Photoresponsive aqueous foams with controllable stability from nonionic azobenzene surfactants in multiple-component systems.

The controllability of foam stability is a vital feature that allows for practical applications of foam systems. Light, as an external stimulus, offers unique opportunities to tune the foam stability in a non-invasive manner with high spatiotemporal precision. However, most of the reported photoresposive foams were generated from ionic type surfactants, limiting their applications in industrial complex systems with multiple components. Herein, we design and synthesize a series of nonionic azobenzene surfactants with different polyoxyethylene glycol (EO) chain lengths (BEO-n-Azo, n, referring to the EO chain length, is 14, 19 and 23, respectively) to prepare photoresponsive foams. Detailed insights into the effects of EO chain length on photoisomerization properties, surface tension, as well as foamability and controllable stability of photoresponsive foams are presented. The results demonstrate that photoresposive foams are generated not only from single-component solutions of BEO-n-Azo, but also from multiple-component complex systems doped with BEO-n-Azo, providing a promising strategy to broaden applications of photoresponsive foams in industrial processes.

A clinical application of dynamic contrast-enhanced CT (DCE-CT) in patients with variously differentiated breast ductal carcinoma.

PURPOSE: To explore the hemodynamic characteristics of variously differentiated breast ductal carcinoma (BDC) using the dynamic contrast-enhanced CT (DCE-CT) based CT perfusion imaging (CTPI), including the specific perfusion parameter values, and to identify potential clinical applications in the cell differentiation degree of BDC. MATERIALS AND METHODS: Forty patients with breast ductal carcinoma confirmed by needle puncture biopsy were studied prospectively using CTPI on a 64-slice spiral CT scanner. The acquired volume data were used for calculations, mapping, and analysis by using a tumor perfusion protocol in the CT perfusion software package to measure 4 parameters namely, blood flow (BF), blood volume (BV), mean transit time (MTT), and the permeability surface (PS) area product. The different differentiated BDC with CT perfusion parameters were divided into 3 groups of high, moderate and poor differentiation. The comparison among these groups were then made using statistical data analysis software. RESULTS: The patients were categorized into three groups of 12, 13, and 15 highly, moderately and poorly differentiated ductal carcinoma cases, respectively. Comparing the perfusion parameters values of the three groups, BF, BV, and PS values increased from highly to poorly differentiated BDC cases. Differences between the highly and moderately or poorly differentiated groups were all statistically significant for BF, BV, and PS values (p < 0.05), while MTT value showed no statistical difference among the three groups (p > 0.05). CONCLUSION: CTPI is a functional imaging technology from the perspective of hemodynamics with potential clinical applications. Three parameters of BF, BV and PS values have potential to serve as indicators of the cell differentiation degree of the breast ductal carcinoma.

A simple hydrogen peroxide-activatable Bodipy for tumor imaging and type I/II photodynamic therapy.

Tumor microenvironment-activatable photosensitizers have gained significant attention for cancer theranostics. Considering the hypoxic environment of solid tumors, activatable phototheranostic agents with type I PDT are desired to obtain improved cancer treatment efficiency. Herein, we report a simple, effective and multifunctional Bodipy photosensitizer for tumor imaging and type I/II photodynamic therapy. The photosensitizer featuring a methylphenylboronic acid pinacol ester group at the meso-position of Bodipy specifically responds to tumor-abundant H2O2. Its photophysical properties were characterized using steady-state and time-resolved transient optical spectroscopies. The fluorescence (ΦF = 0.09%) and singlet oxygen efficacy (ΦΔ = 10.2%) of the Bodipy units were suppressed in the caged dyads but significantly enhanced (ΦF = 0.72%, ΦΔ = 20.3%) upon H2O2 activation. Fluorescence emission spectroscopy and continuous wave electron paramagnetic resonance (EPR) spectroscopy confirmed that the Bodipy photosensitizer generates reactive oxygen species (ROS) via both electron transfer-mediated type I and energy transfer-mediated type II mechanisms. In vitro experiments demonstrated rapid internalization into tumor cells, enhanced brightness stimulated by tumor microenvironments, and tumor cell death (phototoxicity, IC50 = 0.5 µM). In vivo fluorescence imaging indicated preferential accumulation of this Bodipy photosensitizer in tumor sites, followed by decaging by tumor-abundant H2O2, further elevating the signal-to-background ratio (SBR) of imaging. Besides outstanding performance in tumor imaging, a prominent inhibition of tumor growth was observed. Given its simple molecular skeleton, this Bodipy photosensitizer is a competitive candidate for cancer theranostics.

The Electrical-Triggered High Contrast and Reversible Color-Changing Janus Fabric Based on Double Side Coating.

A sensitive electro-thermochromic Janus fabric driven by voltage is demonstrated via a facial double side coating. The graphene forms a conductive layer that allows Joule heating to supply the thermal resource for the electro-thermochromic behavior of polyester fabric. The thermochromic dye with reversible color-changing property is coated on the opposite side of the graphene layer. The color of electro-thermochromic Janus fabric changes from blue to white with a gradual heating that exceeded 45 °C at the applied voltage of 10 V. The switching rate of color is rapid with the increase of temperature from the room temperature to above 45 °C in 8 s, resulting from the superior resistive heating of the graphene. The electrical conductivity of the electro-thermochromic Janus fabric is not disturbed once undergoing a bending angle range from 30° to 150° and the temperature remains stable after 1000 bending cycles which clearly indicates the excellent flexibility of the fabric. The steady signal in the heating/cooling curve is observed after 500 cycles, pointing out the outstanding durability of the electro-thermochromic Janus fabric under the supplied voltage. It is realizable that the color of electro-thermochromic Janus fabric is triggered accurately by varying the supplied voltage. The simplicity of this design makes it attractive for the application of flexible electro-thermochromic textile, such as active visual camouflage, personal thermal management, and information displays.