Efficient radiolabeling of mesoporous silica nanoparticles for single-cell PET imaging.

Purpose: Nanoparticles are highly efficient vectors for ferrying contrast agents across cell membranes, enabling ultra-sensitive in vivo tracking of single cells with positron emission tomography (PET). However, this approach must be fully characterized and understood before it can be reliably implemented for routine applications.

Methods: We developed a Langmuir adsorption model that accurately describes the process of labeling mesoporous silica nanoparticles (MSNP) with Ga.

Molecular Imaging of Tumor-Infiltrating Lymphocytes in Living Animals Using a Novel mCD3 Fibronectin Scaffold.

The interaction between cancer cells and immune cells in the tumor microenvironment (TME) plays a crucial role in determining tumor growth, metastasis, and response to treatment. Tumor-infiltrating lymphocytes (TILs) in TME could be a predictive marker for treatment response in various therapeutic interventions, including chemotherapy and immunotherapy. Thus, imaging the tumor immune microenvironment is important for selecting the optimal treatment strategies in cancer therapy.

Regiospecific Coelenterazine Analogs for Bioassays and Molecular Imaging.

Bioluminescence (BL) generated by luciferase-coelenterazine (CTZ) reactions is broadly employed as an optical readout in bioassays and in vivo molecular imaging. In this study, we demonstrate a systematic approach to elucidate the luciferase-CTZ binding chemistry with a full set of regioisomeric CTZ analogs, where all the functional groups were regiochemically modified. When the chemical structures were categorized into Groups 1-6, the even-numbered Groups (2, 4, and 6) of the CTZ analogs are found to be exceptionally bright with NanoLuc enzyme.

Increased [F]FDG uptake of radiation-induced giant cells: a single-cell study in lung cancer models.

Positron emission tomography (PET), a cornerstone in cancer diagnosis and treatment monitoring, relies on the enhanced uptake of fluorodeoxyglucose ([F]FDG) by cancer cells to highlight tumors and other malignancies. While instrumental in the clinical setting, the accuracy of [F]FDG-PET is susceptible to metabolic changes introduced by radiation therapy. Specifically, radiation induces the formation of giant cells, whose metabolic characteristics and [F]FDG uptake patterns are not fully understood.

Synthesis and Evaluation of Clinically Translatable Targeted Microbubbles Using a Microfluidic Device for In Vivo Ultrasound Molecular Imaging.

The main aim of this study is to synthesize contrast microbubbles (MB) functionalized with engineered protein ligands using a microfluidic device to target breast cancer specific vascular B7-H3 receptor in vivo for diagnostic ultrasound imaging. We used a high-affinity affibody (ABY) selected against human/mouse B7-H3 receptor for engineering targeted MBs (TMBs). We introduced a C-terminal cysteine residue to this ABY ligand for facilitating site-specific conjugation to DSPE-PEG-2K-maleimide (M.

Preclinical Evaluation of Zr-Panitumumab for Biology-Guided Radiation Therapy.

Purpose: Biology-guided radiation therapy (BgRT) uses real-time line-of-response data from on-board positron emission tomography (PET) detectors to guide beamlet delivery during therapeutic radiation. The current workflow requires F-fluorodeoxyglucose (FDG) administration daily before each treatment fraction. However, there are advantages to reducing the number of tracer injections by using a PET tracer with a longer decay time.

Recent Trends and Opportunities for the Targeted Immuno-Nanomaterials for Cancer Theranostics Applications.

The targeted delivery of cancer immunotherapies has increased noticeably in recent years. Recent advancements in immunotherapy, particularly in blocking the immune checkpoints (ICs) axis, have shown favorable treatment outcomes for multiple types of cancer including melanoma and non-small-cell lung cancer (NSLC). Engineered micromachines, including microparticles, and nanoplatforms (organic and inorganic), functionalized with immune agonists can effectively deliver immune-targeting molecules to solid tumors.

Remotely controlled near-infrared-triggered photothermal treatment of brain tumours in freely behaving mice using gold nanostars.

Current clinical brain tumour therapy practices are based on tumour resection and post-operative chemotherapy or X-ray radiation. Resection requires technically challenging open-skull surgeries that can lead to major neurological deficits and, in some cases, death. Treatments with X-ray and chemotherapy, on the other hand, cause major side-effects such as damage to surrounding normal brain tissues and other organs.

FN3 linked nanobubbles as a targeted contrast agent for US imaging of cancer-associated human PD-L1.

PD-L1 (programmed death-ligand 1) targeted therapies may be useful for several cancers. The use of non-invasive diagnostic and prognostic molecular imaging platforms could improve clinical assessment of PD-L1 tumor status during these therapies. Contrast enhanced ultrasound molecular imaging (CE-USMI) techniques may offer versatile and cost-effective ways to detect and quantify the expression levels of cellular targets in vivo.

On Demand Biosensors for Early Diagnosis of Cancer and Immune Checkpoints Blockade Therapy Monitoring from Liquid Biopsy.

Recently, considerable interest has emerged in the development of biosensors to detect biomarkers and immune checkpoints to identify and measure cancer through liquid biopsies. The detection of cancer biomarkers from a small volume of blood is relatively fast compared to the gold standard of tissue biopsies. Traditional immuno-histochemistry (IHC) requires tissue samples obtained using invasive procedures and specific expertise as well as sophisticated instruments.

A Humanized Anti-GPC3 Antibody for Immuno-Positron Emission Tomography Imaging of Orthotopic Mouse Model of Patient-Derived Hepatocellular Carcinoma Xenografts.

Glypican-3 (GPC3) is an attractive diagnostic marker for hepatocellular carcinoma (HCC). We previously reported the potential of an Zr-labeled murine anti-GPC3 antibody (clone 1G12) for immunoPET imaging of HCC in orthotopic patient-derived xenograft (PDX) mouse models. We now humanized the murine antibody by complementarity determining region (CDR) grafting, to allow its clinical translation for human use.

Permeabilizing Cell Membranes with Electric Fields.

The biological impact of exogenous, alternating electric fields (AEFs) and direct-current electric fields has a long history of study, ranging from effects on embryonic development to influences on wound healing. In this article, we focus on the application of electric fields for the treatment of cancers. In particular, we outline the clinical impact of tumor treating fields (TTFields), a form of AEFs, on the treatment of cancers such as glioblastoma and mesothelioma.

PET Imaging of TIGIT Expression on Tumor-Infiltrating Lymphocytes.

Purpose: Therapeutic checkpoint inhibitors on tumor-infiltrating lymphocytes (TIL) are being increasingly utilized in the clinic. The T-cell immunoreceptor with Ig and ITIM domains (TIGIT) is an inhibitory receptor expressed on T and natural killer cells. The TIGIT signaling pathway is an alternative target for checkpoint blockade to current PD-1/CTLA-4 strategies.

Two Patient Studies of a Companion Diagnostic Immuno-Positron Emission Tomography (PET) Tracer for Measuring Human CA6 Expression in Cancer for Antibody Drug Conjugate (ADC) Therapy.

An antigen binding fragment (BFab) derived from a tumor-associated mucin 1-sialoglycotope antigen (CA6) targeting antibody (huDS6) was engineered. We synthesized a companion diagnostic positron emission tomography (PET) tracer by radiolabeling BFab with [Cu] to measure CA6 expression on cancer tissues prior to anti-human CA6 (huDS6-DM4 antibody-drug conjugate) therapy for ovarian and breast cancer patients. After chemotherapy, the ovarian patient received PET scan with F-2-fluoro-2-deoxyglucose ([F]FDG: 10 mCi), followed by [Cu]-DOTA-BFab ([Cu]BFab; 5.

Copper-64-immunoPET imaging: bench to bedside.

Positron emission tomography (PET) is a growing non-invasive diagnostic and molecular imaging tool in nuclear medicine, that is used to identify several diseases including cancer. The immunoPET probe is made up of monoclonal antibodies (mAbs) or its fragments or similar molecules that tagged with positron radioisotopes (Ga, Cu, Zr) bound together by a bifunctional chelator (BFC). This probe is designed to identify a specific disease.

Reconstructed Apoptotic Bodies as Targeted "Nano Decoys" to Treat Intracellular Bacterial Infections within Macrophages and Cancer Cells.

() is a highly pathogenic facultative anaerobe that in some instances resides as an intracellular bacterium within macrophages and cancer cells. This pathogen can establish secondary infection foci, resulting in recurrent systemic infections that are difficult to treat using systemic antibiotics. Here, we use reconstructed apoptotic bodies (ReApoBds) derived from cancer cells as "nano decoys" to deliver vancomycin intracellularly to kill by targeting inherent "eat me" signaling of ApoBds.

Ligand-activated BRET9 imaging for measuring protein-protein interactions in living mice.

Bioluminescence resonance energy transfer (BRET) is a commonly used assay system for studying protein-protein interactions and protein folding in vivo. Conventional BRET systems have solely depended on an overlap of the energy donor and acceptor spectra. In this study, we engineered a conceptually unique ligand-activatable BRET system (termed BRET9), where a full-length Artificial Luciferase variant 23 (ALuc23), acting as the energy donor, is sandwiched between a protein pair of interest, FRB and FKBP12, and linked to a fluorescent protein as the energy acceptor.

Engineering of a novel subnanomolar affinity fibronectin III domain binder targeting human programmed death-ligand 1.

The programmed death-ligand 1 (PD-L1) is a major checkpoint protein that helps cancer cells evade the immune system. A non-invasive imaging agent with rapid clearance rate would be an ideal tool to predict and monitor the efficacy of anti-PD-L1 therapy. The aim of this research was to engineer a subnanomolar, high-affinity fibronectin type 3 domain (FN3)-based small binder targeted against human PD-L1 (hPD-L1) present on tumor cells.

Evaluation of integrin αvβ cystine knot PET tracers to detect cancer and idiopathic pulmonary fibrosis.

Advances in precision molecular imaging promise to transform our ability to detect, diagnose and treat disease. Here, we describe the engineering and validation of a new cystine knot peptide (knottin) that selectively recognizes human integrin αvβ with single-digit nanomolar affinity. We solve its 3D structure by NMR and x-ray crystallography and validate leads with 3 different radiolabels in pre-clinical models of cancer.

FN3 Protein Conjugates for Cancer Diagnosis and Imaging Studies.

Bioconjugation of biologically useful proteins is in great demand (e.g., conjugation to biotins, metal chelators, and drug carriers to target specific tissues for both in vitro and in vivo use).

Highly bright and stable NIR-BRET with blue-shifted coelenterazine derivatives for deep-tissue imaging of molecular events .

: Bioluminescence imaging (BLI) is one of the most widely used optical platforms in molecular imaging, but it suffers from severe tissue attenuation and autoluminescence . : Here, we developed a novel BLI platform on the basis of bioluminescence resonance energy transfer (BRET) for achieving a ~300 nm shift of the emission (NIR-BRET) by synthesizing an array of 18 novel coelenterazine (CTZ) derivatives, named "Bottle Blue (BBlue)" and a unique iRFP-linked RLuc8.6-535SG fusion protein as a probe.

Tumor treating fields increases membrane permeability in glioblastoma cells.

Glioblastoma is the most common yet most lethal of primary brain cancers with a one-year post-diagnosis survival rate of 65% and a five-year survival rate of barely 5%. Recently the U.S.

A Novel Engineered Small Protein for Positron Emission Tomography Imaging of Human Programmed Death Ligand-1: Validation in Mouse Models and Human Cancer Tissues.

Purpose: To design and evaluate a small engineered protein binder targeting human programmed death-1 ligand (hPD-L1) for PET imaging in four mouse tumor models, and in human cancer specimens. The hPD-L1 protein binder, FN3, was engineered using a 12-kDa human fibronectin type-3 domain (FN3) scaffold. The binder's affinity was assayed in CT26 mouse colon carcinoma cells stably expressing hPD-L1 (CT26/hPD-L1).

Quantification of Cerenkov Luminescence Imaging (CLI) Comparable With 3-D PET Standard Measurements.

Cerenkov luminescence imaging (CLI) is commonly performed using two-dimensional (2-D) conventional optical imaging systems for its cost-effective solution. However, quantification of CLI comparable to conventional three-dimensional positron emission tomography (PET) is challenging using these systems due to both the high attenuation of Cerenkov radiation (CR) on mouse tissue and nonexisting depth resolution of CLI using 2-D imaging systems (2-D CLI). In this study, we developed a model that estimates effective tissue attenuation coefficient and corrects the tissue attenuation of CLI signal intensity independent of tissue depth and size.

A blood biomarker for monitoring response to anti-EGFR therapy.

Background And Objective: To monitor therapies targeted to epidermal growth factor receptors (EGFR) in non-small cell lung cancer (NSCLC), we investigated Peroxiredoxin 6 (PRDX6) as a biomarker of response to anti-EGFR agents.

Methods: We studied cells that are sensitive (H3255, HCC827) or resistant (H1975, H460) to gefitinib. PRDX6 was examined with either gefitinib or vehicle treatment using enzyme-linked immunosorbent assays.