First-in-human liver-tumour surgery guided by multispectral fluorescence imaging in the visible and near-infrared-I/II windows

Tumor-microenvironment-activated bimetallic oxide nanoplatform for second near-infrared region fluorescence-guided colon tumor surgery and multimodal synergistic therapy

Colon cancer, characterized by its high incidence and mortality rates, continues to present a significant challenge in cancer treatment. To address this, we present a novel ZnCe based nanocarrier featuring stacked mesopores and rough surface, indocyanine Green (ICG) is encapsulated within these mesopores (ZnCe&ICG). This innovative nanoplatform demonstrates effective accumulation in tumor regions and can be triggered to generate efficacious reactive oxygen species (ROS) in the weakly acidic and high H2O2 conditions typical of tumor microenvironments. Enhanced fluorescent imaging using improved tumor-to-background ratio has proven effective in precisely delineating tumor margins from surrounding healthy tissue. With the guidance of this second near-infrared region (NIR II, 1000-1700 nm) fluorescence imaging technique, tumors are completely excised, resulting in negligible instances of in situ recurrence or metastasis observed 30 days following surgery. Notably, under 808 nm laser irradiation, the nanoplatform exhibits a high photothermal conversion efficiency, leading to localized heating that further amplifies ROS production via multi ion synergetic catalysis for tumor cell killing. These results underscore the potential of tumor microenvironment-responsive ZnCe-based nanocomposite as a fluorescence imaging contrast agent and chemodynamic agent for cancer treatment, particularly when combined with NIR light activation.

Minimized background tumor imaging through self-assembled disulfide dicyanine nanoparticles

Fluorescence imaging holds great potential as a powerful diagnostic tool for tumor cell visualization. However, a significant challenge in fluorescence imaging is the high background signal, which obscures the tumor-specific signal and reduced the signal-to-noise ratio (SNR) of imaging, thereby reducing the accuracy of tumor detection and delineation. In this research, we designed and synthesized an amphiphilic disulfide dicyanine ss-diCy7, which can self-assemble into nanoparticles with uniform dispersion in aqueous environments. The fluorescence intensity of these nanoparticles is significantly reduced by 96% due to aggregation-induced quenching arising from π-π stacking. The nanoparticles exhibit a highly specific response to glutathione (GSH) in vitro, resulting in a substantial enhancement of fluorescence intensity by a 24-fold. The enhancement was also achieved in cell and mouse imaging experiments. In addition, in the mouse tumor model, ss-diCy7 nanoparticles demonstrated superior performance compared to traditional mono-cyanine dyes, offering a reduced background signal and prolonged fluorescence duration. This work is anticipated to contribute to the high-resolution tumor imaging.

Glutathione-Responsive Near-Infrared-II Fluorescence Probe for Early and Accurate Detection of In Situ and Metastatic Tumors

In situ and metastatic malignant tumors are primary diseases that threaten human life. Among all the metastases, liver metastasis is the most difficult to detect. As most imaging probes have high liver accumulation, it is difficult to distinguish tiny metastases from normal liver tissue with strong background signal. In this study, the design of a novel second near-infrared window (NIR-II) fluorescence probe for precise detection of carcinoma in situ and liver metastases is presented. The probe called Tg-RGD utilizes a commercially available cyanine dye IR-806 as the signaling moiety, a disulfide bond linker as the responsive moiety, an RGD-capped poly(ethylene glycol) (PEG) as the water soluble enhancer, and the tumor targeting moiety. Tg-RGD shows good glutathione (GSH) responsiveness and selectivity, where its NIR-II fluorescence intensity can enhance 50-fold after activation. In vivo study indicates that Tg-RGD shows much better imaging and targeting effects than Tg-PEG with a similar structure but without RGD moiety for both orthotopic breast cancer and osteosarcoma. Most importantly, Tg-RGD can detect tiny liver metastases with high signal-to-background ratio (3.2). Thus, this study reports a high-performance tumor-specific NIR-II fluorescence probe for in situ and tiny metastatic tumor detection, and may further broaden the applications into related tumor lesions.

Near-infrared II cyanine fluorophores with large stokes shift engineered by regulating respective absorption and emission

Fluorescence bioimaging in the near-infrared II window is a promising area due to its deep tissue penetration and high contrast. However, efficient design strategies for near-infrared II fluorophores with large Stokes shifts are still scarce. Here, we develop a series of near-infrared II fluorophores (termed VIPIs) with large Stokes shifts (167-260 nm in chloroform) by conjugating p-aminostyryl to hemicyanines. Time dependent density functional theory calculation and transient absorption spectra reveal that the excitation process is predominantly localized within the cyanine moiety, whereas the emission process involves the charge transfer from the cyanine to styryl moiety. We demonstrate the applications of VIPIs in multicolor imaging and conjugatable modification. Finally, we show that VIPI-4 liposomes can image the fine bone structure of knee joint of female mice over 1300 nm. This work provides insights into the excited-state photophysical processes in near-infrared II window, offering inspiration for designing fluorophores with extended emission and large Stokes shifts.

High-Resolution Multicolor Shortwave Infrared Dynamic In Vivo Imaging with Chromenylium Nonamethine Dyes

Imaging in the shortwave infrared (SWIR) region offers fast, high-resolution visualization of in vivo targets in a multiplexed manner. These methods require bright, bathochromically shifted fluorescent dyes with sufficient emission at SWIR wavelengths-ideally above 1500 nm for high-resolution deep tissue imaging. Polymethine dyes are a privileged class of contrast agents due to their excellent absorption and high degree of modularity. In this work, we push flavylium and chromenylium dyes further into the SWIR region through polymethine chain extension. This panel of nonamethine dyes boasts absorbances as red as 1149 nm and tail emission beyond 1500 nm. These dyes are the brightest organic fluorophores at their respective bandgaps to date, with εmax ∼ 105 M-1 cm-1 and ΦF up to 0.5%. Using two nonamethine dyes, Chrom9 and JuloFlav9, we performed two-color all-SWIR multiplexed imaging (Excitation at 1060 and 1150 nm; Emission collection at >1500 nm), enhancing the depths and resolutions able to be obtained in multicolor SWIR imaging with small molecule contrast agents. Finally, we combine the nonamenthine dyes with other SWIR-emissive fluorophores and demonstrate five-color awake imaging in an unrestrained mouse, simultaneously pushing the multiplexing, resolution, and speed limits of in vivo optical imaging.

Construction of Sonosensitizer-Drug Co-Assembly Based on Deep Learning Method

Drug co-assemblies have attracted extensive attention due to their advantages of easy preparation, adjustable performance and drug component co-delivery. However, the lack of a clear and reasonable co-assembly strategy has hindered the wide application and promotion of drug-co assembly. This paper introduces a deep learning-based sonosensitizer-drug interaction (SDI) model to predict the particle size of the drug mixture. To analyze the factors influencing the particle size after mixing, the graph neural network is employed to capture the atomic, bond, and structural features of the molecules. A multi-scale cross-attention mechanism is designed to integrate the feature representations of different scale substructures of the two drugs, which not only improves prediction accuracy but also allows for the analysis of the impact of molecular structures on the predictions. Ablation experiments evaluate the impact of molecular properties, and comparisons with other machine and deep learning methods show superiority, achieving 90.00% precision, 96.00% recall, and 91.67% F1-score. Furthermore, the SDI predicts the co-assembly of the chemotherapy drug methotrexate (MET) and the sonosensitizer emodin (EMO) to form the nanomedicine NanoME. This prediction is further validated through experiments, demonstrating that NanoME can be used for fluorescence imaging of liver cancer and sonodynamic/chemotherapy anticancer therapy.

High-contrast in vivo fluorescence imaging exploiting wavelengths beyond 1880 nm

The second near-infrared (NIR-II) window is widely acknowledged for its excellent potential in in vivo fluorescence imaging. Currently, NIR-II fluorescence imaging predominantly operates within the 900-1880 nm spectral range, while the region beyond 1880 nm has been disregarded due to the large light absorption of water. Based on a refined understanding of the effect of light absorption on imaging, we propose an approach that utilizes the previously neglected region surrounding the water absorption peak at ~1930 nm for imaging. Both simulations and experiments confirm that the water absorption contributes positively to imaging, enabling high-contrast in vivo fluorescence imaging in the 1880-2080 nm window. To further assess the applicability of this approach in different biological media, we extend our focus to fluorescence imaging in adipose tissue. This leads to the expansion of the imaging window to 1700-2080 nm, owing to the unique light absorption characteristics of adipose tissue. Our results demonstrate that the 1700-2080 nm region provides optimal imaging quality in adipose tissue, attributing to its moderate absorption and low scattering. This work advances our understanding of the interplay between light absorption and photon scattering in bioimaging, providing an insight for selecting optimal imaging windows to achieve high-contrast fluorescence imaging.

Evaluation of indocyanine green inhalation to detect air leak sites during video-assisted thoracoscopic surgery: a prospective study

BACKGROUND

This study aimed to investigate the feasibility and clinical benefits of indocyanine green (ICG) inhalation for detecting air leak sites during video-assisted thoracoscopic surgery (VATS).

METHODS

Between February 2023 and May 2023, a total of 288 patients underwent VATS were enrolled in this study. Among the population, 72 patients received ICG inhalation test following the traditional submersion sealing test. And 216 patients only underwent the submersion sealing test were matched using 1:3 propensity score matching analysis. The results of ICG inhalation test and the clinical outcomes were compared.

RESULTS

In the ICG group, 48 air leak sites were detected in 25 patients (25/72, 34.7%). The conventional submersion sealing test identified 30 air leak sites, while the ICG inhalation test detected 47 sites. Among these detected air leak sites, 34 sites were repaired by suturing or stapling. The postoperative air leak rate in the ICG group (20.8%) was significantly lower than the control group (37.0%, P = 0.011). ICG inhalation test was a favorable factor for reducing postoperative air leaks (OR: 0.40; 95%CI: 0.20-0.78; P = 0.008).

CONCLUSIONS

The ICG inhalation test facilitates the identification of air leak sites that may have been overlooked in the conventional submersion sealing test. This technique is useful to reduce postoperative air leaks for patients undergoing VATS.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2300067603 on January 13rd 2023.

Manipulating ICG J-Aggregation and Disaggregation for Imaging-Guided Cancer Therapy with Self-Reporting Efficiency

Integrating imaging guided therapy and therapeutic effect self-reporting would highly benefit clinic applications. J-type aggregates of organic dyes with corresponding photothermal effect have made them popular agents for photoacoustic (PA) imaging and photothermal therapy (PTT). However, approaches to manipulate the disaggregation of J-aggregate with corresponding organic dye fluorescence recovery have rarely been reported, which limits the full exploration of J-aggregate in therapeutic applications. Herein, indocyanine green (ICG) J-aggregate is designed in a micelle structure (J-ICG-Micelle) by co-assembling ICG with DSPE-Pep-PEG, which contains peptide KADEVDAC that recognized and cleaved by caspase-3. Taking advantages of the red-shifted absorbance of J-ICG-Micelle, it achieves PA imaging navigated delivery process with an indication of tumor accumulation time and position to perform PTT. Corresponding cell apoptosis and caspase-3 generation cleaves peptide KADEVDAC and results in fluorescence recovery of ICG, which self-reports therapeutic effect in real time, and the intensity for fluorescence recovery demonstrates similar tendency as H&E staining at tumor sections. The as-presented J-ICG-Micelle would have a promising contribution to precise cancer therapy.

Noninvasively Real-Time Monitoring In-Vivo Immune Cell and Tumor Cell Interaction by NIR-II Nanosensor

Immunocytotherapy holds significant promise as a novel cancer treatment, but its effectiveness is often hindered by delayed responses, requiring evaluations every 2-3 weeks based on current diagnostic methods. Early assessment of immune cell-tumor cell interactions could provide more timely insights into therapeutic efficacy, enabling adjustments to treatment plans. In this study, a noninvasive nanosensor (C8R-DSNP) for real-time monitoring of in vivo immune cell activities in the second near-infrared long-wavelength (NIR-II-L) window (1500-1900 nm), which offers deep tissue transparency, is reported. The C8R-DSNP responds rapidly to caspase-8, a key apoptotic signaling molecule generated during interactions between natural killer (NK-92) cells and tumor cells. Using ratiometric NIR-II-L fluorescence imaging, dynamic in vivo observations of NK-92 cells' engagement with tumor cells in a mouse model are captured. These results demonstrate tumor cells apoptosis that happens as early as 4.5 h after NK-92 cells infusion. Additionally, in vitro urine imaging confirmed the initiation of apoptosis via cleaved fluorescent small molecules, while single-cell tracking within blood vessels and tumors further elucidated immune cell dynamics. This real-time NIR-II-L monitoring approach offers valuable insights for optimizing immunocytotherapy strategies.

A new EGFR and c-Met bispecific NIR-II fluorescent probe for visualising colorectal cancer and metastatic lymph nodes

BACKGROUND

The aim of the study was to increase the specificity and targeting of tumour imaging, targeting molecules that enable the simultaneous recognition and binding of multiple tumour-associated receptors. We constructed a NIR-II fluorescence probe based on a bispecific antibody to epidermal growth factor receptor (EGFR) and cellular mesenchymal-epithelial transition factor (c-Met) for visualising colorectal cancers (CRCs) and metastatic lymph nodes.

METHODS

The expression of EGFR and c-Met in tumour and metastatic lymph node specimens from patients with CRC was examined using immunohistochemistry. The EGFR and c-Met bispecific antibody (Rybrevant) was labelled, and its cell-specific binding ability was assessed using laser confocal microscopy. Subcutaneous CRC and orthotopic tumour models were constructed to evaluate the fluorescence imaging of the probe in vivo. To assess the performance of Rybrevant-IRDye800CW in the differential diagnosis of metastatic lymph nodes, a CRC lymph node metastasis model was constructed using human CRC cells implanted in mouse claw pads. Finally, surgically resected CRC tumours and lymph node specimens were incubated with Rybrevant-IRDye800CW for fluorescence NIR-II imaging to evaluate the efficacy of Rybrevant-IRDye800CW for preclinical visualisation.

FINDINGS

The combined expression rate of EGFR and c-Met in CRC and metastatic lymph nodes was significantly higher than the single-target expression rate. The bispecific probe Rybrevant-IRDye800CW was successfully synthesised, and its fluorescence signal could be extended up to 1600 nm using NIR-II imaging. Cell incubation experiments showed that the fluorescence intensity of Rybrevant-IRDye800CW was strongly correlated with EGFR and c-Met overexpression of the cells. NIR-II in vivo fluorescence imaging showed that double-positively expressing subcutaneous tumours significantly uptook Rybrevant-IRDye800CW after tail vein injection of the probe, which rapidly accumulated within the tumours in about 6 h. In EGFR and or c-Met blockade assays, subcutaneous tumours showed weaker uptake of Rybrevant-IRDye800CW. Similarly, Rybrevant-IRDye800CW was specifically identified in orthotopic CRC and lymph node metastasis models, with all orthotopic tumours showing high tumour-to-background ratios in NIR-II imaging. In a NIR-II preclinical study, Rybrevant-IRDye800CW could specifically identify fresh human CRC and its metastatic lymph node tissue.

INTERPRETATION

This study confirmed the complementary EGFR and c-Met expression in CRC and its metastatic lymph nodes. Compared to single-target probes, EGFR and c-Met dual-specific fluorescent probes identified CRC and its metastatic lymph nodes using NIR-II imaging. Thus, NIR-II-guided R0 surgery was performed to resect the CRC and metastatic lymph nodes.

FUNDINGS

This study was supported by the Beijing Natural Science Foundation (Grant numbers: L222054, 7244517, 4232058, L248026, L232020), National Natural Science Foundation of China (NSFC) (92059207, 92359301, 92259303, 62027901, 81930053, 81227901, U21A20386), CAS Youth Interdisciplinary Team (JCTD-2021-08), and the Fundamental Research Funds for the Central Universities (Grant no. JK2024-2-35-02).

Advances in Lanthanide-Based NIR-IIb Probes for In Vivo Biomedical Imaging

The past decades have witnessed the significant development and practical interest of in vivo biomedical imaging technologies and optical materials in the second-near infrared (NIR-II, 1000-1700 nm) window. Imaging with the extended emission wavelength toward the long-wavelength end (NIR-IIb, 1500-1700 nm) further offers micrometer imaging resolution and centimeter tissue penetration depth by taking advantage of the much-reduced photon scattering and near-zero tissue autofluorescence background, which have become a very hot research area. This review focuses on the recent advances in the development of lanthanide-based NIR-IIb probes for in vivo biomedical applications. The progress including ratiometric imaging, multiplexed imaging for wide-field and microscopy, lifetime multiplexing and sensing, persistent luminescence, and multimodal imaging is summarized. Challenges and future directions concerning the investigation of the photophysical and photochemical properties of NIR-IIb probes, the selection of near-infrared cameras as well as the potential extension of the NIR-IIb imaging sub-window are pointed out. This review will inspire readers who have a strong interest in developing optical imaging technology and long-wavelength fluorescence probes for high-contrast in vivo biomedical applications.

Fibroblast activation protein peptide-targeted NIR-I/II fluorescence imaging for stable and functional detection of hepatocellular carcinoma

PURPOSE

Cancer-associated fibroblasts (CAFs) are the primary stromal component of the tumor microenvironment in hepatocellular carcinoma (HCC), affecting tumor progression and post-resection recurrence. Fibroblast activation protein (FAP) is a key biomarker of CAFs. However, there is limited evidence on using FAP as a target in near-infrared (NIR) fluorescence imaging for HCC. Thus, this study aims to develop a novel NIR fluorescent imaging strategy targeting FAP+ CAFs in HCC.

METHODS

The ICG-FAP-TATA probe was synthesized by conjugating a novel cyclization anti-FAP peptide with an indocyanine green derivative (ICG-NH2) as fluorophore, capable for NIR window I (NIR-I, 700-900 nm) and II (NIR-II, 1000-1700 nm) imaging. Its efficacy in lesion localization and other potential applications was evaluated.

RESULTS

In vivo imaging of subcutaneous HCC models revealed that ICG-FAP-TATA specifically targeted FAP+ CAFs in the stroma and detected differences in CAFs loading within lesions. The fluorescence intensity/tumor-to-background ratio (TBR) positively correlated with FAP expression (R2 > 0.8, p < 0.05). Ex vivo incubation of tumor tissues with ICG-FAP-TATA provided stable fluorescence imaging of tumors in subcutaneous and orthotopic HCC models, including different cell line co-culture systems (LM3-luc, MHCC97H-luc, HepG2-luc + LX2), and various liver backgrounds (healthy/fibrotic) (n = 5 per group). TBR of the tumor mice models was higher for NIR-II than NIR-I imaging (3.89 ± 1.27 vs. 2.64 ± 0.64, p < 0.05). Moreover, NIR-I/II imaging of fresh tissues from seven patients with HCC undergoing surgery incubated with ICG-FAP-TATA visually provided the spatial distribution heterogeneity of CAFs. The targeted fluorescence was relatively enriched more in the blood flow direction and at the tumor edge, both of which were associated with tumor metastasis (all p < 0.05).

CONCLUSION

This study presents a rapid and effective method for detecting HCC lesions, locating FAP+ CAFs, and visualizing high-risk areas for tumor metastasis at the macroscopic level. It offers a new promising approach with translational potential for imaging HCC.

GSH-Responsive Semiconducting Polymer as a Nanotheranostic Platform for NIR-II Imaging-Guided Chemo-Photothermal Therapy

The development of multifunctional nanotheranostic platforms with stimuli-responsive capabilities holds significant potential for enhancing cancer diagnosis and treatment. Herein, a glutathione (GSH)-responsive semiconducting polymer (SP) nanotheranostic system, SP/DOX-SS-PEG nanoparticles (NPs), is presented, designed for combined near-infrared II (NIR-II) fluorescence imaging (FI) and chemo-photothermal therapy. The amphiphilic SP (SP-SS-PEG) is synthesized through a multi-step reaction sequence, including Suzuki coupling, amidation, and thiol-disulfide exchange reactions, and subsequently encapsulates the anticancer drug doxorubicin (DOX) through self-assembly, resulting in the formation of GSH-responsive SP/DOX-SS-PEG NPs. These SP/DOX-SS-PEG NPs exhibit high photothermal stability and significant GSH-triggered DOX release. In vitro studies demonstrate that SP/DOX-SS-PEG NPs display enhanced cellular uptake and robust cytotoxicity against 4T1 cancer cells under 808 nm laser irradiation. Upon intravenous injection in tumor-bearing mice, NIR-II FI reveals efficient tumor accumulation and prolonged retention of the NPs. In vivo anti-tumor efficacy studies indicate that SP/DOX-SS-PEG NPs combined with 808 nm laser irradiation achieve the most significant inhibition of tumor growth, with minimal systemic toxicity. Taken together, these findings highlight the promising potential of SP/DOX-SS-PEG NPs as a multifunctional platform for precision cancer theranostics, integrating efficient NIR-II imaging, GSH-triggered drug release, and dual chemo-photothermal therapy.

In Situ and Real-Time Multi-Modality Imaging Guided Orderly Triple-Therapy of Tumors with a Multifunctional Nanodrug

Effective integration of different therapeutic methods is a promising way to improve the overall efficacy of tumor therapy, which needs to be guided by in situ and real-time monitoring of each therapeutic process. Here a multifunctional AuNR@SiO2@MnO2@DNA prodrugs (ASMD) nanodrug is designed for orderly photothermal therapy (PTT)/chemodynamic therapy (CDT)/gene therapy (GT) triple-therapy of tumors, which can be guided by the in situ and real-time photoacoustic (PA)/magnetic resonance (MR)/fluorescence (FL) multi-modality imaging. The gold nanorod in ASMD can generate a PA signal and perform PTT. The MnO2 in ASMD can respond to the glutathione inside tumor cells to release Mn2+, which can generate MR signal and perform CDT by catalyzing the degradation of intracellular H2O2 to generate ·OH. The DNA prodrugs can perform a cascade response in the presence of the released Mn2+ and the intracellular microRNA 21, which can turn on the quenched FL signal and release small-interfering RNA and antisense oligonucleotide to perform GT. Guiding by the in situ and real-time PA/MR/FL multi-modality imaging of each therapeutic process, an orderly PTT/CDT/GT triple-therapy of tumors is established, which provides a significant and promising strategy to develop more efficient and practical therapeutic programs for tumors.

Radionuclide-Activated Luminescence for Cancer Theranostics

Within dielectric media, charged particles emitted from medical radionuclides induce polarization of surrounding molecules, which subsequently generate Cerenkov luminescence (CL) upon returning to their ground state. This CL emission confers clinically approved radiotracers with distinctive potential for applications in phototheranostics. However, the utility of CL in vivo has been severely constrained by its ultraviolet-weighted emission spectrum and extremely low photon flux, particularly in living imaging and triggering photodynamic therapy. Certain optical probes, encompassing fluorescent agents and nanoparticle scintillators, can be activated by radionuclides to generate red-shifted emissions with amplified luminescence intensity compared to CL. This phenomenon, termed radionuclide-activated luminescence (RL), represents a promising strategy for enhancing radionuclide-induced tumor phototheranostic outcomes. This review systematically summarizes the advances in RL technology, highlighting the development of various RL probes and their innovative applications in laser-free optical bioimaging and cancer phototherapy. It further delves into the confronting challenges and prospects of RL technology, aiming to provide a comprehensive overview and practical insights to advance the integration of radiotheranostics and phototheranostics in clinical practice.

Signal-to-Noise Ratio Imaging and Real-Time Sharpening of Tumor Boundaries for Image-Guided Cancer Surgery

Fluorescence-guided cancer surgery is of considerable current interest in bioanalytical chemistry, engineering, and medicine, but its clinical utility is still hampered by the diffusive (scattering) nature of human tissues and large variations among different patients. Here, we report a new method based on signal-to-noise (contrast-to-noise) ratio (SNR or CNR) imaging for real-time delineation and sharpening of tumor boundaries during image-guided cancer surgery. In particular, we show that in vivo tumor fluorescence signals (both intensity and standard deviation) are strongly correlated with those of the surrounding tissue of the same tissue type and that this relationship is maintained as a function of time for fluorescent tracers such as indocyanine green. This dynamic relationship permits a precise removal of nonspecific background fluorescence from tumor fluorescence. As a result, single-pixel SNR values have been calculated, mapped, and displayed across a large surgical field at 60 frames per second. Pathological validation studies indicate that these SNR values correspond to statistical confidence levels similar (but not identical) to those of normal distributions. When the tumor fluorescence has an SNR of 3, pathological data show a confidence level of approximately 95% in identifying the true tumor lesions. For clinical relevance, we have also carried out first-in-human clinical studies for both oral and esophageal tumors, achieving tumor margin precisions of 1-2 mm with 87.5% histological accuracy and no false positives.

Surgery or Percutaneous Ablation for Liver Tumors? The Key Points Are: When, Where, and How Large

The most recent comparisons between liver resection (LR) and percutaneous thermal ablation (PTA) reported similar efficacy and survival outcomes for primary and secondary liver tumors ≤ 3 cm in size. Nevertheless, LR still remains the most popular treatment strategy worldwide, and percutaneous ablation is usually reserved to patients who are not surgical candidates. However, in our opinion, the debate should no longer be what is the most effective treatment for patients with resectable small liver cancer who are not candidates for liver transplantation, but rather when LR or PTA are best suited to the individual patient. Subcapsular tumors or tumors closely adjacent to critical structures or vulnerable organs should undergo LR because ablation can often not achieve an adequate safety margin. Conversely, PTA should be considered the first choice to treat central tumors because it has lower complication rates, lower costs, and shorter hospital stay. Furthermore, recent technical improvements in tumor targeting and accurate assessment of the extent of the safety margin, such as stereotactic navigation, fusion imaging and software powered by Artificial Intelligence enabling the immediate comparison between the pre-procedure planned margins and the ablation area, are also changing the approach to tumors larger than 3 cm. The next trials should be aimed at investigating up to what tumor size PTA supported by these advanced technologies can achieve outcomes comparable to LR.

In vivo dynamic visualization and evaluation of collagen degradation utilizing NIR-II fluorescence imaging in mice models

Collagen-based biomaterials are gaining prominence in tissue engineering, attributed to their remarkable biocompatibility, inherent biodegradability, and unparalleled capacity to facilitate tissue repair and regeneration. However, the ability to dynamically visualize and quantitatively assess collagen degradation in vivo remains a critical challenge, hindering the development of optimized biomaterials for clinical applications. To address this, a novel approach was developed to monitor the injury microenvironment by conjugating second near-infrared quantum dots with solid collagen. This live imaging system offered high-resolution, real-time tracking of collagen degradation both in vitro and in vivo, enabling a deeper understanding of the degradation behavior under various conditions. This system was applied to mouse models with different cartilage defects, including critical-sized defect (CSD), minor defect (Minor) and sham surgery (Sham) groups for a 28-day in vivo monitoring. Among them, the CSD group exhibited the fastest and most stable collagen degradation, indicating that the degradation rate was closely linked to the severity of the injury. Transcriptomic analysis further identified key signaling pathways that might drive rapid collagen degradation by promoting collagenase activity and tissue remodeling in cartilage defect conditions. In summary, our study provided valuable insights into the mechanisms of collagen degradation under different injury conditions, contributing to innovative strategies for designing collagen-related biomaterials in the future.

Gradient-Metasurface-Contact Photodetector for Visible-to-Near-Infrared Spin Light

Spin light detection is a rapidly advancing field with significant impact on diverse applications in biology, medicine, and photonics. Developing integrated circularly polarized light (CPL) detectors is pivotal for next-generation compact polarimeters. However, previous compact CPL detectors, based on natural materials or artificial resonant nanostructures, exhibit intrinsically weak CPL polarization sensitivity, are susceptible to other polarization states, and suffer from limited bandwidths. A gradient-metasurface-contact CPL photodetector is demonstrated operating at zero-bias with a high discrimination ratio (≈1.6 ✗ 104), broadband response (500-1100 nm), and immunity to non-CPL field components. The photodetector integrates InSe flakes with CPL-selective metasurface contacts, forming an asymmetric junction interface driven by CPL-dependent unidirectional propagating surface plasmon waves, generating zero-bias vectorial photocurrents. Furthermore, it is implemented the developed CPL photodetector in a multivalued logic system and demonstrated the optical decoding of CPL-encrypted communication signals. This metasurface contact engineering represents a new paradigm in light property detection, paving the way for future integrated optoelectronic systems for on-chip polarization detection.

Upconversion Nanoparticle-Delivery Flexible Optrodes for Long-Lasting Multichannel Electrophysiology and Transcranial NIR Optogenetics

Near-infrared (NIR) activatable nanoparticles enable remote, cell-type-specific manipulation of neuronal activity, whereas flexible microelectrode arrays (FMAs) facilitate long-term, multichannel recording of neural signals. Despite the recent development of multifunctional neural probes, integrating these techniques into a single, minimally invasive device remains challenging. Here, we present a novel optrode that combines NIR-activatable upconversion nanoparticles (UCNPs) with FMAs. The UCNPs and FMAs are coencapsulated in a nanoliter-scale polymer carrier and delivered into the same brain regions through a single surgery, ensuring highly spatial congruence between the manipulated and recorded neuronal populations. Chronically implanted devices enable simultaneous multichannel recording and transcranial modulation of opsin-defined neuronal populations over extended periods. The flexibility and minimal invasiveness of our optrodes provide a powerful tool for the long-term and spatially precise interrogation of neural circuit functions.

Advances in Organic Small Molecule-Based Fluorescent Probes for Precision Detection of Liver Diseases: A Perspective on Emerging Trends and Challenges

Liver disease poses a significant challenge to global health, and its early diagnosis is crucial for improving treatment outcomes and patient prognosis. Since fluctuation of key biomarkers during the onset and progression of liver diseases can directly reflect liver health and normal/abnormal function, biomarker-based assays are vital tools for the early detection of liver disease. In this context, small molecule fluorescent probes have undeniably emerged as indispensable tools for diagnosis and analysis, with an ever-growing number of small molecule-based fluorescent probes being developed over recent years, with the sole aim of monitoring relevant biomarkers of liver disease. This perspective will focus on the development and application of probes developed primarily over the last 10 years for diagnosing a range liver disease-related processes. It will outline the foundational design strategies for developing promising probes, their optical response to key biomarkers, and how they have been demonstrated in proof-of-concept imaging applications. Current challenges and new developments in the field will be discussed, with the aim of providing insights and highlighting opportunities in the field.

Deep Learning Enhanced Near Infrared-II Imaging and Image-Guided Small Interfering Ribonucleic Acid Therapy of Ischemic Stroke

Small interfering RNA (siRNA) targeting the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome has emerged as a promising therapeutic strategy to mitigate infarct volume and brain injury following ischemic stroke. However, the clinical translation of siRNA-based therapies is significantly hampered by the formidable blood-brain barrier (BBB), which restricts drug penetration into the central nervous system. To address this challenge, we have developed an innovative long-circulating near-infrared II (NIR-II) nanoparticle platform YWFC NPs, which is meticulously engineered to enhance BBB transcytosis and enable efficient delivery of siRNA targeting NLRP3 (siNLRP3@YWFC NPs) in preclinical models of ischemic stroke. Furthermore, we integrated advanced deep learning neural network algorithms to optimize in vivo NIR-II imaging of the cerebral infarct penumbra, achieving an improved signal-to-background ratio at 72 h poststroke. In vivo studies employing middle cerebral artery occlusion (MCAO) mouse models demonstrated that image-guided therapy with siNLRP3@YWFC NPs, guided by prolonged NIR-II imaging, resulted in significant therapeutic benefits.

Tracking the Fate of Therapeutic Proteins Using Ratiometric Imaging of Responsive Shortwave Infrared Probes

Monoclonal antibodies (mAbs) are essential agents for cancer treatment and diagnosis. Advanced optical imaging strategies have the potential to address specific questions regarding their complex in vivo life cycle. This study presents responsive shortwave infrared (SWIR) probes and an associated imaging scheme to assess mAb biodistribution, cellular uptake, and proteolysis. Specifically, we identify a Pegylated benzo-fused norcyanine derivative (Benz-NorCy7) that is activated in acidic environments and can be appended to mAbs without significant changes in optical properties. As a mAb conjugate, this agent shows high tumor specificity in a longitudinal imaging study in a murine model. To enable independent tracking of mAb uptake and lysosomal uptake and retention, a two-color ratiometric imaging strategy was employed using an "always-ON" heptamethine cyanine dye (λex = 785 nm) and the pH-responsive Benz-NorCy7 (λex = 890 nm). To assess proteolytic catabolism, we append a cleavable carbamate to Benz-NorCy7 to create turn-ON probes. These agents facilitate the comparison of two common peptide linkers and provide insights into their in vivo properties. Overall, these studies provide a strategy to assess the fate of protein-based therapeutics using optical imaging.

GCN5-targeted dual-modal probe across the blood-brain barrier for borders display in invasive glioblastoma

Glioblastoma (GBM) is a highly invasive malignancy with a poor prognosis, primarily attributable to its diffuse infiltration into adjacent brain tissue, thereby complicating effective surgical resection. Current imaging modalities often struggle to accurately identify tumor boundaries. Here, we identify general control non-repressed protein 5 (GCN5) as a promising molecular target for GBM imaging, as it is expressed in GBM lesions within brain tissue, and its expression levels are significantly correlated with GBM grading. We develop a dual-modal probe with a particle size of 20 nm, capable of efficiently traversing the blood-brain barrier (BBB) to target GCN5 through adsorptive-mediated transcytosis (AMT). The probe employs dendrimers (Den) as carriers, which are loaded with a small molecule inhibitor specifically designed to target GCN5. This probe enhances the preoperative delineation of GBM boundaries using magnetic resonance imaging (MRI) and facilitates intraoperative fluorescence image-guided surgical procedures. Our work introduces a promising tool for boundary delineation, offering new opportunities for the precise resection of GBM.

Deep Equilibrium Unfolding Learning for Noise Estimation and Removal in Optical Molecular Imaging

In clinical optical molecular imaging, the need for real-time high frame rates and low excitation doses to ensure patient safety inherently increases susceptibility to detection noise. Faced with the challenge of image degradation caused by severe noise, image denoising is essential for mitigating the trade-off between acquisition cost and image quality. However, prevailing deep learning methods exhibit uncontrollable and suboptimal performance with limited interpretability, primarily due to neglecting underlying physical model and frequency information. In this work, we introduce an end-to-end model-driven Deep Equilibrium Unfolding Mamba (DEQ-UMamba) that integrates proximal gradient descent technique and learnt spatial-frequency characteristics to decouple complex noise structures into statistical distributions, enabling effective noise estimation and suppression in fluorescent images. Moreover, to address the computational limitations of unfolding networks, DEQ-UMamba trains an implicit mapping by directly differentiating the equilibrium point of the convergent solution, thereby ensuring stability and avoiding non-convergent behavior. With each network module aligned to a corresponding operation in the iterative optimization process, the proposed method achieves clear structural interpretability and strong performance. Comprehensive experiments conducted on both clinical and in vivo datasets demonstrate that DEQ-UMamba outperforms current state-of-the-art alternatives while utilizing fewer parameters, facilitating the advancement of cost-effective and high-quality clinical molecular imaging.

Efficacy and safety of indocyanine green fluorescence navigation versus conventional laparoscopic hepatectomy for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Indocyanine green (ICG) fluorescence imaging technology is increasingly widely used in laparoscopic hepatectomy. However, previous studies have produced conflicting results regarding whether it is truly superior to traditional laparoscopic hepatectomy. This study investigated the clinical effect of laparoscopic hepatectomy for hepatocellular carcinoma (HCC) using ICG imaging technology.

METHODS

A systematic review and meta-analysis, based on the preferred reporting items for systematic reviews and meta-analysis statement, were conducted (PROSPERO: CRD42024532356). A computer search was conducted in databases including CNKI, Wanfang, PubMed, Embase, Cochrane Library, and Web of Science from January 1, 1990, to April 30, 2024.

RESULTS

A total of 17 articles were included after screening, comprising 4 randomized controlled trials and 13 case-control studies, with 1620 patients in total. Among these, there were 743 cases in the fluorescence laparoscopy group and 877 cases in the non-fluorescence laparoscopy group. Hepatectomy guided by indocyanine green fluorescence navigation significantly reduced operation time (MD = - 23.25, 95% CI: - 36.35 to - 10.15, P = 0.0005), intraoperative blood loss (MD = - 51.04, 95% CI: - 69.52 to - 32.56, P < 0.00001), and intraoperative transfusion rate (OR = 0.43, 95% CI: 0.27 to 0.69, P = 0.0004), while increasing the R0 resection rate (OR = 2.93, 95% CI: 1.73 to 4.96, P < 0.0001) and decreasing the postoperative complication rate (OR = 0.59, 95% CI: 0.43 to 0.82, P = 0.002). However, there was no statistically significant difference in postoperative length of hospital stay (MD = - 0.67, 95% CI: - 1.51 to 0.18, P = 0.12).

CONCLUSION

In the treatment of HCC, hepatectomy guided by indocyanine green fluorescence navigation demonstrates superior efficacy and safety, its application and promotion are warranted.

Near-Infrared II Fluorescence Imaging Highlights Tumor Angiogenesis in Hepatocellular Carcinoma with a VEGFR-Targeted Probe

Hepatocellular carcinoma (HCC) is typically characterized by rich vascularity, with angiogenesis playing a crucial role in its growth and invasion. Molecular imaging of specific receptors in blood vessels is crucial in HCC diagnosis. In particular, in vivo imaging utilizing the second near-infrared (NIR-II) window offers improved tissue penetration, reduced light scattering, and lower autofluorescence. Despite the great potential of the NIR-II window, developing safe and effective probes to provide better imaging performance for HCC is urgently needed. In this study, NIR-II imaging integrated with a vascular endothelial growth factor receptor (VEGFR)-targeted probe generated by combining a VEGFR-targeted peptide with indocyanine green (ICG) is used to characterize HCC-related angiogenesis at a resolution of 56.0 µm. For the first time, liver metabolic curves and parameters of liver function reserve (LFR) are obtained by fitting NIR-II fluorescence signals with high spatiotemporal resolution, showing significant differences between HCC mice and controls. Moreover, unlike ICG, the targeting probe has a targeted effect on blood vessels in vivo. The tumor-to-normal (T/N) ratio in NIR-II imaging reaches up to 3.30 after post-injection of the targeting probe. The results indicate that the VEGFR-targeted probe is a powerful tool for NIR-II fluorescence imaging to enhance early diagnosis of HCC.

Chromenylium Star Polymers: Merging Water Solubility and Stealth Properties with Shortwave Infrared Emissive Fluorophores

Fluorescence imaging in the shortwave infrared (SWIR) region has emerged as a vital tool for studying mammals. SWIR emissive polymethine dyes are well-suited to this endeavor; however, advancing in vivo imaging utility with these dyes is primarily limited by hydrophobicity and/or nonspecific protein association. Herein, we take a distinct approach to combine hydrophilicity and stealth behavior to construct bright, SWIR emissive chromenylium fluorophores by employing a well-defined poly(2-methyl-2-oxazoline) (POx) star polymer architecture, which we refer to as chromenylium stars, or "CStars." Of these polymer-shielded dyes, the variant containing five POx chains (CStar30) boasts particularly enhanced aqueous solubility and SWIR brightness, enabling high-resolution SWIR imaging in mice. The swift renal clearance and stealth behavior displayed in vivo also achieves improved noninvasive visualization of the lymphatic system. Further, CStar's orthogonal biodistribution to an FDA-approved dye, indocyanine green (ICG), facilitates excitation-multiplexed SWIR imaging in two colors to achieve simultaneous visualization of both fluid dynamics and protein dynamics in the same animal in real time at video-rate frame counts.

Spatially Selective MicroRNA Imaging in Human Colorectal Cancer Tissues Using a Multivariate-Gated Signal Amplification Nanosensor

MicroRNA (miRNA) is involved in the genesis in viand development of colorectal cancer. The in vivo imaging of miRNA at the tumor sites is essential for understanding its role in colorectal cancer pathology and therapeutic target identification. However, achieving accurate imaging of miRNA at the tumor sites is hindered by the low abundance of miRNAs in tumor cells and nonspecific signal leakage in normal tissues. Here, we report a multivariate-gated catalytic hairpin assembly (CHA) nanosensor for the specific amplified imaging of microRNA-21 (miR-21) in human colorectal cancer tissues to reveal the underlying miR-21-associated molecular mechanism. The endogenous glutathione and exogenous near-infrared multivariate-gated design in combination with CHA probes improves the signal strength of target miR-21 and reduces the background interference. The nanosensor enables specific amplified imaging of miR-21 in vivo, and the signal-to-background ratios are 1.6-fold compared with traditional CHA methods. With the assistance of the designed nanosensor, we achieve the preliminary identification of tumor tissues and normal tissues from human clinical surgical resection samples. The overexpressed miR-21 is found to suppress the core mismatch repair recognition protein human mutS homologue 2 involved in DNA damage recognition and repair to inhibit the therapeutic efficacy of colorectal cancer. The strategy of probe design, which combines multivariate-gated activation methods with a signal amplification system, is applicable for accurate miRNA imaging and disease-relevant molecular mechanism research.

The Medical Basis for the Photoluminescence of Indocyanine Green

Indocyanine green (ICG), a near-infrared (NIR) fluorescent dye with unique photoluminescent properties, is a helpful tool in many medical applications. ICG produces fluorescence when excited by NIR light, enabling accurate tissue visualization and real-time imaging. This study investigates the fundamental processes behind ICG's photoluminescence as well as its present and possible applications in treatments and medical diagnostics. Fluorescence-guided surgery (FGS) has been transformed by ICG's capacity to visualize tumors, highlight blood flow, and facilitate lymphatic mapping, all of which have improved surgical accuracy and patient outcomes. Furthermore, the fluorescence of the dye is being studied for new therapeutic approaches, like photothermal therapy, in which NIR light can activate ICG to target and destroy cancer cells. We go over the benefits and drawbacks of ICG's photoluminescent qualities in therapeutic contexts, as well as current studies that focus on improving its effectiveness, security, and adaptability. More precise disease detection, real-time monitoring, and tailored therapy options across a variety of medical specialties are made possible by the ongoing advancement of ICG-based imaging methods and therapies. In the main part of our work, we strive to take into account the latest reports; therefore, we used clinical articles going back to 2020. However, for the sake of the theoretical part, the oldest article used by us is from 1995.

Side Chain Phenyl Isomerization-Induced Spatial Conjugation for Achieving Efficient Near-Infrared II Phototheranostic Agents

The contradiction of near-infrared II (NIR-II) emission and photothermal effects limits the development of phototheranostic agents (PTAs) in many emerging cutting-edge applications. Organic aggregates present a promising opportunity for the balance of competitive relaxation processes through the manipulation of molecular structure and packing. Herein, side chain phenyl isomerization-induced spatial conjugation was proposed for constructing A-D-A type NIR-II PTAs with simultaneous enhancement of fluorescence brightness and photothermal properties. Three pairs of mutually isomeric fluorophores, whose phenyls respectively located at the outside (o-series) and inside (i-series) of the side chain, were designed and synthesized. The positional isomerization of the phenyl endows the o-series crystals with strong spatial conjugation between the phenyl group on the side chain and the backbone, as well as interlocked planar network, which is different to that observed in the i-series. Thus, all o-series nanoparticles (NPs) exhibit red-shifted absorption, enhanced NIR-II emission, and superior photothermal properties than their i-series counterparts. A prominent member of the o-series, o-ITNP NPs, demonstrated efficacy in facilitating NIR-II angiography, tumor localization, and NIR-II imaging-guided tumor photothermal therapy. The success of this side chain phenyl isomerization strategy paves the way for precise control of the aggregation behavior and for further development of efficient NIR-II PTAs.

Optical imaging guidance in oncologic surgery and interventional oncology

Over recent decades, optical imaging (OI) has become an integral part of medical imaging, offering significant advantages over other modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI). OI is distinguished by its real-time imaging capability, cost-effectiveness, portability, absence of ionizing radiation, and high patient acceptability. The introduction of advanced optical dyes (including FDA-approved agents like indocyanine green, Cytalux, and Gleolan) has greatly enhanced its clinical utility. OI has shown clear benefits in the management of patients with cancer, originally by open surgery and now extending to minimally invasive, image-guided interventional procedures. This review highlights recent developments in OI for oncology, emphasizing its benefits for clinicians in guiding surgical and interventional procedures.

Activatable Molecular Probes With Clinical Promise for NIR-II Fluorescent Imaging

The second near-infrared window (NIR-II) fluorescence imaging has been widely adopted in basic scientific research and preclinical applications due to its exceptional spatiotemporal resolution and deep tissue penetration. Among the various fluorescent agents, organic small-molecule fluorophores are considered the most promising candidates for clinical translation, owing to their well-defined chemical structures, tunable optical properties, and excellent biocompatibility. However, many currently available NIR-II fluorophores exhibit an "always-on" fluorescence signal, which leads to background noise and compromises diagnostic accuracy during disease detection. Developing NIR-II activatable organic small-molecule fluorescent probes (AOSFPs) for accurately reporting pathological changes is key to advancing NIR-II fluorescence imaging toward clinical application. This review summarizes the rational design strategies for NIR-II AOSFPs based on four core structures (cyanine, hemicyanine, xanthene, and BODIPY). These NIR-II AOSFPs hold substantial potential for clinical translation. Furthermore, the recent advances in NIR-II AOSFPs for NIR-II bioimaging are comprehensively reviewed, offering clear guidance and direction for their further development. Finally, the prospective efforts to advance NIR-II AOSFPs for clinical applications are outlined.

Conversion therapy strategy: A novel GPC3-targeted multimodal organic phototheranostics platform for mid-late-stage hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is typically diagnosed at intermediate to advanced stage, making surgical treatment unfeasible. Conversion therapy aims to reduce tumor stage, improve hepatic resection feasibility, and lower recurrence rates. Since traditional therapies are often accompanied by uncertainty of efficacy, there is an urgent need to explore new treatment strategies. Near-infrared phototheranostics technology provides a new way for HCC diagnosis and treatment by its excellent optical properties. However, complex preparation and poor biocompatibility of phototheranostics probes limit clinical application. In this study, we developed a fluorescence/magnetic resonance dual-modality imaging (FLI/MRI) as well as photothermal/photodynamic therapy (PTT/PDT) GPC3-targeted multifunctional phototheranostics probe, IR820-GPC3-Gd NPs (IGD NPs), to improve the efficiency of conversion therapy for HCC. The IGD NPs were simply prepared with the IR820 as the core. Conjugating the HCC-specific targeting molecule GPC3 peptide and the MRI agent DOTA-Gd through click chemistry. IGD NPs target HCC cells through GPC3, releasing heat and reactive oxygen species (ROS) under noninvasive 808 nm laser irradiation to reduce tumor size and achieve downstaging. High-sensitivity FLI/MRI precisely delineates tumor boundaries, providing real-time surgical navigation and prognosis assessment. This novel probe offers a feasible and effective treatment option for advanced HCC.

Efficacy and safety of fluorescence navigation combined with 3D imaging in precise liver resection: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the effectiveness and safety of fluorescence navigation combined with three-dimensional imaging (FN&3DI) technology in precise liver resection.

METHODS

A systematic search was conducted in the PubMed, Web of Science, Embase, and Cochrane Library databases for all English-language publications on fluorescence-guided navigation combined with three-dimensional (3D) imaging technology-assisted precise liver resection, with a cutoff date of July 2024. After assessing the quality of the included studies and extracting relevant data, a meta-analysis was performed using Stata 12.0 software.

RESULTS

A total of 6 studies involving 451 patients were included in this study, with 207 patients in the FN&3DI group and 244 patients in the conventional surgery (CS) group. The meta-analysis results showed that the FN&3DI group exhibited significantly lower values than the CS group in terms of intraoperative blood loss [mean difference (MD) = -97.90, 95 % confidence intervals (CI) = -151.15 to -44.66, P = 0.000], intraoperative blood transfusion rates [odds ratios (OR) = 2.96, 95 % CI = 1.71-5.10, P = 0.000], hospital stay (MD = -0.91, 95 % CI = -1.78 to -0.04, P = 0.041), and overall postoperative complications (OR = 1.68, 95 % CI = 1.11 to 2.53, P = 0.014). However, the FN&3DI group exhibited significantly longer surgery time (MD = 57.36, 95 % CI = 13.31-101.40, P = 0.011), but no statistically significant difference was noted in conversion rate, R0 resection margins, and postoperative recurrence between the two groups.

CONCLUSION

Fluorescence navigation combined with 3D imaging technology is safe and feasible for guiding precise liver resection.

Oligonucleotide probes for imaging and diagnosis of bacterial infections

The rise of infectious diseases as a public health concern has necessitated the development of rapid and precise diagnostic methods. Imaging techniques like nuclear and optical imaging provide the ability to diagnose infectious diseases within the body, eliminating delays caused by sampling and pre-enrichments of clinical samples and offering spatial information that can aid in a more informed diagnosis. Traditional molecular probes are typically created to image infected tissue without accurately identifying the pathogen. In contrast, oligonucleotides can be tailored to target specific RNA sequences, allowing for the identification of pathogens, and even generating antibiotic susceptibility profiles by focusing on drug resistance genes. Despite the benefits that nucleic acid mimics (NAMs) have provided in terms of stabilizing oligonucleotides, the inadequate delivery of these relatively large molecules into the cytoplasm of bacteria remains a challenge for widespread use of this technology. This review summarizes the key advancements in the field of oligonucleotide probes for in vivo imaging, highlighting the most promising delivery systems described in the literature for developing optical imaging through in vivo hybridization.

High Spatiotemporal Near-Infrared II Fluorescence Lifetime Imaging for Quantitative Detection of Clinical Tumor Margins

Accurate detection of tumor margins is essential for successful cancer surgery. While indocyanine green (ICG)-based near-infrared (NIR) fluorescence (FL) surgical navigation enhances the visual identification of tumor margins, its accuracy remains subjective, underscoring the need for quantitative approaches. In this study, a high spatiotemporal fluorescence lifetime (FLT) imaging technology is developed in the second near-infrared window (NIR-II, 1000-1700 nm) for quantitative tumor margin detection, utilizing folate receptor-targeted ICG nanoprobes (FPH-ICG). FPH-ICG exhibits a significantly prolonged NIR-II FLT (750 ± 7 ps vs 260 ± 3 ps) and increased NIR-II FL brightness (FPH-ICG/ICG = 3.8). In vitro and in vivo studies confirm that FPH-ICG specifically targets folate receptor-α (FRα) on SK-OV-3 ovarian cancer cells, achieving high-contrast NIR-II FL imaging with a signal-to-background ratio of 10.8. Notably, NIR-II FLT imaging demonstrates superior accuracy (90%) and consistency in defining tumor margins compared to NIR-II FL imaging (58%) in both SK-OV-3 tumor-bearing mice and clinical tumor samples. These findings underscore the potential of NIR-II FLT imaging as a quantitative tool for guiding surgical tumor margin detection.

Preclinical advance in nanoliposome-mediated photothermal therapy in liver cancer

Liver cancer is a highly lethal malignant tumor with a high incidence worldwide. Therefore, its treatment has long been a focus of medical research. Although traditional treatment methods such as surgery, radiotherapy, and chemotherapy have increased the survival rate of patients, their efficacy remains unsatisfactory owing to the nonspecific distribution of drugs, high toxicity, and drug resistance of tumor tissues. In recent years, the application of nanotechnology in the medical field has opened a new avenue for the treatment of liver cancer. Among these treatment methods, photothermal therapy (PTT) based on nanoliposomes has attracted wide attention owing to its unique targeting and high efficiency. This article reviews the latest preclinical research progress of nanoliposome-based PTT for liver cancer and its metastasis, discusses the preclinical challenges in this field, and proposes directions for improvement, with the aim of improving the effectiveness of liver cancer treatment.

Broadband Near-Infrared Fibers Derived from Nanocrystal-Glass Composites for Miniature Arrays Light Sources

Broadband near-infrared (NIR) fiber arrays are highly desirable for multiplexed fluorescence endoscopic, however, there is a challenge for the development of miniature light sources with highly efficient broadband NIR emissions. Here the synthesis of a MgAl2O4:Cr3+ nanocrystal-glass composite (NGC) with an Cr3+-clusters-induced broadband NIR emission possessing is presented and external quantum efficiency of 44% and a full width at half maximum of 297 nm, and the NGC fiber is further fabricated through a template solidification strategy, resulting in the construction of an all-fiber coupling system by fusing them with commercial quartz fiber that achieves an optical coupling efficiency of 95.2%. Furthermore, these NGC fibers are regularly arranged into fiber bundle as an array light source to enhance NIR luminescence and imaging ability, and the fluorescence imaging of 4 mm biological tissue penetration is realized, as well as the multiplexed fluorescence imaging, under the irradiation of the NIR fiber bundle. This study provides general and efficient fiber fabrication guidelines toward NIR array light sources, opening the new routes for fluorescence endoscopes.

Evolution in optical molecular imaging techniques guided nerve imaging from 2009 to 2023: a bibliometric and visualization analysis

Background

Recent years, the use of optical molecular imaging (OMI) techniques guided nerve imaging has made significant progress. However, a comprehensive bibliometric analysis in this field is currently lacking. In this study, we aim to shed light on the current status, identify the emerging hot topics, and provide valuable insights for researchers within this field.

Methods

In this study, we collected 414 research via the Web of Science Core Collection (WoSCC) from 2009 to 2023. CiteSpace, VOSviewer and R package "bibliometrix" were used for analysis of countries, institutions, journals, etc., to evaluate the trends.

Results

The amounts of publications in relation to OMI guided nerve imaging has been increasing. United States and China contributed to over 60% of the publications. The Shanghai Jiao Tong University contributed the highest number of publications. Investigative Ophthalmology and Visual Science is considered the most prestigious and prolific journal in the field. It is also widely regarded as the most cited journal. Among the top 10 authors in terms of output, Hehir CAT has the highest number of citations. The "neurosciences neurology," "science technology other topics," and "ophthalmology" are representative research areas. The main cluster of keywords in this field includes "axonal regeneration," "mouse," and "optical coherence tomography."

Conclusion

This bibliometric investigation offers a comprehensive portrayal of the structure of knowledge and the progression patterns, presents an all-encompassing synthesis of findings, discerns and illustrates the forefront within OMI guided nerve imaging for the first time. It will provide a valuable reference for relevant scholars.

Recent Advances in Indocyanine Green-Based Probes for Second Near-Infrared Fluorescence Imaging and Therapy

Fluorescence imaging, a highly sensitive molecular imaging modality, is being increasingly integrated into clinical practice. Imaging within the second near-infrared biological window (NIR-II; 1,000 to 1,700 nm), also referred to as shortwave infrared, has received substantial attention because of its markedly reduced autofluorescence, deeper tissue penetration, and enhanced spatiotemporal resolution as compared to traditional near-infrared (NIR) imaging. Indocyanine green (ICG), a US Food and Drug Administration-approved NIR fluorophore, has long been used in clinical applications, including blood vessel angiography, vascular perfusion monitoring, and tumor detection. Recent advancements in NIR-II imaging technology have revitalized interest in ICG, revealing its extended tail fluorescence beyond 1,000 nm and reaffirming its potential as a clinically translatable NIR-II fluorophore for in vivo imaging and theranostic applications for diagnosing various diseases. This review emphasizes the notable advances in the use of ICG and its derivatives for NIR-II imaging and image-guided therapy from both fundamental and clinical perspectives. We also provide a concise conclusion and discuss the challenges and future opportunities with NIR-II imaging using clinically approved fluorophores.

Aggregation control of anionic pentamethine cyanine enabling excitation wavelength selective NIR-II fluorescence imaging-guided photodynamic therapy

Near-infrared (NIR)-II fluorescence imaging-guided photodynamic therapy (PDT) has shown great potential for precise diagnosis and treatment of tumors in deep tissues; however, its performance is severely limited by the undesired aggregation of photosensitizers and the competitive relationship between fluorescence emission and reactive oxygen species (ROS) generation. Herein, we report an example of an anionic pentamethine cyanine (C5T) photosensitizer for high-performance NIR-II fluorescence imaging-guided PDT. Through the counterion engineering approach, a triphenylphosphine cation (Pco) modified with oligoethylene glycol chain is synthesized and adopted as the counterion of C5T, which can effectively suppress the excessive and disordered aggregation of the resulting C5T-Pco by optimizing the dye amphipathicity and enhancing the cyanine-counterion interactions. Dynamic tuning of fluorescence characteristics and ROS generation is achieved at the aggregate level, resulting in an impressive type I ROS generation under 760 nm light irradiation, accompanied by efficient NIR-II fluorescence emission excited at 808 nm. As a result, excitation wavelength selective NIR-II fluorescence imaging-guided PDT has been successfully demonstrated for tumor diagnosis and therapeutics of female mice.

Amphiphilic hemicyanine molecular probes crossing the blood-brain barrier for intracranial optical imaging of glioblastoma

Intracranial optical imaging of glioblastoma (GBM) is challenging due to the scarcity of effective probes with blood-brain barrier (BBB) permeability and sufficient imaging depth. Herein, we describe a rational strategy for designing optical probes crossing the BBB based on an electron donor-π-acceptor system to adjust the lipid/water partition coefficient and molecular weight of probes. The amphiphilic hemicyanine dye (namely, IVTPO), which exhibits remarkable optical properties and effective BBB permeability, is chosen as an efficient fluorescence/photoacoustic probe for in vivo real-time imaging of orthotopic GBM with high resolution through the intact skull. Abnormal leakage of IVTPO adjacent to the developing tumor is unambiguously observed at an early stage of tumor development prior to impairment of BBB integrity, as assessed by commercial Evans blue (EB). Compared with EB, IVTPO demonstrates enhanced optical imaging capability and improved tumor-targeting efficacy. These results offer encouraging insights into medical diagnosis of intracranial GBM.

Recent progress towards the development of fluorescent probes for the detection of disease-related enzymes

Normal physiological functions as well as regulatory mechanisms for various pathological conditions depend on the activity of enzymes. Thus, determining the in vivo activity of enzymes is crucial for monitoring the physiological metabolism and diagnosis of diseases. Traditional enzyme detection methods are inefficient for in vivo detection, which have different limitations, such as high cost, laborious, and inevitable invasive procedures, low spatio-temporal resolution, weak anti-interference ability, and restricted scope of application. Because of its non-destructive nature, ultra-environmental sensitivity, and high spatiotemporal resolution, fluorescence imaging technology has emerged as a potent tool for the real-time visualization of live cells, thereby imaging the motility of proteins and intracellular signalling networks in tissues and cells and evaluating the binding and attraction of molecules. In the last few years, significant advancements have been achieved in detecting and imaging enzymes in biological systems. In this regard, the high sensitivity and unparalleled spatiotemporal resolution of fluorescent probes in association with confocal microscopy have garnered significant interest. In this review, we focus on providing a concise summary of the latest developments in the design of fluorogenic probes used for monitoring disease-associated enzymes and their application in biological imaging. We anticipate that this study will attract considerable attention among researchers in the relevant field, encouraging them to pursue advances in the development and application of fluorescent probes for the real-time monitoring of enzyme activity in live cells and in vivo models while ensuring excellent biocompatibility.

High-Definition, Video-Rate Triple-Channel NIR-II Imaging Using Shadowless Lamp Excitation and Illumination

Multichannel imaging in the second near-infrared (NIR-II) window offers vital and comprehensive information for complex surgical environments, yet a simple, high-quality, video-rate multichannel imaging method with low safety risk remains to be proposed. Centered at the superior NIR-IIx window of 1400-1500 nm, triple-channel imaging coordinated with 1000-1100 and 1700-1880 nm (NIR-IIc) achieves exceptional clarity and an impressive signal-to-crosstalk ratio as high as 22.10. To further simplify the light source and lower the safety risk, we develop a type of in vivo multichannel imaging-assisted surgical navigation mode at a video frame rate of 25 fps under shadowless lamp excitation and illumination instead of extra excitation light sources. This work provides a reference for real-time, high-imaging-performance multichannel imaging with minimal crosstalk and introduces a practical fluorescence surgical navigation paradigm.

Advances in prostate-specific membrane antigen-targeted theranostics: from radionuclides to near-infrared fluorescence technology

Prostate-Specific Membrane Antigen (PSMA) is a highly expressed and structurally unique target specific to prostate cancer (PCa). Diagnostic and therapeutic approaches in nuclear medicine, coupling PSMA ligands with radionuclides, have shown significant clinical success. PSMA-PET/CT effectively identifies tumors and metastatic lymph nodes for imaging purposes, while 177Lu-PSMA-617 (Pluvicto) has received FDA approval for treating metastatic castration-resistant PCa (mCRPC). Despite their success, radionuclide-based diagnostic and therapeutic methods face limitations such as high costs and significant side effects. Recently, near-infrared (NIR) fluorescence imaging and phototherapy have advanced significantly in biomedical applications. It's benefits, such as deep tissue penetration, real-time precision, and minimal side effects, have driven broader clinical adoption, especially in fluorescence-guided surgery (FGS). This review suggests combining NIR dyes with PSMA ligands to enable targeted, high-resolution imaging with superior signal-to-background ratios, facilitating precise FGS. NIR techniques can also aid pathological diagnosis in ex vivo specimens. Furthermore, combining photosensitizers with PSMA ligands allows localized photothermal (PTT) or photodynamic therapy (PDT) under NIR irradiation, producing heat or reactive oxygen species (ROS) to treat PCa. This review aims to extend the clinical success of radionuclide-based PSMA targeting by exploring advances in NIR-based FGS and phototherapy, presenting a promising new diagnostic and therapeutic approach.

NIR-II-excited off-on-off fluorescent nanoprobes for sensitive molecular imaging in vivo

Strong background interference signals from normal tissues have significantly compromised the sensitive fluorescence imaging of early disease tissues with exogenous probes in vivo, particularly for sensitive fluorescence imaging of early liver disease due to the liver's significant uptake and accumulation of exogenous nanoprobes, coupled with high tissue autofluorescence and deep tissue depth. As a proof-of-concept study, we herein report a near-infrared-II (NIR-II, 1.0-1.7 μm) light-excited "off-on-off" NIR-II fluorescent probe (NDP). It has near-ideal zero initial probe fluorescence but can turn on its NIR-II fluorescence in liver cancer tissues and then turn off the fluorescence again upon migration from cancer to normal tissues to minimize background interference. Due to its low background, a blind study employing our probes could identify female mice with orthotopic liver tumors with 100% accuracy from mixed subjects of healthy and tumor mice, and implemented sensitive locating of early orthotopic liver tumors with sizes as small as 4 mm. Our NIR-II-excited "off-on-off" probe design concept not only provides a promising molecular design guideline for sensitive imaging of early liver cancer but also could be generalized for sensitive imaging of other early disease lesions.

Integrating Ultrabright Polymer Dots and Stereo NIR-II Imager for Assessing Anti-Angiogenic Drugs in Oral Cancer Model

The development of efficient platforms for the evaluation of anti-angiogenic agents is critical in advancing cancer therapeutics. In this study, we exploited an ultrabright semiconducting polymer dots (Pdots) integrating with a three-dimensional (3D) near-infrared-II (NIR-II) fluorescence imaging system designed to assess the efficacy of potent anti-angiogenic agents PX-478 and BPR0C261 in an oral squamous cell carcinoma (OSCC) tumour model, which depends on angiogenesis for dissemination. PX-478, a hypoxia-inducible factor-1α (HIF-1α) inhibitor, and BPR0C261, a microtubule-disrupting agent, were administrated into tumour-bearing mice established using murine MTCQ1 tongue cancer cells through intraperitoneal injection and oral gavage, respectively. Our findings showed that PX-478 and BPR0C261 significantly inhibited tumour growth and extended the life span of tumour-bearing mice without decreasing the body weights. The Pdots-based NIR-II vascular imaging demonstrated that the tumour vascularity was suppressed by PX-478 and BPRC0261. Accordingly, the excised tumours treated with anti-angiogenic agents showed less blood vessels than that treated with vehicles. The expression of endothelial markers CD31 was also found to be reduced in tumours treated with PX-478 and BPRC0261 using immunohistochemical (IHC) staining and Western blot analysis. Furthermore, PX-478 could suppress the expression of HIF-1α and vascular endothelial growth factor-A (VEGF-A), but BPRC0261 only suppressed VEGF-A. Taken together, this innovative 3D NIR-II imaging system combining the biocompatible Pdots with unique optical specificity enables non-invasive, real-time monitoring the efficacy of anti-angiogenic compounds.