Advanced Fluorescence Imaging Technology in the Near-Infrared-II Window for Biomedical Applications

Synthesis and photoluminescent characterization of ceramic phosphors Li2MgGeO4:Ln3+ (Ln3+ = Pr3+ or Tm3+) under different excitation wavelengths

In the current work, germanate phosphors Li₂MgGeO₄:Ln³⁺ (Ln = Pr, Tm) have been synthesized and then investigated using luminescence spectroscopy. The X-ray diffraction analysis demonstrate that ceramic compounds Li₂MgGeO₄ containing Pr³⁺ and Tm³⁺ ions crystallize in a monoclinic crystal lattice. Luminescence properties of Pr³⁺ and Tm³⁺ ions have been examined under different excitation wavelengths. The most intense blue emission band related to the ¹D₂ → ³F₄ transition of Tm³⁺ is overlaps well with broad band located near 500 nm, which is assigned to F-type centers. These effects are not evident for Pr³⁺ ions. Ceramic phosphors Li₂MgGeO₄:Ln³⁺ (Ln = Pr, Tm) are characterized based on measurements of the excitation/emission spectra and their decays. The experimental results indicate that germanate ceramics Li₂MgGeO₄ doped with trivalent rare earth ions can be applied as inorganic phosphors emitting orange (Pr³⁺) or blue (Tm³⁺) light.

Single Atom-Engineered NIR-II Gold Clusters with Ultrahigh Brightness and Stability for Acute Kidney Injury

Near-infrared-II (NIR-II) imaging has shown great potential for monitoring the pathological progression and deep tissue imaging but is limited to present unmet NIR-II agent. Present fluorophores show a promising prospect for NIR-II imaging, but brightness and photostability are still highly challenging during real-time monitoring. In this work, atom-engineered NIR-II Au₂₄ Cd₁  clusters with ultrahigh brightness, stability, and photostability are developed via single atomic Cd doping. Single atom Cd substitutions contribute to Cd 4d state in HOMO and redistribution of energy level near the gap, exhibiting 56-fold fluorescence enhancement of Au₂₄ Cd₁  clusters. Meanwhile, single atomic Cd reinforces CdAu bond energy, formation energy, and stabilized cluster structure, leading to persistent stability for up to 1 month without decay, as well as excellent photostability of 1 h without photobleaching, much longer than clinically approved indocyanine green (<5 min). In vivo imaging shows gold clusters can monitor acute kidney injury (AKI) even after 72 h of injury, enabling evaluating progression at a very long window. Meanwhile, the bioactive gold clusters can alleviate AKI-induced oxidative stress damage and acute neuroinflammation. Single atom-engineered gold clusters exhibit molecular tracking and diagnostic prospect in kidney-related diseases.

Renal-Clearable Probe with Water Solubility and Photostability for Biomarker-Activatable Detection of Acute Kidney Injuries via NIR-II Fluorescence and Optoacoustic Imaging

Acute kidney injuries (AKI) have serious short-term or long-term complications with high morbidity and mortality rate, thus posing great health threats. Developing high-performance NIR-II probes for noninvasive in situ detection of AKI via NIR-II fluorescent and optoacoustic dual-mode imaging is of great significance. Yet NIR-II chromophores often feature long conjugation and hydrophobicity, which prevent them from being renal clearable, thus limiting their applications in the detection and imaging of kidney diseases. To fully exploit the advantageous features of heptamethine cyanine dye, while overcoming its relatively poor photostability, and to strive to design a NIR-II probe for the detection and imaging of AKI with dual-mode imaging, herein, we have developed the probe PEG3-HC-PB, which is renal clearable, water soluble, and biomarker activatable and has good photostability. As for the probe, its fluorescence (900-1200 nm) is quenched due to the existence of the electron-pulling phenylboronic group (responsive element), and it exhibits weak absorption with a peak at 830 nm. Meanwhile, in the presence of the overexpressed H₂O₂ in the renal region in the case of AKI, the phenylboronic group is converted to the phenylhydroxy group, which enhances NIR-II fluorescent emission (900-1200 nm) and absorption (600-900 nm) and eventually produces conspicuous optoacoustic signals and NIR-II fluorescent emission for imaging. This probe enables detection of contrast-agent-induced and ischemia/reperfusion-induced AKI in mice using real-time 3D-MSOT and NIR-II fluorescent dual-mode imaging via response to the biomarker H₂O₂. Hence, this probe can be used as a practicable tool for detecting AKI; additionally, its design strategy could provide insight into the design of other large-conjugation NIR-II probes with multifarious biological applications.

Redox ferrocenylseleno compounds modulate longitudinal and transverse relaxation times of FNPs-Gd MRI contrast agents for multimodal imaging and photo-Fenton therapy

Developing a feasible way to feature longitudinal (T₁) and transverse (T₂) relaxation performance of contrast agents for magnetic resonance imaging (MRI) is important in cancer diagnosis and therapy. Improved accessibility to water molecule is essential for accelerating the relaxation rate of water protons around the contrast agents. Ferrocenyl compounds have reversible redox property for modulating the hydrophobicity/hydrophilicity of assemblies. Thus, they could be the candidates that can change water accessibility to the contrast agent surface. Herein, we incorporated ferrocenylseleno compound (FcSe) with Gd³⁺-based paramagnetic UCNPs, to obtain FNPs-Gd nanocomposites using T₁-T₂ MR/UCL trimodal imaging and simultaneous photo-Fenton therapy. When the surface of NaGdF₄:Yb,Tm UNCPs was ligated by FcSe, the hydrogen bonding between hydrophilic selenium and surrounding water molecules accelerated their proton exchange to initially endow FNPs-Gd with high r₁ relaxivity. Then, hydrogen nuclei from FcSe disrupted the homogeneity of the magnetic field around the water molecules. This facilitated T₂ relaxation and resulted in enhanced r₂ relaxivity. Notably, upon the near-infrared light-promoted Fenton-like reaction in the tumor microenvironment, hydrophobic ferrocene(II) of FcSe was oxidized into hydrophilic ferrocenium(III), which further increased the relaxation rate of water protons to obtain r₁ = 1.90±0.12 mM^-1 s^-1 and r₂ = 12.80±0.60 mM^-1 s^-1. With an ideal relaxivity ratio (r₂/r₁) of 6.74, FNPs-Gd exhibited high contrast potential of T₁-T₂ dual-mode MRI in vitro and in vivo. This work confirms that ferrocene and selenium are effective boosters that enhance the T₁-T₂ relaxivities of MRI contrast agents, which could provide a new strategy for multimodal imaging-guided photo-Fenton therapy of tumors. STATEMENT OF SIGNIFICANCE: T₁-T₂ dual-mode MRI nanoplatform with tumor-microenvironment-responsive features has been an attractive prospect. Herein, we designed redox ferrocenylseleno compound (FcSe) modified paramagnetic Gd³⁺-based UCNPs, to modulate T₁-T₂ relaxation time for multimodal imaging and H₂O₂-responsive photo-Fenton therapy. Selenium-hydrogen bond of FcSe with surrounding water molecules facilitated water accessibility for fast T₁ relaxation. Hydrogen nucleus in FcSe perturbed the phase coherence of water molecules in an inhomogeneous magnetic field and thus accelerated T₂ relaxation. In tumor microenvironment, FcSe was oxidized into hydrophilic ferrocenium via NIR light-promoted Fenton-like reaction which further increased both T₁ and T₂ relaxation rates; Meanwhile, the released toxic •OH performed on-demand cancer therapy. This work confirms that FcSe is an effective redox mediate for multimodal imaging-guided cancer therapy.

Recent Progress in NIR-II Fluorescence Imaging-guided Drug Delivery for Cancer Theranostics

Fluorescence imaging in the second near-infrared window (NIR-II) has become a prevalent choice owing to its appealing advantages like deep penetration depth, low autofluorescence, decent spatiotemporal resolution, and a high signal-to-background ratio. This would expedite the innovation of NIR-II imaging-guided drug delivery (IGDD) paradigms for the improvement of the prognosis of patients with tumors. This work systematically reviews the recent progress of such NIR-II IGDD-mediated cancer therapeutics and collectively brings its essence to the readers. Special care has been taken to assess their performances based on their design approach, such as enhancing their drug loading and triggering release, designing intrinsic and extrinsic fluorophores, and/ or overcoming biological barriers. Besides, the state-of-the-art NIR-II IGDD platforms for different therapies like chemo-, photodynamic, photothermal, chemodynamic, immuno-, ion channel, gas-therapies, and multiple functions such as stimulus-responsive imaging and therapy, and monitoring of drug release and therapeutic response, have been updated. In addition, for boosting theranostic outcomes and clinical translation, the innovation directions of NIR-II IGDD platforms are summarized, including renal-clearable, biodegradable, sub-cellular targeting, and/or afterglow, chemiluminescence, X-ray excitable NIR-IGDD, and even cell therapy. This review will propel new directions for safe and efficient NIR-II fluorescence-mediated anticancer drug delivery.

In situ orderly self-assembly strategy affording NIR-II-J-aggregates for in vivo imaging and surgical navigation

J-aggregation, an effective strategy to extend wavelength, has been considered as a promising method for constructing NIR-II fluorophores. However, due to weak intermolecular interactions, conventional J-aggregates are easily decomposed into monomers in the biological environment. Although adding external carriers could help conventional J-aggregates stabilize, such methods still suffer from high-concentration dependence and are unsuitable for activatable probes design. Besides, these carriers-assisted nanoparticles are risky of disassembly in lipophilic environment. Herein, by fusing the precipitated dye (HPQ) which has orderly self-assembly structure, onto simple hemi-cyanine conjugated system, we construct a series of activatable, high-stability NIR-II-J-aggregates which overcome conventional J-aggregates carrier's dependence and could in situ self-assembly in vivo. Further, we employ the NIR-II-J-aggregates probe HPQ-Zzh-B to achieve the long-term in situ imaging of tumor and precise tumor resection by NIR-II imaging navigation for reducing lung metastasis. We believe this strategy will advance the development of controllable NIR-II-J-aggregates and precise bioimaging in vivo.

Tracking tumor heterogeneity and progression with near-infrared II fluorophores

Heterogeneous cells are the main feature of tumors with unique genetic and phenotypic characteristics, which can stimulate differentially the progression, metastasis, and drug resistance. Importantly, heterogeneity is pervasive in human malignant tumors, and identification of the degree of tumor heterogeneity in individual tumors and progression is a critical task for tumor treatment. However, current medical tests cannot meet these needs; in particular, the need for noninvasive visualization of single-cell heterogeneity. Near-infrared II (NIR-II, 1000-1700 nm) imaging exhibits an exciting prospect for non-invasive monitoring due to the high temporal-spatial resolution. More importantly, NIR-II imaging displays more extended tissue penetration depths and reduced tissue backgrounds because of the significantly lower photon scattering and tissue autofluorescence than traditional the near-infrared I (NIR-I) imaging. In this review, we summarize systematically the advances made in NIR-II in tumor imaging, especially in the detection of tumor heterogeneity and progression as well as in tumor treatment. As a non-invasive visual inspection modality, NIR-II imaging shows promising prospects for understanding the differences in tumor heterogeneity and progression and is envisioned to have the potential to be used clinically.

An "AND" Molecular Logic Gate as a Super-Enhancers for De Novo Designing Activatable Probe and Its Application in Atherosclerosis Imaging

Developing activatable fluorescent probes with superlative fluorescence enhancement factor (F/F0 ) to improve the signal-to-noise (S/N) ratio is still an urgent issue. "AND" molecular logic gates are emerging as a useful tool for enhanced probes selectivity and accuracy. Here, an "AND" logic gate is developed as super-enhancers for designing activatable probes with huge F/F0 and S/N ratio. It utilizes lipid-droplets (LDs) as controllable background input and sets the target analyte as variable input. The fluorescence is tremendously quenching due to double locking, thus an extreme F/F0 ratio of target analyte is obtained. Importantly, this probe can transfer to LDs after a response occurs. The target analyte can be directly visualized through the spatial location without a control group. Accordingly, a peroxynitrite (ONOO- ) activatable probe (CNP2-B) is de novo designed. The F/F0 of CNP2-B achieves 2600 after reacting with ONOO- . Furthermore, CNP2-B can transfer from mitochondria to lipid droplets after being activated. The higher selectivity and S/N ratio of CNP2-B are obtained than commercial probe 3'-(p-hydroxyphenyl) fluorescein (HPFin vitro and in vivo. Therefore, the atherosclerotic plaques at mouse models are delineated clearly after administration with in situ CNP2-B probe gel. Such input controllable "AND" logic gate is envisioned to execute more imaging tasks.

Peptide-mediated Aqueous Synthesis of NIR-II Emitting Ag2 S Quantum Dots for Rapid Photocatalytic Bacteria Disinfection

Pathogenic microorganisms in the environment are a great threat to global human health. The development of disinfection method with rapid and effective antibacterial properties is urgently needed. In this study, a biomimetic silver binding peptide AgBP2 was introduced to develop a facile synthesis of biocompatible Ag₂ S quantum dots (QDs). The AgBP2 capped Ag₂ S QDs exhibited excellent fluorescent emission in the second near-infrared (NIR-II) window, with physical stability and photostability in the aqueous phase. Under 808 nm NIR laser irradiation, AgBP2-Ag₂ S QDs can serve not only as a photothermal agent to realize NIR photothermal conversion but also as a photocatalyst to generate reactive oxygen species (ROS). The obtained AgBP2-Ag₂ S QDs achieved a highly effective disinfection efficacy of 99.06 % against Escherichia coli within 25 min of NIR irradiation, which was ascribed to the synergistic effects of photogenerated ROS during photocatalysis and hyperthermia. Our work demonstrated a promising strategy for efficient bacterial disinfection.

Biomimetic Approach to Promote Cellular Uptake and Enhance Photoacoustic Properties of Tumor-Seeking Dyes

The attachment of glucose to drugs and imaging agents enables cancer cell targeting via interactions with GLUT1 overexpressed on the cell surface. While an added benefit of this modification is the solubilizing effect of carbohydrates, in the context of imaging agents, aqueous solubility does not guarantee decreased π-stacking or aggregation. The resulting broadening of the absorbance spectrum is a detriment to photoacoustic (PA) imaging since the signal intensity, accuracy, and image quality all rely on reliable spectral unmixing. To address this major limitation and further enhance the tumor-targeting ability of imaging agents, we have taken a biomimetic approach to design a multivalent glucose moiety (mvGlu). We showcase the utility of this new group by developing aza-BODIPY-based contrast agents boasting a significant PA signal enhancement greater than 11-fold after spectral unmixing. Moreover, when applied to targeting cancer cells, effective staining could be achieved with ultra-low dye concentrations (50 nM) and compared to a non-targeted analogue, the signal intensity was >1000-fold higher. Lastly, we employed the mvGlu technology to develop a logic-gated acoustogenic probe to detect intratumoral copper (i.e., Cu(I)), which is an emerging cancer biomarker, in a murine model of breast cancer. This exciting application was not possible using other acoustogenic probes previously developed for copper sensing.

Dynamic 3D imaging of cerebral blood flow in awake mice using self-supervised-learning-enhanced optical coherence Doppler tomography

Cerebral blood flow (CBF) is widely used to assess brain function. However, most preclinical CBF studies have been performed under anesthesia, which confounds findings. High spatiotemporal-resolution CBF imaging of awake animals is challenging due to motion artifacts and background noise, particularly for Doppler-based flow imaging. Here, we report ultrahigh-resolution optical coherence Doppler tomography (µODT) for 3D imaging of CBF velocity (CBFv) dynamics in awake mice by developing self-supervised deep-learning for effective image denoising and motion-artifact removal. We compare cortical CBFv in awake vs. anesthetized mice and their dynamic responses in arteriolar, venular and capillary networks to acute cocaine (1 mg/kg, i.v.), a highly addictive drug associated with neurovascular toxicity. Compared with awake, isoflurane (2-2.5%) induces vasodilation and increases CBFv within 2-4 min, whereas dexmedetomidine (0.025 mg/kg, i.p.) does not change vessel diameters nor flow. Acute cocaine decreases CBFv to the same extent in dexmedetomidine and awake states, whereas decreases are larger under isoflurane, suggesting that isoflurane-induced vasodilation might have facilitated detection of cocaine-induced vasoconstriction. Awake mice after chronic cocaine show severe vasoconstriction, CBFv decreases and vascular adaptations with extended diving arteriolar/venular vessels that prioritize blood supply to deeper cortical capillaries. The 3D imaging platform we present provides a powerful tool to study dynamic changes in vessel diameters and morphology alongside CBFv networks in the brain of awake animals that can advance our understanding of the effects of drugs and disease conditions (ischemia, tumors, wound healing).

Glutathione-Activated Emission of Ultrasmall Gold Nanoparticles in the Second Near-Infrared Window for Imaging of Early Kidney Injury

Biomarker-activatable luminescent probes with high sensitivity and specificity show great promise in advanced bioimaging applications. However, the lack of stable biomarkers at an early stage is currently a major obstacle for sensitive early disease imaging. Herein, we develop a facile in vivo ligand exchange strategy to achieve renal-clearable activatable luminescent gold nanoparticles (AuNPs), which are independent of biomarkers for sensitive and long-time imaging of early kidney injury. Significantly activated emission in the second near-infrared region (∼1026 nm) is realized from the ligand exchange of triphenylphosphine-3,3',3″-trisulfonic acid (TPPTS)-coated AuNPs (∼1.4 nm, TPPTS-AuNPs) with quantitative amounts of glutathione (GSH). The abundant GSH in cells, particularly in liver sinusoids, is then demonstrated successfully to activate the emission of TPPTS-AuNPs with an extremely low background for both cell imaging and in vivo visualization of visceral organs (e.g., liver and kidneys). In addition, the in vivo GSH-exchanged TPPTS-AuNPs show enhanced interactions with acidic renal tubular epithelial cells, resulting in sensitive (contrast index, ∼3.9) and long-time (>6.5 h) noninvasive monitoring of acidosis-induced early kidney injury. This facile ligand exchange strategy opens new possibilities for designing activatable luminescent probes independent of biomarkers for earlier disease diagnosis and treatment.

Maximal emission beyond 1200 nm dicyanovinyl-functionalized squaraine for in vivo vascular imaging

The first maximum emission wavelength beyond 1200 nm acceptor-substituted squaraine fluorophore with ultra-high brightness and photostability has been developed. It can be co-assembled with bovine serum albumin to form an excellent biocompatible dye-protein nanocomplex with significant fluorescence enhancement for high-resolution vascular imaging.

Multifunctional Layered Double Hydroxides for Drug Delivery and Imaging

Two-dimensional nanomaterials, particularly layered double hydroxides (LDHs), have been widely applied in the biomedical field owing to their biocompatibility, biodegradability, controllable drug release/loading ability, and enhanced cellular permeability. Since the first study analyzing intercalative LDHs in 1999, numerous studies have investigated their biomedical applications, including drug delivery and imaging; recent research has focused on the design and development of multifunctional LDHs. This review summarizes the synthetic strategies and in-vivo and in-vitro therapeutic actions and targeting properties of single-function LDH-based nanohybrids and recently reported (from 2019 to 2023) multifunctional systems developed for drug delivery and/or bio-imaging.

1,4-Bisvinylbenzene-Bridged BODIPY Dimers for Fluorescence Imaging in the Second Near-Infrared Window

Herein, we report a class of 1,4-bisvinylbenzene-bridged BODIPY dimers with fluorescence emission in the second near-infrared window (NIR-II, 1000-1700 nm). These dyes show excellent NIR-II fluorescence properties and can be easily functionalized to achieve good water-solubility or tumor-targeting ability. In vivo imaging results demonstrate that these dyes have high resolution and deep-penetration NIR-II imaging ability, which enable them to be used as promising NIR-II imaging agents.

NIR-II fluorescent nanoprobe-labeled lateral flow biosensing platform: A high-performance point-of-care testing for carcinoembryonic antigen

Fluorescent lateral flow immunoassay (LFA) is one of the most common analytical platforms for point-of-care testing (POCT), which is capable of facile and early screening of biomarkers. Notably, fluorescent probes play a decisive role in analytical performances of LFA. Herein, we report a novel LFA based on the rare earth doped nanoparticles (RENPs) emitting in the second near-infrared (NIR-II) window for the detection of biomarkers, such as carcinoembryonic antigen (CEA). Benefiting from the dual fluorescent emission at NIR-II window, strong fluorescent penetration, low autofluorescence and excellent photostability of RENPs, this proposed NIR-II LFA displays a good linear relationship ranging from 1 to 320 ng mL^-1. The detection limit is as low as 0.37 ng mL^-1, which is of 13.5 times lower than the clinical cutoff value. Overall, NIR-II LFA biosensing platform based RENPs not only exhibits high sensitivity, accuracy and specificity, but also have characteristics of rapidity, simplicity and low cost. It holds high potential for early diagnosis of tumor biomarkers in POCT.

Ultrasensitive Urinary Diagnosis of Organ Injuries Using Time-Resolved Luminescent Lanthanide Nano-bioprobes

Urinary sensing of synthetic biomarkers that are released into urine after specific activation in an in vivo disease environment is an emerging diagnosis strategy to overcome the insensitivity of a previous biomarker assay. However, it remains a great challenge to achieve sensitive and a specific urinary photoluminescence (PL) diagnosis. Herein, we report a novel urinary time-resolved PL (TRPL) diagnosis strategy by exploiting europium complexes of diethylenetriaminepentaacetic acid (Eu-DTPA) as synthetic biomarkers and designing the activatable nanoprobes. Notably, TRPL of Eu-DTPA in the enhancer can eliminate the urinary background PL for ultrasensitive detection. We achieved sensitive urinary TRPL diagnosis of mice kidney and liver injuries by using simple Eu-DTPA and Eu-DTPA-integrated nanoprobes, respectively, which cannot be realized by traditional blood assays. This work demonstrates the exploration of lanthanide nanoprobes for in vivo disease-activated urinary TRPL diagnosis for the first time, which might advance the noninvasive diagnosis of diverse diseases via tailorable nanoprobe designs.

Non-invasive molecular imaging for precision diagnosis of metastatic lymph nodes: opportunities from preclinical to clinical applications

Lymph node metastasis is an indicator of the invasiveness and aggressiveness of cancer. It is a vital prognostic factor in clinical staging of the disease and therapeutic decision-making. Patients with positive metastatic lymph nodes are likely to develop recurrent disease, distant metastasis, and succumb to death in the coming few years. Lymph node dissection and histological analysis are needed to detect whether regional lymph nodes have been infiltrated by cancer cells and determine the likely outcome of treatment and the patient's chances of survival. However, these procedures are invasive, and tissue biopsies are prone to sampling error. In recent years, advanced molecular imaging with novel imaging probes has provided new technologies that are contributing to comprehensive management of cancer, including non-invasive investigation of lymphatic drainage from tumors, identifying metastatic lymph nodes, and guiding surgeons to operate efficiently in patients with complex lesions. In this review, first, we outline the current status of different molecular imaging modalities applied for lymph node metastasis management. Second, we summarize the multi-functional imaging probes applied with the different imaging modalities as well as applications of cancer lymph node metastasis from preclinical studies to clinical translations. Third, we describe the limitations that must be considered in the field of molecular imaging for improved detection of lymph node metastasis. Finally, we propose future directions for molecular imaging technology that will allow more personalized treatment plans for patients with lymph node metastasis.

In Vivo Precision Evaluation of Lymphatic Function by SWIR Luminescence Imaging with PbS Quantum Dots

Advancements in lymphography technology are essential for comprehensive investigation of the lymphatic system and its function. Here, a shortwave infrared (SWIR) luminescence imaging of lymphatic vessels is proposed in both normal and lymphatic dysfunction in rat models with PbS quantum dots (PbS Qdots). The lymphography with PbS Qdots can clearly and rapidly demonstrate the normal lymphatic morphology in both the tail and hind limb. More importantly, compared to ICG, SWIR luminescence imaging with PbS Qdots can easily identify the dominant lymphatic vessel and node with higher luminescence signal in rats. Moreover, lymphatic pump is identified as segment contracting sections with a size of ≈1 cm in rat by in vivo SWIR lymphograhy, which propose a direct feature for precise evaluation of lymphatic function. Notably, in vivo SWIR luminescence imaging with PbS Qdots also clearly deciphers the in vivo pattern of morphological and function recovery from lymphatic system in rat model. In summary, SWIR luminescence imaging with PbS Qdots can improve the lymphography and thus deepen the understanding of the morphology and structure of the lymphatic system as well as lymphatic function such as lymphatic pump, which will facilitate the diagnosis of lymphatic dysfunction in the future.

NIR-II Self-Luminous Molecular Probe for In Vivo Inflammation Tracking and Cancer PDT Effect Self-Evaluating

Optical imaging in the second near-infrared (NIR-II, 900-1700 nm) window has been extensively investigated for bioimaging. However, a strong autofluorescence background from real-time excitation light significantly reduces the images' quality of NIR-II fluorescence (FL) imaging. To resolve this issue, a NIR-II self-luminous small molecule (CLPD) based on bioluminescence (BL) resonance energy transfer (BRET) mechanism is first developed. The reactive oxygen species (ROS) can trigger NIR-II BL and reduce the NIR-II FL signals of the CLPD simultaneously, enabling ROS-correlated ratiometric BL/FL imaging. CLPD is used for high-contrast NIR-II BL imaging of osteoarthritis as well as guiding the treatment process by ratiometric BL/FL imaging. Moreover, CLPD is applied for NIR-II BL imaging of tumor triggered by the generated ROS during PDT. A correlation between the ratiometric NIR-II BL/FL signal and tumor size is constructed, providing a trustworthy tool for early assessment of PDT effect. Overall, this study presents a novel NIR-II self-luminous small molecular probe for in vivo imaging and provides a strategy for design a self-evaluation system of therapeutic effect.

Rational Design of Polymethine Dyes with NIR-II Emission and High Photothermal Conversion Efficiency for Multimodal-Imaging-Guided Photo-Immunotherapy

Phototheranostics have emerged and flourished as a promising pattern for cancer theranostics owing to their precise photoinduced diagnosis and therapeutic to meet the demands of precision medicine. The diagnosis information and therapeutic effect are directly determined by the fluorescence imaging ability and photothermal conversion efficiency (PCE) of phototheranostic agents. Hence, how to balance the competitive radiative and nonradiative processes of phototheranostic agents is the key factor to evaluate the phototheranostic effect. Herein, molecules named ICRs with high photostaibility  are rationally designed, exhibiting fluorescence emission in the second near-infrared window (NIR-II, 1000-1700 nm) and high PCE, which are related to the strong donor-acceptor (D-A) interaction and high reorganization energy Noteworthily, ICR-Qu with stronger D-A interaction and a large-sized conjugated unit encapsulated in nanoparticles exhibits high PCE (81.1%). In addition, ICR-QuNPs are used for fluorescence imaging (FLI), photoacoustic imaging (PAI), and photothermal imaging (PTI) to guide deep-tissue photonic hyperthermia, achieving precise removal and inhibition of breast cancer. Furthermore, combined with α-PD-1, ICR-QuNPs show huge potential to be a facile and efficient tool for photo-immunotherapy. More importantly, this study not only reports an "all-in-one" polymethine-based phototheranostic agent, but also sheds light on the exploration of versatile organic molecules for future practical applications.

Fe-Doped Carbon Dots as NIR-II Fluorescence Probe for In Vivo Gastric Imaging and pH Detection

Carbon dots (CDs) with excellent cytocompatibility, tunable optical properties, and simple synthesis routes are highly desirable for use in optical bioimaging. However, the majority of existing CDs are triggered by ultraviolet/blue light, presenting emissions in the visible/first near-infrared (NIR-I) regions, which do not allow deep tissue penetration. Emerging research into CDs with NIR-II emission in the red region has generated limited designs with poor quantum yield, restricting their in vivo imaging applications due to low penetration depth. Developing novel CDs with NIR-II emissions and high quantum yield has significant and far-reaching applications in bioimaging and photodynamic therapy. Here, it is developed for the first time Fe-doped CDs (Fe-CDs) exhibiting the excellent linear relationship between 900-1200 nm fluorescence-emission and pH values, and high quantum yield (QY-1.27%), which can be used as effective probes for in vivo NIR-II bioimaging. These findings demonstrate reliable imaging accuracy in tissue as deep as 4 mm, reflecting real-time pH changes comparable to a standard pH electrode. As an important example application, the Fe-CDs probe can non-invasively monitor in vivo gastric pH changes during the digestion process in mice, illustrating its potential applications in aiding imaging-guided diagnosis of gastric diseases or therapeutic delivery.

In Vivo Fluorescence Imaging-Guided Development of Near-Infrared AIEgens

In vivo fluorescence imaging has received extensive attention due to its distinguished advantages of excellent biosafety, high sensitivity, dual temporal-spatial resolution, real-time monitoring ability, and non-invasiveness. Aggregation-induced emission luminogens (AIEgens) with near-infrared (NIR) absorption and emission wavelengths are ideal candidate for in vivo fluorescence imaging for their large Stokes shift, high brightness and superior photostability. NIR emissive AIEgens provide deep tissue penetration depth as well as low interference from tissue autofluorescence. Here in this review, we summarize the molecular engineering strategies for constructing NIR AIEgens with high performances, including extending π-conjugation system and strengthen donor (D)-acceptor (A) interactions. Then the encapsulation strategies for increasing water solubility and biocompatibility of these NIR AIEgens are highlighted. Finally, the challenges and prospect of fabricating NIR AIEgens for in vivo fluorescence imaging are also discussed. We hope this review would provide some guidelines for further exploration of new NIR AIEgens.

Fluorescence, ultrasonic and photoacoustic imaging for analysis and diagnosis of diseases

Biomedical imaging technology, which allows us to peer deeply within living subjects and visually explore the delivery and distribution of agents in living things, is producing tremendous opportunities for the early diagnosis and precise therapy of diseases. In this feature article, based on reviewing the latest representative examples of progress together with our recent efforts in the bioimaging field, we intend to introduce three typical kinds of non-invasive imaging technologies, i.e., fluorescence, ultrasonic and photoacoustic imaging, in which optical and/or acoustic signals are employed for analyzing various diseases. In particular, fluorescence imaging possesses a series of outstanding advantages, such as high temporal resolution, as well as rapid and sensitive feedback. Hence, in the first section, we will introduce the latest studies on developing novel fluorescence imaging methods for imaging bacterial infections, cancer and lymph node metastasis in a long-term and real-time manner. However, the issues of imaging penetration depth induced by photon scattering and light attenuation of biological tissue limit their widespread in vivo imaging applications. Taking advantage of the excellect penetration depth of acoustic signals, ultrasonic imaging has been widely applied for determining the location, size and shape of organs, identifying normal and abnormal tissues, as well as confirming the edges of lesions in hospitals. Thus, in the second section, we will briefly summarize recent advances in ultrasonic imaging techniques for diagnosing diseases in deep tissues. Nevertheless, the absence of lesion targeting and dependency on a professional technician may lead to the possibility of false-positive diagnosis. By combining the merits of both optical and acoustic signals, newly-developed photoacoustic imaging, simultaneously featuring higher temporal and spatial resolution with good sensitivity, as well as deeper penetration depth, is discussed in the third secretion. In the final part, we further discuss the major challenges and prospects for developing imaging technology for accurate disease diagnosis. We believe that these non-invasive imaging technologies will introduce a new perspective for the precise diagnosis of various diseases in the future.

Ag-doped InP/ZnS quantum dots for type-I photosensitizers

Water-soluble Ag-doped InP/ZnS quantum dots (QDs) with high photoluminescence quantum yield were synthesized and characterized. Their maximum two- and three-photon absorption cross sections are determined as ∼1.7 × 10⁴ GM at 820 nm and ∼1.7 × 10^-76 cm⁶ s² photon^-2 at 1260 nm. Importantly, for the first time, we demonstrated that Ag-doped InP/ZnS QDs can be used for type-I photodynamic therapy and are more suitable for the hypoxic environment of tumors.

Single-Excitation Triple-Emission Down-/Up-Conversion Nanoassemblies for Tumor Microenvironment-Enhanced Ratiometric NIR-II Fluorescence Imaging and Chemo-/Photodynamic Combination Therapy

Tumor microenvironment-mediated ratiometric second near-infrared (NIR-II) fluorescence imaging and photodynamic therapy contribute to accurate diagnosis and highly efficient therapy of deep tumors. However, it is challenging to integrate these functions into one nanodrug due to the difficulty in preparing triple-emission nanoprobes. In this work, single-excitation triple-emission (wavelength at 660, 1060, and 1550 nm) down-/up-conversion nanoassemblies were prepared by conjugating dual-ligands-stabilized gold nanoclusters (_cgAuNCs) into down-/up-conversion nanoparticles (D/UCNPs), which simultaneously realized ratiometric NIR-II fluorescence imaging and chemo-/photodynamic combination therapy toward tumors upon exposure to an 808 nm laser. The presence of dual ligands endowed _cgAuNCs with an enhanced NIR-II fluorescence response to endogenous glutathione, allowing in situ ratiometric NIR-II fluorescence imaging of tumors using the prepared nanoassemblies. Additionally, the stabilizing ligand cyclodextrin of _cgAuNCs facilitated the loading of the antitumor drug doxorubicin, and D/UCNPs could be modified with the photosensitizer methylene blue. Such a spatially separated functionalization method enabled chemo-/photodynamic combination therapy. This study provides new insights into the design of multifunctional nanoplatforms for tumor diagnosis and treatment.

Molecular Engineering of pH-Responsive NIR Oxazine Assemblies for Evoking Tumor Ferroptosis via Triggering Lysosomal Dysfunction

Ferroptosis, a newly discovered form of regulated cell death, is emerging as a promising approach to tumor therapy. However, the spatiotemporal control of cell-intrinsic Fenton chemistry to modulate tumor ferroptosis remains challenging. Here, we report an oxazine-based activatable molecular assembly (PTO-Biotin Nps), which is capable of triggering the lysosomal dysfunction-mediated Fenton pathway with excellent spatiotemporal resolution via near-infrared (NIR) light to evoke ferroptosis. In this system, a pH-responsive NIR photothermal oxazine molecule was designed and functionalized with a tumor-targeting hydrophilic biotin-poly(ethylene glycol) (PEG) chain to engineer well-defined nanostructured assemblies within a single-molecular framework. PTO-Biotin Nps possesses a selective tropism to lysosome accumulation inside tumor cells, accommodated by its enhanced photothermal activity in the acidic microenvironment. Upon NIR light activation, PTO-Biotin Nps promoted lysosomal dysfunction and induced cytosolic acidification and impaired autophagy. More importantly, photoactivation-mediated lysosomal dysfunction via PTO-Biotin Nps was found to markedly enhance cellular Fenton reactions and evoke ferroptosis, thereby improving antitumor efficacy and mitigating systemic side effects. Overall, our study demonstrates that the molecular engineering approach of pH-responsive photothermal oxazine assemblies enables the spatiotemporal modulation of the intrinsic ferroptosis mechanism, offering a novel strategy for the development of metal-free Fenton inducers in antitumor therapy.

Small-molecule fluorogenic probes for mitochondrial nanoscale imaging

Mitochondria are inextricably linked to the development of diseases and cell metabolism disorders. Super-resolution imaging (SRI) is crucial in enhancing our understanding of mitochondrial ultrafine structures and functions. In addition to high-precision instruments, super-resolution microscopy relies heavily on fluorescent materials with unique photophysical properties. Small-molecule fluorogenic probes (SMFPs) have excellent properties that make them ideal for mitochondrial SRI. This paper summarizes recent advances in the field of SMFPs, with a focus on the chemical and spectroscopic properties required for mitochondrial SRI. Finally, we discuss future challenges in this field, including the design principles of SMFPs and nanoscopic techniques.

Chemically engineering cells for precision medicine

Cell-based therapy holds great potential to address unmet medical needs and revolutionize the healthcare industry, as demonstrated by several therapeutics such as CAR-T cell therapy and stem cell transplantation that have achieved great success clinically. Nevertheless, natural cells are often restricted by their unsatisfactory in vivo trafficking and lack of therapeutic payloads. Chemical engineering offers a cost-effective, easy-to-implement engineering tool that allows for strengthening the inherent favorable features of cells and confers them new functionalities. Moreover, in accordance with the trend of precision medicine, leveraging chemical engineering tools to tailor cells to accommodate patients individual needs has become important for the development of cell-based treatment modalities. This review presents a comprehensive summary of the currently available chemically engineered tools, introduces their application in advanced diagnosis and precision therapy, and discusses the current challenges and future opportunities.

Dual-targetable fluorescent probe for mapping the fluctuation of peroxynitrite in drug-induced liver injury model

Drug-induced liver injury (DILI) is one of the most common and serious adverse drug reactions which can cause acute liver failure or even death in severe cases. With the incidence rate increasing over the years, DILI has became a frequent clinical liver disease and a global public health problem. As a biomarker of DILI, the detection of peroxynitrite (ONOO^-) has became a powerful tool for the early diagnosis of liver injury. Here, we synthesized five mitochondria-targetable probes, 1-5, for detecting endogenous ONOO^-. Through dye-screening, probe 5 was stood out by its excellent performance. In the presence of ONOO^-, the fluorescence signal of probe 5 reduced 40-fold in 19 s with a low detection limit (9.36 nM). At the same time, the transformation can be observed with the naked eye under sunlight or UV lamp without being affected by the other reactive species. Even better, with low toxicity and high biocompatibility, probe 5 could successfully detect endogenous ONOO^- in the mitochondrion of cells. Finally, probe 5 could specifically target the liver, and can be employed for monitoring the therapeutic effect of hepatoprotective medicine after drug-induced hepatotoxicity in vivo. In brief, probe 5 has the practical application capability for diagnosing the severity of the liver injury and researching the therapeutic effect of antidote in complex bio-systems.

An oral ratiometric NIR-II fluorescent probe for reliable monitoring of gastrointestinal diseases in vivo

Early monitoring of gastrointestinal diseases via orally delivered NIR-II ratiometric fluorescent probes represents a promising noninvasive diagnostic modality, but is challenging due to the limitation of harsh digestive environment. Here, we report a single-component NIR-II ratiometric molecular nanoprobe (LC-1250 NP) to monitor gastrointestinal disease with high specificity to its biomarker H₂O₂ via oral administration. LC-1250 NP displays stable fluorescence in the channel of 1250 long-pass (F_1250LP) before and after the gastrointestinal disease detection as the reference, while it presents significantly enhanced fluorescence signal in the response channel of 1150 nm short-pass (F_1150SP) in diseased gastrointestinal environment due to the intramolecular cyclization of LC-1250 molecules activated by H₂O₂. The fluorescence ratio (F_1150SP/F_1250LP) increases linearly with the concentration of H₂O₂ with a low detection limit of 20 nM. Therefore, when delivered orally, LC-1250 NP can accurately map the diseased areas and surmount the false-positive interference from biological heterogeneity by NIR-II ratiometric fluorescence imaging, providing sensitive and reliable evaluation for the progress of gastroenteritis.

Core-satellite nanoreactors based on cationic photosensitizer modified hollow CuS nanocage for ROS diffusion enhanced phototherapy of hypoxic tumor

Photodynamic therapy (PDT) efficiency is directly affected by the reactive oxygen species (ROS) generated by photosensitizers. However, ROSs' ultrashort life span and limited diffusion distance restrict the PDT efficiency. Therefore, it is important to control the delivery strategy of photosensitizers for PDT treatment. Herein, the core-satellite nanoreactors were fabricated with oxygen generation and ROS diffusion properties. The hollow CuS encapsulating horseradish peroxidase (HRP) was combined with the cationic photosensitizers (PEI-Ce6). The unique photosensitizers delivery strategy makes the nanoreactors achieve ROS diffusion-enhanced PDT effect. First, HRP in "core" (HRP@CuS) can decompose hydrogen peroxide (H₂O₂) to O₂, increasing O₂ levels on the surface of the nanoreactor. Second, the Ce6 molecules covalent-linked with PEI are uniformly dispersed on the surface of CuS as a "satellite", avoiding Ce6 aggregation and causing more Ce6 molecules be activated to produce more ¹O₂. Due to the Ce6 was on the surface of the CuS nanocages, the generated ROS may ensure a larger diffusion range. Meanwhile, the inherently CuS nanocages exhibit photothermal and photoacoustic (PA) effect. The photothermal effect further enhances the ROS diffusion. Under the guidance of PA imaging, nanoreactors exhibit highly efficient hypoxic tumor ablation via photodynamic and photothermal effect. Overall, the core-satellite nanoreactors provide an effective strategy for tumor therapy, further promoting the research of photosensitizers delivery.

Increasing Molecular Planarity through Donor/Side-Chain Engineering for Improved NIR-IIa Fluorescence Imaging and NIR-II Photothermal Therapy under 1064 nm

Developing conjugated small molecules (CSM) with intense NIR-II (1000-1700 nm) absorption for phototheranostic is highly desirable but remains a tremendous challenge due to a lack of reliable design guidelines. This study reports a high-performance NIR-II CSM for phototheranostic by tailoring molecular planarity. A series of CSM show bathochromic absorption extended to the NIR-II region upon the increasing thiophene number, but an excessive number of thiophene results in decreased NIR-IIa (1300-1400 nm) brightness and photothermal effects. Further introduction of terminal nonconjugated alkyl chain can enhance NIR-II absorption coefficient, NIR-IIa brightness, and photothermal effects. Mechanism studies ascribe this overall enhancement to molecular planarity stemming from the collective contribution of donor/side-chain engineering. This finding directs the design of NIR-II CSM by rational manipulating molecular planarity to perform 1064 nm mediated phototheranostic at high efficiency.

Albumin-Consolidated AIEgens for Boosting Glioma and Cerebrovascular NIR-II Fluorescence Imaging

The application of an exogenous polymer matrix to construct aggregation-induced emission (AIE) nanoprobes promotes the utility of AIE luminogens (AIEgens) in diagnosing brain diseases. However, the limited fluorescence (FL) and low active-targeting abilities of AIE-based nanoprobes impede their imaging application. Here, we employed endogenous albumin as an effective matrix to encapsulate AIEgens to enhance FL quantum yield (QY) and active-targeting ability. The albumin-consolidated strategy effectively inhibited the intramolecular vibration of AIEgens and enhanced endocytosis mediated by the gp60 receptor. The QYs of three kinds of albumin-based AIE nanoprobes with FL emissions ranging from the visible (400-650 nm) to the second near-infrared (NIR-II, 1000-1700 nm) region was at least 10% higher, and the tumor-targeting efficiency was ∼25% higher, compared with those of nanoprobes constructed by the exogenous polymer. Albumin-based AIE nanoprobes have achieved active-targeting NIR-II imaging of brain tumors and cerebrovascular imaging with a high signal-to-background ratio (SBR, ∼90) and high resolution (∼70 μm) in mouse models. Therefore, the albumin-based AIE nanoprobes will enable FL imaging-guided surgery of brain tumors and cerebral ischemia, which will improve surgical efficacy to prevent recurrence and side effects.

Rational Design of Asymmetric Polymethines to Attain NIR(II) Bioimaging at >1100 nm

Organic molecules having emission in the NIR(II) region are emergent and receiving enormous attention. Unfortunately, attaining accountable organic emission intensity around the NIR(II) region is hampered by the dominant internal conversion operated by the energy gap law, where the emission energy gap and the associated internal reorganization energy λ_int play key roles. Up to the current stage, the majority of the reported organic NIR(II) emitters belong to those polymethines terminated by two symmetric chromophores. Such a design has proved to have a small λ_int that greatly suppresses the internal conversion. However, the imposition of symmetric chromophores is stringent, limiting further development of organic NIR(II) dyes in diversity and versatility. Here, we propose a new concept where as far as the emissive state of the any asymmetric polymethines contains more or less equally transition density between two terminated chromophores, λ_int can be as small as that of the symmetric polymethines. To prove the concept, we synthesize a series of new polymethines terminated by xanthen-9-yl-benzoic acid and 2,4-diphenylthiopyrylium derivatives, yielding AJBF1112 and AEBF1119 that reveal emission peak wavelength at 1112 and 1119 nm, respectively. The quantum yield is higher than all synthesized symmetric polymethines of 2,4-diphenylthiopyrylium derivatives (SC1162, 1182, 1185, and 1230) in this study. λ_int were calculated to be as small as 6.2 and 7.3 kcal/mol for AJBF1112 and AEBF1119, respectively, proving the concept. AEBF1119 was further prepared as a polymer dot to demonstrate its in vitro specific cellular imaging and in vivo tumor/bone targeting in the NIR(II) region.

Noninvasive Gastrointestinal Tract Imaging Using BSA-Ag2Te Quantum Dots as a CT/NIR-II Fluorescence Dual-Modal Imaging Probe in Vivo

The combination of high-resolution computed tomography (CT) and the real-time sensitive second near-infrared window (NIR-II) fluorescence bioimaging can provide complementary information for the diagnosis, progression and prognosis of gastrointestinal disorders. Ag₂Te quantum dots (QDs) are a kind of promising CT/NIR-II fluorescence dual-modal imaging probe due to their high atomic number and narrow bandgap. However, conventional Ag₂Te QDs synthesized by oil phase approaches often suffer from complicated steps, harsh reaction conditions, and toxic organic solvents. Herein, we report the synthesis of bovine serum albumin (BSA)-Ag₂Te QDs using a biomineralization approach for CT/NIR-II fluorescence dual-modal imaging of the gastrointestinal tract. The BSA-Ag₂Te QDs are fabricated in a facile one-pot approach under mild conditions and exhibit homogeneous size, favorable monodispersity, admirable aqueous solubility, excellent X-ray attenuation properties, and outstanding NIR-II fluorescence performance. In vivo imaging experiments show that BSA-Ag₂Te QDs can be used in gastrointestinal tract CT/NIR-II dual-modal imaging with high spatiotemporal resolution and sensitivity. In addition, in an intestinal obstruction mouse model, accurate lesion positioning and imaging-guided obstruction relief surgery are successfully realized based on BSA-Ag₂Te QDs. Besides, BSA-Ag₂Te QDs have outstanding biocompatibility in vitro and in vivo. This study presents a high-performance and biosafe CT/NIR-II fluorescence dual-modal imaging probe for visualizing the gastrointestinal tract in vivo.

Design strategies and applications of smart optical probes in the second near-infrared window

Over the last decade, a series of synergistic advances in the synthesis chemistries and imaging instruments have largely boosted a significant revolution, in which large-scale biomedical applications are now benefiting from optical bioimaging in the second near-infrared window (NIR-II, 1000-1700 nm). The large tissue penetration and limited autofluorescence associated with long-wavelength imaging improve translational potential of NIR-II imaging over common visible-light (400-650 nm) and NIR-I (750-900 nm) imaging, with ongoing profound effects on the studies of precision medicine. Unfortunately, the majority of NIR-II probes are designed as "always-on" luminescent imaging contrasts, continuously generating unspecific signals regardless of whether they reach pathological locations. Thus, in vivo imaging by traditional NIR-II probes usually suffers from weak detect precision due to high background noise. In this context, the advances of optical imaging now enter into an era of precise control of NIR-II photophysical kinetics. Developing NIR-II optical probes that can efficiently activate their luminescent signal in response to biological targets of interest and substantially suppress the background interferences have become a highly prospective research frontier. In this review, the merits and demerits of optical imaging probes from visible-light, NIR-I to NIR-II windows are carefully discussed along with the lens of stimuli-responsive photophysical kinetics. We then highlight the latest development in engineering methods for designing smart NIR-II optical probes. Finally, to appreciate such advances, challenges and prospect in rapidly growing study of smart NIR-II probes are addressed in this review.

Photostable Small-Molecule NIR-II Fluorescent Scaffolds that Cross the Blood-Brain Barrier for Noninvasive Brain Imaging

The second near-infrared (NIR-II, 1000-1700 nm) fluorescent probes have significant advantages over visible or NIR-I (600-900 nm) imaging for both depth of penetration and level of resolution. Since the blood-brain barrier (BBB) prevents most molecules from entering the central nervous system, NIR-II dyes with large molecular frameworks have limited applications for brain imaging. In this work, we developed a series of boron difluoride (BF₂) formazanate NIR-II dyes, which had tunable photophysical properties, ultrahigh photostability, excellent biological stability, and strong brightness. Modulation of the aniline moiety of BF₂ formazanate dyes significantly enhances their abilities to cross the BBB for noninvasive brain imaging. Furthermore, the intact mouse brain imaging and dynamic dye diffusion across the BBB were monitored using these BF₂ formazanate dyes in the NIR-II region. In murine glioblastoma models, these dyes can differentiate tumors from normal brain tissues. We anticipate that this new type of small molecule will find potential applications in creating probes and drugs relevant to theranostic for brain pathologies.

Multifunctional AuPd-cluster nanotheranostic agents with a cascade self-regulating redox tumor-microenvironment for dual-photodynamic synergized enzyme catalytic therapy

Photodynamic therapy (PDT) has emerged as a promising strategy with higher selectivity and spatiotemporal control than conventional therapies. However, deep hypoxia in tumours has hampered the clinical use of PDT. In this study, a novel multifunctional cluster nanotheranostic agent (AuPd-BSA CN) was fabricated to generate a high amount of reactive oxygen species, regardless of oxygen dependence under 660 nm laser irradiation. The structure and properties of the AuPd-BSA CN were characterised using various technologies. The synthesised AuPd-BSA CN with high biocompatibility served as a superior photodynamic agent, showing prominent antitumour properties under laser irradiation. Additionally, the glucose oxidase-like activity of the AuPd-BSA CN synergistically enhanced the therapeutic performance. Notably, the intrinsic characteristics of the AuPd-BSA CN include dual-modal second near-infrared window fluorescence/photoacoustic imaging capabilities for monitoring and tracking the in vivo tumour therapeutic process. This work provides innovative insights into the AuPd-BSA CN as an "all-in-one" nanoplatform for cancer therapy.

Single-step extraction of small-diameter single-walled carbon nanotubes in the presence of riboflavin

We propose a novel approach to disperse and extract small-diameter single-walled carbon nanotubes (SWCNTs) using an aqueous solution of riboflavin and Sephacryl gel. The extraction of small-diameter semiconducting SWCNTs was observed, regardless of the initial diameter distribution of the SWCNTs. Dispersion of SWCNTs occurs due to the adsorption of π-conjugated isoalloxazine moieties on the surface of small-diameter nanotubes and interactions between hydroxy groups of ribityl chains with water. During the SWCNT extraction, specific adsorption of riboflavin to SWCNTs leads to the minimization of interactions between the SWCNTs and gel media. Our experimental findings are supported by ab initio calculations demonstrating the impact of the riboflavin wrapping pattern around the SWCNTs on their interaction with the allyl dextran gel.

Near-Infrared Dyes: Towards Broad-Spectrum Antivirals

Broad antiviral activity in vitro is known for many organic photosensitizers generating reactive oxygen species under irradiation with visible light. Low tissue penetration of visible light prevents further development of antiviral therapeutics based on these compounds. One possible solution to this problem is the development of photosensitizers with near-infrared absorption (NIR dyes). These compounds found diverse applications in the photodynamic therapy of tumors and bacterial infections, but they are scarcely mentioned as antivirals. In this account, we aimed to evaluate the therapeutic prospects of various NIR-absorbing and singlet oxygen-generating chromophores for the development of broad-spectrum photosensitizing antivirals.

Nanoparticles for super-resolution microscopy: intracellular delivery and molecular targeting

Following an overview of the approaches and techniques used to acheive super-resolution microscopy, this review presents the advantages supplied by nanoparticle based probes for these applications. The various clases of nanoparticles that have been developed toward these goals are then critically described and these discussions are illustrated with a variety of examples from the recent literature.

Current Status and Future Perspectives of Lactate Dehydrogenase Detection and Medical Implications: A Review

The demand for glucose uptake and the accompanying enhanced glycolytic energy metabolism is one of the most important features of cancer cells. Unlike the aerobic metabolic pathway in normal cells, the large amount of pyruvate produced by the dramatic increase of glycolysis in cancer cells needs to be converted to lactate in the cytoplasm, which cannot be done without a large amount of lactate dehydrogenase (LDH). This explains why elevated serum LDH concentrations are usually seen in cancer patient populations. LDH not only correlates with clinical prognostic survival indicators, but also guides subsequent drug therapy. Besides their role in cancers, LDH is also a biomarker for malaria and other diseases. Therefore, it is urgent to develop methods for sensitive and convenient LDH detection. Here, this review systematically summarizes the clinical impact of lactate dehydrogenase detection and principles for LDH detection. The advantages as well as limitations of different detection methods and the future trends for LDH detection were also discussed.