optimum SDS concentration for maximum quenching and best detection and quantification limits. Lower SDS concentration (0.05mol L- 1) was found the optimum for maximum quenching, lower detection and quantification limits. Fluorescence quenching of pyrene by the studied amines was treated with the Stern-Volmer equation that resulted in a Stern-Volmer constants (Ksv). Ksv reflects the sensitivity of pyrene for studied amines. Ksv varied between 1.962 × 104 - 0.020 × 103 mol L- 1. A sensitivity, detection limit (DL), quantification limit (QL) of pyrene for studied amines was found in the order Benzylamine > phenethylamie > trimethylamine > 1-phenylethylamine. DL varied from 4.53 × 10- 7 to 4.55 × 10- 4 mol L- 1 and QL varied from 1.51 × 10- 6 to 1.52 × 10- 3 mol L- 1. Method showed excellent reproducibility and is fruitful for the studied amines in environmental samples.

Detection of Lipase Activity in Cells by a Fluorescent Probe Based on Formation of Self-Assembled Micelles.

SummaryReliable and sensitive detection of lipase activity is essential for the early diagnosis and monitoring of acute pancreatitis or progression of digestive diseases. However, the available fluorescent probes for detection of lipase activity are only implemented in a hexane-water two-phase system due to the nature of heterogeneous catalysis of lipase, thus limiting their applications in direct imaging of lipase activity in living cells and tissues. Here we designed and synthesized a “turn on” fluorescent probe CPP based on self-assembled micelles for hydrolysis of lipase. The CPP probe exhibits high selectivity and excellent sensitivity for the detection of lipase in such a homogeneous system and is successfully applied for monitoring lipase activity in pancreatic AR42J cells, tissues, and serums. Taken together, the fluorescent CPP probe not only provides a tool for diagnostic potential in pancreatic disease but also demonstrates an application potential for micelle self-assembly-based development of biological probes.

Development of self-assembled monolayer of stearic acid grafted chitosan on mild steel and inhibition of corrosion in hydrochloric acid

Abstract Chitosan (CS) based systems are extensively used as a green alternative for corrosion protection of mild steel (MS) possessing good film-forming properties, chelation with metal and nontoxic nature. In this study, a self-assembled monolayer of stearic acid grafted chitosan was developed via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide mediated coupling reaction and casted on the MS surface. From the fluorescence intensity of the fluorescent probe pyrene, the critical micelle concentration (66 μg/mL) of self-aggregates in aqueous solution was determined. The purified chitosan grafted films were characterized by apposite analytical techniques. The film developed was employed for corrosion protection of MS in 0.5 and 1 N HCl via electrochemical and non-electrochemical techniques. The results showed that stearic acid grafted chitosan (CSA) films do offer better corrosion protection to MS than bare CS film.

Adsorption behaviors and mechanisms of quaternary ammonium salt collectors on quartz samples with different particle sizes

In this study, the flotation behavior of quartz samples with different particle sizes was systematically studied by conducting a microflotation experiment wherein different quaternary ammonium salt (QAS) collectors were used. The mechanism of QAS adsorption on the surfaces of the quartz samples was revealed by adsorption experiments and micro-polarity characteristics at the quartz-water interface. The microflotation experiment showed that the carbon chain length of the QAS collectors and the particle sizes of the quartz samples had a significant effect on flotation recovery. Long carbon chain collectors, tetradecyltrimethylammonium chloride (TTAC) and cetyltrimethylammonium chloride (CTAC), exhibited a better collection capability than that exhibited by short carbon chain collectors, decyltrimethylammonium chloride (103C) and dodecyltrimethylammonium chloride (DTAC). The adsorption experiments showed the adsorption amount of CTAC and DTAC on the surfaces of the quartz increased with decrease in quartz particle size. The adsorption isotherms of QAS collectors on the quartz particles were consistent with the typical “double plateau model.” The shape of the adsorption isotherm was affected by the particle sizes of the quartz and the carbon chain length of the collector. A pyrene fluorescence test showed that the maximum value of I3:I1 (I3:I1max) of the long carbon chain CTAC was larger than that of the short carbon chain DTAC. When the I3:I1 max was reached, the required concentration of CTAC was less than that of DTAC. With the increase in the DTAC concentration, the fluorescence intensity of pyrene in the supernatant initially decreased, and then increased, thereby indicating that the DTAC adsorption on the surfaces of the quartz particles gradually saturated.

Solvent Effect on the Solid-Surface Fluorescence of Pyrene on Cellulose Diacetate Matrices

The effect of the solvent nature (acetonitrile, ethanol, dimethyl sulfoxide, and dioxane) and its concentration on the fluorescence intensity of pyrene sorbed on the cellulose diacetate (CDA) film from a water-organic solution was studied. Dimethyl sulfoxide and ethanol are shown to be the most effective solvent additives for pyrene solid-surface fluorescence (SSF). The maximum SSF signal of pyrene was found upon sorption of the substance from aqueous media containing 1.2-4.2 vol% DMSO. For the pyrene quantitation the concentration dependence of its SSF intensity at the maximum of the spectrum at λem = 394 nm and λexp = 320 nm was plotted. The dependence has a linear character in the pyrene concentration range 2·10−6 - 2·10-8 g/L, and the limit of pyrene detection is 2·10-11 g/L. The possibility of determining benzo(a)pyrene using SSF technique with the CDA matrix is proved. The proposed method is promising for use in environmental monitoring of polycyclic aromatic hydrocarbons.

Critical aggregates concentration of fatty esters present in biodiesel determined by turbidity and fluorescence.

Biodiesel for combustible engine is available as mixture of fossil diesel and fatty esters obtained by transesterification of vegetable oils. The use of biodiesel reduces the amount of SOx, mainly. However, it was already observed that biodiesel has a different behavior in environment in cases of accidental spill and groundwater contamination. It was noticed that the biodegradation of hydrocarbons (cyclic and aliphatic) in the presence of biodiesel are speeded, although the mechanism is still unclear. Considering the chemical structure of fatty esters, it was investigated the formation of aggregates in water solution by fatty esters present in commercial biodiesel. In Brazil, biodiesel is composed by 95% of fossil diesel and 5% of fatty esters mixture. In this work, fatty esters were treated as neutral surfactant, i.e., it was treated as a molecule with polar and non-polar part. Turbidity and fluorescence were used to determine the critical aggregates concentration (CAC). Water solutions containing fatty esters were examined exploiting changes in turbidity and fluorescence intensity of pyrene. Abrupt changes were attributed to aggregates formation, following the same behavior of traditional amphiphilic compounds. It was determined the CAC for ethyl palmitate, ethyl stearate, ethyl oleate, and ethyl linoleate. The values of CAC for fatty esters varied from 1.91 to 4.27μmol/L, while CAC for the mixture of esters (biodiesel) was 2.01 for methyl esters and 1.19 for ethyl esters, both prepared using soybean oil. The aggregates formation was also determined by fluorescence measurements considering the changes in intensity of peaks I and III of pyrene. Pyrene senses the changes in environment polarity. The values found of CAC by fluorescence for individual ethyl esters varied from 1.85 to 3.21μmol/L, while mixtures of ethyl esters was 2.23 and 2.07μmol/L for mixture of methyl esters. The results clearly showed that fatty esters form aggregates and might be responsible for speed degradation of compounds by accommodation of them in inner part of aggregates.

Preparation and evaluation of reduction-responsive nano-micelles for miriplatin delivery.

A reduction-responsive amphiphilic core-shell micelle for miriplatin delivery was prepared and evaluated. A pyrene-terminated poly(2-(dimethylamino) ethyl acrylate) was synthesized through reversible addition-fragmentation chain transfer polymerization with 4-cyano-4-(ethylthiocarbonothioylthio) pentanoic acid as reversible addition-fragmentation chain transfer reagent and further modified by 2,2'-dithiodiethanol and 1-pyrenebutyric acid. Self-assembled blank micelles and drug-loaded micelles were obtained by dialysis method, and the particle size was proved to be about 40 nm with narrow dispersity by dynamic laser light scattering. Morphology results showed that blank micelles and drug-loaded micelles were spherical nanoparticles confirmed by transmission electron microscope, and the critical micelle concentration was as low as 6.09 µg/mL via pyrene fluorescence probe method. The reductive sensitivity of disulfide bond in BMs was further verified by changes in particle size, pyrene fluorescence intensity ratio (I338/I333), and morphology after treatment by dithiothreitol. Moreover, drug release rate invitro of drug-loaded micelles was evaluated and the results suggested that this amphiphilic pyrene-modified poly(2-(dimethylamino) ethyl acrylate) can be used as reduction-triggered controlled release drug delivery carrier for hydrophobic drug.

Usage of cellulose acetate membranes for the sorption-luminescence determination of pyrene in aqueous media

The applicability of cellulose acetate membranes (CAMs) as a solid matrix for the luminescence determination of pyrene in aqueous micellar solutions is shown. The effect of the concentrations of various surfactants, namely, anionic sodium dodecyl sulfate (SDS), cationic cetyltrimethylammonium bromide (CTAB), and nonionic polyoxyethylene (10) mono-4-isooctyl phenyl ether (TX-100), on the fluorescence of pyrene in aqueous micellar solutions before and after sorption preconcentration and in an adsorbed state on a CAM has been studied. It has been found that the fluorescence intensity of pyrene on the solid-phase matrix increases as a result of pyrene solubilization in surfactant hemimiceles formed on the sorbent surface. The highest degree of pyrene extraction on CAMs has been achieved in the presence of cationic CTAB micelles. The CAM has a negative surface potential (−31.5 ± 2.5 mV), which affects the hydrocarbon recovery. The degree of extractlion and the polarity index of a microenvironment of pyrene molecules in solutions decrease in the order CTAB → SDS → TX-100.

Cellulose diacetate films as a solid-phase matrix for fluorescence analysis of pyrene traces in aqueous media

We report on the possibility of using cellulose diacetate (CDA) films as a solid-phase matrix for the fluorescence analysis of pyrene in aqueous micellar media. We examined the effect of the concentration of three surfactants—the anionic sodium dodecyl sulfate (SDS), the cationic cetyltrimethylammonium bromide (CTAB), and the nonionic polyoxyethylene (10) mono-4-isooctylphenyl ether (TX-100)—on the fluorescence of pyrene in aqueous micellar solutions before and after sorptional concentration and as adsorbed on CDA films. The increased fluorescence intensity of pyrene on the solid-phase matrix was due to pyrene solubilization in the surfactant hemimicelles formed on the sorbent surface. The highest degree of pyrene recovery on CDA was achieved in the presence of micelles of the cationic CTAB. The surface electric potential of the CDA films was negative (−31.5 ± 2.5 mV), affecting the hydrocarbon recovery degree. The recovery degree and the polarity index of the pyrene molecules’ microenvironment in solution decreased in the sequence CTAB > SDS > TX-100.

Hexadecyltrimethylammonium bromide micellization in glycine, diglycine, and triglycine aqueous solutions as a function of surfactant concentration and temperatures

Micellization behavior of hexadecyltrimethylammonium bromide (HTAB) was investigated conductometrically in aqueous solutions containing 0.02 mol kg−1glycine (Gly), diglycine (Gly-Gly), and triglycine (Gly-Gly-Gly) as a function of surfactant concentration at different temperatures. The critical micelle concentration (CMC) of HTAB exhibits a decreasing trend as the number of carbon atoms increases from Gly to Gly-Gly-Gly, favoring the micelle formation. The values of CMC and the degree of counterion dissociation of the micelles were utilized to evaluate the standard free energy for transferring the surfactant hydrophobic chain out of the solvent to the interior of the micelle, ΔGHP○, free energy associated with the surface contributions, ΔGS○, standard free energy, ΔGm○, enthalpy, ΔHm○, and entropy, ΔSm○ of micellization were also calculated. The results show that the micellization of HTAB in aqueous solutions as well as in aqueous Gly/Gly-Gly/Gly-Gly-Gly solutions is primarily governed by the entropy gain due to the transfer of the hydrophobic groups of the surfactant from the solvent to the interior part of the micelle. The CMC obtained by fluorometric method is in close agreement with those obtained conductometrically. Furthermore, decrease in the I1/I3 ratio of pyrene fluorescence intensity suggests the solubilization of the additives by the surfactant micelles and that this solubilization increases as the hydrophobicity increases from Gly to Gly-Gly-Gly.

Synthesis of novel thermoresponsive micelles by graft copolymerization of N-isopropylacrylamide on poly(ε-caprolactone-co-α-bromo-ε-caprolactone) as macroinitiator via ATRP

α-Bromo-e-caprolactone (α-BrCL) was synthesized from α-bromocyclohexanone by using 3-chloroperoxybenzoic acid. α-BrCL was then used as a comonomer in the ring-opening polymerization of e-caprolactone (CL) initiated with aluminum isopropoxide to synthesize poly(CL-co-α-BrCL) copolymer. This copolymer was used as the macroinitiator in the atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAAm) for the synthesis of stimuli-responsive and biodegradable PCL-g-PNIPAAm copolymer. A core-shell type nano-structure was formed with a hydrophilic outer shell and a hydrophobic inner core from these copolymers, which exhibited a phase transition temperature around 31 °C. The copolymers were characterized by 1H-NMR and FT-IR spectroscopies. Number-average molecular weight of the poly(CL-co-α-BrCL) and PCL-g-PNIPAAm copolymers was calculated from corresponding 1H-NMR spectra to be 5770 and 6810 gmol−1, respectively. Thermal stability of the copolymer was investigated by thermogravimetric analysis (TGA) and crystallization behavior was studied by differential scanning calorimetry (DSC). Transmission electron microscopy (TEM) showed that the self-assemble micelle aggregates had well defined spherical shape. From the fluorescence spectra, fluorescence intensity of pyrene in the copolymer micelles increased and red-shifted as the copolymer concentration increases, indicating the formation of self-assemble polymeric micelles in water. The critical micelle concentration was found to be 3.2 × 10−3 mg/mL. TEM results showed that micelles have spherical shapes with a diameter of about 70 nm. The obtained micelles can be desirable for potential applications in biomedical fields, such as drug delivery systems.

Effects of dissolved state of aminoalkyl methacrylate copolymer E/HCl on solubility enhancement effect for poorly water-soluble drugs

Eudragit® E/HCl salt (E–SD) displays a good antireprecipitation effect on solid dispersion formulations of poorly water-soluble drugs. To elucidate the mechanism underlying the antireprecipitation effect of E–SD, a study on supersaturation was conducted using a dissolution test method with test fluids at varying pH and ionic strength values. Both pH and ionic strength of the test fluid were shown to influence the antireprecipitation effect of E–SD; a strong antireprecipitation effect was observed at a neutral pH (pH 6∼7) and an ionic strength of 0.1 to 1.0. To investigate E–SD in its dissolved state in each test fluid, fluorescence measurement using pyrene as a probe molecule and dynamic light-scattering (DLS) measurement were conducted. The total fluorescence intensity of pyrene increased with increasing E–SD concentrations. Further, small nanoparticles were observed using DLS measurement. These results suggest that E–SD may form a micelle-like structure in the dissolved test fluid.

Control of pyrene fluorescence intensity by in situ addition of CO2 to an amidine/amine mixture or CO2 removal from an amidinium carbamate ionic liquid

Addition of CO(2) to an equimolar amidine/amine mixture leads to formation of a switchable ionic liquid, an amidinium carbamate, and appearance of strong fluorescence by a solute, pyrene. Passing a 'displacement gas', N(2), through the ionic liquid or heating it regenerates the amidine/amine mixture and quenches the fluorescence almost totally. No switching or appreciable fluorescence is found when an amidinium dithiocarbamate is the medium.

Europium Coordination Complexes as Potential Anticancer Drugs: Their Partitioning and Permeation Into Lipid Bilayers as Revealed by Pyrene Fluorescence Quenching

The present study was undertaken to evaluate the membrane-associating properties of a series of novel antitumor agents, Eu(III) coordination complexes (EC), using the pyrene fluorescence quenching as an analytical instrument. Analysis of EC-induced decrease in pyrene fluorescence intensity in terms of partition and solubility-diffusion models allowed us to evaluate the partition and permeation coefficients of the examined compounds into the lipid vesicles prepared from zwitterionic lipid phosphatidylcholine (PC) and its mixtures with cholesterol (Chol) and anionic lipid cardiolipin (CL). The drug-lipid interactions were found to have the complex nature determined by both EC structure and lipid bilayer composition. High values of the obtained partition and permeation coefficients create the background for the development of EC liposomal formulations.

Amphipathicity and self-assembly behavior of amphiphilic alginate esters

Amphiphilic alginate esters (Alg-Cn) with different degree of substitution (DS) and hydrophobic alkyl length were synthesized by the reaction between partially protonated sodium alginate and aliphatic alcohols (octanol, dodecanol or hexadecanol) and characterized by conventional methods. The critical micelles concentration (CMC) of Alg-Cn was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe, conductance and surface tension (SFT). Formation and characteristics of the self-assembly micelles of Alg-Cn were studied by transmission electron microscopy (TEM) and Zetasizer Nano Series method. The results indicate that CMC value and the self-assembled micelle size decreased with the increasing of the hydrophobic alkyl chain length, as the DS of Alg-Cn is similar.

Calcium-sensitive Activity and Conformation of Caenorhabditis elegans Gelsolin-like Protein 1 Are Altered by Mutations in the First Gelsolin-like Domain

The gelsolin family of actin regulatory proteins is activated by Ca(2+) to sever and cap actin filaments. Gelsolin has six homologous gelsolin-like domains (G1-G6), and Ca(2+)-dependent conformational changes regulate its accessibility to actin. Caenorhabditis elegans gelsolin-like protein-1 (GSNL-1) has only four gelsolin-like domains (G1-G4) and still exhibits Ca(2+)-dependent actin filament-severing and -capping activities. We found that acidic residues (Asp-83 and Asp-84) in G1 of GSNL-1 are important for its Ca(2+) activation. These residues are conserved in GSNL-1 and gelsolin and previously implicated in actin-severing activity of the gelsolin family. We found that alanine mutations at Asp-83 and Asp-84 (D83A/D84A mutation) did not disrupt actin-severing or -capping activity. Instead, the mutants exhibited altered Ca(2+) sensitivity when compared with wild-type GSNL-1. The D83A/D84A mutation enhanced Ca(2+) sensitivity for actin severing and capping and its susceptibility to proteolytic digestion, suggesting a conformational change. Single mutations caused minimal changes in its activity, whereas Asp-83 and Asp-84 were required to stabilize Ca(2+)-free and Ca(2+)-bound conformations, respectively. On the other hand, the D83A/D84A mutation suppressed sensitivity of GSNL-1 to phosphatidylinositol 4,5-bisphosphate inhibition. The structure of an inactive form of gelsolin shows that the equivalent acidic residues are in close contact with G3, which may maintain an inactive conformation of the gelsolin family.

Structural studies on maturing actin filaments

We have previously reported that actin undergoes a conformational transition (which we named "maturation") during polymerization, and that the actin-binding protein, caldesmon (CaD), when added at an early phase of polymerization, interferes with this process (Huang et al. J Biol Chem 2010; 285:71). The pre-transition filament is characterized by relatively low pyrene-fluorescence intensity when pyrene-labeled actin is used as a reporter of subunit assembly into filaments, whereas the mature filament emits a characteristic enhanced fluorescence. Previously reported co-sedimentation experiments suggest that filament formation is not inhibited by the presence of CaD, despite blocking the transition associated with filament maturation. In this study we visualized structural effects of CaD on the assembly of actin filaments by TIRF and electron microscopy. CaD-free actin forms "rough" filaments with irregular edges and indistinct subunit organization during the initial phase (∼20 min under our conditions) of polymerization as reported previously by others (Steinmetz et al. J Cell Biol 1997; 138:559; Galinska-Rakoczy et al. J Mol Biol 2009; 387:869), which most likely correspond to the pre-transition state preceding the maturation step. Later during the polymerization process "mature" filaments exhibit a smoother F-actin appearance with easily detectible double helically arranged actin subunits. While the inclusion of the actin-binding domain of CaD during actin polymerization does not affect the elongation rate, it is associated with a prolonged pre-transition phase, characterized by a delayed alteration (rough to smooth) of the appearance of filaments, consistent with a later onset of the maturation process.

RGD peptide-mediated chitosan-based polymeric micelles targeting delivery for integrin-overexpressing tumor cells

BackgroundSolid tumors need new blood vessels to feed and nourish them as well as to allow tumor cells to escape into the circulation and lodge in other organs, which is termed “angiogenesis.” Some tumor cells within solid tumors can overexpress integrins αvβ3 and αvβ5, which can specifically recognize the peptide motif Arg-Gly-Asp (RGD). Thus, the targeting of RGD-modified micelles to tumor vasculature is a promising strategy for tumor-targeting treatment.MethodsRGD peptide (GSSSGRGDSPA) was coupled to poly(ethylene glycol)-modified stearic acid-grafted chitosan (PEG-CS-SA) micelles via chemical reaction in the presence of N,N′-Disuccinimidyl carbonate. The critical micelle concentration of the polymeric micelles was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe. The micelle size, size distribution, and zeta potential were measured by light scattering and electrophoretic mobility. Doxorubicin (DOX) was chosen as a model anticancer drug to investigate the drug entrapment efficiency, in vitro drug-release profile, and in vitro antitumor activities of drug-loaded RGD-PEG-CS-SA micelles in cells that overexpress integrins (ανβ3 and ανβ5) and integrin-deficient cells.ResultsUsing DOX as a model drug, the drug encapsulation efficiency could reach 90%, and the in vitro drug-release profiles suggested that the micelles could be used as a controlled-release carrier for the hydrophobic drug. Qualitative and quantitative analysis of cellular uptake indicated that RGD-modified micelles could significantly increase the DOX concentration in integrin-overexpressing human hepatocellular carcinoma cell line (BEL-7402), but not in human epithelial carcinoma cell line (Hela). The competitive cellular-uptake test showed that the cellular uptake of RGD-modified micelles in BEL-7402 cells was significantly inhibited in the presence of excess free RGD peptides. In vitro cytotoxicity tests demonstrated DOX-loaded RGD-modified micelles could specifically enhance the cytotoxicity against BEL-7402 compared with DOX-loaded PEG-CS-SA and doxorubicin hydrochlorate.ConclusionThis study suggests that RGD-modified PEG-CS-SA micelles are promising drug carriers for integrin-overexpressing tumor active targeting therapy.