Phthalocyanine-Assembled "One-For-Two" Nanoparticles for Combined Photodynamic-Photothermal Therapy of Multidrug-Resistant Bacteria.

The treatment of diseases caused by drug-resistant bacterial infections urgently requires new types of broad-spectrum antimicrobial materials. Herein, we introduce a supramolecular self-assembly, NanoPcN, which realizes the combination of type I photodynamic activity and photothermal effects by modifying zinc(II) phthalocyanine with a 3-(dimethylamino) phenoxy group. Antibacterial experiments demonstrate that this "one-for-two" property endows NanoPcN with excellent antimicrobial efficacy, not only against Gram-positive and Gram-negative bacteria but also against multidrug-resistant bacteria. An ultralow concentration of NanoPcN (50 nM) almost completely inhibited the growth of methicillin-resistant Staphylococcus aureus upon 655 nm laser irradiation (0.5 W/cm2) for 2 min, and the antibacterial effect was significantly stronger than that of the known photosensitizers methylene blue and tetraphenylporphyrin tetrasulfonic acid. Thus, the construction of "one-for-two" materials through a simple molecular structure modification paves a feasible way for the development of effective broad-spectrum antibacterial agents.

Activity-Based NIR Enzyme Fluorescent Probes for the Diagnosis of Tumors and Image-Guided Surgery.

Near-infrared (NIR) activatable fluorescent probes have been considered to be the effective edge tools for the investigation of cell biology and disease diagnosis because of their outstanding advantages. Related genes involved in tumor genesis and progression regulate the overexpression of certain enzymes. Owing to the distinctive characteristics of quick reaction time and favorable pharmacokinetics, enzyme-reactive NIR optical probes have shown great potential in the diagnosis of tumorigenesis and in image-guided intraoperative surgeries with high signal-to-noise ratios. In this review, we mainly summarize the latest advancements in enzyme-reactive NIR fluorescent probes from design strategy to biomedical application. Specifically, some challenges and prospects in this field are presented at the end of the review, which will be beneficial to innovatively construct new multifunctional fluorescent probes and actively promote their clinical transformation in the future.

Optical and Fluorescent Dual Sensing of Aminoalcohols by in Situ Generation of BODIPY-like Chromophore.

A novel multifunctional aminophenylboronic acid connected to a diphenylketone gives both circular dichroism and fluorescence signals by in situ generation of a BODIPY-like chromophore in the presence of aminoalcohols. DFT calculations were used to understand the role of each functional group in the mechanism. This new sensor can distinguish different aminoalcohols and quantitatively indicate the concentration of the substrate, allowing for the convenient determination of the ee of racemic mixtures with a single probe.

An Activatable AIEgen Probe for High-Fidelity Monitoring of Overexpressed Tumor Enzyme Activity and Its Application to Surgical Tumor Excision.

Monitoring fluctuations in enzyme overexpression facilitates early tumor detection and excision. An AIEgen probe (DQM-ALP) for the imaging of alkaline phosphatase (ALP) activity was synthesized. The probe consists of a quinoline-malononitrile (QM) core decorated with hydrophilic phosphate groups as ALP-recognition units. The rapid liberation of DQM-OH aggregates in the presence of ALP resulted in aggregation-induced fluorescence. The up-regulation of ALP expression in tumor cells was imaged using DQM-ALP. The probe permeated into 3D cervical and liver tumor spheroids for imaging spatially heterogeneous ALP activity with high spatial resolution on a two-photon microscopy platform, providing the fluorescence-guided recognition of sub-millimeter tumorigenesis. DQM-ALP enabled differentiation between tumor and normal tissue ex vivo and in vivo, suggesting that the probe may serve as a powerful tool to assist surgeons during tumor resection.

Aminopeptidase N Activatable Fluorescent Probe for Tracking Metastatic Cancer and Image-Guided Surgery via in Situ Spraying.

The recurrence of malignant tumors is mostly caused by incompleted surgical resection. Especially, it is difficult for surgeons to detect and accurately remove metastatic tumors by predominantly using visual examination and palpation owing to the lack of effective means to specifically distinguish the boundary range between normal and tumor tissues. Thus, the development of activated fluorescent probe with superior tumor-to-normal (T/N) tissue ratios is particularly urgent in clinics. In view of CD13/aminopeptidase N (APN) regarded as a cancer-specific biomarker, mediating with progression, invasion, and migration of malignant tumor, herein, we reported an APN-responsive fluorescent probe YH-APN and demonstrated its application to distinguish cancer cells. Through in situ spraying manner, fluorescent superior tumor-to-normal (T/N) tissue ratios (subcutaneous transplantation tumor, 13.86; hepatic metastasis, 4.42 and 6.25; splenic metastasis, 4.99) were achieved. More importantly, we have demonstrated the ability to image metastasis tumor tissue less than 1 mm in diameter, highlighting the potential for this probe to be used as a tool in surgical resection. This research may spur the use of enzyme-activatable fluorescent probes for the progress of tumor diagnosis and image-guided surgery (IGS).