Search

Plasmonic nanomaterials bearing targeting ligands are of great interest for surface‐enhanced Raman scattering (SERS)‐based bioimaging applications. However, the practical utility of SERS‐based imaging strategies is hindered by the lack of a straightforward method to synthesize highly sensitive SERS‐active nanostructures with high yield and efficiency. In this work, leveraging DNA origami principles, the first‐in‐class design of a SERS‐based plasmonically coupled nanoprobe for targeted cancer imaging (SPECTRA) is reported. The nanoprobe harnesses a cancer cell targeting DNA aptamer sequence and vibrational tag with stretching frequency in the cell‐silent Raman window. Through the integration of aptamer sequence specific for DU145 cells, the unique capabilities of SPECTRA for targeted imaging of DU145 cells are shown. The results demonstrate that the scalability, cost‐effectiveness, and reproducibility of this method of fabrication of SERS nanoprobes can serve as a versatile platform for creating nanoprobes with broad applications in the fields of cancer biology and biomedical imaging. [ABSTRACT FROM AUTHOR]

Abstract Background Mesothelin (MSLN) has been implicated in cancer migration, invasion, and prognosis, making it a potential tumor marker. However, the precise role of MSLN in the migration and invasion of malignant pleural mesothelioma (MPM) remains elusive, and effective noninvasive methods for assessing MSLN status are currently lacking. In this study, we focused on MSLN expression and elucidated the underlying mechanisms by which MSLN regulates migration and invasion in MPM. Building upon this knowledge, we developed an MRI nanoprobe that targets MSLN to assess its status in vitro and in vivo by comparing T2 signal intensity and T2 values on magnetic resonance imaging examinations. This nanoprobe combines the anatomical information obtained from MRI with biological information obtained from MSLN for comprehensive evaluation of MPM. Results Notably, we observed that MSLN expression in the epithelial type of MPM was higher and increased continuously with tumor growth than that in other types. In addition, MSLN upregulation promoted N-cadherin, matrix metalloproteinase-7, and MMP9 expression and resulted in higher migration/invasion ability and shorter survival. We synthesized MSLN-targeted nanoprobes (Fe3O4@SiO2-PEG-MSLN, FSPM) to assess MSLN expression by comparing the T2 signal intensity and T2 value of different cell lines and mice after 14, 28, and 42 days of modeling. Remarkably, MSLN-targeted nanoprobes demonstrated excellent targeting capabilities. In vitro studies revealed a pronounced reduction in T2 signal intensity and T2 values of the epithelial type as the probe concentration increased. In addition, in vivo experiments demonstrated a gradual decline in these parameters over time, particularly in the epithelial type as compared to the biphasic type, corresponding to the dynamic expression patterns of MSLN during different growth stages. Conclusion Our comprehensive research succeeded in confirming the regulatory mechanisms by which MSLN influences migration and invasion. Moreover, we introduced a promising method for monitoring MSLN expression that may help in facilitating the early detection, histological subtype identification, and assessment of migration, invasion, and prognosis in MPM.

Background: Mesothelin (MSLN) has been implicated in cancer migration, invasion, and prognosis, making it a potential tumor marker. However, the precise role of MSLN in the migration and invasion of malignant pleural mesothelioma (MPM) remains elusive, and effective noninvasive methods for assessing MSLN status are currently lacking. In this study, we focused on MSLN expression and elucidated the underlying mechanisms by which MSLN regulates migration and invasion in MPM. Building upon this knowledge, we developed an MRI nanoprobe that targets MSLN to assess its status in vitro and in vivo by comparing T2 signal intensity and T2 values on magnetic resonance imaging examinations. This nanoprobe combines the anatomical information obtained from MRI with biological information obtained from MSLN for comprehensive evaluation of MPM. Results: Notably, we observed that MSLN expression in the epithelial type of MPM was higher and increased continuously with tumor growth than that in other types. In addition, MSLN upregulation promoted N-cadherin, matrix metalloproteinase-7, and MMP9 expression and resulted in higher migration/invasion ability and shorter survival. We synthesized MSLN-targeted nanoprobes (Fe3O4@SiO2-PEG-MSLN, FSPM) to assess MSLN expression by comparing the T2 signal intensity and T2 value of different cell lines and mice after 14, 28, and 42 days of modeling. Remarkably, MSLN-targeted nanoprobes demonstrated excellent targeting capabilities. In vitro studies revealed a pronounced reduction in T2 signal intensity and T2 values of the epithelial type as the probe concentration increased. In addition, in vivo experiments demonstrated a gradual decline in these parameters over time, particularly in the epithelial type as compared to the biphasic type, corresponding to the dynamic expression patterns of MSLN during different growth stages. Conclusion: Our comprehensive research succeeded in confirming the regulatory mechanisms by which MSLN influences migration and invasion. Moreover, we introduced a promising method for monitoring MSLN expression that may help in facilitating the early detection, histological subtype identification, and assessment of migration, invasion, and prognosis in MPM. [ABSTRACT FROM AUTHOR]

Fluorescence imaging is an indispensable method for studying biological processes non-invasively in cells and transparent organisms. Extension into the shortwave infrared (SWIR, 1000-2000 nm) region of the electromagnetic spectrum has allowed for imaging in mammals with unprecedented depth and resolution for optical imaging. In this review, we summarize recent advances in imaging technologies, dye scaffold modifications, and incorporation of these dyes into probes for SWIR imaging in mice. Finally, we offer an outlook on the future of SWIR detection in the field of chemical biology.

Inspired by the principle of in situ self‐assembly, the development of enzyme‐activated molecular nanoprobes can have a profound impact on targeted tumor detection. However, despite their intrinsic promise, obtaining an optical readout of enzyme activity with high specificity in native milieu has proven to be challenging. Here, a fundamentally new class of Raman‐active self‐assembling bioorthogonal enzyme recognition (nanoSABER) probes for targeted tumor imaging is reported. This class of Raman probes presents narrow spectral bands reflecting their vibrational fingerprints and offers an attractive solution for optical imaging at different bio‐organization levels. The optical beacon harnesses an enzyme‐responsive peptide sequence, unique tumor‐penetrating properties, and vibrational tags with stretching frequencies in the cell‐silent Raman window. The design of nanoSABER is tailored and engineered to transform into a supramolecular structure exhibiting distinct vibrational signatures in presence of target enzyme, creating a direct causality between enzyme activity and Raman signal. Through the integration of substrate‐specific for tumor‐associated enzyme legumain, unique capabilities of nanoSABER for imaging enzyme activity at molecular, cellular, and tissue levels in combination with machine learning models are shown. These results demonstrate that the nanoSABER probe may serve as a versatile platform for Raman‐based recognition of tumor aggressiveness, drug accumulation, and therapeutic response. [ABSTRACT FROM AUTHOR]

The near-infrared (NIR) fluorescence imaging modality has great potential for application in biomedical imaging research owing to its unique characteristics, such as low tissue autofluorescence and noninvasive visualization with high spatial resolution. Although a variety of NIR fluorophores are continuously reported, the commercially available NIR fluorophores are still limited, owing to complex synthetic processes and poor physicochemical properties. To address this issue, a small molecular NIR fluorophore (SMF800) was designed and developed in the present work to improve in vivo target-specific fluorescence imaging. After conjugation with pamidronate (PAM) and bovine serum albumin (BSA), the SMF800 conjugates exhibited successful in vivo targeting in bone and tumor tissues with low background uptake, respectively. The improved in vivo performance of the SMF800 conjugate demonstrated that the small molecular NIR fluorophore SMF800 can be widely used in a much broader range of imaging applications. The structure of SMF800, which was developed by considering two important physicochemical properties, water solubility and conjugatability, is first introduced. Therefore, this work suggests a simple and rational approach to design small, hydrophilic, and conjugatable NIR fluorophores for targeted bioimaging. [ABSTRACT FROM AUTHOR]

Early detection of fatal and disabling diseases such as cancer, neurological and autoimmune dysfunctions is still desirable yet challenging to improve quality of life and longevity. Peptoids (N-substituted glycine oligomers) are a relatively new class of peptidomimetics, being highly versatile and capable of mimicking the architectures and the activities of the peptides but with a marked resistance to proteases and a propensity to cross the cellular membranes over the peptides themselves. For these properties, they have gained an ever greater interest in applications in bioengineering and biomedical fields. In particular, the present manuscript is to our knowledge the only review focused on peptoids for diagnostic applications and covers the last decade's literature regarding peptoids as tools for early diagnosis of pathologies with a great impact on human health and social behavior. The review indeed provides insights into the peptoid employment in targeted cancer imaging and blood-based screening of neurological and autoimmune diseases, and it aims to attract the scientific community's attention to continuing and sustaining the investigation of these peptidomimetics in the diagnosis field considering their promising peculiarities. [ABSTRACT FROM AUTHOR]

Late detection, peritoneal dissemination, chemoresistance and weak response to targeted therapeutics lead to high mortality in ovarian cancer. More efficient and specific tumor imaging and therapeutic agents are needed to improve the resection rate of surgery and to eliminate residual disease. The expression patterns of follicle-stimulating hormone (FSH) receptor make it a suitable target for ovarian cancer. Here, we report a strategy to develop an organic near-infrared probe for FSH receptor-targeted tumor imaging and photothermal therapy. The FSH-Rh760 probe was conjugated from the Rh760 fluorophore with the FSH β subunit 33–53 peptide. FSH-Rh760 specifically distinguished peritoneal metastatic ovarian cancerous foci from surrounding normal tissues with a high tumor-to-background ratio. The fluorescence signals in tumors peaked at 2 h and were cleared at 120 h postinjection. FSH-Rh760 treatment rapidly increased the abdomen temperature of mice up to ∼43 °C upon exposure to a near-infrared laser and effectively suppressed peritoneal tumor growth with tumor specificity. No significant systemic toxicities were observed. This study demonstrates the targeting ability and biocompatibility of FSH receptor-targeted theranostics and highlights its potential for clinical application in imaging-guided precision tumor resection and photothermal therapy to eliminate cancer lesions intraoperatively and postoperatively.

Abstract Inspired by the principle of in situ self‐assembly, the development of enzyme‐activated molecular nanoprobes can have a profound impact on targeted tumor detection. However, despite their intrinsic promise, obtaining an optical readout of enzyme activity with high specificity in native milieu has proven to be challenging. Here, a fundamentally new class of Raman‐active self‐assembling bioorthogonal enzyme recognition (nanoSABER) probes for targeted tumor imaging is reported. This class of Raman probes presents narrow spectral bands reflecting their vibrational fingerprints and offers an attractive solution for optical imaging at different bio‐organization levels. The optical beacon harnesses an enzyme‐responsive peptide sequence, unique tumor‐penetrating properties, and vibrational tags with stretching frequencies in the cell‐silent Raman window. The design of nanoSABER is tailored and engineered to transform into a supramolecular structure exhibiting distinct vibrational signatures in presence of target enzyme, creating a direct causality between enzyme activity and Raman signal. Through the integration of substrate‐specific for tumor‐associated enzyme legumain, unique capabilities of nanoSABER for imaging enzyme activity at molecular, cellular, and tissue levels in combination with machine learning models are shown. These results demonstrate that the nanoSABER probe may serve as a versatile platform for Raman‐based recognition of tumor aggressiveness, drug accumulation, and therapeutic response.

Specific identification and monitoring of senescent cells are essential for the in-depth understanding and regulation of senescence-related life processes and diseases. Fluorescent sensors providing real-time and in situ information with spatiotemporal resolution are unparalleled tools and have contributed greatly to this field. This review focuses on the recent progress in fluorescent sensors for molecularly targeted imaging and real-time tracking of cellular senescence. The molecular design, sensing mechanisms, and biological activities of the sensors are discussed. The sensors are categorized by the types of markers and targeting ligands. Accordingly, their molecular recognition and fluorescent performance towards senescence biomarkers are summarized. Finally, the perspective and challenges in this field are discussed, which are expected to assist future design of next-generation sensors for monitoring cellular senescence. [ABSTRACT FROM AUTHOR]

Simple Summary: There is evidence that oncological radicality with complete tumor removal may improve the survival of patients undergoing surgery for hepatopancreatobiliary malignancies. However, the complexity of vital vascular structures close to or embedded within the pancreas and the liver may increase both the surgical difficulty and the risk of achieving a non-radical resection. Preoperative staging after neoadjuvant therapy is usually challenged by the inability of correctly used imaging methods to distinguish vital tumors from fibrosis. Additionally, the inability to define the exact tumor borders often transfers to the operating room as well. Recently, more research has focused on the development of novel intraoperative imaging modalities and targeted contrast agents to improve preoperative and intraoperative diagnostics. We review current advances made in preclinical research and discuss clinical possibilities and future perspectives, including the characteristics of the ideal contrast agent. Hepatopancreatobiliary surgery belongs to one of the most complex fields of general surgery. An intricate and vital anatomy is accompanied by difficult distinctions of tumors from fibrosis and inflammation; the identification of precise tumor margins; or small, even disappearing, lesions on currently available imaging. The routine implementation of ultrasound use shifted the possibilities in the operating room, yet more precision is necessary to achieve negative resection margins. Modalities utilizing fluorescent-compatible dyes have proven their role in hepatopancreatobiliary surgery, although this is not yet a routine practice, as there are many limitations. Modalities, such as photoacoustic imaging or 3D holograms, are emerging but are mostly limited to preclinical settings. There is a need to identify and develop an ideal contrast agent capable of differentiating between malignant and benign tissue and to report on the prognostic benefits of implemented intraoperative imaging in order to navigate clinical translation. This review focuses on existing and developing imaging modalities for intraoperative use, tailored to the needs of hepatopancreatobiliary cancers. We will also cover the application of these imaging techniques to theranostics to achieve combined diagnostic and therapeutic potential. [ABSTRACT FROM AUTHOR]

In vivo imaging has enabled impressive advances in biological research, both preclinical and clinical, and researchers have an arsenal of imaging methods available. Bioluminescence imaging is an advantageous method for in vivo studies that allows for the simple acquisition of images with low background signals. Researchers have increasingly been looking for ways to improve bioluminescent imaging for in vivo applications, which we sought to achieve by developing a bioluminescent probe that could specifically target cells of interest. We chose pancreatic ductal adenocarcinoma (PDAC) as the disease model because it is the most common type of pancreatic cancer and has an extremely low survival rate. We targeted the epidermal growth factor receptor (EGFR), which is frequently overexpressed in pancreatic cancer cells, using an EGFR-specific affibody to selectively identify PDAC cells and delivered a Gaussia luciferase (GLuc) bioluminescent protein for imaging by engineering a fusion protein with both the affibody and the bioluminescent protein. This fusion protein was then complexed with a G5-PAMAM dendrimer nanocarrier. The dendrimer was used to improve the protein stability in vivo and increase signal strength. Our targeted bioluminescent complex had an enhanced uptake into PDAC cells in vitro and localized to PDAC tumors in vivo in pancreatic cancer xenograft mice. The bioluminescent complexes could delineate the tumor shape, identify multiple masses, and locate metastases. Through this work, an EGFR-targeted bioluminescent–dendrimer complex enabled the straightforward identification and imaging of pancreatic cancer cells in vivo in preclinical models. This argues for the targeted nanocarrier-mediated delivery of bioluminescent proteins as a way to improve in vivo bioluminescent imaging. [ABSTRACT FROM AUTHOR]

Objective To perform quantum dots(QDs)imaging of breast cancer cells and breast cancer tissue paraffin specimens by using nucleic acid aptamer W3 binding specificity on breast cancer cells. Methods The binding specificity of nucleic acid aptamer W3 to breast cancer cell lines was detected by flow cytometry, and based on the binding reaction principle of biotin and streptomyces avidin, the quantum dot targeting imaging of nucleic acid aptamer W3 on breast cancer cell lines and tissue specimens of clinical patients was observed by fluorescence microscopy, and its clinical significance was further analyzed. Results The nucleic acid aptamer W3 specifically binded to breast cancer cell lines with high malignancy,and after coupling quantum dots QD605(W3-QDs), it achieved targeted imaging of breast cancer cell lines and breast cancer tissues with high malignancy, and the fluorescence intensity of breast cancer tissues with high malignancy degree was significantly higher than that of breast cancer tissues with low malignancy. Conclusions The nucleic acid aptamer W3 may achieve target imaging of breast cancer after coupling quantum dots, which can be used for early diagnosis of breast cancer.

Copyright of Journal of China Medical University is the property of Journal of China Medical University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Prostate cancer is the second most frequent malignancy in men worldwide and the fifth leading cause of death by cancer. Although most patients initially benefit from therapy, many of them will progress to metastatic castration-resistant prostate cancer, which still remains incurable. The significant mortality and morbidity rate associated with the progression of the disease results mainly from a lack of specific and sensitive prostate cancer screening systems, identification of the disease at mature stages, and failure of anticancer therapy. To overcome the limitations of conventional imaging and therapeutic strategies for prostate cancer, various types of nanoparticles have been designed and synthesized to selectively target prostate cancer cells without causing toxic side effects to healthy organs. The purpose of this review is to briefly discuss the selection criteria of suitable nanoparticles, ligands, radionuclides, and radiolabelling strategies for the development of nanoparticle-based radioconjugates for targeted imaging and therapy of prostate cancer and to evaluate progress in the field, focusing attention on their design, specificity, and potential for detection and/or therapy. [ABSTRACT FROM AUTHOR]

Single-chain polymer nanoparticles (SCNPs) are a well-defined and uniquely sized class of polymer nanoparticles. The advances in polymer science over the past decades have enabled the development of a variety of intramolecular crosslinking systems, leading to particles in the 5–20 nm size regime. Which is aligned with the size regime of proteins and therefore making SCNPs an interesting class of NPs for biomedical applications. The high modularity of SCNP design and the ease of their functionalization have led to growing research interest. In this review, we describe different crosslinking systems, as well as the preparation of functional SCNPs and the variety of biomedical applications that have been explored. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background In this study we investigated the expression of vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) and prostate-specific membrane antigen (PSMA) to analyze their potency as targets for the detection of lymph node (LN) metastases of urothelial carcinoma of the bladder. Methods Antigen expression was determined in 40 samples with urothelial carcinoma and compared to 17 matched samples without metastases by immunohistochemistry. The total immunostaining score (TIS 0–12) was determined as the product of a proportion score (PS 0–4) and intensity score (IS 0–3). Results VEGF expression was high in primary tumor and LN metastases (median TIS 8 in both) and VEGF expression was also seen in LNs without metastases (median TIS 6). EGFR expression was low in primary tumor and LN metastases (median TIS 3 and 2 respectively) and absent in LNs without metastases. PSMA expression was low in samples with urothelial carcinoma (median TIS 2). Conclusion VEGF shows moderate to high expression levels in both primary tumors and LN metastases and could be a candidate as a target agent for imaging modalities of urothelial carcinoma. EGFR and PSMA do show low staining levels in tumor tissue with urothelial carcinoma and do not seem suitable as target agents. Trial registration: The Medical Ethics Review Board of the University Medical Center Groningen approved this study on 14 December 2017 (METc UMCG 2017/639). Trial registration number (UMCG Research Register): 201700868.

Abstract Advances in diagnostic imaging have provided unprecedented opportunities to detect diseases at early stages and with high reliability. Diagnostic imaging is also crucial to monitoring the progress or remission of disease and thus is often the central basis of therapeutic decision-making. Currently, several diagnostic imaging modalities (computed tomography, magnetic resonance imaging, and positron emission tomography, among others) are routinely used in clinics and present their own advantages and limitations. In vivo near-infrared (NIR) fluorescence imaging has recently emerged as an attractive imaging modality combining low cost, high sensitivity, and relative safety. As a preclinical tool, it can be used to investigate disease mechanisms and for testing novel diagnostics and therapeutics prior to their clinical use. However, the limited depth of tissue penetration is a major challenge to efficient clinical use. Therefore, the current clinical use of fluorescence imaging is limited to a few applications such as image-guided surgery on tumors and retinal angiography, using FDA-approved dyes. Progress in fluorophore development and NIR imaging technologies holds promise to extend their clinical application to oncology, cardiovascular diseases, plastic surgery, and brain imaging, among others. Nanotechnology is expected to revolutionize diagnostic in vivo fluorescence imaging through targeted delivery of NIR fluorescent probes using antibody conjugation. In this review, we discuss the latest advances in in vivo fluorescence imaging technologies, NIR fluorescent probes, and current and future clinical applications. Graphical Abstract

Objective: Recently, development of multifunctional contrast agent for effective targeted molecular computedtomography (CT) imaging of cancer cells stays a major problem. In this study, we explain the ability of Triptorelinpeptide-targeted multifunctional bismuth nanoparticles (Bi2S3@ BSA-Triptorelin NPs) for molecular CT imaging.Materials and Methods: In this experimental study, the formed nanocomplex of Bi2S3@ BSA-Triptorelin NPswas characterized using different methods. The MTT cytotoxicity test was performed to determine the appropriateconcentration of nanoparticles in the MCF-7 cells. The X-ray attenuation intensity and Contrast to Noise Ratio (CNR) oftargeted and non-targeted nanoparticles were measured at the concentrations of 25, 50, and 75 μg/ml and X-ray tubevoltages of 90, 120 and 140 kVp.Results: We showed that the formed Bi2S3@ BSA-Triptorelin NPs with a Bi core size of approximately ~8.6 nm are nontoxicin a given concentration (0-200 μg/ml). At 90, 120, and 140 tube potentials (kVp), the X-ray attenuation of targeted cells were1.35, 1.36, and 1.33-times, respectively, more than non-targeted MCF-7cells at the concentration of 75 μg/ml. The CNRvalues at 90, 120, and 140 kVp tube potentials were 171.5, 153.8 and 146.3 c/ϭ, respectively.Conclusion: These findings propose that the diagnostic nanocomplex of Bi2S3@ BSA-Triptorelin NPs can be appliedas a good contrast medium for molecular CT techniques.

Background: Mesothelin (MSLN) has been implicated in cancer migration, invasion, and prognosis, making it a potential tumor marker. However, the precise role of MSLN in the migration and invasion of malignant pleural mesothelioma (MPM) remains elusive, and effective noninvasive methods for assessing MSLN status are currently lacking. In this study, we focused on MSLN expression and elucidated the underlying mechanisms by which MSLN regulates migration and invasion in MPM. Building upon this knowledge, we developed an MRI nanoprobe that targets MSLN to assess its status in vitro and in vivo by comparing T2 signal intensity and T2 values on magnetic resonance imaging examinations. This nanoprobe combines the anatomical information obtained from MRI with biological information obtained from MSLN for comprehensive evaluation of MPM. Results: Notably, we observed that MSLN expression in the epithelial type of MPM was higher and increased continuously with tumor growth than that in other types. In addition, MSLN upregulation promoted N-cadherin, matrix metalloproteinase-7, and MMP9 expression and resulted in higher migration/invasion ability and shorter survival. We synthesized MSLN-targeted nanoprobes (Fe3O4@SiO2-PEG-MSLN, FSPM) to assess MSLN expression by comparing the T2 signal intensity and T2 value of different cell lines and mice after 14, 28, and 42 days of modeling. Remarkably, MSLN-targeted nanoprobes demonstrated excellent targeting capabilities. In vitro studies revealed a pronounced reduction in T2 signal intensity and T2 values of the epithelial type as the probe concentration increased. In addition, in vivo experiments demonstrated a gradual decline in these parameters over time, particularly in the epithelial type as compared to the biphasic type, corresponding to the dynamic expression patterns of MSLN during different growth stages. Conclusion: Our comprehensive research succeeded in confirming the regulatory mechanisms by which MSLN influences migration and invasion. Moreover, we introduced a promising method for monitoring MSLN expression that may help in facilitating the early detection, histological subtype identification, and assessment of migration, invasion, and prognosis in MPM. [ABSTRACT FROM AUTHOR]

Early detection of fatal and disabling diseases such as cancer, neurological and autoimmune dysfunctions is still desirable yet challenging to improve quality of life and longevity. Peptoids (N-substituted glycine oligomers) are a relatively new class of peptidomimetics, being highly versatile and capable of mimicking the architectures and the activities of the peptides but with a marked resistance to proteases and a propensity to cross the cellular membranes over the peptides themselves. For these properties, they have gained an ever greater interest in applications in bioengineering and biomedical fields. In particular, the present manuscript is to our knowledge the only review focused on peptoids for diagnostic applications and covers the last decade’s literature regarding peptoids as tools for early diagnosis of pathologies with a great impact on human health and social behavior. The review indeed provides insights into the peptoid employment in targeted cancer imaging and blood-based screening of neurological and autoimmune diseases, and it aims to attract the scientific community’s attention to continuing and sustaining the investigation of these peptidomimetics in the diagnosis field considering their promising peculiarities.

The near-infrared (NIR) fluorescence imaging modality has great potential for application in biomedical imaging research owing to its unique characteristics, such as low tissue autofluorescence and noninvasive visualization with high spatial resolution. Although a variety of NIR fluorophores are continuously reported, the commercially available NIR fluorophores are still limited, owing to complex synthetic processes and poor physicochemical properties. To address this issue, a small molecular NIR fluorophore (SMF800) was designed and developed in the present work to improve in vivo target-specific fluorescence imaging. After conjugation with pamidronate (PAM) and bovine serum albumin (BSA), the SMF800 conjugates exhibited successful in vivo targeting in bone and tumor tissues with low background uptake, respectively. The improved in vivo performance of the SMF800 conjugate demonstrated that the small molecular NIR fluorophore SMF800 can be widely used in a much broader range of imaging applications. The structure of SMF800, which was developed by considering two important physicochemical properties, water solubility and conjugatability, is first introduced. Therefore, this work suggests a simple and rational approach to design small, hydrophilic, and conjugatable NIR fluorophores for targeted bioimaging.

Purpose: We synthesized folic acid-conjugated Fe3O4/Au-pralidoxime chloride Nanoparticles (Fe2O3/Au@PAM NPs) for use as dual-modal contrast agents for Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) in the diagnosis of breast cancer. Materials and Methods: Fe2O3/Au@PAM NPs labeled or not to folic acid were synthesized and analyzed by dynamic light scattering, transmission electron microscopy, and vibrating sample magnetometry. The ability of these NPs to create image contrast was also investigated in silico and in vitro (in MCF-7 breast cancer cells and A549 lung cancer cells) with CT and MRI. Results: Dynamic light scattering and transmission electron microscopy revealed that the Fe2O3/Au@PAM NPs were nearly spherical. The average diameter of Fe2O3/Au NPs increased from 11.6 nm to 98 nm after folic acid conjugation. The saturation magnetization values of Fe2O3/Au@PAM NPs with and without folic acid conjugation were 25.56 and 32.6 emu/g, respectively. Conjugation of folic acid to NPs greatly improved their uptake by cancer cells. The additional coating of NPs with FA reduced the T2 relaxation time and signal intensity for MRI. Folic acid-labeled MCF-7 cells had a radiodensity measurement of 208 Hunsfield Units (HU) compared to 95 HU for A549 cells. For breast cancer cells, NPs labeled with folic acid significantly improved the X-ray absorption coefficient as a sign of active cellular uptake compared to NPs without labeling. Conclusion: Folic acid-labeled Fe2O3/Au@PAM NPs can serve as dual CT/MRI contrast agents and improve the sensitivities of both modalities for the detection of cancer cells.

Background: In this study we investigated the expression of vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) and prostate-specific membrane antigen (PSMA) to analyze their potency as targets for the detection of lymph node (LN) metastases of urothelial carcinoma of the bladder. Methods: Antigen expression was determined in 40 samples with urothelial carcinoma and compared to 17 matched samples without metastases by immunohistochemistry. The total immunostaining score (TIS 0–12) was determined as the product of a proportion score (PS 0–4) and intensity score (IS 0–3). Results: VEGF expression was high in primary tumor and LN metastases (median TIS 8 in both) and VEGF expression was also seen in LNs without metastases (median TIS 6). EGFR expression was low in primary tumor and LN metastases (median TIS 3 and 2 respectively) and absent in LNs without metastases. PSMA expression was low in samples with urothelial carcinoma (median TIS 2). Conclusion: VEGF shows moderate to high expression levels in both primary tumors and LN metastases and could be a candidate as a target agent for imaging modalities of urothelial carcinoma. EGFR and PSMA do show low staining levels in tumor tissue with urothelial carcinoma and do not seem suitable as target agents. Trial registration: The Medical Ethics Review Board of the University Medical Center Groningen approved this study on 14 December 2017 (METc UMCG 2017/639). Trial registration number (UMCG Research Register): 201700868. [ABSTRACT FROM AUTHOR]

Simple Summary: Hyperpolarized 129Xe (HP 129Xe) MRI was used to demonstrate the feasibility of targeted imaging of lung cancer using two cancer-specific surface-modified iron oxide nanoparticles (IONPs) as negative contrast agents; polyethylene glycol-coated IONPs (PEG-IONPs), and dextran-coated IONPs conjugating folate on their surface (FA@Dex-IONPs). After the intravenous injection of IONPs, HP 129Xe signal reductions were observed at cancer sites for both PEG-IONPs and FA@Dex-IONPs administered in mice. By targeted imaging with HP 129Xe MRI, characteristic differences in pharmacokinetics between PEG-IONPs and FA@Dex-IONPs were successfully monitored. In particular, FA@Dex-IONPs were found to show superior pharmacokinetics for HP 129Xe MRI in terms of prolonged clearance due to their binding to overexpressed folate receptors in lung cancer cells. Hyperpolarized 129Xe (HP 129Xe) MRI enables functional imaging of various lung diseases but has been scarcely applied to lung cancer imaging. The aim of this study is to investigate the feasibility of targeted imaging of lung cancer with HP 129Xe MRI using surface-modified iron oxide nanoparticles (IONPs) as molecular targeting contrast agents. A mouse model of lung cancer (LC) was induced in nine mice by intra-peritoneal injection of urethane. Three months after the urethane administration, the mice underwent lung imaging with HP 129Xe MRI at baseline (0 h). Subsequently, the LC group was divided into two sub-groups: mice administered with polyethylene glycol-coated IONPs (PEG-IONPs, n = 4) and folate-conjugated dextran-coated IONPs (FA@Dex-IONPs, n = 5). The mice were imaged at 3, 6, and 24 h after the intravenous injection of IONPs. FA@Dex-IONPs mice showed a 25% reduction in average signal intensity at cancer sites at 3 h post injection, and a 24% reduction at 24 h post injection. On the other hand, in PEG-IONPs mice, while a signal reduction of approximately 28% was observed at cancer sites at 3 to 6 h post injection, the signal intensity was unchanged from that of the baseline at 24 h. Proton MRI of LC mice (n = 3) was able to detect cancer five months after urethane administration, i.e., later than HP 129Xe MRI (3 months). Furthermore, a significant decrease in averaged 1H T2 values at cancer sites was observed at only 6 h post injection of FA@Dex-IONPs (p < 0.05). As such, the targeted delivery of IONPs to cancer tissue was successfully imaged with HP 129Xe MRI, and their surface modification with folate likely has a high affinity with LC, which causes overexpression of folate receptors. [ABSTRACT FROM AUTHOR]

To overcome the limitations of brown adipose tissue (BAT) imaging with MRI and PET/CT, near-infrared (NIR) fluorescence imaging has been utilized in living animals because it is highly sensitive, noninvasive, nonradioactive, and cost-effective. To date, only a few NIR fluorescent dyes for detecting BAT have been reported based on the structure-inherent targeting strategy. Among them, IR-786, a commercial cyanine dye, was used firstly for quantitative NIR imaging of BAT perfusion in 2003. Owing to the high cytotoxicity, poor water solubility, and strong nonspecific background uptake of IR-786, the chemical structure of IR-786 should be redesigned to be more hydrophilic and less toxic so that it can show more BAT-specific accumulation. Here, we developed a BAT-specific NIR dye, BF800-AM, by incorporating the tyramine linker in the original structure of IR-786. After modifying the physicochemical properties of IR-786, in vivo results showed significant uptake of the newly designed BF800-AM in the BAT with improved signal-to-background ratio. Additional in vivo studies using mouse tumor models revealed that BF800-AM targeting to BAT is independent of tumor tissues, as distinct from IR-786 showing uptake in both tissues. Therefore, BF800-AM can be used for improved noninvasive visualization of BAT mass and activity in living animals. [ABSTRACT FROM AUTHOR]

The high level of reactive oxygen species (ROS) in the rheumatoid arthritis (RA) microenvironment (RAM) and its persistent inflammatory nature can promote damage to joints, bones, and the synovium. Targeting strategies that integrate effective RAM regulation with imaging-based monitoring could lead to improvements in the diagnosis and treatment of RA. Here, we report the combined use of small interfering RNAs (siRNAsT/I) and Prussian blue nanoparticles (PBNPs) to silence the expression of proinflammatory cytokines TNF-a/IL-6 and scavenge the ROS associated with RAM. To enhance the in vitro and in vivo biological stability, biocompatibility, and targeting capability of the siRNAsT/I and PBNPs, macrophage membrane vesicles were used to prepare biomimetic nanoparticles, M@PsiRNAsT/I. The resulting constructs were found to suppress tumor necrosis factor-a/interleukin-6 expression and overcome the hypoxic nature of RAM, thus alleviating RA-induced joint damage in a mouse model. The M@P-siRNAsT/I of this study could be monitored via near-infrared photoacoustic (PA) imaging. Moreover, multispectral PA imaging without the need for labeling permitted the real-time evaluation of M@PsiRNAsT/I as a putative RA treatment. Clinical microcomputed tomography and histological analysis confirmed the effectiveness of the treatment. We thus suggest that macrophage-biomimetic M@P-siRNAsT/I and their analogs assisted by PA imaging could provide a new strategy for RA diagnosis, treatment, and monitoring. [ABSTRACT FROM AUTHOR]

Advances in diagnostic imaging have provided unprecedented opportunities to detect diseases at early stages and with high reliability. Diagnostic imaging is also crucial to monitoring the progress or remission of disease and thus is often the central basis of therapeutic decision-making. Currently, several diagnostic imaging modalities (computed tomography, magnetic resonance imaging, and positron emission tomography, among others) are routinely used in clinics and present their own advantages and limitations. In vivo near-infrared (NIR) fluorescence imaging has recently emerged as an attractive imaging modality combining low cost, high sensitivity, and relative safety. As a preclinical tool, it can be used to investigate disease mechanisms and for testing novel diagnostics and therapeutics prior to their clinical use. However, the limited depth of tissue penetration is a major challenge to efficient clinical use. Therefore, the current clinical use of fluorescence imaging is limited to a few applications such as image-guided surgery on tumors and retinal angiography, using FDA-approved dyes. Progress in fluorophore development and NIR imaging technologies holds promise to extend their clinical application to oncology, cardiovascular diseases, plastic surgery, and brain imaging, among others. Nanotechnology is expected to revolutionize diagnostic in vivo fluorescence imaging through targeted delivery of NIR fluorescent probes using antibody conjugation. In this review, we discuss the latest advances in in vivo fluorescence imaging technologies, NIR fluorescent probes, and current and future clinical applications. [ABSTRACT FROM AUTHOR]

Specific identification and monitoring of senescent cells are essential for the in-depth understanding and regulation of senescence-related life processes and diseases. Fluorescent sensors providing real-time and in situ information with spatiotemporal resolution are unparalleled tools and have contributed greatly to this field. This review focuses on the recent progress in fluorescent sensors for molecularly targeted imaging and real-time tracking of cellular senescence. The molecular design, sensing mechanisms, and biological activities of the sensors are discussed. The sensors are categorized by the types of markers and targeting ligands. Accordingly, their molecular recognition and fluorescent performance towards senescence biomarkers are summarized. Finally, the perspective and challenges in this field are discussed, which are expected to assist future design of next-generation sensors for monitoring cellular senescence.

In vivo imaging has enabled impressive advances in biological research, both preclinical and clinical, and researchers have an arsenal of imaging methods available. Bioluminescence imaging is an advantageous method for in vivo studies that allows for the simple acquisition of images with low background signals. Researchers have increasingly been looking for ways to improve bioluminescent imaging for in vivo applications, which we sought to achieve by developing a bioluminescent probe that could specifically target cells of interest. We chose pancreatic ductal adenocarcinoma (PDAC) as the disease model because it is the most common type of pancreatic cancer and has an extremely low survival rate. We targeted the epidermal growth factor receptor (EGFR), which is frequently overexpressed in pancreatic cancer cells, using an EGFR-specific affibody to selectively identify PDAC cells and delivered a Gaussia luciferase (GLuc) bioluminescent protein for imaging by engineering a fusion protein with both the affibody and the bioluminescent protein. This fusion protein was then complexed with a G5-PAMAM dendrimer nanocarrier. The dendrimer was used to improve the protein stability in vivo and increase signal strength. Our targeted bioluminescent complex had an enhanced uptake into PDAC cells in vitro and localized to PDAC tumors in vivo in pancreatic cancer xenograft mice. The bioluminescent complexes could delineate the tumor shape, identify multiple masses, and locate metastases. Through this work, an EGFR-targeted bioluminescent–dendrimer complex enabled the straightforward identification and imaging of pancreatic cancer cells in vivo in preclinical models. This argues for the targeted nanocarrier-mediated delivery of bioluminescent proteins as a way to improve in vivo bioluminescent imaging.

Hepatopancreatobiliary surgery belongs to one of the most complex fields of general surgery. An intricate and vital anatomy is accompanied by difficult distinctions of tumors from fibrosis and inflammation; the identification of precise tumor margins; or small, even disappearing, lesions on currently available imaging. The routine implementation of ultrasound use shifted the possibilities in the operating room, yet more precision is necessary to achieve negative resection margins. Modalities utilizing fluorescent-compatible dyes have proven their role in hepatopancreatobiliary surgery, although this is not yet a routine practice, as there are many limitations. Modalities, such as photoacoustic imaging or 3D holograms, are emerging but are mostly limited to preclinical settings. There is a need to identify and develop an ideal contrast agent capable of differentiating between malignant and benign tissue and to report on the prognostic benefits of implemented intraoperative imaging in order to navigate clinical translation. This review focuses on existing and developing imaging modalities for intraoperative use, tailored to the needs of hepatopancreatobiliary cancers. We will also cover the application of these imaging techniques to theranostics to achieve combined diagnostic and therapeutic potential.

Commercial X-ray computed tomography (CT) contrast agents (CAs) are not appropriate for multicolor CT imaging and are limited due to a lack of tumor targeting. In this contribution, to favor the combination of high Z elements like bismuth and iodine for a broad range of X-ray photon energy, BiOI nanoparticles (NPs) are synthesized with hyaluronic acid (HA) coating to target the tumor cells with CD44 overexpression. The crystal structure of BiOI NPs is determined by X-ray powder diffraction, and the size of NPs is determined by a transmission electron microscope at about 14 ± 3 nm. The dynamic diameter of the NPs (DLS) in PBS buffer was measured at about 100 nm. Fourier transform infrared spectroscopy and thermal gravimetric analysis confirm the coating of BiOI NPs with HA. The stability of the NPs was also investigated via UV–vis spectroscopy. The immunocytochemistry process is performed to investigate the targeting ability of synthesized NPs on the human colon cancer cells with CD44 antigen. Finally, the X-ray attenuation of prepared HA-coated BiOI NPs is higher than Iohexol as the commercially available iodinated contrasting agent at the same concentrations, which can be administrated at much lower doses to achieve similar contrast to Iohexol. [Display omitted] [ABSTRACT FROM AUTHOR]

A purely organic supramolecular assembly emitting three‐photon room‐temperature phosphorescence (RTP) is constructed from a macrocyclic host, cucurbit[8]uril (CB[8]), and 4‐bromophenyl pyridine salt having an alkyl chain length of 6 or 12 carbon atoms (6C and 12C, respectively). Benefiting from macrocyclic host confined guests, the encapsulation of 12C and 6C in the CB[8] cavity results in three‐photon absorption and subsequent near‐infrared (NIR) phosphorescence emission. Notably, secondary assembly with sulfonated β‐cyclodextrin (SCD) further enhances the phosphorescence emission of the multilevel supramolecular assembly. NIR‐delayed fluorescence via a light‐harvesting phosphorescent energy transfer system is achieved by adding Nile blue as a substrate. Comparison of 12C/CB[8]/SCD and 6C/CB[8]/SCD shows that a long hydrophobic layer is more conducive to stabilizing NIR‐delayed fluorescence emission. These findings indicate that multilevel supramolecular assemblies can be used for three‐photon‐excited NIR‐delayed fluorescence and RTP imaging of cancer cells, which greatly expands the biological applications of pure organic RTP materials. [ABSTRACT FROM AUTHOR]

Objective: Recently, development of multifunctional contrast agent for effective targeted molecular computed tomography (CT) imaging of cancer cells stays a major problem. In this study, we explain the ability of Triptorelin peptide-targeted multifunctional bismuth nanoparticles (Bi2S3@ BSA-Triptorelin NPs) for molecular CT imaging. Materials and Methods: In this experimental study, the formed nanocomplex of Bi2S3@ BSA-Triptorelin NPs was characterized using different methods. The MTT cytotoxicity test was performed to determine the appropriate concentration of nanoparticles in the MCF-7 cells. The X-ray attenuation intensity and Contrast to Noise Ratio (CNR) of targeted and non-targeted nanoparticles were measured at the concentrations of 25, 50, and 75 µg/ml and X-ray tube voltages of 90, 120 and 140 kVp. Results: We showed that the formed Bi2S3@ BSA-Triptorelin NPs with a Bi core size of approximately ~8.6 nm are nontoxic in a given concentration (0-200 µg/ml). At 90, 120, and 140 tube potentials (kVp), the X-ray attenuation of targeted cells were 1.35, 1.36, and 1.33-times, respectively, more than non-targeted MCF-7cells at the concentration of 75 μg/ml. The CNR values at 90, 120, and 140 kVp tube potentials were 171.5, 153.8 and 146.3 c/ϭ, respectively. Conclusion: These findings propose that the diagnostic nanocomplex of Bi2S3@ BSA-Triptorelin NPs can be applied as a good contrast medium for molecular CT techniques. [ABSTRACT FROM AUTHOR]

PSMA-11-HBED and PSMA-11-HYNIC are well-known prostate cancer (PCa) ligands, which strongly bind to prostate- specific membrane antigen (PSMA) on PCa epithelial cells. In this study, we announced the synthesis, physico-chemical properties and in vitro binding assay of targeted iron oxide nanoparticles (IONPs) by the PSMA-11 peptides as an MRI nanocontrast agent for early PCa discernment. IONPs were coated with carboxymethylated dextran (CMD-IONPs) and also with bovine serum albumin (BSA-IONPs), then conjugated with two different amounts of PSMA-11-HYNIC (T-CMD-IONPs) and PSMA-11-HBED (T-BSA-IONPs). In addition, the cellular viability, relaxometry measurements in aqueous and in vitro media, as well as quantitative cell uptake of the synthesized formulations were evaluated. At diagnostic concentrations, IONPs showed no cytotoxicity. A comparison of T-BSA-IONPs and T-CMD-IONPs with non-targeted IONPs at concentration 750 μ M indicates that LNCaP PSMA + prostate cancer cells took up, respectively, 5.02 and 1.77 times as much IONPs. The results validated distinguished r 2 (m M - 1 s - 1) values at 1.5 T MRI scanner as 160 for CMD-IONPs and 68 for BSA-IONPs. Moreover, targeted-IONPs in-vitro had higher r 2 values than untargeted IONPs. The contrast to noise ratio (CNR) between targeted and non-targeted IONPs at concentration 750 μ M were calculated as 4.65 and 3.95 for T-BSA-IONPs and T-CMD-IONPs, respectively. The study confirms that the novel T-BSA-IONPs and T-CMD-IONPs nanoprobes are suitable negative contrast agents for molecular imaging of PCa. [ABSTRACT FROM AUTHOR]

Prostate cancer is the second most frequent malignancy in men worldwide and the fifth leading cause of death by cancer. Although most patients initially benefit from therapy, many of them will progress to metastatic castration-resistant prostate cancer, which still remains incurable. The significant mortality and morbidity rate associated with the progression of the disease results mainly from a lack of specific and sensitive prostate cancer screening systems, identification of the disease at mature stages, and failure of anticancer therapy. To overcome the limitations of conventional imaging and therapeutic strategies for prostate cancer, various types of nanoparticles have been designed and synthesized to selectively target prostate cancer cells without causing toxic side effects to healthy organs. The purpose of this review is to briefly discuss the selection criteria of suitable nanoparticles, ligands, radionuclides, and radiolabelling strategies for the development of nanoparticle-based radioconjugates for targeted imaging and therapy of prostate cancer and to evaluate progress in the field, focusing attention on their design, specificity, and potential for detection and/or therapy.

Abstract Background Surgically induced nerve damage is a common but debilitating side effect in oncological surgery. With the aim to use fluorescence guidance to enable nerve-sparing interventions in future surgery, a fluorescent tracer was developed that specifically targets myelin protein zero (P0). Results Truncated homotypic P0 protein-based peptide sequences were C-terminally functionalized with the far-red cyanine dye Cy5. The lead compound Cy5-P0 101–125 was selected after initial solubility, (photo)physical and in vitro evaluation (including P0-blocking experiments). Cy5-P0 101–125 (K D = 105 ± 17 nM) allowed in vitro and ex vivo P0-related staining. Furthermore, Cy5-P0 101–125 enabled in vivo fluorescence imaging of the Sciatic nerve in mice after local intravenous (i.v.) administration and showed compatibility with a clinical fluorescence laparoscope during evaluation in a porcine model undergoing robot-assisted surgery. Biodistribution data revealed that i.v. administered [ 111 In]In-DTPA-P0 101–125 does not enter the central nervous system (CNS). Conclusion P0 101–125 has proven to be a potent nerve-specific agent that is able to target P0/myelin under in vitro, ex vivo, and in vivo conditions without posing a threat for CNS-related toxicity.

Objective: The low detection rate of early and small tumors remains a clinical problem that urgently needs to be solved in the accurate diagnosis and treatment of upper urinary tract urothelial carcinoma (UTUC). The objective of this study is to evaluate the feasibility of CD47 as a target for optical molecular imaging of human UTUC and conduct preliminary ex vivo imaging experiments. Methods: We firstly analyzed the genome-wide mRNA expression data from Gene Expression Omnibus (GEO). Paraffin-embedded tissue specimens comprising UTUC and normal urothelium were collected. All tissue specimens were used for immunohistochemistry to compare CD47 protein expression in normal and cancer tissue. Meanwhile, 12 patients undergoing radical nephroureterectomy were prospectively included in ex vivo imaging experiments. Freshly isolated upper urinary tract specimens were incubated with anti-CD47-Alexa Fluor 790 and then imaged under white light and near-infrared (NIR) light. Standard histopathologic evaluation was performed, and findings were correlated with CD47-targeted NIR molecular imaging. Results: The GEO data revealed that CD47 mRNA expression was higher in UTUC specimens than that in paracancer normal tissue. In immunohistochemical analysis, the CD47 protein expression level was higher in both non-muscle-invasive and muscle-invasive (stage ≥T2) UTUCs than that in normal uroepithelium, and the localization of CD47 protein was the tumor cell membrane. In the ex vivo imaging experiments, all patients were pathologically diagnosed with UTUC, and no adverse effects of anti-CD47-Alexa Fluor 790 on the histological structure of the tumor and normal uroepithelium were observed. In the NIR grayscale images, the mean fluorescence intensity of the tumor tissue was significantly higher than that of the adjacent normal background tissue, which greatly improved the visualization of the tumor. Conclusions: CD47-targeted NIR molecular imaging could be a feasible and powerful strategy for the accurate diagnosis of UTUC. Larger-scale randomized trials are needed. [ABSTRACT FROM AUTHOR]

Marta Truffi,1 Marta Sevieri,2 Lucia Morelli,3 Matteo Monieri,2 Serena Mazzucchelli,2 Luca Sorrentino,2 Raffaele Allevi,2 Arianna Bonizzi,2 Pietro Zerbi,2 Beatrice Marchini,2 Erika Longhi,2 Gianluca Matteo Sampietro,4 Francesco Colombo,4 Davide Prosperi,3 Miriam Colombo,3 Fabio Corsi2,5 1Nanomedicine and Molecular Imaging Laboratory, Istituti Clinici Scientifici Maugeri IRCCS, Pavia 27100, Italy; 2Department of Biomedical and Clinical Sciences “Luigi Sacco, Università degli studi di Milano, Milano, 20157, Italy; 3NanoBioLab, Department of Biotechnology and Biosciences, Università degli studi di Milano-Bicocca, Milano, 20126, Italy; 4IBD Surgery Unit, ASST Fatebenefratelli Sacco - Ospedale “Luigi Sacco” Polo Universitario, Milano, 20157, Italy; 5Surgery Department, Breast Unit, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, 27100, ItalyCorrespondence: Fabio CorsiSurgery Department, Breast Unit, Istituti Clinici Scientifici Maugeri IRCCS, via Maugeri 4, Pavia 27100, ItalyTel +39 02 5031 9850Fax +39 02 5031 9846Email fabio.corsi@icsmaugeri.itPurpose: Assessment of inflammatory bowel disease (IBD) currently relies on aspecific clinical signs of bowel inflammation. Specific imaging of the diseased bowel regions is still lacking. Here, we investigate mucosal addressin cell adhesion molecule 1 (MAdCAM-1) as a reliable and specific endothelial target for engineered nanoparticles delivering imaging agents to obtain an exact mapping of diseased bowel foci.Materials and Methods: We generated a nanodevice composed of PLGA-PEG coupled with anti-MAdCAM-1 antibody half-chains and loaded with quantum dots (P@QD-MdC NPs). Bowel localization and systemic biodistribution of the nanoconjugate were analyzed upon injection in a murine model of chronic IBD obtained through repeated administration of dextran sulfate sodium salt. Specificity for diseased bowel regions was also assessed ex vivo in human specimens from patients with IBD. Potential for development as contrast agent in magnetic resonance imaging was assessed by preliminary study on animal model.Results: Synthesized nanoparticles revealed good stability and monodispersity. Molecular targeting properties were analyzed in vitro in a cell culture model. Upon intravenous injection, P@QD-MdC NPs were localized in the bowel of colitic mice, with enhanced accumulation at 24 h post-injection compared to untargeted nanoparticles (p< 0.05). Nanoparticles injection did not induce histologic lesions in non-target organs. Ex vivo exposure of human bowel specimens to P@QD-MdC NPs revealed specific recognition of the diseased regions vs uninvolved tracts (p< 0.0001). After loading with appropriate contrast agent, the nanoparticles enabled localized contrast enhancement of bowel mucosa in the rectum of treated mice.Conclusion: P@QD-MdC NPs efficiently detected bowel inflammation foci, accurately following the expression pattern of MAdCAM-1. Fine-tuning of this nanoconjugate with appropriate imaging agents offers a promising non-invasive tool for specific IBD diagnosis.Keywords: polymeric nanoparticles, inflamed bowel, adhesion molecule, targeted imaging

ObjectiveThe low detection rate of early and small tumors remains a clinical problem that urgently needs to be solved in the accurate diagnosis and treatment of upper urinary tract urothelial carcinoma (UTUC). The objective of this study is to evaluate the feasibility of CD47 as a target for optical molecular imaging of human UTUC and conduct preliminary ex vivo imaging experiments.MethodsWe firstly analyzed the genome-wide mRNA expression data from Gene Expression Omnibus (GEO). Paraffin-embedded tissue specimens comprising UTUC and normal urothelium were collected. All tissue specimens were used for immunohistochemistry to compare CD47 protein expression in normal and cancer tissue. Meanwhile, 12 patients undergoing radical nephroureterectomy were prospectively included in ex vivo imaging experiments. Freshly isolated upper urinary tract specimens were incubated with anti-CD47-Alexa Fluor 790 and then imaged under white light and near-infrared (NIR) light. Standard histopathologic evaluation was performed, and findings were correlated with CD47-targeted NIR molecular imaging.ResultsThe GEO data revealed that CD47 mRNA expression was higher in UTUC specimens than that in paracancer normal tissue. In immunohistochemical analysis, the CD47 protein expression level was higher in both non-muscle-invasive and muscle-invasive (stage ≥T2) UTUCs than that in normal uroepithelium, and the localization of CD47 protein was the tumor cell membrane. In the ex vivo imaging experiments, all patients were pathologically diagnosed with UTUC, and no adverse effects of anti-CD47-Alexa Fluor 790 on the histological structure of the tumor and normal uroepithelium were observed. In the NIR grayscale images, the mean fluorescence intensity of the tumor tissue was significantly higher than that of the adjacent normal background tissue, which greatly improved the visualization of the tumor.ConclusionsCD47-targeted NIR molecular imaging could be a feasible and powerful strategy for the accurate diagnosis of UTUC. Larger-scale randomized trials are needed.

Silicon‐based micro and nanoparticles are ideally suited for use as biomedical imaging agents because of their biocompatibility, biodegradability, and simple surface chemistry that facilitates drug loading and targeting. A method to hyperpolarize silicon particles using dynamic nuclear polarization (DNP), which increases magnetic resonance (MR) imaging signals by several orders‐of‐magnitude through enhanced nuclear spin alignment, was developed to allow silicon particles to function as contrast agents for in vivo magnetic resonance imaging. In this review, we describe the application of the DNP technique to silicon particles and nanoparticles for background‐free real‐time molecular MR imaging. This review provides a summary of the state‐of‐the‐science in silicon particle hyperpolarization with a detailed protocol for hyperpolarizing silicon particles. This information will foster awareness and spur interest in this emerging area of nanoimaging and provide a path to new developments and discoveries to further advance the field. This article is categorized under:Diagnostic Tools > In Vivo Nanodiagnostics and ImagingTherapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic DiseaseTherapeutic Approaches and Drug Discovery > Emerging Technologies [ABSTRACT FROM AUTHOR]

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an extremely challenging disease with a high mortality rate and a short overall survival time. The poor prognosis can be explained by aggressive tumor growth, late diagnosis, and therapy resistance. Consistent efforts have been made focusing on early tumor detection and novel drug development. Various strategies aim at increasing target specificity or local enrichment of chemotherapeutics as well as imaging agents in tumor tissue. Aptamers have the potential to provide early detection and permit anti-cancer therapy with significantly reduced side effects. These molecules are in-vitro selected single-stranded oligonucleotides that form stable three-dimensional structures. They are capable of binding to a variety of molecular targets with high affinity and specificity. Several properties such as high binding affinity, the in vitro chemical process of selection, a variety of chemical modifications of molecular platforms for diverse function, non-immunoreactivity, modification of bioavailability, and manipulation of pharmacokinetics make aptamers attractive targets compared to conventional cell-specific ligands. To explore the potential of aptamers for early diagnosis and targeted therapy of PDAC - as single agents and in combination with radiotherapy - we summarize the generation process of aptamers and their application as biosensors, biomarker detection tools, targeted imaging tracers, and drug-delivery carriers. We are furthermore discussing the current implementation aptamers in clinical trials, their limitations and possible future utilization.

Shuguang Wen,1– 3,* Weili Wang,4,* Ruimin Liu,3 Pengcheng He1 1Department of Hematology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, People’s Republic of China; 2Department of Hematology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People’s Republic of China; 3Basic Medical College, Henan University, Kaifeng 475000, People’s Republic of China; 4State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, People’s Republic of China*These authors contributed equally to this workCorrespondence: Pengcheng HeDepartment of Hematology, The First Affiliated Hospital of Xi’an Jiaotong University, No. 277 Yanta West Road, Xi’an 710061, People’s Republic of ChinaTel +86 189 9123 2609Email hepengcheng@xjtu.edu.cnBackground: Fluorescent metallic nanodots (NDs) have become a promising nanoprobe for a wide range of biomedical applications. Because Ag NDs have a high tendency to be oxidized, their synthesis and storage are a big challenge. Thus, the method for preparing stable Ag NDs is urgently needed. Surface modification and functionalization can enrich the capability of Ag NDs.Methods: In this work, fluorescent Ag NDs were synthesized in deoxygenated water by using porcine pancreatic α-amylase (PPA) as the stabilizing/capping agent. The absorption and fluorescence of PPA-protected Ag NDs (PPA@AgNDs) were measured with a spectrophotometer and a spectrofluorometer, respectively. The morphology of PPA@AgNDs was characterized by high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM). The biocompatibility of PPA@AgNDs was evaluated by tetrazolium (MTT)-based assay. PolyLys-Cys-SH (sequence: KKKKKKC) peptides were conjugated to PPA@AgNDs via heterobifunctional crosslinkers. PolyLys-Cys-linked PPA@AgNDs absorbed 5-aminolevulinic acid (ALA) by electrostatic interaction at physiological pH. The capability of tumor targeting was evaluated by intravenously injecting PPA@AgND-ALA into 4T1 breast cancer xenograft mouse models. Photodynamic therapy (PDT) against tumors was performed under 635 nm laser irradiation.Results: PPA@AgNDs emitted at 640 nm with quantum yield of 2.1%. The Ag NDs exhibited strong photostability over a long period and a fluorescence lifetime of 5.1 ns. PPA@AgNDs easily entered the cells to stain the nuclei, showing the capabilities of living cell imaging with negligible cytotoxicity. ALA-loaded PPA@AgNDs (PPA@AgND-ALA) presented the superiority of passive tumor targeting via the enhanced permeability and retention (EPR) effect. Tumors were visualized in the near-infrared (NIR) region with reduced background noise. ALA molecules released from PPA@AgND-ALA was converted into the photosensitizer (PS) of protoporphyrin IX (PpIX) intracellularly and intratumorally, which greatly improved the PDT efficacy.Conclusion: Our approach opens a new way to design a novel theranostic nanoplatform of PPA@AgND-ALA for effective tumor targeting and fluorescence image-guided PDT.Keywords: α-amylase, Ag nanodots, peptides, targeted imaging, photodynamic therapy

Hyperpolarized 129Xe (HP 129Xe) MRI enables functional imaging of various lung diseases but has been scarcely applied to lung cancer imaging. The aim of this study is to investigate the feasibility of targeted imaging of lung cancer with HP 129Xe MRI using surface-modified iron oxide nanoparticles (IONPs) as molecular targeting contrast agents. A mouse model of lung cancer (LC) was induced in nine mice by intra-peritoneal injection of urethane. Three months after the urethane administration, the mice underwent lung imaging with HP 129Xe MRI at baseline (0 h). Subsequently, the LC group was divided into two sub-groups: mice administered with polyethylene glycol-coated IONPs (PEG-IONPs, n = 4) and folate-conjugated dextran-coated IONPs (FA@Dex-IONPs, n = 5). The mice were imaged at 3, 6, and 24 h after the intravenous injection of IONPs. FA@Dex-IONPs mice showed a 25% reduction in average signal intensity at cancer sites at 3 h post injection, and a 24% reduction at 24 h post injection. On the other hand, in PEG-IONPs mice, while a signal reduction of approximately 28% was observed at cancer sites at 3 to 6 h post injection, the signal intensity was unchanged from that of the baseline at 24 h. Proton MRI of LC mice (n = 3) was able to detect cancer five months after urethane administration, i.e., later than HP 129Xe MRI (3 months). Furthermore, a significant decrease in averaged 1H T2 values at cancer sites was observed at only 6 h post injection of FA@Dex-IONPs (p < 0.05). As such, the targeted delivery of IONPs to cancer tissue was successfully imaged with HP 129Xe MRI, and their surface modification with folate likely has a high affinity with LC, which causes overexpression of folate receptors.

To overcome the limitations of brown adipose tissue (BAT) imaging with MRI and PET/CT, near-infrared (NIR) fluorescence imaging has been utilized in living animals because it is highly sensitive, noninvasive, nonradioactive, and cost-effective. To date, only a few NIR fluorescent dyes for detecting BAT have been reported based on the structure-inherent targeting strategy. Among them, IR-786, a commercial cyanine dye, was used firstly for quantitative NIR imaging of BAT perfusion in 2003. Owing to the high cytotoxicity, poor water solubility, and strong nonspecific background uptake of IR-786, the chemical structure of IR-786 should be redesigned to be more hydrophilic and less toxic so that it can show more BAT-specific accumulation. Here, we developed a BAT-specific NIR dye, BF800-AM, by incorporating the tyramine linker in the original structure of IR-786. After modifying the physicochemical properties of IR-786, in vivo results showed significant uptake of the newly designed BF800-AM in the BAT with improved signal-to-background ratio. Additional in vivo studies using mouse tumor models revealed that BF800-AM targeting to BAT is independent of tumor tissues, as distinct from IR-786 showing uptake in both tissues. Therefore, BF800-AM can be used for improved noninvasive visualization of BAT mass and activity in living animals.

The quest to develop ideal nanoparticles capable of molecular, cellular, and tissue level imaging is ongoing. Since certain imaging probes and nanoparticles face drawbacks such as low aqueous solubility, increased ROS generation leading to DNA damage, apoptosis, and high cellular/organ toxicities, the development of versatile and biocompatible nanocarriers becomes necessary. Protein nanoparticles (PNPs) are one such promising class of nanocarriers that possess most of the desirable properties of an ideal nanocarrier for bioimaging applications. PNPs demonstrate high aqueous solubility, minimal cytotoxicity, and multi‐cargo loading capacity. They are also amenable to surface‐functionalization, as well as modulation of their hydrophobicity and hydrophilicity. The use of PNPs for bioimaging applications has made rapid advancements in the past two decades. Being comparatively less explored, the field opens up a plethora of opportunities and focus areas to engineer ideal bioimaging protein nanocarriers. The use of PNPs as carriers of their natural ligands as well as other heavy metals and fluorescent probes, along with drug molecules for combined theranostic applications has been reported. In addition, surface functionalization to impart specificity of targeting the PNPs has been shown to reduce nonspecific cellular interactions, thus reducing systemic toxicity. PNPs have been explored for their application in imaging of numerous cancers, cardiovascular diseases as well as imaging of the brain using near infrared fluorescence (NIRF) imaging, magnetic resonance imaging (MRI), X‐ray computed tomography (CT), positron emission tomography (PET), single‐photon emission computed tomography (SPECT), ultrasound (US), and photoacoustic (PA) imaging. This article is categorized under:Biology‐Inspired Nanomaterials > Protein and Virus‐Based StructuresDiagnostic Tools > In Vivo Nanodiagnostics and Imaging [ABSTRACT FROM AUTHOR]

Background: Three‐dimensional (3D) whole‐brain vessel wall imaging (VWI) has demonstrated exquisite image quality for delineating intracranial atherosclerotic disease (ICAD) and reliability for quantifying normal vessel dimensions. However, its reliability in quantifying plaque morphology remains unknown. Purpose: To evaluate the plaque morphologic quantification reliability of 3D whole‐brain VWI in patients via comparison with 3D targeted VWI and 2D turbo spin‐echo (TSE). Study Type: Prospective. Population: Thirty‐three patients with symptomatic ICAD. Field Strength/Sequence: A 3D and 2D TSE acquired at 3.0 T. Assessment: Each participant underwent two VWI sessions with an interval of 7–10 days. Three readers identified in consensus all the plaques on both whole‐brain and targeted 3D VWI. Their lumen and vessel wall area and volume, plaque burden, percent stenosis, and vessel wall remodeling were measured for by two independent readers. At each culprit plaque determined by a radiologist, the lumen and vessel wall area, plaque burden, plaque‐to‐wall contrast ratio (CR), and plaque enhancement ratio (ER) were measured for 2D and 3D VWI methods. Statistical Tests: Intra‐class correlation coefficient (ICC) was used to evaluate for 3D VWI's interobserver/intraobserver agreement, interscan repeatability, and agreement with 2D TSE in each plaque morphologic measurements. Paired t test was performed for detecting the differences in plaque‐to‐wall CR and plaque ER between the two 3D methods. Results: Eighty‐four plaques were detected by both 3D VWI methods. Whole‐brain VWI provided excellent interobserver/intraobserver agreement (ICCs: 0.79–0.99/0.95–0.99), interscan repeatability (ICCs: 0.85–0.99), agreement with 2D TSE (ICC: 0.80–0.94) in all morphologic measurements. ICCs of whole‐brain VWI (0.79–0.99) were higher or equal to those of targeted VWI (0.76–0.99). The plaque‐to‐wall CR and plaque ER were significantly higher on whole‐brain VWI than on targeted VWI. Data Conclusion: The 3D whole‐brain VWI provides excellent interobserver/intraobserver agreement, interscan repeatability, and agreement with 2D TSE in plaque morphologic quantification of ICAD and outperforms 3D targeted VWI. Level of Evidence: 2 Technical Efficacy Stage: 2 [ABSTRACT FROM AUTHOR]