Enhanced Visualisation of Colorectal Tumours via Topical Application of EMI-137 using a Viscous Formulation in an ex vivo setting

Research Square · 2025-05-14

Enhanced Visualisation of Colorectal Tumours via Topical Application of EMI-137 in a Methylcellulose-Based Formulation: An ex vivo Feasibility Study

Molecular Imaging and Biology · 2025-08-18

BACKGROUND: Fluorescence-guided molecular imaging may improve colorectal cancer (CRC) patient outcomes by enabling early detection and better surgical treatment, relying on developing targeted fluorescent tracers to highlight tumours. This study investigates visualising primary colon tumours by topically applying EMI-137, a targeted fluorescent tracer designed to bind to c-Met receptor. We introduce a novel viscous formulation to enhance the tracer's performance, aiming for a clear, robust fluorescent signal by improving contact with mucosal surface of ex vivo colon specimens. METHODS: We evaluated fluorescence properties of EMI-137 in phosphate-buffered saline (PBS) and in methylcellulose (m-cellulose) and determined emission spectrum of the tracer in both formulations. Flow cytometry was used to determine EMI-137's specificity for c-Met receptor and its optimal concentration. Live-cell imaging visually confirmed EMI-137's fluorescence signal for the c-Met receptor, highlighting its distinctive characteristics across various solvents. In a prospective cohort study, freshly excised colon cancer specimens were incubated with EMI-137 in PBS or m-cellulose. Specimens underwent a meticulous washing process. Near-infrared fluorescence imaging was performed and compared with histopathological analysis to validate detection accuracy. RESULTS: Fluorospectrometry showed that m-cellulose enhanced EMI-137's fluorescence intensity compared to PBS. Flow cytometry showed dose-dependent binding of EMI-137 in HT-29 cells, with an optimum at 500 nM. Microscopy confirmed targeting of c-Met receptors. Topical EMI-137 dissolved in m-cellulose visualised colon tumours effectively, resulting in a high tumour-to-background ratio. Histopathological analysis confirmed c-Met expression in these colon tumours. CONCLUSION: EMI-137 in a novel viscous vehicle effectively imaged c-Met expressing colon tumors, potentially facilitating fluorescent-guided tumor imaging.

Dose optimization of second window indocyanine green in meningioma patients

Clinical Neurology and Neurosurgery · 2024-06-12 · 2 citations

Cardiac inotropy and cardiac calcium sensitization of PanLN800(-Forte), a cationic heptamethine indocyanine fluorescent contrast agent for intraoperative pan lymph node imaging

Toxicology and Applied Pharmacology · 2024-12-30

INTRODUCTION: Accurate staging of malignancies often requires comprehensive evaluation of lymph nodes. However, finding these lymph nodes during oncological surgery is a daunting and time-consuming task, which increases the risk of missed lymph nodes and complications. Near-infrared (NIR) fluorescence imaging with the experimental fluorescent contrast agent PanLN800(-Forte) could provide real-time identification of lymph nodes and may solve this longstanding problem. In the current study we performed the preclinical toxicology evaluation of PanLN800(-Forte) towards its clinical translation for intraoperative pan lymph node imaging in thoracic surgery. METHODS: A single extended dose toxicology study was conducted to determine the safety and potential toxicity of PanLN800(-Forte) after administration of a single intravenous dose to Wistar Han rats. The study included a control group and two treatment groups (5.0 mg/kg and 15.0 mg/kg PanLN800(-Forte)), each consisting of 10 male and 10 female rats. Experimental endpoints included moribundity/mortality, clinical signs, body weights, body weight gains, clinical pathology, toxicity, and gross necropsy observations. RESULTS: Unexpected acute mortality was observed after administration of 5.0 mg/kg PanLN800(-Forte) to rats. No clear cause of sudden death was found after gross necropsy and pathology observations. To understand the mechanism of toxicity of PanLN800(-Forte), several additional tests were performed. By elimination, acute cardiac toxicity appears to be the cause of acute mortality in rats, in which PanLN800(-Forte) was found to be a potent inotrope acting as a cardiac calcium sensitizer. CONCLUSION: PanLN800(-Forte) is not a viable fluorescent contrast agent for lymph node imaging in surgery because of cardiac calcium sensitization but may be a novel treatment for heart failure.

Non-Small Cell Lung Cancer Imaging Using a Phospholipase A2 Activatable Fluorophore

Chemical & Biomedical Imaging · 2024-06-20 · 5 citations

Lung cancer, the most common cause of cancer-related death in the United States, requires advanced intraoperative detection methods to improve evaluation of surgical margins. In this study we employed DDAO-arachidonate (DDAO-A), a phospholipase A2 (PLA2) activatable fluorophore, designed for the specific optical identification of lung cancers in real-time during surgery. The in vitro fluorescence activation of DDAO-A by porcine sPLA2 was tested in various liposomal formulations, with 100 nm extruded EggPC showing the best overall characteristics. Extruded EggPC liposomes containing DDAO-A were tested for their stability under various storage conditions, demonstrating excellent stability for up to 4 weeks when stored at −20 °C or below. Cell studies using KLN 205 and LLC1 lung cancer cell lines showed DDAO-A activation was proportional to cell number. DDAO-A showed preferential activation by human recombinant cPLA2, an isoform highly specific to arachidonic acid-containing lipids, when compared to a control probe, DDAO palmitate (DDAO-P). In vivo studies with DBA/2 mice bearing KLN 205 lung tumors recapitulated these results, with preferential activation of DDAO-A relative to DDAO-P following intratumoral injection. Topical application of DDAO-A-containing liposomes to human (n = 10) and canine (n = 3) lung cancers ex vivo demonstrated the preferential activation of DDAO-A in tumor tissue relative to adjacent normal lung tissue, with fluorescent tumor-to-normal ratios (TNR) of up to 5.2:1. The combined results highlight DDAO-A as a promising candidate for clinical applications, showcasing its potential utility in intraoperative and back-table imaging and topical administration during lung cancer surgeries. By addressing the challenge of residual microscopic disease at resection margins and offering stability in liposomal formulations, DDAO-A emerges as a potentially valuable tool for advancing precision lung cancer surgery and improving curative resection rates.

Second window ICG predicts postoperative MRI gadolinium enhancement in high grade gliomas and brain metastases

Neurosurgical Focus Video · 2022-01-01 · 5 citations

A prospective trial evaluating the utility of second window indocyanine green (SWIG) in predicting postoperative MRI gadolinium enhancement was performed on high-grade gliomas (HGGs) and brain metastases. Compared to white light alone, SWIG demonstrated a higher sensitivity, negative predictive value, and accuracy in predicting residual neoplasm on MRI. The specificity of SWIG for predicting MRI enhancement was higher in HGGs than brain metastases. Clinically, near-infrared (NIR) imaging was better able to predict tumor recurrence than postoperative MRI. These results illustrate how SWIG is able to take advantage of gadolinium-like distribution properties to extravasate into the tumor microenvironment, enabling guidance in surgical resection. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21204.

Indocyanine green fluorescence-guided surgery in head and neck cancer: A systematic review

American Journal of Otolaryngology · 2022-08-02 · 26 citations

長期免疫細胞追跡のための二重モードPET/近赤外蛍光ナノタグ【JST・京大機械翻訳】

Biomaterials · 2021-01-01

Molecular Imaging Using Raman Scattering

Molecular Imaging · 2021-01-01 · 1 citations

This chapter introduces Raman scattering as a promising imaging modality in the biomedical field. We will discuss the history of how Raman scattering was discovered and explain the underlying principles. In the next section, the application of Raman spectroscopy in discriminating normal from diseased tissues, by probing their chemical compositions, will be addressed. Then, coherent Raman scattering and its underlying mechanism are discussed, and how it can be used to directly and indirectly demarcate the infiltrative tumor margins during surgery. Lastly, contrast-enhanced Raman imaging, which uses exogenous molecularly targeted surface-enhanced Raman scattering nanoparticles to highlight disease and disease markers will be discussed to further outline the role of Raman imaging in biomedical applications.

Applications of indocyanine green in brain tumor surgery: review of clinical evidence and emerging technologies

Neurosurgical FOCUS · 2021-01-01 · 108 citations

Indocyanine green (ICG) is a water-soluble dye that was approved by the FDA for biomedical purposes in 1956. Initially used to measure cardiocirculatory and hepatic functions, ICG's fluorescent properties in the near-infrared (NIR) spectrum soon led to its application in ophthalmic angiography. In the early 2000s, ICG was formally introduced in neurosurgery as an angiographic tool. In 2016, the authors' group pioneered a novel technique with ICG named second-window ICG (SWIG), which involves infusion of a high dose of ICG (5.0 mg/kg) in patients 24 hours prior to surgery. To date, applications of SWIG have been reported in patients with high-grade gliomas, meningiomas, brain metastases, pituitary adenomas, craniopharyngiomas, chordomas, and pinealomas.The applications of ICG have clearly expanded rapidly across different specialties since its initial development. As an NIR fluorophore, ICG has advantages over other FDA-approved fluorophores, all of which are currently in the visible-light spectrum, because of NIR fluorescence's increased tissue penetration and decreased autofluorescence. Recently, interest in the latest applications of ICG in brain tumor surgery has grown beyond its role as an NIR fluorophore, extending into shortwave infrared imaging and integration into nanotechnology. This review aims to summarize reported clinical studies on ICG fluorescence-guided surgery of intracranial tumors, as well as to provide an overview of the literature on emerging technologies related to the utility of ICG in neuro-oncological surgeries, including the following aspects: 1) ICG fluorescence in the NIR-II window; 2) ICG for photoacoustic imaging; and 3) ICG nanoparticles for combined diagnostic imaging and therapy (theranostic) applications.