A liposomal hydrogel with enzyme triggered release for infected wound.

A novel liposomal hydrogel with enzyme triggered release of drug as drug carrier was presented for usage of infected wound. The liposomal hydrogel was prepared by an acombined method of thin-film evaporation and supercritical carbon dioxide technique (TE-scCO) with freeze-drying. In the liposomal hydrogel, curcumin as a model drug was embedded in the bilayer of the liposomes, and the liposomes were encapsulated in the gelatin-chitosan hydrogel.

Preparation, microstructure and function of liposome with light responsive switch.

A novel liposome with photo-responsiveness was prepared by a combined method of thin film hydration and supercritical carbon dioxide technique. In liposomes, curcumin and 4-butylazobenzene-4-hexyloxy-trimethyl-ammoniumtrifluoro-acetate (BHA) were used as model drug and photo-responsive reversible switch, respectively. Optimum incubation temperature of drug was determined by using phase transition temperature of the liposomes.

In situ synthesis of fluorescent magnetosomes using an organic membrane as a soft template.

A novel approach was presented for the in situ synthesis of fluorescent magnetosomes by biological mineralization and carbonization processes for the first time. The surface structures, magnetism and fluorescence were studied, and the cytotoxicity tests and fluorescent trace in liposomes were probed. The fluorescent magnetosomes exhibit not only unique fluorescence and ferromagnetic properties but also low toxicity and superior imaging capability.

Easy synthesis of highly fluorescent carbon dots from albumin and their photoluminescent mechanism and biological imaging applications.

A simple and green approach was developed to synthesize highly fluorescent carbon dots (CDs) using albumin as a carbon source in aqueous solution at room temperature. The CDs were characterized by excellent monodispersion, superior photostability, pH-independent emission, long fluorescence lifetime and high quantum yield (QY). The photoluminescent (PL) mechanism of CDs was explored by means of time-resolved PL decay, and the results revealed that PL originated from the emission of both defect state and intrinsic state.

Folate-polydiacetylene-liposome for tumor targeted drug delivery and fluorescent tracing.

A novel folate-polydiacetylene-liposome (FP-PL) with both targeted drug delivery and fluorescence tracing was prepared by thin film rehydration method. The simulated drug delivery was performed in Bcap-37 breast cancer cells and Hs578Bst normal cells in vitro. The internalization and distribution of FP-PLs in the cells were presented by fluorescence cell imaging.

Thermal and photic stimuli-responsive polydiacetylene liposomes with reversible fluorescence.

A novel reversible fluorescent switch of a polydiacetylene liposome (PDA liposome) was realized by alternating heating and UV irradiation processes. The reversible fluorescence switching of the PDA liposome was mainly caused by the microstructural changes of the PDA backbone in the PDA liposomes under the alternating conditions of heating and UV irradiation.

An improved method for ratiometric fluorescence detection of pH and Cd2+ using fluorescein isothiocyanate-quantum dots conjugates.

In this study, thioglycolic acid capped-CdTe quantum dots (QDs) were modified by polyethylenimine (PEI), and then combined with fluorescein isothiocyanate (FITC) to fabricate FITC-CdTe conjugates. The self-assembly of FITC, CdTe and PEI was ascribed to electrostatic interactions in aqueous solution. The resulting conjugates were developed toward two routes.

Controllable release from magnetoliposomes by magnetic stimulation and thermal stimulation.

Liposomes with superparamagnetic iron oxide nanoparticles embedded in membrane were prepared by the supercritical carbon dioxide (scCO(2)) method. The cargos can be released from liposomes by both triggered agents, temperature and alternating current electromagnetic field (AMF). The release mechanism was explained from the view of microstructure change investigated by fluorescence probe method.

Smart photothermal-triggered bilayer phase transition in AuNPs-liposomes to release drug.

Novel thermosensitive liposomes with embedded Au nanoparticles (AuNPs) in the liposome bilayer were prepared by a combination method of film build and supercritical CO(2) incubation. These AuNPs-liposomes possess AuNPs that are embedded in the bilayer and a drug that is encapsulated in the central aqueous compartment. The AuNPs in the liposomes can strongly absorb light energy and efficiently convert the absorbed energy to heat.

Temperature-dependent stability and DPPH scavenging activity of liposomal curcumin at pH 7.0.

This paper investigated the influences of temperature on the stability and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of curcumin encapsulated in liposome at pH 7.0. Liposomal curcumin showed higher stability and DPPH scavenging activity than free curcumin at 25°C.

Microstructure study of liposomes decorated by hydrophobic magnetic nanoparticles.

Magnetoliposomes, consisting of liposomes and magnetic nanoparticles (MNPs), have been tailored as very promising delivery vehicles in biotechnology and biomedicine applications. In this paper, liposomes with hydrophobic MNPs were prepared. The hydrophobic MNPs were successfully embedded in the lipid bilayer, which was proved by the results obtained from transmission electron microscope, atomic force microscope, differential scanning calorimetry and steady state fluorescence measurements.

Rhodamine 6G conjugated-quantum dots used for highly sensitive and selective ratiometric fluorescence sensor of glutathione.

Rhodamine 6G (R6G) and 3-mercaptopropionic acid (MPA) capped-CdTe quantum dots (QDs) were conjugated by electrostatic interactions in aqueous solution. The R6G-QDs conjugate was utilized as a photoluminescence (PL) ratiometric sensor for the detection of glutathione (GSH). In this method, intentional introduction of GSH destroyed the conjugation of R6G and QDs, and induced regular PL change of R6G-QDs conjugates due to the competitive chelation between GSH and MPA ligand on the surface of QDs.

A near-infrared-emitting CdTe/CdS core/shell quantum dots-based OFF-ON fluorescence sensor for highly selective and sensitive detection of Cd2+.

A near-infrared-emitting CdTe/CdS core/shell quantum dots (QDs)-based photoluminescence (PL) sensor was designed and applied for highly selective and sensitive detection of Cd(2+). This sensor was based on a PL "OFF-ON" mode. First, the addition of ammonium pyrrolidine dithiocarbamate (APDC) led to remarked PL quenching of QDs.

The effect of the spacer rigidity on the aggregation behavior of two ester-containing Gemini surfactants.

Two Gemini surfactants with very similar structure but different spacer rigidity, namely 1-dodecanaminium,N,N'-[[(2E)-1,4-dioxo-2-butene-1,4-diyl]bis(oxy-2,1-ethanediyl)]bis[N,N-dimethyl-,bromide] (12-fo-12) and 1-dodecanaminium, N,N'-[(1,4-dioxo-1,4-butanediyl)bis(oxy-2,1-ethanediyl)] bis[N,N-dimethyl-, bromide] (12-su-12), and their monomeric counterpart 1-dodecanaminium, N-[2-(acetyloxy)ethyl]-N,N-dimethyl-, bromide (DTAAB) were synthesized and their aggregation behavior in aqueous solutions was studied by measurements of surface tension, conductivity, isothermal titration calorimetry, dynamic light scattering, and transmission electron microscopy. It was found that the Krafft point of 12-fo-12 was 18.6°C, significantly higher than that of 12-su-12 (7.

Effects of curcumin concentration and temperature on the spectroscopic properties of liposomal curcumin.

The spectroscopic properties of liposomal curcumin in pH 7.0 sodium phosphate buffer were studied at various curcumin concentrations and temperatures. At 25 °C, liposomal curcumin exhibited much higher values than free curcumin in absorption maximum, fluorescence maximum, and fluorescence anisotropy.

Spectrometric study of AOT-hydrolysis reaction in water/AOT/isooctane microemulsions using phenolphthalein as a chemical probe.

The kinetics of the alkaline hydrolysis of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in water/AOT/isooctane microemulsions has been studied by monitoring the absorbance change of the phenolphthalein in the system with time. The apparent first-order rate constant k(obs) has been obtained and found to be dependent on both the molar ratio of water to AOT ω and the temperature. The dependences of k(obs) on ω have been analyzed by a pseudophase model which gives the true rate constants k(i) of the AOT-hydrolysis reaction on the interface and the partition coefficients K(wi) for the distribution of OH(-) between aqueous and interface pseudophases at various temperatures; the latter is almost independent of the temperature and ω.

Spectrometric study on the interaction of dodecyltrimethylammonium bromide with curcumin.

The interaction between dodecyltrimethylammonium bromide (DTAB) and curcumin has been studied in pH 5.0 sodium phosphate buffer using absorption and fluorescence measurements. With increasing DTAB concentration (C(DTAB)) from 0 to 20 mM, the absorption peak of curcumin at 430 nm, corresponding to the conjugated structure of curcumin, first weakens gradually into a shoulder but increases back into one peak with much higher absorption intensity.

Heat capacities and asymmetric criticality of coexistence curves for benzonitrile + alkanes and dimethyl carbonate + alkanes.

The critical behavior of isobaric heat capacities per unit volume for a series of critical binary solutions {benzonitrile + octane, or dodecane, or hexadecane} and {dimethyl carbonate + nonane, or decane, or dodecane} were studied. The corresponding exponent was obtained to be in consistent with the 3D-Ising value. The amplitudes in one-phase and two-phase regions were deduced, which were used to test some critical amplitude ratios.

Determination of the interaction enthalpy between microemulsion droplets by isothermal titration microcalorimetry.

A new experimental design for the measurement of the real heat of dilution of the microemulsion droplets by isothermal titration microcalorimetry (ITC) has been reported and used to study the interaction enthalpies of the droplets for the system of water/sodium bis(2-ethylhexyl)-sulfosuccinate (AOT)/toluene. The results are in good agreement with those determined from light-scattering experiments.

Study of the alkaline fading of phenolphthalein in microemulsions.

The reactions of the alkaline fading of phenolphthalein (PN) have been studied in water/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/isooctane microemulsions by monitoring the absorbance changes of PN in the system with the time and the results compared with those found for the same reactions in aqueous solutions. It was found that the values of the equilibrium constants and the forward reaction rate constants in the microemulsions were significantly larger than that in aqueous solutions and decreased with increasing the molar ratio of water to AOT (ω), except for that with low ω. The temperature dependence of the reaction rate constant was analyzed to obtain the values of free energy, enthalpy, and entropy of activation, which suggests the existence of an isokinetic relationship and a common mechanism for the reactions occurring in the microemulsions with different ω.

Photoinduced drug release from thermosensitive AuNPs-liposome using a AuNPs-switch.

A thermosensitive liposome with embedded AuNPs in a bilayer was prepared using supercritical CO(2). The AuNPs-liposome can absorb a certain wavelength light, convert optical energy into heat, induce phase transition, and release drug. The results show that drug release from the liposome is due to the photothermic effects inducing phase transition of the liposome rather than destruction of the liposome structure.

Light scattering and sum rules of three coexisting phases for quasiternary solutions near the tricritical point.

The upper critical temperatures (T(U)) and the lower critical temperatures (T(L)) were precisely determined for 11 quasiternary solutions of water +n-decane and +n-undecane +tert-butanol with various mass ratios of n-decane to n-undecane. Measurements of angular dependence of the scattered light intensity for each of the three liquid coexisting phases and each of the 11 solutions at the middle temperatures T(m)=(T(U)+T(L))/2 are reported. From the light scatting data, the zero-angle scattering intensities I(0) and the correlation lengths xi at T(m) in each of the phases were calculated and used to test the Griffiths sum rules.

Interactions and aggregations in aqueous and brine solutions of poly(diallydimethylammonium chloride)/sodium bis(2-ethylhexyl) sulfosuccinate.

The interactions between the anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and the polycation poly(diallydimethylammonium chloride) (PDDAC), the aggregations of AOT and PDDAC-bound AOT in PDDAC/AOT aqueous solutions, and the influence of salt on the interactions and aggregations have been studied by isothermal titration calorimetry (ITC), dynamic light scattering (DLS), and negative staining transmission electron microscopy (TEM). The adsorptions of AOT onto PDDAC and the formations of PDDAC-bound AOT micelles, free AOT micelles, and AOT vesicles were examined, and the corresponding critical concentrations were determined. Combining calculations of thermodynamic parameters with the above three experimental techniques, it was shown that the micellization of free AOT is driven by entropy gain, while the adsorption of AOT onto PDDAC and the micellization of PDDAC-bound AOT are driven by both enthalpy and entropy.

Tricritical phenomena in quasi-ternary mixtures of water + n-decane + n-undecane + tert-butanol.

Coexistence curves for the quasi-ternary system of water + n-decane + n-undecane + tert-butanol have been determined by measurements of the refractive index in three coexisting liquid phases. The binary mixtures of n-decane + n-undecane constructed the quasi-pure components in which the mass fraction beta of n-decane controls the approach to the tricritical point. The coexistence curves can be fitted to Scott's extended theory and can be extrapolated to a tricritical point at (44.