It remains highly challenging to identify small molecule‐based photothermal agents with a high photothermal conversion efficiency (PTCE). Herein, we adopt a double bond‐based molecular motor concept to develop a new class of small photothermal agents to break the current design bottleneck. As the double‐bond is twisted by strong twisted intramolecular charge transfer (TICT) upon irradiation, the excited agents can deactivate non‐radiatively through the conical intersection (CI) of internal conversion, which is called photoinduced nonadiabatic decay. Such agents possess a high PTCE of 90.0 %, facilitating low‐temperature photothermal therapy in the presence of a heat shock protein 70 inhibitor. In addition, the behavior and mechanism of NIR laser‐triggered molecular motions for generating heat through the CI pathway have been further understood through theoretical and experimental evidence, providing a design principle for highly efficient photothermal and photoacoustic agents.
Photoacoustic agents have been of vital importance for improvingthe imaging contrast and reliability against selfinterference from endogenous substances.H erein, we synthesized as eries of thiadiazoloquinoxaline (TQ)-based semiconducting polymers (SPs) with ab road absorption covering from NIR-I to NIR-II regions.A mong them, the excited s-BDT-TQE, ar epeating unit of SPs,s hows al arge dihedral angle and narrowa diabatic energy as well as low radiative decay, attributing to its strongly electron-deficient ester-substituted TQ-segment. In addition, its more vigorous molecular motions trigger ah igher reorganization energy that further yields an efficient photoinduced nonradiative decay, which has been carefully examined and understood by theoretical calculation. Thus,B DT-TQE SP-cored nanoparticles with twisted intramolecular charge transfer (TICT) feature exhibit ah igh NIR-II photothermal conversion efficiency (61.6 %) and preferable PA tracking of in situ hepatic tumor growth for more than 20 days.This study highlights aunique strategy for constructing efficient NIR-II photoacoustic agents via TICTenhanced PNRD effect, advancing their applications for in vivo bioimaging.
Membrane fouling is one of the most important challenges faced in membrane ultrafiltration operations. The copolymers of polysulfone-graft-methyl acrylate were synthesized by homogeneous photo-initiated graft copolymerization. The variables affecting the degree of grafting, such as the time of UV (Ultraviolet-visible) irradiation and the concentrations of the methyl acrylate and photoinitiator, were investigated. The graft copolymer membranes were prepared by the phase inversion method. The chemical and morphological changes were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR/FT-IR), scanning electron microscopy, and water contact angles measurements. Results revealed that methyl acrylate groups were present on the membranes and the graft degree of methyl acrylate had remarkable effect on the performance of membranes. Pure water contact angle on the membrane surface decreases with the increase of methyl acrylate graft degree, which indicated that the hydrophilicity of graft copolymer membranes was improved. The permeation fluxes of pure water and bovine serum albumin solution were measured to evaluate the antifouling property of graft copolymer membranes, the results of which have shown an enhancement of antifouling property for graft copolymer membranes.
Bromodomain-containing protein 4 (BRD4) is a potential therapeutic target of skin squamous cell carcinoma (SCC). I-BET726 is a novel BRD4 inhibitor. Its potential effect in skin SCC cells was tested in the present study. We show that I-BET726 potently inhibited survival, proliferation, cell cycle progression, and migration in established (A431/SCC-9/SCC-12/SCC-13 lines) and primary human skin SCC cells. I-BET726 induced significant apoptosis activation in skin SCC cells. It was more efficient in inhibiting skin SCC cells than known BRD4 inhibitors (JQ1, CPI203, and AZD5153). I-BET726 not only downregulated BRD4-regulated proteins (c-Myc, Bcl-2, and cyclin D1), but also inhibited sphingosine kinase 1 (SphK1) and Akt signalings in SCC cells. Restoring Akt activation, by a constitutively active S473D mutant Akt1 ("caAkt1"), partially inhibited I-BET726-induced cytotoxicity in A431 cells. In vivo, I-BET726 oral administration potently inhibited A431 xenograft growth in severe combined immunodeficient mice. Downregulation of BRD4-regulated proteins and inhibition of the SphK1-Akt signaling were detected in I-BET726-treated A431 xenograft tumor tissues. Together, I-BET726 inhibits skin SCC cell growth in vitro and in vivo.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.