Recent advances of versatile fluorophores for multifunctional biomedical imaging in the NIR-II region.

Fluorescence imaging in the second near-infrared region (NIR-II, 1000-1700 nm) enables high-resolution visualization of deep-tissue biological architecture and physiopathological events, due to the reduced light absorption, scattering and tissue autofluorescence. Numerous versatile NIR-II fluorescent probes have been reported over the past decades. In this review, we first provide a detailed account of the advantages of fluorescence imaging in the NIR-II region.

Nanocrystals for Deep-Tissue Luminescence Imaging in the Near-Infrared Region.

imaging technologies have emerged as a powerful tool for both fundamental research and clinical practice. In particular, luminescence imaging in the tissue-transparent near-infrared (NIR, 700-1700 nm) region offers tremendous potential for visualizing biological architectures and pathophysiological events in living subjects with deep tissue penetration and high imaging contrast owing to the reduced light-tissue interactions of absorption, scattering, and autofluorescence. The distinctive quantum effects of nanocrystals have been harnessed to achieve exceptional photophysical properties, establishing them as a promising category of luminescent probes.

Small Molecular Fluorescent Probes: Application Progress of Specific Bacteria Detection and Antibacterial Phototherapy.

Bacterial infection is one of the leading causes of death worldwide and is easy to cause large-scale diseases. It is an urgent need to develop effective methods for the specific detection and treatment of bacterial infections. Recently, small molecular fluorescent probes, bridging the capability of imaging detection and sterilization, have attracted increasing attention.

High-fidelity ATP imaging an isothermal cascade catalytic amplifier.

Artificial catalytic DNA circuits that can identify, transduce and amplify the biomolecule of interest have supplemented a powerful toolkit for visualizing various biomolecules in cancer cells. However, the non-specific response in normal tissues and the low abundance of analytes hamper their extensive biosensing and biomedicine applications. Herein, by combining tumor-responsive MnO nanoparticles with a specific stimuli-activated cascade DNA amplifier, we propose a multiply guaranteed and amplified ATP-sensing platform the successive cancer-selective probe exposure and stimulation procedures.

Programmable Assembly of Multivalent DNA-Protein Superstructures for Tumor Imaging and Targeted Therapy.

Programmable DNA materials hold great potential in biochemical and biomedical researches, yet the complicated synthesis, and the low stability and targeting efficacy in complex biological milieu limit their clinical translations. Here we show a one-pot assembly of DNA-protein superstructures as drug vehicles with specifically high affinity and stability for targeted therapy. This is achieved by biomimetic assembly of programmable polymer DNA wire into densely packed DNA nanosphere with an alkaline protein, protamine.

Visualization of Vaccine Dynamics with Quantum Dots for Immunotherapy.

The direct visualization of vaccine fate is important to investigate its immunoactivation process to elucidate the detailed molecular reaction process at single-molecular level. Yet, visualization of the spatiotemporal trafficking of vaccines remains poorly explored. Here, we show that quantum dot (QD) nanomaterials allow for monitoring vaccine dynamics and for amplified immune response.

Precision photothermal therapy and photoacoustic imaging by activatable thermoplasmonics.

Phototherapy holds great promise for disease treatment; however, traditional "always-on" photoagents have been restricted to clinical translation due to their nonspecific response and side effects on normal tissues. Here, we show a tumor microenvironment activated photothermal and photoacoustic agent as an activatable prodrug and probe that allows precise cancer diagnosis and treatment. Such an revitalized therapeutic and contrast agent is achieved controllable plasmonic heating for thermoplasmonic activation.

Precision Spherical Nucleic Acids Enable Sensitive FEN1 Imaging and Controllable Drug Delivery for Cancer-Specific Therapy.

Accurate diagnosis and targeted therapy are essential to precision theranostics. However, nonspecific response of theranostic agents in healthy tissues impedes their practical applications. Here, we design an activatable DNA nanosphere for specifically in situ sensing of cancer biomarker flap endonuclease 1 (FEN1) and spatiotemporally modulating drug release.

Multiple Blockades of the HGF/Met Signaling Pathway for Metastasis Suppression Using Nanoinhibitors.

The hepatocyte growth factor (HGF)/HGF receptor (Met) signaling pathway serves as a potential target for preventing tumor metastasis yet poorly explored. Here, we developed a Met-targeted nanoinhibitor to efficiently suppress metastasis via a multiple blockading HGF/Met signaling pathway. A biocompatible nanovector comprising multiple type of inhibitors enables interrupting extracellular domain dimerization and intracellular domain phosphorylation simultaneously.

Regulation of redox balance using a biocompatible nanoplatform enhances phototherapy efficacy and suppresses tumor metastasis.

Many cancer treatments including photodynamic therapy (PDT) utilize reactive oxygen species (ROS) to kill tumor cells. However, elevated antioxidant defense systems in cancer cells result in resistance to the therapy involving ROS. Here we describe a highly effective phototherapy through regulation of redox homeostasis with a biocompatible and versatile nanotherapeutic to inhibit tumor growth and metastasis.

Quantum dot-pulsed dendritic cell vaccines plus macrophage polarization for amplified cancer immunotherapy.

Dendritic cell (DC) vaccines hold great potential in cancer immunotherapy, but the suboptimal design of DC vaccines and the immunosuppressive tumor microenvironment largely impair their anti-tumor efficacy. Here, quantum dot (QD) pulsed-DC vaccines integrating with tumor-associated macrophage polarization are developed for amplified anti-tumor immunity. Semiconductor QDs are engineered with diverse functions to act as fluorescence nanoprobes, immunomodulatory adjuvants, and nanocarriers to load tumor antigens and Toll-like receptor 9 agonists.

Programming DNA Nanoassembly for Enhanced Photodynamic Therapy.

Photodynamic therapy (PDT) has extraordinary promise for the treatment of many cancers. However, its clinical progress is impaired by the intrinsic hypoxic tumor microenvironment that limits PDT efficacy and the safety concern associated with biological specificity of photosensitizers or vehicles. Now it is demonstrated that rationally designed DNA nanosponges can load and delivery photosensitizer effectively, target tumor precisely, and relieve hypoxia-associated resistance remarkably to enhance the efficacy of PDT.

Highly sensitive glutathione assay and intracellular imaging with functionalized semiconductor quantum dots.

Glutathione (GSH) plays a vital role in biological systems and is associated with human pathology. The engineering of semiconductor quantum dots (QDs) as fluorescent probes for GSH sensing and bioimaging is a potential yet rarely reported approach. Herein, we report the in situ growth of manganese dioxide nanosheets (MnO2) on silica-coated semiconductor quantum dots (QD@SiO2), to prepare a stable and biocompatible fluorescent nanoprobe (QD@SiO2-MnO2) for the selective and sensitive detection of GSH.

Stimuli-responsive multifunctional metal-organic framework nanoparticles for enhanced chemo-photothermal therapy.

Construction of stimuli-responsive multifunctional nanoparticles is critical for nanotherapeutic delivery. Though metal-organic frameworks (MOFs) have been emerged as promising delivery vehicles, the therapeutic efficacy of MOFs in cancer treatment is limited by the lack of a general approach for the preparation of stimuli-responsive multifunctional MOFs. We show that the combination of a versatile coating material polydopamine with MOFs enables facile integration of different functional therapeutics, obtaining stimuli-responsive multifunctional MOFs with extensive photothermal efficiency and outstanding capability to abrogate tumors by chemo-photothermal therapy.

Plasmonic and Photothermal Immunoassay via Enzyme-Triggered Crystal Growth on Gold Nanostars.

Immunoassay is commonly used for the detection of disease biomarkers, but advanced instruments and professional operating are often needed with current techniques. The facile readout strategy for immunoassay is mainly limited to the gold nanoparticles-based colorimetric detection. Here, we show that photothermal nanoparticles can be applied for biosensing and immunoassay with temperature as readout.

Interfacial engineering of carbon dots with benzenediboronic acid for fluorescent biosensing.

Glucose assay is highly important in clinical diagnostics of diabetes. Herein, we engineered the surface of carbon dots by complexation with functional ligand and constructed fluorescent biosensors for the detection of hydrogen peroxide and glucose. In this study, benzenediboronic acid is conjugated to the surface of citric acid-derived carbon dots through formation of boronate complexes with the nanoparticles.