Near-infrared Imaging Research Articles

Cr3+-Doped LiAlO2 NIR-I Emitting Phosphors with Superior Resistance to Thermal Quenching for Night Vision Monitoring and Bioimaging.

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) as a new NIR light source has outstanding application potential in the fields of NIR spectroscopy analysis, sensing, imaging, and pattern recognition. Therefore, the development of NIR phosphors with good NIR luminescence thermal stability has attracted much attention. To this end, we developed LiAlO2:Cr3+ garnet-type NIR phosphors by a high-temperature solid-state reaction method. Under 405 nm excitation, the Cr3+ ions located in tetrahedrons of LiAlO2 emit NIR emission in a broadband NIR emission that covers 650-900 nm mixed with several sharp narrowband R-line emissions, which showed excellent luminescence thermal stability with integrated intensity of emission measured at 573 K is ∼90.86% of that measured at 303 K caused by good structural rigidity and low thermal expansion coefficient of the matrix material. An NIR pc-LED device assembled with the optimized LiAlO2:Cr3+ and a commercially available purple LED chip emitted NIR output power of ∼98.172 mW at a driving current of 300 mA and demonstrated an electro-optical conversion efficiency of ∼9.09%, while demonstrated it has excellent application potential in the fields of night vision monitoring and biomedical imaging.

Enhancing the tissue penetration to improve sonodynamic immunotherapy for pancreatic ductal adenocarcinoma using membrane-camouflaged nanoplatform.

Sonodynamic therapy (SDT) is a promising strategy as an "in situ vaccine" to enhance activation of antitumor immune responses in solid tumors. However, the dense extracellular matrix (ECM) in pancreatic ductal adenocarcinoma (PDAC) lead to hypoxia and limited penetration of most drugs, aggravating the immunosuppressive tumor microenvironment and limiting the efficacy of synergistic sonodynamic immunotherapy. Therefore, it is essential to regulate ECM in order to alleviate tumor hypoxia and enhance the efficacy of sonodynamic immunotherapy for PDAC. The CPIM nanoplatform, consisting of a macrophage membrane-coated oxygen and drug delivery system (CM@PFOB-ICG-α-Mangostin), was synthesized using ultrasound and extrusion methods. The in vivo homologous targeting and hypoxia alleviation capabilities of CPIM were evaluated through near-infrared (NIR) imaging and photoacoustic (PA) imaging. The tumor growth inhibition potential and ability to reprogram the tumor microenvironment by the CPIM nanoplatform were also investigated. Co-delivery of α-Mangostin inhibits CAFs and enhances stromal depletion, thereby facilitating better infiltration of macromolecules. Additionally, the nanoemulsion containing perfluorocarbon (PFC) can target tumor cells and accumulate within them through homologous targeting. The US irradiation results in the rapid release of oxygen, serving as a potential source of sonodynamic therapy for hypoxic tumors. Moreover, CPIM reshapes the immunosuppressive microenvironment increasing the population of cytotoxic T lymphocytes (CTLs), and enhancing their anti-tumor immune response through the use of anti-PDL1 antibodies to block immune checkpoints. The present study offers a potential strategy for the co-delivery of oxygen and α-Mangostin, aiming to enhance the penetration of tumors to improve SDT. This approach effectively addresses the existing limitations of immune checkpoint blockade (ICB) treatment in solid tumors, while simultaneously boosting the immune response through synergistic sonodynamic immunotherapy.

Wide FOV metalens for near-infrared capsule endoscopy: advancing compact medical imaging

Abstract This study presents the design, fabrication, and characterization of a wide field-of-view (FOV) metalens optimized for capsule endoscopy. The metalens achieved a 165° FOV with a high modulation transfer function (MTF) of 300 lines per millimeter (lp/mm) across the entire FOV, operating in the near-infrared (NIR) narrow-bandpass imaging at 940 nm. The performance of the metalens-based system is evaluated using two bandwidths, 12 nm and 32 nm, showing MTF values of 0.2 and 0.3 at 250 lp/mm, respectively. The metalens-based system maintains a compact form factor with a total track length of 1.4 mm and a diameter of 1.58 mm. Compared to a traditional 108° FOV endoscope, the nano-optic capsule endoscope demonstrated superior performance in terms of FOV, contrast, and resolution. This advancement represents a significant step toward enhancing diagnostic capabilities in medical imaging, offering improved performance in a more compact package compared to conventional optics.

Frugal engineering-inspired wearable augmented reality goggle system enables fluorescence-guided cancer surgery

Disparities in surgical outcomes often result from subjective decisions dictated by surgical training, experience, and available resources. To improve outcomes, surgeons have adopted advancements in robotics, endoscopy, and intra-operative imaging including fluorescence-guided surgery (FGS), which highlights tumors and anatomy in real-time. However, technical, economic, and logistic challenges hinder widespread adoption of FGS beyond high-resource centers. To overcome these impediments, we combined laser diodes, Raspberry Pi cameras and computers, off-the-shelf optical components, and 3D-printed parts to make a battery-powered, compact, dual white light and NIR imaging system that has comparable performance to existing bulkier, pricier, and wall-powered technologies. We combined these components with off-the-shelf augmented reality (AR) glasses to create a fully-wearable fluorescence imaging AR Raspberry Pi-based goggle system (FAR-Pi) and validated performance in a pre-clinical cancer surgery model. Novel device design ensures distance-independent coalignment between real and augmented views. As an open-source, affordable, and adaptable system, FAR-Pi is poised to democratize access to FGS and improve health outcomes worldwide.

Intraoperative evaluation of tumor margins using a TROP2 near-infrared imaging probe to enable human breast-conserving surgery.

Intraoperative surgical margin assessment remains a challenge during breast-conserving surgery. Here, we report a combined strategy of immuno-positron emission tomography (PET) for preoperative detection of breast cancer and guided assessment of margins in breast-conserving surgery through second near-infrared (NIR-II) fluorescence imaging of trophoblastic cell surface antigen 2 (TROP2). We demonstrated that the intensity of PET signals in the tumors was nearly five times higher than in normal breast tissue with a zirconium-89 tracer conjugated to sacituzumab govitecan (SG) in a mouse spontaneous breast cancer model, enabling the identification of tumors. We further generated a NIR-II probe of indocyanine green conjugated to SG (ICG-SG) and developed a rapid incubation imaging method for intraoperative margin assessment in a relevant time window for the operation workflow. The ICG-SG NIR-II fluorescence image guidance was first verified to remove tumors completely and accurately in mouse breast cancer models. Moreover, the rapid incubation imaging method was applied to distinguish benign and malignant breast lesions in samples from 26 patients with breast cancer. Therefore, we have developed both nuclide and optical probes targeting TROP2 for rapid and precise identification of tumor margins during breast-conserving surgery in humans.

A near-infrared triggered multi-functional indocyanine green nanocomposite with NO gas release function inducing improved photothermal therapy

The integration of photothermal and near-infrared (NIR) imaging capabilities of indocyanine green (ICG) small molecules has attracted considerable attention in tumor diagnosis and treatment. However, the abnormal upregulation of cellular heat shock proteins (HSPs) induced by photothermal therapy (PTT) enhances cellular heat resistance, thereby severely affecting the efficacy of PTT. In this study, to address the impact of HSPs on the efficacy of PTT while obtaining high-quality NIR fluorescence imaging in the NIR region, we designed a targeted peptide@ICG nanofluorescent probe encapsulated in liposomes. The introduced cRGD targeting peptide not only possesses tumor-targeting capabilities but also features LA as the last amino acid in the targeting peptide, which can generate nitric oxide (NO) under reactive oxygen species (ROS) triggering. It can happen under 808 nm single-light source NIR light, and the guanidine group in the peptide decomposes and combines with singlet oxygen molecules to generate NO gas molecules, thereby exerting an elevated photothermal effect by inhibiting the expression of HSP70. In addition, the nanoprobes enable deep imaging and treatment of glioma in situ and can be combined with a laser speckle contrast imaging (LSCI) system for multimodal imaging. This composite probe demonstrates synergistic tumor therapeutic effects of photodynamic therapy (PDT), PTT, and gas therapy, offering a promising strategy for cancer treatment.

Imaging the innermost circumstellar environment of the red supergiant WOH G64 in the Large Magellanic Cloud

Significant mass loss in the red supergiant (RSG) phase has great influence on the evolution of massive stars and their final fate as supernovae. We present near-infrared interferometric imaging of the circumstellar environment of the dust-enshrouded RSG WOH G64 in the Large Magellanic Cloud. WOH G64 was observed with the GRAVITY instrument at ESO's Very Large Telescope Interferometer (VLTI) at 2.0--2.45 mu m . We succeeded in imaging the innermost circumstellar environment of WOH G64 -- the first interferometric imaging of an RSG outside the Milky Way. The reconstructed image reveals elongated compact emission with a semimajor and semiminor axis of sim 2 and sim 1.5 mas (sim 13 and 9 $R_ star ), respectively. The GRAVITY data show that the stellar flux contribution at 2.2 mu m \ at the time of our observations in 2020 is much lower than predicted by the optically and geometrically thick dust torus model based on the VLTI/MIDI data taken in 2005 and 2007. We found a significant change in the near-infrared spectrum of WOH G64: while the (spectro)photometric data taken at 1--2.5 mu m \ before 2003 show the spectrum of the central RSG with H$_2$O absorption, the spectra and prime photometric data taken after 2016 are characterized by a monotonically rising continuum with very weak signatures of H$_2$O . This spectral change likely took place between December 2009 and 2016. On the other hand, the mid-infrared spectrum obtained in 2022 with VLT/VISIR agrees well with the spectra obtained before 2007. The compact emission imaged with GRAVITY and the near-infrared spectral change suggest the formation of hot new dust close to the star, which gives rise to the monotonically rising near-infrared continuum and the high obscuration of the central star. The elongation of the emission may be due to the presence of a bipolar outflow or effects of an unseen companion.

Progression in Near-Infrared Fluorescence Imaging Technology for Lung Cancer Management.

Lung cancer is a major threat to human health and a leading cause of death. Accurate localization of tumors in vivo is crucial for subsequent treatment. In recent years, fluorescent imaging technology has become a focal point in tumor diagnosis and treatment due to its high sensitivity, strong selectivity, non-invasiveness, and multifunctionality. Molecular probes-based fluorescent imaging not only enables real-time in vivo imaging through fluorescence signals but also integrates therapeutic functions, drug screening, and efficacy monitoring to facilitate comprehensive diagnosis and treatment. Among them, near-infrared (NIR) fluorescence imaging is particularly prominent due to its improved in vivo imaging effect. This trend toward multifunctionality is a significant aspect of the future advancement of fluorescent imaging technology. In the past years, great progress has been made in the field of NIR fluorescence imaging for lung cancer management, as well as the emergence of new problems and challenges. This paper generally summarizes the application of NIR fluorescence imaging technology in these areas in the past five years, including the design, detection principles, and clinical applications, with the aim of advancing more efficient NIR fluorescence imaging technologies to enhance the accuracy of tumor diagnosis and treatment.

Ex vivo fluorescence-guided resection margin assessment in breast cancer surgery using a topically applied, cathepsin-activatable imaging agent

Up to 40 % of breast cancer patients have a tumor-positive resection margin (TPRM) – defined as cancer cells at the surface of the resected specimen – after breast-conserving surgery (BCS), necessitating re-resection or boost radiation. To prevent these additional treatments, intraoperative near-infrared (NIR) fluorescence imaging with the topically applied, cathepsin-activatable imaging agent AKRO-6qcICG might be used to detect TPRMs and guide additional resection. Here, to validate its performance, the agent is topically applied to all surfaces of freshly resected breast cancer specimens (n = 11 patients) and to 3–5 mm thick tissue slices of the specimens (n = 26 patients). NIR fluorescence images of the resection surfaces and tissue slices are acquired and correlated to final histopathology. AKRO-6qcICG detects TPRMs with a sensitivity, specificity, PVV, and NPV of 100 %, 67 %, 10 %, and 100 %, respectively. On the tissue slices, the fluorescence signal has a median tumor-to-background ratio of 1.8. These findings indicate that topically applied AKRO-6qcICG can visualize TPRMs ex vivo with a high sensitivity and NPV, with sufficient contrast to adjacent healthy breast tissue.

Energy-Transfer-Enhanced Cr3+/Ni2+ Co-doped Broadband Near-Infrared Phosphor for Fluorescence Thermometers and Near-Infrared Window Imaging.

Here, near-infrared broad dual-band emission phosphors were achieved through energy transfer between Cr3+ and Ni2+ ions in the β-Ga2O3 host. All samples co-doped with Cr3+ and Ni2+ exhibit dual-band emission covering 600-1700 nm under 430 nm excitation. Thanks to the doping of Cr3+ ions, the emission intensity of Ga2O3:Cr3+, Ni2+ phosphors has increased by about 2.4 times and the internal quantum efficiency has increased by 83.2% compared to Ga2O3:Ni2+ phosphors. Meanwhile, when the fluorescence lifetime was monitored at 745 nm, an efficient energy transfer between Cr3+ and Ni2+ ions in the β-Ga2O3 host was verified. Due to the significant differences in the emission temperature-sensitive properties of Cr3+ and Ni2+ ions, a thermometer was designed utilizing fluorescence intensity ratio technology, achieving a maximum relative sensitivity of 5.26% K-1, which surpasses most optical temperature measurement phosphors. This suggests that Ga2O3:Cr3+, Ni2+ samples hold promise as potential candidates for optical thermometer materials. Additionally, the broadband near-infrared emission of the Ga2O3:Cr3+, Ni2+ sample has been investigated for potential applications in component analysis and night vision, demonstrating its versatility for multifunctional applications.

Lymphatic magnetic resonance imaging abnormalities in children with repaired tetralogy of Fallot.

Tetralogy of Fallot patients face an elevated risk of developing chylothorax and pleural effusions post-surgery. This patient group exhibits risk factors known to compromise the lymphatic system, such as elevated central venous pressure, pulmonary flow changes, and hypoxia. This study investigates the morphology and function of the lymphatic system in tetralogy of Fallot patients through lymphatic magnetic resonance imaging and near-infrared fluorescence imaging, respectively. Post-repair tetralogy of Fallot patients aged 6-18 years were recruited, along with age and gender-matched controls. Magnetic resonance imaging was used to assess the morphology of the thoracic lymphatic vessels and the thoracic, while near-infrared fluorescence imaging was used to assess lymphatic activity utilising lymph rate, velocity, and pressure. Nine patients and 10 controls were included. Echocardiography revealed that 2/3 of the patients had moderate-severe pulmonary regurgitation, while none displayed signs of elevated central venous pressure. Magnetic resonance imaging identified three patients with type 3 (out of 4 types) lymphatic abnormalities, while controls had none. The thoracic ducts showed severe (one patient) and moderate (one patient) tortuosity. Mean thoracic duct diameters were 3.3 mm ±1.1 in patients and 3.0 mm ± 0.8 in controls (p-value = 0.53). Near-infrared fluorescence imaging revealed no anomalous patterns. Despite no presence of clinical lymphatic disease, 3/9 of the repaired tetralogy of Fallot patients exhibited lymphatic morphological abnormalities. The significance of these anomalies remains uncertain currently. Further research is needed to determine whether these lymphatic alterations in this patient cohort are a result of congenital malformations, haemodynamic shifts, or prenatal and early-life saturation levels.

Real-time robust liver and gallbladder segmentation during laparoscopic cholecystectomy using convolutional neural networks: an analysis

Aim: Images in different laparoscopic cholecystectomy datasets are acquired using various camera models, parameters, and settings, with the annotation methods varying by institution. These factors result in inconsistent inference performance of the network model. This study aims to identify the optimal network model architecture for liver and gallbladder segmentation from several options. Then, the performance and robustness of the optimal network model are evaluated using an independent dataset that is not included in the training. Methods: The public dataset, CholecSeg8k, was utilized as the input for the network model training, validation, and testing. A local private dataset from KPJ Damansara Hospital, Selangor, Malaysia, was used for testing purposes only. For the implementation of liver and gallbladder segmentation, segmentation models, a public Python library was employed. Results: Among the experiments, highly accurate liver and gallbladder segmentation results were achieved using the feature pyramid network (FPN) architecture as the network model, with the Inception-ResNet-v2 architecture as the network backbone. The best-trained network model resulted in a loss of 0.070955, a mean intersection over union (IoU) score of 0.95896, and a mean F1-score of 0.9773 on the test set. However, visualized results for the private dataset contained considerable false-negative areas. Conclusion: The proposed automated technique has the potential to serve as an alternative to the conventional indocyanine green injection along with near-infrared fluorescence imaging (ICG-NIRF)-based method for liver and gallbladder segmentation during laparoscopic cholecystectomy. Future work will focus on enhancing the results of the private dataset. Additionally, a surgeon-assistant robotic arm that will use the liver and gallbladder segmentation results for camera steering will be analyzed.

Generation of NIR Spectral Band from RGB Image with Wavelet Domain Spectral Extrapolation Generative Adversarial Network

Near-infrared (NIR) imaging exhibits outstanding penetration capabilities and robust anti-interference characteristics. However, acquiring high-resolution and high-fidelity NIR images is difficult due to the limited mobility, high cost, and low resolution of NIR imaging hardware. In this paper, we proposed a new end-to-end Wavelet Domain Spectral Extrapolation Generative Adversarial Network (WSEGAN) to generate highly realistic NIR images from RGB images. Since RGB and NIR images have different types of noise and artifacts, which affects the quality of NIR images generation. We design a generator with a discrete wavelet transform and an attention mechanism to capture multi-resolution contextual information, and a multi-scale discriminator to capture detailed and global features. Then, the proposed approach is evaluated by three different datasets to achieve optimal results regarding both visual effects and quantitative evaluation. The normalized difference vegetation index (NDVI) is utilized to validate the effectiveness of the generated NIR images. The result demonstrates a strong correlation between the generated images and the actual vegetation distribution. More importantly, the proposed network is testified to generate NIR images to be fused with the RGB image source for agricultural target detection tasks. In dark conditions, results show that using multi-modal data instead of RGB images improves mAP0.5 detection accuracy by 4% on the CAPSICUM dataset and by 8% on the KIWI dataset across five object detection methods. This follows the physical significance of the NIR imaging and demonstrates the potential use of the NIR images generated by the proposed method.

Nondestructively Determining Soluble Solids Content of Blueberries Using Reflection Hyperspectral Imaging Technique

Effectively detecting the quality of blueberries is crucial for ensuring that high-quality products are supplied to the fresh market. This study developed a nondestructive method for determining the soluble solids content (SSC) of blueberry fruit by using a near-infrared hyperspectral imaging technique. The reflection hyperspectral images in the 900–1700 nm waveband range were collected from 480 fresh blueberry samples. An image analysis pipeline was developed to extract the spectrums of blueberries from the hyperspectral images. A regression model for quantifying SSC values was successfully established based on the full range of wavebands, achieving the highest RP2 of 0.8655 and the lowest RMSEP value of 0.4431 °Brix. Furthermore, three variable selection methods, namely the Successive Projections Algorithm (SPA), interval PLS (iPLS), and Genetic Algorithm (GA), were utilized to identify the feature wavebands for modeling. The models calibrated from feature wavebands generated an RMSEP of 0.4643 °Brix, 0.4791 °Brix, and 0.4764 °Brix, as well as the RP2 of 0.8507, 0.8397, and 0.8420 for SPA, iPLS, and GA, respectively. Furthermore, a pseudo-color distribution diagram of the SSC values within blueberries was successfully generated based on established models. This study demonstrated a novel approach for blueberry quality detection and inspection by jointly using hyperspectral imaging and machine learning methodologies. It can serve as a valuable reference for the development of grading equipment systems and portable testing devices for fruit quality assurance.

Microenvironment-Activatable Probe for Precise NIR-II Monitoring and Synergistic Immunotherapy in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) represents an insidious autoimmune inflammatory disorder that severely lowers the life quality by progressively destructing joint functions and eventually causing permanent disability, posing a serious public health problem. Here, an advanced theranostic probe is introduced that integrates activatable second near-infrared (NIR-II) fluorescence imaging for precise RA diagnosis with multi-pronged RA treatments. A novel molecular probe comprising a long-wavelength aggregation-induced emission unit and a manganese carbonyl cage motif is synthesized, which enables NIR-II fluorescence activation and concurrently releasing therapeutic carbon monoxide (CO) gas in inflamed joint microenvironment. This molecular probe self-assembles into a biocompatible nanoprobe, which is subsequently conjugated with anti-IL-6R antibody to afford active-targeting ability of RA. The nanoprobe exhibits significant turn-on NIR-II fluorescence signal at the RA lesion, enabling highly sensitive RA diagnosis and real-time therapeutic monitoring. The combination of ROS scavenging, on-demand CO gas release, and IL-6 signaling blockade results in potent therapeutic effect and synergistic immunomodulation impact, significantly alleviating the RA symptoms and preventing joint destruction. This research introduces a novel paradigm for the development of high-performance, activatable theranostic strategies to facilitate precise detection and enhanced treatment of RA-related diseases.

The Role of Indocyanine Green With Near-Infrared Imaging for the Intraoperative Detection and Enhancement of Endometriosis Lesions: A Narrative Review.

Background: There is a clinical need for improved intraoperative detection of endometriosis, and the use of Indocyanine Green with Near-Infrared Imaging (NIR-ICG) is a novel technique for this purpose. The aim of this review is to determine whether NIR-ICG is an effective tool for endometriosis detection and establish an evidence-based methodology for its use.Methods: This review searches Ovid MEDLINE and Embase through July 2023 and considers primary literature published in English describing the use of NIR-ICG to detect endometriosis intraoperatively. Case studies, video demonstrations and articles describing NIR-ICG used for other surgical roles were not considered. Identified studies were screened independently by two authors, and data was extracted by a single author.Results: NIR-ICG was found to enhance the detection of endometriosis in six out of the nine included studies with additional lesion identification, and to have an unchanged or reduced efficacy compared to current standards in the remaining three. Across all studies there were lesions missed by NIR-ICG which were detected by conventional imaging. A greater duration of time between dye administration and visualisation of lesions was found to be more effective for detection. The ideal ICG protocol proposed from this review is a fixed amount of dye proportional to patient weight prior to surgery (0.25-0.3 mg/kg) followed by a longer waiting time before imaging (10-30 min).Conclusion: NIR-ICG has a possible role to enhance the identification of endometriosis intraoperatively as an adjunct to conventional white light imaging, particularly deeper infiltrating disease. However, substantial further research is required in this field.

Pre-clinical study of IR808 dye for cervical cancer in vitro and in vivo imaging.

There is an urgent need for improved methods for early screening and rapid diagnosis of cervical cancer since current conventional screening methods are plagued by operator subjectivity and unnecessary biopsies. IR808 is a tumour-targeting near-infrared (NIR) fluorescent dye that permits NIR imaging without the requirement of chemical conjugation. Our study investigates an IR808-based strategy for real-time monitoring of the cervix in vivo and rapid assessment of cervical specimens in vitro. We investigated the uptake of IR808 in vitro using normal cervical epithelial cells and three cervical cancer cell lines. The biodistribution of IR808 was examined in vivo via intravenous injection into tumour-bearing mice. Additionally, in vitro tissues were stained with IR808 to simulate the identification of cervical tumors in the clinical setting. Biocompatibility of the dye in both cellular and animal models was also examined. IR808 exhibited significant tumour-to-background ratios in fluorescence molecular imaging of in vivo tumors in nude mice. The application of NIR fluorescent dye IR808 in specific imaging screening, safe and non-invasive real-time monitoring, and rapid identification of cervical tumors from tissue specimens is expected to improve current screening methods for cervical cancer.

Targeted blood-brain barrier penetration and precise imaging of infiltrative glioblastoma margins using hybrid cell membrane-coated ICG liposomes

Surgical resection remains the primary treatment modality for glioblastoma (GBM); however, the infiltrative nature of GBM margins complicates achieving complete tumor removal. Additionally, the blood-brain barrier (BBB) poses a formidable challenge to effective probe delivery, thereby hindering precise imaging-guided surgery. Here, we introduce hybrid cell membrane-coated indocyanine green (ICG) liposomes (HM-Lipo-ICG) as biomimetic near-infrared (NIR) fluorescent probes for targeted BBB penetration and accurate delineation of infiltrative GBM margins. HM-Lipo-ICG encapsulates clinically approved ICG within its core and utilizes a hybrid cell membrane exterior, enabling specific targeting and enhanced BBB permeation. Quantitative assessments demonstrate that HM-Lipo-ICG achieves BBB penetration efficiency 2.8 times higher than conventional ICG liposomes. Mechanistically, CD44 receptor-mediated endocytosis facilitates BBB translocation of HM-Lipo-ICG. Furthermore, HM-Lipo-ICG enables high-contrast NIR imaging, achieving a signal-to-background ratio of 6.5 in GBM regions of an orthotopic glioma mouse model, thereby improving tumor margin detection accuracy fourfold (84.4% vs. 22.7%) compared to conventional ICG liposomes. Application of HM-Lipo-ICG facilitates fluorescence-guided precision surgery, resulting in complete resection of GBM cells. This study underscores the potential of hybrid cell membrane-coated liposomal probes in precisely visualizing and treating infiltrative GBM margins.Graphical abstract

Development and In vitro and In vivo efficacy investigation of multifunctional, targeted, theranostic liposomes for imaging and photodynamic therapy of glioblastoma

The challenge of effectively diagnosing and treating glioblastoma, which has a high incidence and low survival rate, remains unresolved. Consequently, research efforts have increased to develop specific and effective diagnostic and therapeutic agents. In this study, N-acetyl glucosamine-modified, IR780-encapsulated, PEG-coated, nanosized, 68Ga-labeled, neutral, and positively charged theranostic liposomes were developed for GLUT1 targeting for PET/CT and NIR imaging and PDT/PTT of GBM. Characterization, in vitro release profile, stability, radiolabeling efficiency, and labeling stability were evaluated. In vitro cell uptake studies were conducted in RG2 and U87 GBM cell lines, NIR images were obtained in the RG2 and U87 cell lines, and fluorescence microscope images were obtained in the RG2 cell line. PDT/PTT activities were assessed after exposure to NIR light (808 nm, 0.8–1 W/cm2). Cytotoxicity was studied in RG2, U87, and L929 cell lines. In vivo studies were performed in GBM model nude mice. The liposomes had an optimum mean particle size (181–193 nm), high encapsulation efficiency (79–84 %), and zeta potential (−5 to −7 mV). The maximum 68Ga labeling efficiency was achieved with an incubation at 80 °C, pH: 3.5, and 5 min. Liposomes remained stable for 30 days at 4 °C. While the intracellular uptake of targeted formulations was higher than non-targeted ones, it was similar for positively charged and neutral formulations. In U87 and RG2 cell lines, cell viability remained above 50 % for liposomal formulations at a concentration of 1.5 μg/mL exposed to NIR light (808 nm, 0.8–1 W/cm2). The formulations showed significant PDT/PTT activity under NIR light and lower cytotoxicity in the L929 than in RG2 and U87 cell lines. In vivo bioluminescence images and biodistribution studies in U87 tumor-bearing nude mice revealed higher tumor uptake of targeted, IR780-encapsulated liposomal formulations in tumor tissue compared to non-targeted ones. Liposomal formulations showed higher tumor uptake than the free IR780 solution. The data suggest that targeted liposomes have potential as theranostic agents for PDT/PTT and multifunctional glioblastoma imaging.

Enhancement of photoresponse for InGaAs infrared photodetectors using plasmonic WO3-x/CsyWO3-xnanocrystals.

Fast and accurate detection of light in the near-infrared (NIR) spectral range plays a crucial role in modern society, from alleviating speed and capacity bottlenecks in optical communications to enhancing the control and safety of autonomous vehicles through NIR imaging systems. Several technological platforms are currently under investigation to improve NIR photodetection, aiming to surpass the performance of established III-V semiconductor p-i-n (PIN) junction technology. These platforms include in situ-grown inorganic nanocrystals and nanowire arrays, as well as hybrid organic-inorganic materials such as graphene-perovskite heterostructures. However, challenges remain in nanocrystal and nanowire growth, large-area fabrication of high-quality 2D materials, and the fabrication of devices for practical applications. Here, we explore the potential for tailored semiconductor nanocrystals to enhance the responsivity of planar metal-semiconductor-metal (MSM) photodetectors. MSM technology offers ease of fabrication and fast response times compared to PIN detectors. We observe enhancement of the optical-to-electric conversion efficiency by up to a factor of ~2.5 through the application of plasmonically-active semiconductor nanorods and nanocrystals. We present a protocol for synthesizing and rapidly testing the performance of non-stoichiometric tungsten oxide (WO3-x) nanorods and cesium-doped tungsten oxide (CsyWO3-x) hexagonal nanoprisms prepared in colloidal suspensions and drop-cast onto photodetector surfaces. The results demonstrate the potential for a cost-effective and scalable method exploiting tailored nanocrystals to improve the performance of NIR optoelectronic devices.