Search

Photodynamic therapy (PDT) could induce apoptosis by releasing reactive oxygen species (ROS) to treat tumor. Application of pH/light dual-activated nanoparticles could generate ROS in the acidic tumor microenvironment under 808 nm laser irradiation for precise treatment. L-arginine (L-Arg) triggered by ROS is an efficient nitric oxide (NO) donor for gas therapy. In addition, it is reported that peroxynitrite (ONOO-) produced by rapid reaction of ROS and NO could sensitize PDT and induce apoptosis for synergistic treatment. Herein, we developed the L-Arg loaded pH/light dual-activated PEGylated photosensitizer for self-assembly into nanoparticles named Rho-Arg. As measured by fluorescence spectroscopy, the pKa of Rho-Arg was 5.5, which is suitable for applying in the tumor microenvironment. The nanoplatform was firstly activated under the acidic condition of tumor, and then illuminated by 808 nm laser to controllably release ROS, and sequentially produced NO and ONOO-. In conclusion, the Rho-Arg nanoplatform may provide a promising synergistic therapy tool for tumor treatment. • "Dual lock" control enables effective precision treatment. • An excellent nitric oxide donor. • Photodynamic therapy combined with gas therapy for tumor suppression. • Quickly generate ONOO- sensitized photodynamic therapy. [ABSTRACT FROM AUTHOR]

The antibiotic therapy usually leads to the bacterial resistance, and the traditional photosensitizer was in "always on" state with damage to normal tissue. Fortunately, the activatable near-infrared photosensitizer has a high depth of tissue penetration, and can be specifically released with low side effect. Therefore, we designed and synthesized a penicillin G acylase (PGA) activable photosensitizer (NFh-PGA), which could be activated to produce NFh-OH. NFh-OH can product singlet oxygen (1O 2) under near-infrared light 730 nm excitation, and have an excellent antibacterial effect in vitro and in vivo. The probe accelerates the healing of bacterial infection wounds by near-infrared imaging guiding PDT. This work provides a strategy for the integrated design of diagnosis and treatment of bacterial infection. [Display omitted] ● A novel activable photosensitizer (NFh-PGA) by PGA was developed. ● The fluorescence and phototherapeutic ability of the probe kept the OFF state in the normal physiological environment. ● The NFh-PGA could be specifically activated and efficiently generating singlet oxygen (1O 2) under 730 nm laser. ● The NFh-PGA played an excellent bactericidal effect and accelerated the healing speed of infected wounds. [ABSTRACT FROM AUTHOR]

Carboxylesterase (CE) localized in the lumen of the endoplasmic reticulum (ER) hydrolyzes many prodrugs to exert therapeutic effect, such as anticoagulant clopidogrel and anticarcinogen irinotecan. Diabetes might induce CE to show a decreasing level, and thus impact the therapy effect. Hence, it is crucial to monitor the change of CE in treatment for diabetes for using drug rationally. We attempted to develop novel near-infrared fluorescent probes to detect CE activity in the ER with high selectivity and sensitivity in cells and in vivo , and help to guide the use of CE-related medications. Moreover, the excellent chemodosimeter (Hecy-1) could be applied in detecting CE level in tumor cells and LO2 cells. In glucose-induced CE changes of LO2 cells, Hecy-1 still showed admirable imaging ability. This research may further promote the study of intracellular fine biological activities of CE and the development of diabetes diagnosis. [Display omitted] • Hecy-1 could accurately distinguish carboxylesterase with excellent selectivity and sensitivity. • The probe could detect carboxylesterase level in diabetes group and treatment group for therapy effect. • A platform may further promote the study of intracellular biological activities and diabetes diagnosis. [ABSTRACT FROM AUTHOR]

Acetylcholinesterase (AChE) plays an important role in the process of chemotherapy drug-induced cell apoptosis and is also an apoptosis marker to diagnose disease and assay the effect of the drug. Thus, we designed and synthesized a novel near-infrared fluorescent probe (NFL-SF) to detect AChE activity, which contained near-infrared (NIR) fluorophore NFL-OH and 2-thienylformyl chloride as the recognition unit. The probe has higher specificity and sensitivity to AChE and excellent biocompatibility. With the increasing concentration of AChE, the probe displayed an enhanced fluorescence signal at 745 nm for 30 min, with the detection limit of 0.2 mU/mL. In addition, NFL-SF not only detected exogenous AChE activity, but also effectively monitored the endogenous AChE activity of chemotherapeutic drug-induced cell apoptosis in living cells. When the AChE activity was inhibited with donepezil, the fluorescence intensity of the NIR channel was significantly reduced. Notably, the probe was successfully applied to in vivo imaging of nude mice. We believe that this probe could provide a strategy for rapidly and visually monitoring AChE activity. • A novel AChE near-infrared fluorescent probe was designed based on the PET. • The probe has excellent selectivity and sensitivity towards AChE. • The probe NFL-SF could effectively monitor AChE activity in vitro and in vivo chemotherapeutic drugs-induced cell apoptosis. [ABSTRACT FROM AUTHOR]