Cancer Imaging Agents Research Articles

Albumin Based Nanoparticles for Detection of Pancreatic Cancer Cells.

Molecular imaging of cancer cells using effective drug targeting systems are most interested research area in recent years. Albumin protein is a soluble and most abundant protein in circulatory system. It has a ligand-binding function and acts as a transport protein. Researchers are interested in developing albumin based nanostructured specific anti-tumor drugs in cancer therapy. Pancreatic cancer treatment or drug design for targeted pancreatic cancer cell has great importance due to it has a high mortality rate comparing other cancer types. In this article, our goal is to develop new targeting nanoparticles based on the conjugation of albumin and Hyaluronic Acid (HA) for pancreatic cancer cells. In this article, we proposed a new technique for conjugation of albumin (BSA) and HA in nano formation. Firstly, cationic BSA is synthesized. Then, BSA-HA conjugation is obtained by interacted cationic BSA with 1000 ppm HA. Secondly, nano BSA-HA particles and nano BSA particles were synthesized according to AmiNoAcid Decorated and Light Underpinning Conjugation Approach (ANADOLUCA) method which provides a special cross-linking strategy for biomolecules using ruthenium-based amino acid monomer haptens. After characterization studies, in vitro cytotoxic activity of synthesized nano BSA-HA particles were determined for PANC-1 ATCC® CRL146 cells. According to the data, nano BSA and nano BSA-HA particles synthesized uniquely using special ruthenium-based amino acid decorated cross-linking agent, (MATyr)2-Ru-(MATyr)2.based on ANDOLUCA method. Characterization results showed that there was not any change in protein folding structures during nano formation process. In addition, nano protein particles gained fluorescence feature. When interacting synthesized nano BSA and nano BSA-HA particles with pancreatic cells, it was found that BSA nanoparticles were usually around cells and membranes, but BSA-HA nanoparticles were identified around the cells, in the cytoplasm inside the cell, and next to the cell nucleus. So, nano BSA-HA particles could be used as cancer cell imaging agent for PANC-1 ATCC® CRL146 cells. The satisfactory conclusion of this study is that synthesized nano BSA-HA particles are fundamental materials for targeting pancreatic cancer cells due to HA receptors located on pancreatic cancer cells and imaging agents due to fluorescence feature of the BSA-HA nanoparticles.

Synthesis, Characterization, and Evaluation of Near-IR Boron Dipyrromethene Bioconjugates for Labeling of Adenocarcinomas by Selectively Targeting the Epidermal Growth Factor Receptor.

A series of five boron dipyrromethene (BODIPY) bioconjugates containing an epidermal growth factor receptor (EGFR)-targeted pegylated LARLLT peptide and/or a glucose or biotin ethylene diamine group were synthesized, and the binding capability of the new conjugates to the extracellular domain of EGFR was investigated using molecular modeling, surface plasmon resonance, fluorescence microscopy, competitive binding assays, and animal studies. The BODIPY conjugates with a LARLLT peptide were found to bind specifically to EGFR, whereas those lacking the peptide bound weakly and nonspecifically. All BODIPY conjugates showed low cytotoxicity (IC50 > 94 μM) in HT-29 cells, both in the dark and upon light activation (1.5 J/cm2). Studies of nude mice bearing subcutaneous human HT-29 xenografts revealed that only BODIPY conjugates bearing the LARLLT peptide showed tumor localization 24 h after intravenous administration. The results of our studies demonstrate that BODIPY bioconjugates bearing the EGFR-targeting peptide 3PEG-LARLLT show promise as near-IR fluorescent imaging agents for colon cancers overexpressing EGFR.

Abstract PD4-12: Use of 64Cu-DOTA-trastuzumab positron emission tomography (PET) to predict response to ado-trastuzumab emtansine (TDM1)

Abstract Background: We have demonstrated that 64Cu-DOTA trastuzumab is an effective PET imaging agent for HER2 positive breast cancer and are now seeking to evaluate the methodology for prediction of response and benefit to ado-trastuzumab emtansine (TDM1) in women with metastatic disease. Methods: Patients with metastatic breast cancer were eligible if they had biopsy confirmed HER2 + disease, at least 1 site of metastasis 2.0 cm or larger outside the biopsy site, and were to receive TDM1 as therapy. Pretreatment staging included 18F-FDG/PET. Prior to injection of 64Cu-DOTA-trastuzumab, patients received 45 mg of cold trastuzumab to reduce liver uptake. PET-CT scans were obtained at 21-25 h and 47-48 h over fields of view chosen in reference to 18F-FDG scans. TDM1 was administered at a dose of 3.6 mg/kg every 3 weeks. Restaging 18F-FDG/PET was performed every 2 cycles, and response to therapy was determined by PERCIST criteria. The radiolabel uptake was measured in terms of maximum voxel standardized uptake value (SUVmax). Results: Ten women enrolled on study and are evaluable for response; three continue on TDM1 for 22-40 months and four patients remained on treatment for at least 1 year. The median age was 54.5 years (48-83 years); seven received prior trastuzumab-containing chemotherapy 3 wks to 55 months prior to study entry. HER2 was positive by IHC in 5 and by FISH in 5 (3 were 2+ by IHC; 1 was 1+ and 1 indeterminate). Complete or partial metabolic response was observed in 5 patients. Patients had their average SUVmax on 64Cu-DOTA trastuzumab PET (aSUVmax) assessed in addition to individual assessments on up to 8 lesions on both Day1 and Day2. The mean aSUVmax was (6.3, 8.8) for responding patients and (4.4, 5.2) for non-responder (day1, day2). The difference between responders and non-responders on Day1 aSUVmax was marginally significant (p=0.06), but significant on Day2 (p=0.04). The three highest aSUVmax on both day1 and day2 were three of the four patients with PFS>1 year. Data on the relationship of 64Cu-DOTA trastuzumab PET to IHC and FISH, and individual lesion SUVmax including evidence suggesting a potential threshold effect will be presented. Conclusions: In women with biopsy confirmed HER2 positive metastatic disease, 64Cu-DOTA-trastuzumab PET imaging is predictive for response to TDM1. Citation Format: Mortimer JE, Bading JR, Frankel P, Tumyan L, Tran TT, Rockne RC, Shively JE, Gidwaney N, Park J, Colcher DM. Use of 64Cu-DOTA-trastuzumab positron emission tomography (PET) to predict response to ado-trastuzumab emtansine (TDM1) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD4-12.

Abstract P2-02-17: Metabolism-driven cancer identification with GLUT5-specific molecular probes

Abstract Background: Current cancer imaging agents are limited in their ability to distinguish cancers from normal cells (low cancer-selectivity) and identify cancers at different stages of development (low cancer-specificity). This limitation makes biopsy mandatory for diagnosis and continuous treatment monitoring. Analysis of biopsy samples may also have some ambiguity in clearly identifying malignant and metastatic cells, resulting in cases of mischaracterization and overdiagnosis. Hence, cancer-selective and cancer-specific imaging agents are needed. Distinguishing cancer types and stages can be achieved by addressing differences in their nutrient uptake, manifested as changes in the expression of facilitative sugar transporters (GLUTs). Here, we present a novel approach to target the enhanced metabolism in breast cancers with sugar-like fluorescently labeled probes – ManCous - engineered for specific uptake by fructose transporter GLUT5. The differential accumulation of these probes in cancer cells parallels the differential activity of GLUT5 and results in active fluorescence accumulation within cancers with the highest levels observed in premalignant phenotypes. Results: Locking fructose conformation in the furanose form was found to provide a sugar-like mimics recognized explicitly by GLUT5. The corresponding coumarin conjugates – ManCous (Figure 1A) - were found to exhibit GLUT5-specific uptake and work as reporters of GLUT5 activity in cells. Differential activity of GLUT5 in cells was found to parallel the differences in the uptake of ManCous. Significant differences in accumulation of ManCou-induced fluorescence were observed between normal and cancer cells and between cancer phenotypes (Figure 1A). Namely, an 8-fold difference in ManCou accumulation was observed between normal and adenocarcinoma MCF7 cells, and 70-fold difference was observed between normal and premalignant MCF10aNeoT cells. The uptaken ManCou were found to be metabolized by hexokinase to form phosphorylated analogs and effectively compete with glucose for hexokinase II (Figure 1B). The probes were found to be non-cytotoxic at concentrations below 100 μM, with higher cytotoxicity towards cancer cells at probe concentrations above 100 μM Conclusions: The dependence of breast cancer cells on fructose provides a firm basis for developing imaging approaches to discriminate between normal and cancer cells as well as potentially between cancer phenotypes. While current probes are restricted to in-vitro imaging, further probe evolution is expected to lead to new in vivo agents, owing to a proper modification of the scaffold with the relevant radioactive (PET) or other imaging entity and retention of transporter specificity. The development of transporter-specific GLUT5 affinity probes could further contribute to enhancing the impact of fructose uptake inhibition for approaching cancer-specific therapies. Citation Format: Ghosh A, Kannan S, Begoyan VV, Weselinski LJ, Rao S, Tanasova M. Metabolism-driven cancer identification with GLUT5-specific molecular probes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-02-17.

Multi-functionalised graphene nanoflakes as tumour-targeting theranostic drug-delivery vehicles.

Graphene nanoflakes (GNFs) consist of a graphene sheet approximately 30 nm in diameter with a pristine aromatic system and an edge terminated with carboxylic acid groups. Their high water solubility and relative ease of functionalisation using carboxylate chemistry means that GNFs are potential scaffolds for the synthesis of theranostic agents. In this work, GNFs were multi-functionalised with derivatives of (i) a peptide-based Glu-NH-C(O)-NH-Lys ligand that binds prostate-specific membrane antigen (PSMA), (ii) a potent anti-mitotic drug (R)-ispinesib, (iii) the chelate desferrioxamine B (DFO), and (iv) an albumin-binding tag reported to extend pharmacokinetic half-life in vivo. Subsequent 68Ga radiochemistry and experiments in vitro and in vivo were used to evaluate the performance of GNFs in theranostic drug design. Efficient 68Ga-radiolabelling was achieved and the particle-loading of (R)-ispinesib and Glu-NH-C(O)-NH-Lys was confirmed using cellular assays. Using dose-response curves and FACS analysis it was shown that GNFs loaded with (R)-ispinesib inhibited the kinesin spindle protein (KSP) and induced G2/M-phase cell cycle arrest. Cellular uptake and blocking experiments demonstrated that GNFs functionalised with the Glu-NH-C(O)-NH-Lys ligand showed specificity toward PSMA expressing cells (LNCaP). The distribution profile and excretion rates of 68Ga-radiolabelled GNFs in athymic nude mice was evaluated using time-activity curves derived from dynamic positron-emission tomography (PET). Image analysis indicated that GNFs have low accumulation and retention in background tissue, with rapid renal clearance. In summary, our study shows that GNFs are suitable candidates for use in theranostic drug design.

Intrinsically absorbing photoacoustic and ultrasound contrast agents for cancer therapy and imaging

Nanoparticles are submicrometer in size and are used in a variety of ways in the biomedical field. They can carry therapeutic drugs, either in the particle core or surface to target cancer sites in the body. Additionally they can contain imaging agents to diagnose and monitor the tumor size using different imaging modalities, such as fluorescence and nuclear magnetic resonance imaging. Novel theranostic nanoparticle agents, called perfluorohexane nanoemulsions (PFH-NEs) were synthesized whose intrinsic properties could be used for both imaging (ultrasound and photoacoustic) and therapy. Compared to other theranostic agents, our PFH-NEs can absorb sufficient near-infrared light to enhance contrast and provide deeper penetration imaging at laser fluences causing minimal damage to healthy tissue. One contrast mechanism (optical absorption/photoacoustics) allows us to validate localization of the agent and another (acoustic impedance/ultrasound) allows the imaging of therapeutic delivery after particle activation. In this work, we show the potential of these PFH-NEs to be used as multimodal imaging agents and for therapy.

Investigation of Vipera Anatolica Venom Disintegrin via Intracellular Uptake with Radiolabeling Study and Cell-Based Electrochemical Biosensing Assay

Snake venoms are a natural biological source that has potential therapeutic value with various protein compounds. Disintegrins originally were discovered as a family of proteins from snake venoms composed of cysteine rich low molecular weight polypeptides. Disintegrins exhibit specific binding and higher affinity toward integrin with potential inhibition of function. Trans-membrane receptors of the integrin family may involve in many pathological conditions such as inflammation and tumor progression with important processes related to invasion and migration. Since disintegrins have the ability to bind to integrins, they could be used for cancer detection and treatment, and in monitoring of therapy in select cancer types. The main purpose of the study is to investigate disintegrin containing Vipera anatolica (VAT) crude venom potential for radiolabeling and intracellular uptake as well as electrochemical biosensing assay against U87MG human brain glioblastoma cells. For this purpose, VAT crude venom containing U87MG cell-specific disintegrin was investigated in terms of radiolabeling and intracellular uptake as well as electrochemical biosensing assay in comparison with echistatin (ECT) disintegrin in cells. The interaction between VAT crude venom and ECT with HEK293 human non-tumorigenic embryonic kidney cells and glioblastoma U87MG cells was electrochemically investigated using pencil graphite electrodes (PGEs). The interaction of the VAT crude venom and ECT with HEK293 and U87MG cells was detected according to the changes in oxidation signals. Then, VAT crude venom and echistatin were labeled with 131I via iodogen method. Intracellular uptakes of radiolabeled molecules were investigated in U87MG cell line. 131I-VAT can be an agent for imaging of glioblastoma cancer. Further work will focus on the production of large quantities of pure VAT disintegrin with a biotechnological approach to improving imaging agent.

A theranostic agent for cancer therapy and imaging in the second near-infrared window.

Theranostic nanoparticles are integrated systems useful for simultaneous diagnosis and imaging guided delivery of therapeutic drugs, with wide ranging potential applications in the clinic. Here we developed a theranostic nanoparticle (~ 24 nm size by dynamic light scattering) p-FE-PTX-FA based on polymeric micelle encapsulating an organic dye (FE) fluorescing in the 1,000-1,700 nm second near-infrared (NIR-II) window and an anti-cancer drug paclitaxel. Folic acid (FA) was conjugated to the nanoparticles to afford specific binding to molecular folate receptors on murine breast cancer 4T1 tumor cells. In vivo, the nanoparticles accumulated in 4T1 tumor through both passive and active targeting effect. Under an 808 nm laser excitation, fluorescence detection above 1,300 nm afforded a large Stokes shift, allowing targeted molecular imaging tumor with high signal to background ratios, reaching a high tumor to normal tissue signal ratio (T/NT) of (20.0 ± 2.3). Further, 4T1 tumors on mice were completed eradicated by paclitaxel released from p-FE-PTA-FA within 20 days of the first injection. Pharmacokinetics and histology studies indicated p-FE-PTX-FA had no obvious toxic side effects to major organs. This represented the first NIR-II theranostic agent developed.

Single vial cold kits optimized for preparation of gastrin releasing peptide receptor (GRPR)-radioantagonist 68Ga-RM2 using three different 68Ge/68Ga generators

68Ga-RM2 is a gastrin releasing peptide receptor (GRPR) antagonist PET (positron emission tomography) radiotracer which is being investigated in clinical trials as a potential prostate cancer imaging agent. Simple, one-step kit formulation of 68Ga-RM2 would facilitate multicentre trials and allow easier integration in hospital radiopharmacy. Herein we report development of three sets of single-vial RM2 cold kits validated for formulation with three respective 68Ge/68Ga generators eluted in 0.6 M, 0.1 M and 0.05 M HCl (hydrochloric acid). Cold kits of varied pH (2, 3, 4 and 5) were prepared using 2 M sodium acetate for three different 68Ge/68Ga generators to determine influence of pH on the radiochemical yield of 68Ga-RM2. Buffer content was optimized with respect to volume of 68GaCl3 eluate to be added (1 mL/2 mL/ 5 mL). Sterility, apyrogenicity and long term stability of cold kits; in vitro and serum stability of 68Ga-RM2 were investigated. In vitro cellular uptake and inhibition studies were performed to demonstrate the specificity of kit-formulated 68Ga-RM2. The radiochemical yield of 68Ga-RM2 formulated from three different generators was observed to be maximum at pH 3 (99 ± 0.5%). Cold kits stored for 6 months at 0 °C also resulted in high radiochemical yield. 68Ga-RM2 exhibited excellent in vitro stability (1 h) and serum stability (1 h). In vitro cellular uptake of 5 ± 0.8% in PC3 cells with >85% inhibition was observed for the 68Ga-RM2 radiotracer indicating its specificity towards GRPR expression. These simple, robust kits shall allow hospitals with different generators to participate in clinical studies of 68Ga-RM2 for screening of GRPR-expressing prostate tumors.

Current Applications of Gold Nanoparticles for Medical Imaging and as Treatment Agents for Managing Pancreatic Cancer

Pancreatic cancer is an extremely heterogeneous, malignant disease with a complicated tumor microenvironment and a dismal prognosis. Extensive stroma surrounding the cancer and the sequestering of chemotherapeutic agents play dominant roles in tumor growth and metastasis and in suppressing the delivery of cytotoxic drugs to tumor cells. Currently, nanoscience is in the forefront of developments aimed at devising novel techniques to treat tumors. Gold nanoparticles (GNPs) are often used as potential imaging and therapeutic agents for cancers, since they offer: (1) Passive targeting because of better permeation and retention effects, (2) photothermal effects caused by efficient light-to-heat conversion, and (3) the potential to use simple gold-thiol bioconjugation chemistry to conjugate desired molecules for targeted drug delivery. Together, these benefits can increase the therapeutic success of GNPs when used in combination with conventional treatment strategies, such as surgery, chemotherapy, or radiotherapy. In this review, we discuss current trends in GNP research in the field of pancreatic cancer theranostics.

Recent Advances in Superparamagnetic Iron Oxide Based Nanoprobes as Multifunctional Theranostic Agents for Breast Cancer Imaging and Therapy.

Breast cancer accounts for nearly one in three cancers, and it is the most common cancer diagnosed among women. The death rate of breast cancer is estimated to be 14%. Hence, accurate diagnosis in early stage and effective treatment in any stage are critical for the survival of breast cancer. Mammogram has been the most common technique administered to detect breast cancer. However, the radiation dose from mammogram is harmful to patients. Fortunately, magnetic resonance imaging (MRI) can diagnose breast cancer without any radiation dose, and enhanced MRI can make earlier and differential diagnosis. Therefore, as contrast materials, superparamagnetic iron oxide based nanoprobes (SPIONs) have generated a great deal of attention. This review covers recent advances in SPIONs as multifunctional theranostic agents. Besides synthesis and surface modification of SPIONs, passive and active targeted imaging is also discussed. Moreover, a serial of potential therapy for breast cancer is further described, such as photodynamic therapy, photothermal therapy, chemotherapy and magnetic hyperthermia therapy. Preparation and surface modification of SPIONs is critical for imaging diagnosis of breast cancer and further potential treatment.

The Distribution and Imaging of 99mTc-nGO-PEG-FA in Human Patu8988 Tumor-Bearing Nude Mice.

Background: To study the distribution and imaging of 99mTc-nGO-PEG-FA in human pancreatic cancer Patu8988 tumor-bearing nude mice, and to explore its usefulness as an imaging reagent for pancreatic cancer. Materials and Methods: Natural graphite powder was used as raw material to prepare the nanosized graphene oxide (nGO) by using the modified Hummers method, and then was covalently modified by polyethylene glycol (PEG) on the surface of nGO. The nGO was further optimized by in vitro cell experiment, and then conjugated with the targeting molecule folic acid (FA) to form nGO-PEG-FA system. The nGO-PEG-FA was finally labeled by radioactive nuclide 99mTc by direct labeling method to form the 99mTc-nGO-PEG-FA molecular imaging probe. Nude mice bearing patu8988 pancreatic cancer xenografts were intravenous injection (I.V.) injected with 99mTc-nGO-PEG-FA, and the distribution of 99mTc-nGO-PEG-FA in nude mice at different time course was investigated by determination of tissue uptake of radioactivity (%ID/g), as well as the single photon emission computed tomography (SPECT) imaging at different time course. Results: The labeling rate of nGO-PEG-FA with 99mTc was (90.08 ± 2.34)%, and the highest binding rate of 99mTc-nGO-PEG-FA with Patu8988 cells was (3.15 ± 0.31)%. The radioactive uptake in tumor reached (5.11 ± 1.23)%ID/g at 6 h after I.V. injection of 99mTc-nGO-PEG-FA in nude mice. Meanwhile, the radioactive uptake in liver, spleen, and lung was also high and reached (10.33 ± 1.22)%ID/g, (5.86 ± 0.59)%ID/g, and (3.55 ± 0.93)%ID/g, respectively, whereas less radioactivity uptake was observed in the heart (1.12 ± 0.33)%ID/g and blood (2.76 ± 0.39)%ID/g, respectively. The tumors can be clearly imaged at 4.0-6.0 h after 99mTc-nGO-PEG-FA injection. Conclusions: 99mTc-nGO-PEG-FA can efficiently target pancreatic cancer, which may be developed as an imaging agent for pancreatic cancer.

Photodynamic therapy and nuclear imaging activities of SubPhthalocyanine integrated TiO2 nanoparticles

In this study, Subphthalocyanine (SubPc) and SubPc integrated TiO2 nanoparticles (SubPc- TiO2) were examined as theranostic agents. In vitro photodynamic therapy (PDT) efficiency of SubPc/SubPc-TiO2 and nuclear imaging potential of 131I labeled SubPc/TiO2-SubPc were determined on hepatocellular carcinoma (HepG2), colorectal adenocarcinoma (HT29) and human healthy lung (WI38) cell lines. As a result, 131I-SubPc and 131I-SubPc-TiO2 have been identified as a nuclear imaging agent for liver cancer. Additionally, 131I-SubPc-TiO2 has been found to be promising for imaging colon tumors. According to the in vitro photodynamic therapy studies, SubPc and SubPc-TiO2 were determined suitable PDT agents for liver and colon tumors. These results suggest that SubPc-TiO2 might be a theranostic agent with both PDT and nuclear imaging potential.

Dendrimer-based magnetic resonance imaging agents for brain cancer

Brain cancer is one of the most lethal and difficult-to-treat cancers because of its physical location and biological barriers. The mainstay of brain cancer treatment is surgical resection, which demands precise imaging for tumor localization and delineation. Thanks to advances in bioimaging, brain cancer can be detected earlier and resected more reliably. Magnetic resonance imaging (MRI) is the most common and preferred method to delineate brain cancer, and a contrast agent is often required to enhance imaging contrast. Dendrimers, a special family of synthetic macromolecules, constitute a particularly appealing platform for constructing MRI contrast agents by virtue of their well-defined three-dimensional structure, tunable nanosize and abundant surface terminals, which allow the accommodation of high payloads and numerous functionalities. Tuning the dendrimer size, branching and surface composition in conjunction with conjugation of MRI functionalities and targeting moieties can alter the relaxivity for MRI, overcome the blood-brain barrier and enhance tumor-specific targeting, hence improving the imaging quality and safety profile for precise and accurate imaging of brain tumors. This short review highlights the recent progress, opportunities and challenges in developing dendrimer-based MRI contrast agents for brain tumor imaging.

Development and Characterization of a Theranostic Micelles System using TPGS with Docetaxel and Coumarin-6: A Dual Polymeric Nanocarrier System

Theranostic micelles and polymeric nanocarrier-based drug delivery system are well known techniques that involve a diagnostic agent in polymeric micelles for a combination of therapy by using a co-delivery approach which can help in detection of a cancer cell in an early stage, increase killing effect and suppress multi-drug resistance (MDS) for better therapeutic effectiveness. The aim of this study is to develop a dual modality micellar system using D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) as a nanocarrier for co-delivery of docetaxel as a model chemotherapeutic drug and coumarin-6 as a model fluorescence imaging agent for simultaneous cancer imaging and therapy in an early stage. The theranostic micelles were prepared by a solvent casting method and characterized by their particle size, drug loading, drug encapsulation efficiency (EE) and in-vitro drug release profile. These dual modality micellar system TPDC6 micelles were successfully developed with average particle size of 79.59±0.57 nm in diameter and drug loading up to 15.46±1.02 % (EE of 78.99±1.26%) and 9.83±0.76 % (EE of 36.20±0.89%) for docetaxel and coumarin-6 respectively. Besides, the in-vitro drug release profile of the micelles revealed a desired sustained and controlled drug release manner for both docetaxel (21.62±0.36%) and coumarin-6 (10.70±0.46%). In conclusion, the micelles size obtained is in the favourable range for passive targeting through enhanced permeability and retention (EPR) effect and the drug loading and encapsulation efficiency attained are adequate for therapy and diagnosis purposes on cancer cells. This dual modality system is taking great advantages for tumour imaging and inhibition of tumour growth which is very important for early cancer detection.

Anti-EpCAM scFv gadolinium chelate: a novel targeted MRI contrast agent for imaging of colorectal cancer.

The development of targeted contrast agents for magnetic resonance imaging (MRI) facilitates enhanced cancer imaging and more accurate diagnosis. In the present study, a novel contrast agent was developed by conjugating anti-EpCAM humanized scFv with gadolinium chelate to achieve target specificity. The material design strategy involved site-specific conjugation of the chelating agent to scFv. The scFv monomer was linked to maleimide-DTPA via unpaired cysteine at the scFv C-terminus, followed by chelation with gadolinium (Gd). Successful scFv-DTPA conjugation was achieved at 1:10 molar ratio of scFv to maleimide-DTPA at pH 6.5. The developed anti-EpCAM-Gd-DTPA MRI contrast agent was evaluated for cell targeting ability, in vitro serum stability, cell cytotoxicity, relaxivity, and MR contrast enhancement. A high level of targeting efficacy of anti-EpCAM-Gd-DTPA to an EpCAM-overexpressing HT29 colorectal cell was demonstrated by confocal microscopy. Good stability of the contrast agent was obtained and no cytotoxicity wasobservedin HT29 cells after 48h incubation with 25-100µM of Gd. Favorable imaging was obtained using anti-EpCAM-Gd-DTPA, including 1.8-fold enhanced relaxivity compared with Gd-DTPA, and MR contrast enhancement observed after binding to HT29. The potential benefit of this contrast agent for in vivo MR imaging of colorectal cancer, as well as other EpCAM positive cancers, is suggested and warrants further investigation.

Novel hydrazide-hydrazone and amide substituted coumarin derivatives: Synthesis, cytotoxicity screening, microarray, radiolabeling and in vivo pharmacokinetic studies

The current work presents the synthesis and biological evaluation of new series of coumarin hydrazide-hydrazone derivatives that showed in vitro broad spectrum antitumor activities against resistant pancreatic carcinoma (Panc-1), hepatocellular carcinoma (HepG2) and leukemia (CCRF) cell lines using doxorubicin as reference standard. Bromocoumarin hydrazide-hydrazone derivative (BCHHD) 11b showed excellent anticancer activity against all tested cancer cell lines. Enzyme assays showed that BCHHD 11b induced apoptosis due to activation of caspases 3/7. Moreover, 11b inhibited GST and CYP3A4 in a dose dependent manner and the induced cell death could be attributed to metabolic inhibition. Moreover, 11b microarray analysis showed significant up- and down-regulation of many genes in the treated cells related to apoptosis, cell cycle, tumor growth and suppressor genes. All of the above presents BCHHD 11b as a potent anticancer agent able to overcome drug resistance. In addition, compound 11b was able to serve as a chemical carrier for 99mTc and the in vivo biodistribution study of 99mTc-11b complex revealed a remarkable targeting ability of 99mTc into solid tumor showing that 99mTc-11b might be used as a promising radiopharmaceutical imaging agent for cancer.

Ovarian Cancer Targeting Phage Clones for In Vivo Near‐Infrared Optical Imaging

Ovarian cancer is the fifth leading cause of cancer deaths in women, which is directly related to inadequate diagnostic methods. Phage display technology may be used to develop peptide‐displaying filamentous phage as cancer detection and imaging agents. Such modalities offer advantages in regard to the high specificity and affinity of peptides, as well as increased avidity by displaying multiple peptides per virion. Additionally, the large size of filamentous phage (0.9 μm) allows for signal amplification by labeling with multiple imaging moieties.Phage display technology was previously used to select phage clones with specific binding to human ovarian cancer cells (SKOV‐3). In short, a 15‐mer fUSE5 phage display library was injected into the tail vein of a nude mouse without tumors, and unbound phage were collected after 15 min of circulation. This pre‐cleared library was then subjected to four rounds of selection in nude mice carrying xenografted SKOV‐3 tumors. During each round, phage were allowed to circulate for 1 h, after which the mouse was sacrificed and the tumor was excised. Tumor‐bound phage were collected by 3‐[(3‐cholamideopropyl) dimethylammonio]‐1‐propanesulfonate (CHAPS) elution, and displayed peptides were identified by DNA sequencing. From the last round of selection, 31 phage clones were identified, and each was subjected to micropanning experiments, in which the binding ratio for SKOV‐3‐to‐normal human ovarian (HS‐832) cells were evaluated. These results showed that phage clones pJ18 and pJ24 exhibited specificity for ovarian cancer cells, exhibiting SKOV‐3‐to‐HS‐832 ratios of 6.57 and 3.55, respectively.To evaluate the tumor targeting capabilities, pJ18, pJ24, and WT phage were labeled with a near‐infrared fluorophore (AF680), and employed in biodistribution and optical imaging studies in mice bearing xenografted SKOV‐3 tumors. In brief, mice were injected with 1012 virions of phage, and the animals were sacrificed after 4 h. The tumor, organs and tissues were excised and fluorescent intensity was measured using a Xenogen IVIS 200 Imaging System. Tumor uptake of pJ24 was significantly higher compared to WT phage. For all phage (pJ18, pJ24, and WT), the liver showed increased fluorescent uptake compared to other organs, indicating that the phage were excreted through the reticuloendothelial system. Next, mice carrying xenografted SKOV‐3 tumors were injected with 1012 virions of AF680‐labeled phage. The animals were imaged pre‐injection (0 h), and after 2 h and 4 h of circulation. The results showed that the ovarian tumors were easily localized and exhibited ample tumor‐to‐background contrast. Further, the tumor fluorescent intensity of pJ18 and pJ24, was significantly higher (p<0.001, p<0.05, respectively) in comparison to WT after 2 h. The fluorescent intensity was lower for both clones after 4 h, however, the uptake of pJ18 remained significantly higher (p<0.01) compared to WT.Taken together, these results indicate that phage clones pJ18 and pJ24 target and image ovarian SKOV‐3 tumors in vivo. This demonstrates the potential us of these phage clones as ovarian cancer detection and imaging agents.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Biocompatibility of Gd-Loaded Chitosan-Hyaluronic Acid Nanogels as Contrast Agents for Magnetic Resonance Cancer Imaging.

Although the research on nanogels incorporating Gd chelates for theranostic applications has grown exponentially in recent years, knowledge about their biocompatibility is limited. We compared the biocompatibility of Gd-loaded hyaluronic acid-chitosan-based nanogels (GdCA⊂CS-TPP/HA) with two chitosan concentrations (2.5 and 1.5 mg·mL−1 respectively) using SVEC4-10 murine lymph node endothelial cells. The sulforhodamine B method and released lactate dehydrogenase (LDH) activity were used as cell viability tests. Reactive oxygen species (ROS), reduced glutathione (GSH) and malondialdehyde (MDA) were measured by spectrophotometric and fluorimetric methods. Nrf-2 protein expression was evaluated by Western blot analysis and genotoxicity by alkaline comet assay. After 24 h, the cells viability was not affected by all types and doses of nanogels. The increase of ROS induced a low decrease of GSH concentration and a time-dependent raise of MDA one was produced by citric GdDOTA⊂CS-TPP/HA with a chitosan concentration of 1.5 mg·mL−1, at the highest dose applied. None of the tested nanogels induced changes in Nrf-2 protein expression. A slight but significant genotoxic effect was caused only by citric GdDOTA⊂CS-TPP/HA where CS concentration was 1.5 mg·mL−1. Our results showed a better biocompatibility with lymph node endothelial cells for Gd-loaded hyaluronic acid-chitosan based nanogels with a concentration in chitosan of 2.5 mg·mL−1.

Biocompatible Semiconductor Quantum Dots as Cancer Imaging Agents.

Approximately 1.7 million new cases of cancer will be diagnosed this year in the United States leading to 600 000 deaths. Patient survival rates are highly correlated with the stage of cancer diagnosis, with localized and regional remission rates that are much higher than for metastatic cancer. The current standard of care for many solid tumors includes imaging and biopsy with histological assessment. In many cases, after tomographical imaging modalities have identified abnormal morphology consistent with cancer, surgery is performed to remove the primary tumor and evaluate the surrounding lymph nodes. Accurate identification of tumor margins and staging are critical for selecting optimal treatments to minimize recurrence. Visible, fluorescent, and radiolabeled small molecules have been used as contrast agents to improve detection during real-time intraoperative imaging. Unfortunately, current dyes lack the tissue specificity, stability, and signal penetration needed for optimal performance. Quantum dots (QDs) represent an exciting class of fluorescent probes for optical imaging with tunable optical properties, high stability, and the ability to target tumors or lymph nodes based on surface functionalization. Here, state-of-the-art biocompatible QDs are compared with current Food and Drug Administration approved fluorophores used in cancer imaging and a perspective on the pathway to clinical translation is provided.