Pancreatic Cancer detection via Galectin-1-targeted Thermoacoustic Imaging: validation in an in vivo heterozygosity model

Noninvasively Deciphering the Immunosuppressive Tumor Microenvironment Using Galectin-1 PET to Inform Immunotherapy Responses

Immune checkpoint blockade (ICB) has achieved groundbreaking results in clinical cancer therapy; however, only a subset of patients experience durable benefits. The aim of this study was to explore strategies for predicting tumor responses to optimize the intervention approach using ICB therapy. Methods: We used a bilateral mouse model for proteomics analysis to identify new imaging biomarkers for tumor responses to ICB therapy. A PET radiotracer was synthesized by radiolabeling the identified biomarker-targeting antibody with 124I. The radiotracer was then tested for PET prediction of tumor responses to ICB therapy. Results: We identified galectin-1 (Gal-1), a member of the carbohydrate-binding lectin family, as a potential negative biomarker for ICB efficacy. We established that Gal-1 inhibition promotes a sensitive immune phenotype within the tumor microenvironment (TME) for ICB therapy. To assess the pre-ICB treatment status of the TME, a Gal-1-targeted PET radiotracer, 124I-αGal-1, was developed. PET imaging with 124I-αGal-1 showed the pretreatment immunosuppressive status of the TME before the initiation of therapy, thus enabling the prediction of ICB resistance in advance. Moreover, the use of hydrogel scaffolds loaded with a Gal-1 inhibitor, thiodigalactoside, demonstrated that a single dose of thiodigalactoside-hydrogel significantly potentiated ICB and adoptive cell transfer immunotherapies by remodeling the immunosuppressive TME. Conclusion: Our study underscores the potential of Gal-1-targeted PET imaging as a valuable strategy for early-stage monitoring of tumor responses to ICB therapy. Additionally, Gal-1 inhibition effectively counteracts the immunosuppressive TME, resulting in enhanced immunotherapy efficacy.

In Vivo Microwave-Induced Thermoacoustic Endoscopy for Colorectal Tumor Detection in Deep Tissue

Optical endoscopy, as one of the common clinical diagnostic modalities, provides irreplaceable advantages in the diagnosis and treatment of internal organs. However, the approach is limited to the characterization of superficial tissues due to the strong optical scattering properties of tissue. In this work, a microwave-induced thermoacoustic (TA) endoscope (MTAE) was developed and evaluated. The MTAE system integrated a homemade monopole sleeve antenna (diameter = 7 mm) for providing homogenized pulsed microwave irradiation to induce a TA signal in the colorectal cavity and a side-viewing focus ultrasonic transducer (diameter = 3 mm) for detecting the TA signal in the ultrasonic spectrum to construct the image. Our MTAE, system combined microwave excitation and acoustic detection; produced images with dielectric contrast and high spatial resolution at several centimeters deep in soft tissues, overcome the current limitations of the imaging depth of optical endoscopy and mechanical wave-based imaging contrast of ultrasound endoscopy, and had the ability to extract complete features for deep location tumors that could be infiltrating and invading adjacent structures. The practical feasibility of the MTAE system was evaluated i n vivo with rabbits having colorectal tumors. The results demonstrated that colorectal tumor progression could be visualized from the changes in electromagnetic parameters of the tissue via MTAE, showing its potential clinical application.

Spectroscopic Assessment of Doxorubicin (DOX)-Gemcitabine (GEM) Gold Complex Nanovector as Diagnostic Tool of Galectin-1 Biomarker

Introduction

The aim of this study is focused on the development of theranostic hybrid nanovectors based on gold-doxorubicin (DOX)-gemcitabine (GEM) complexes and their active targeting with Galectin-1 (Gal-1) as a promising therapeutic and prognostic marker in cancer.

Methods

For this purpose, a gold salt (HAuCl4) interacts with antitumor drugs (DOX; GEM) by chelation and then stabilizes with dicarboxylic acid-terminated polyethylene glycol (PEG) as a biocompatible surfactant. The proposed methodology is fast and reproducible, and leads to the formation of a hybrid nanovector named GEM@DOX IN PEG-AuNPs, in which the chemo-biological stability was improved. All synthetic chemical products were evaluated using various spectroscopic techniques (Raman and UV-Vis spectroscopy) and transmission electron microscopy (TEM).

Results

To conceive a therapeutic application, our hybrid nanovector (GEM@DOX IN PEG-AuNPs) was conjugated with the Galectin-1 protein (Gal-1) at different concentrations to predict and specifically recognize cancer cells. Gal-1 interacts with GEM@DOX in PEG-AuNPs, as shown by SPR and Raman measurements. We observed both dynamic variation in the plasmon position (SPR) and Raman band with Gal-1 concentration.

Discussion

We identified that GEM grafted electrostatically onto DOX IN PEG-AuNPs assumes a better chemical conformation, in which the amino group (NH3+) reacts with the carboxylic (COO-) group of PEG diacide, whereas the ciclopenthanol group at position C-5' reacts with NH3+ of DOX.

Conclusion

This study opens further way in order to built "smart nanomedical devices" that could have a dual application as therapeutic and diagnostic in the field of nanomedicine and preclinical studies associated.

A high-efficient excitation-detection thermoacoustic imaging probe for breast tumor detection

BACKGROUND

Microwave-induced thermoacoustic (TA) imaging (MTAI) is a promising alternative to biomedical imaging due to its high resolution, deep imaging depth, and minimal biohazard. To provide images of different anatomical regions and apply them to different clinical scenarios, the development of miniaturized portable TA probes is imperative.

PURPOSE

This study is aimed to propose a highly efficient handheld non-reflective microwave-acoustic coaxial TA probe to advance the translation of MTAI for the clinical use.

METHODS

The TA probe integrates a hollowed microwave antenna with a forward radiating uniform microwave field and a linear ultrasonic transducer array which is placed in the hole in the middle of the antenna that has almost no effect on the microwave distribution. The integrated probe was evaluated for properties, including the excitation efficiency of the microwave and the reception efficiency of the acoustic signal. Finally, an isolated EMT6 cell tumor was embedded in a sheep mammary gland to simulate the natural breast tumor environment, and the tumor was detected with the proposed MTAI probe to evaluate its practical feasibility.

RESULTS

Compared with the previous TA imaging probe, it has improved the detection efficiency of TA signals by up to 41%, contributing to an improved signal-to-noise ratio (SNR) of the image. The proposed TA probe successfully detected tumors embedded in the breast with a contrast ratio 3.27 times higher than the surrounding tissue in phantom experiments.

CONCLUSION

The proposed TA probe with the features of microwave illumination and ultrasonic detection of coaxial, avoiding TA signal attenuation due to reflection, enables high-efficient TA signal excitation and detection. The proposed TA probe is essential for improving the excitation and detection efficiency of TA signals, and increasing the flexibility of the probe, providing a bright future for the clinical application of MTAI technology.

Serum exosomal and serum glypican-1 are associated with early recurrence of pancreatic ductal adenocarcinoma

Background

The diagnostic performance and prognostic value of serum exosomal glypican 1 (GPC-1) in pancreatic ductal adenocarcinoma (PDAC) remain controversial. In this study, we detected serum exosomal GPC-1 using enzyme-linked immunosorbent assay (ELISA) and determined whether it serves as a predictor of diagnosis and recurrence for early-stage PDAC.

Methods

Serum samples were obtained from patients with 50 PDAC, 6 benign pancreatic tumor (BPT), or 9 chronic pancreatitis (CP) and 50 healthy controls (HCs). Serum exosomes were isolated using an exosome isolation kit. Exosomal and serum GPC-1 levels were measured using ELISA. The freeze–thaw process was carried out to analyze the stability of GPC-1. Receiver operating characteristic (ROC) analysis was employed to assess the diagnostic value of GPC-1. Kaplan–Meier and multivariate Cox analyses were used to evaluate the prognostic value of GPC-1.

Results

The average concentrations of serum exosomal and serum GPC-1 were 1.5 and 0.8 ng/ml, respectively. GPC-1 expression levels were stable under repeated freezing and thawing (d1-5 freeze–thaw cycles vs. d0 P > 0.05). Serum exosomal and serum GPC-1 were significantly elevated in patients with PDAC compared with HCs (P < 0.0001) but were slightly higher compared with that in patients with CP and BPT (P > 0.05). The expression levels of exosomal and serum GPC-1 were elevated 5 days after surgery in patients with PDAC, CP, and BPT (P < 0.05). Patients with high levels of exosomal and serum GPC-1 had a shorter relapse-free survival (RFS) (P = 0.006, and P = 0.010). Multivariate analyses showed that serum exosomal and serum GPC-1 were independent prognostic indicators for early RFS (P = 0.008, and P = 0.041).

Conclusion

ELISA is an effective and sensitive method to detect exosomal and serum GPC-1. The detection of GPC-1 was stable under repeated freezing and thawing cycles and could distinguish early-stage PDAC from HCs but not CP and BPT. Exosomal and serum GPC-1 may be good independent predictors of early recurrence in early-stage PDAC.

Nanocarriers for pancreatic cancer imaging, treatments, and immunotherapies

Pancreatic tumors are highly desmoplastic and immunosuppressive. Delivery and distribution of drugs within pancreatic tumors are compromised due to intrinsic physical and biochemical stresses that lead to increased interstitial fluid pressure, vascular compression, and hypoxia. Immunotherapy-based approaches, including therapeutic vaccines, immune checkpoint inhibition, CAR-T cell therapy, and adoptive T cell therapies, are challenged by an immunosuppressive tumor microenvironment. Together, extensive fibrosis and immunosuppression present major challenges to developing treatments for pancreatic cancer. In this context, nanoparticles have been extensively studied as delivery platforms and adjuvants for cancer and other disease therapies. Recent advances in nanotechnology have led to the development of multiple nanocarrier-based formulations that not only improve drug delivery but also enhance immunotherapy-based approaches for pancreatic cancer. This review discusses and critically analyzes the novel nanoscale strategies that have been used for drug delivery and immunomodulation to improve treatment efficacy, including newly emerging immunotherapy-based approaches. This review also presents important perspectives on future research directions that will guide the rational design of novel and robust nanoscale platforms to treat pancreatic tumors, particularly with respect to targeted therapies and immunotherapies. These insights will inform the next generation of clinical treatments to help patients manage this debilitating disease and enhance survival rates.

Cholecystokinin-B Receptor-Targeted Nanoparticle for Imaging and Detection of Precancerous Lesions in the Pancreas

Survival from pancreatic cancer remains extremely poor, in part because this malignancy is not diagnosed in the early stages, and precancerous pancreatic intraepithelial neoplasia (PanIN) lesions are not seen on routine radiographic imaging. Since the cholecystokinin-B receptor (CCK-BR) becomes over-expressed in PanIN lesions, it may serve as a target for early detection. We developed a biodegradable fluorescent polyplex nanoparticle (NP) that selectively targets the CCK-BR. The NP was complexed to a fluorescent oligonucleotide with Alexa Fluor 647 for far-red imaging and to an oligonucleotide conjugated to Alexa Fluor 488 for localization by immunohistochemistry. Fluorescence was detected over the pancreas of five- to ten-month-old LSL-Kras^G12D/+; P48-Cre (KC) mice only after the injection of the receptor target-specific NP and not after injection of untargeted NP. Ex vivo tissue imaging and selective immunohistochemistry confirmed particle localization only to PanIN lesions in the pancreas and not in other organs, supporting the tissue specificity. A human pancreas tissue microarray demonstrated immunoreactivity for the CCK-BR only in the PanIN lesions and not in normal pancreas tissue. The long-term goal would be to develop this imaging tool for screening human subjects at high risk for pancreatic cancer to enable early cancer detection.

Thermoacoustic tomography from magnetic nanoparticles by single-pulse magnetic field

PURPOSE

A mechanism of single-pulse magnetic field (SMF) inducing magnetic nanoparticles (MNPs) to generate the thermoacoustic (TA) wave is proposed, and its feasibility is proved by simulation and experiment.

METHODS

According to the principle of dimensional consistency, it is proposed that the internal energy variation of MNPs under the adiabatic condition mainly stems from the accumulation of magnetization energy, which leads to the magnetothermal effect, and then the TA wave is excited by thermal expansion. The analytical model of the forward problem is derived based on the method of space-time separation. The magnetization curve of MNPs is obtained from Langevin theory, and a three-dimension simulation model based on the magnetization curve is established to analyze the generation process of the TA wave. In the Experimental section, a gel phantom with a 0.5 mm gap is prepared with the magnetic fluid injecting into the gap, and the cross-sectional image of the gel phantom is reconstructed by the image fusion algorithm based on B-scan imaging.

RESULTS

The simulation analysis shows that the generated TA signal can reflect the boundary information of the MNPs region, and when the MNPs are in the unsaturated magnetized region, the intensity of the TA signal is positively correlated with the concentration of MNPs. The B-scan imaging along the X-axis and Y-axis directions are obtained through the experimental data. After that, the phantom with 0.5 mm gap labeled by MNPs is faithfully reconstructed by combining image morphology processing and image fusion technology based on wavelet transform.

CONCLUSIONS

The results show that the TA tomography from MNPs by SMF uses MNPs as a contrast agent to reconstruct the size and shape of the marked phantom with submillimeter resolution, which is expected to reconstruct the image of the tumor labeled by MNPs in the future. However, it is also a certain challenge to use low-concentration MNPs to image in vivo.

Ultrashort-Pulse-Microwave Excited Whole-Breast Thermoacoustic Imaging with Uniform Field of Large Size Aperture Antenna for Tumor Screening

Microwave-induced thermoacoustic imaging (MTAI) has been widely used in biomedical science, and has the potential as an auxiliary measure for clinical diagnosis and treatment. Recently, there are increasing interests in using ultrashort microwave-pumped thermoacoustic imaging techniques to obtain high-efficiency, high-resolution images. However, the traditional imaging system can only provide uniform radiation in a relatively small area, which limits their large field of view in clinical applications (such as whole-breast imaging, brain imaging). To address this problem, we propose an ultrashort pulse microwave thermoacoustic imaging device with a large size aperture antenna. The system can provide a microwave radiation area of 40 cm 27 cm and a uniform imaging view of 14 cm 14 cm. With 7 cm imaging depth and a 290 m resolution. The practical feasibility of the system for breast tumor screening is tested in phantoms with different shapes and in an ex vivo human breast tumor which is embedded in the excised breast of an ewe (5 cm 5 cm). The tumor can be identified with a contrast of about 1:2. The results demonstrate that the dedicated MTAI system with the uniform large field of view, high imaging resolution, and large imaging depth have the potential for clinical routine breast screening.

Fibroblastic galectin-1-fostered invasion and metastasis are mediated by TGF-β1-induced epithelial-mesenchymal transition in gastric cancer

Background The gastric cancer (GC) microenvironment has important effects on biological behaviors, such as tumor cell invasion and metastasis. However, the mechanism by which the GC microenvironment promotes GC cell invasion and metastasis is unknown. The present study aimed to clarify the effects and mechanism of galectin-1 (GAL-1, encoded by LGALS1) on GC invasion and metastasis in the GC microenvironment. Methods The expression of GAL-1/ LGALS1 was determined using western blotting, immunohistochemistry, and quantitative real-time reverse transcription PCR in GC tissues. Besides, methods including stable transfection, Matrigel invasion and migration assays, and wound-healing assays in vitro; and metastasis assays in vivo, were also conducted. Results GAL-1 from cancer-associated fibroblasts (CAFs) induced the epithelial-mesenchymal transition (EMT) of GC cells though the transforming growth factor beta (TGF-β1)/ Sma- and mad-related protein (Smad) pathway, and affected the prognosis of patients with GC. The level of GAL-1 was high in CAFs, and treating MGC-803 and SGC -7901 cell line with the conditioned medium from CAFs promoted their invasion and metastasis abilities. Overexpression of LGALS1 promoted the expression of TGF-β1 and induced EMT of GC cell lines. A TGF-β1 antagonist inhibited the invasion and migration of GC cells. In vivo, overexpression of LGALS1 promoted GC growth and metastasis, and the TGF-β1 antagonist dramatically reversed these events. Conclusions These findings suggested that high expression of GAL-1 in the GC microenvironment predicts a poor prognosis in patients with GC by promoting the migration and invasion of GC cells via EMT through the TGF-β1/Smad signaling pathway. The results might provide new therapeutic targets to treat GC.

Nanomaterials responding to microwaves: an emerging field for imaging and therapy

In recent years, new microwave-based imaging, sensing and hyperthermia applications have emerged in the field of diagnostics and therapy. For diagnosis, this technology involves the application of low power microwaves, utilising contrast between the relative permittivity of tissues to identify pathologies. This contrast can be further enhanced through the implementation of nanomaterials. For therapy, this technology can be applied in tissues either through hyperthermia, which can help anti-cancer drug tumour penetration or as ablation to destroy malignant tissues. Nanomaterials can absorb electromagnetic radiation and can enhance the microwave hyperthermic effect. In this review we aim to introduce this area of renewed interest and provide insights into current developments in its technologies and companion nanoparticles, as well as presenting an overview of applications for diagnosis and therapy.