In vitro cell interaction and in vivo biodistribution of poly (dl-lactide-co-glycolide) nanospheres with encapsulated selenium nanoparticles for the treatment of liver diseases

The role of selenium as a chemopreventive and chemotherapeutic agent has been supported by a large number of epidemiological, preclinical, and clinical trials [1, 2] suggesting that anti-tumor effect mechanisms of selenium include induction of apoptosis, inhibition of cell proliferation, protection against oxidative stress, and stimulation of immune system. Herein we demonstrate a simple and quick synthesis of uniform, stable, amorphous selenium nanoparticles (SeNps), using ascorbic acid as the reduction agent. The choice of an appropriate stabilizer and reducing agent for preparation of stable selenium nanoparticles is very important. We used bovine serum albumin (BSA) as an organic layer for selenium nanoparticles, i.e., as a capping agent to make them more biocompatibile and protect them from agglomeration in the suspension medium. SeNps were additionally encapsulated within spherical PLGA particles (PLGA/SeNps). One of the most important requirements for the controlled and balanced release of the drug in the body is ideal spherical shape of the particles and narrow distribution of their sizes. The morphology (size and shape) of the particles plays key role in their adhesion and interaction with the cell. The influence of PLGA/SeNps on cell viability, ROS generation in HepG2 cells, as well as anticancer activity against epithelial tumor cells was investigated. Synthesized nanoparticles were characterized by FTIR spectroscopy, FESEM, TEM, HRTEM, and Zeta potential measurements. As a part of this study, we have also performed in vivo dynamic imaging studies in normal mice, using SPECT imaging and a high resolution gamma camera. The PLGA/SeNps nanoparticles have been radiolabelled with Tc-99m, by applying the direct labeling method [3]. Ex vivo biodistribution measurements, as well as in vivo dynamic studies up to 1h p.i. and at 24h were performed, showing increased concentration in liver and spleen. Acknowledgements This study was supported by the Ministry of Science and Technological Development of the Republic of Serbia, under Grant No. III45004: Molecular designing of nanoparticles with controlled morphological and physicochemical characteristics and functional materials based on them. Presented were the results of a study also supported by the COST Action TD1004. References 1. Popova, N. V. Cancer Lett. 2002, 179, 39–42. 2. Li, S.; Zhou, Y.; Wang, R.; Zhang, H.; Dong, Y.; Ip, C. Mol. Cancer Ther. 2007, 6, 1031–1038. 3. Psimadas, D.; Baldi, G.; Ravagli, C.; Bouziotis, P.; Xanthopoulos, S.; Francini, M.; Georgoulias, P.; Loudos, G.; J. Biom. Nan., 2012, 8, 4, 575-585

Poly (DL-lactide-co-glycolide) nanospheres with encapsulated selenium nanoparticles as a system with therapeutic functionality

Selenium (Se) is an essential trace element with important physiological functions and extensive pharmacological actions. The role of selenium as a chemopreventive and chemotherapeutic agent has been supported by a large number of epidemiological, preclinical, and clinical trials. Uniform, stable, amorphous selenium nanoparticles (SeNps) have been synthesized and additionally encapsulated within spherical PLGA particles (PLGA/SeNps). The morphology (size and shape) of the particles plays key role in their adhesion and interaction with the cell. Synthesized particles were characterized by FTIR spectroscopy, FESEM, TEM, HRTEM, and Zeta potential measurements. The influence of PLGA/SeNps on cell viability, ROS generation in HepG2 cells, as well as anticancer activity against epithelial tumor cells was investigated. As a part of this study, we have also performed in vivo dynamic imaging studies in normal mice, using SPECT imaging and a high resolution gamma camera. The PLGA/SeNps nanoparticles have been radiolabelled with Tc-99m, by applying the direct labeling method. Ex vivo biodistribution measurements, as well as in vivo dynamic studies up to 1h p.i. and at 24h were performed, showing increased concentration in liver and spleen

In vivo anticancer evaluation of the hyperthermic efficacy of anti-human epidermal growth factor receptor-targeted PEG-based nanocarrier containing magnetic nanoparticles

Polymeric nanoparticles with targeting moieties containing magnetic nanoparticles as theranostic agents have considerable potential for the treatment of cancer. Here we report the chemical synthesis and characterization of a poly(D,L-lactide-co-glycolide)-b-poly(ethylene glycol)-based nanocarrier containing iron oxide nanoparticles and human epithelial growth factor receptor on the outer shell. The nanocarrier was also radiolabeled with (99m)Tc and tested as a theranostic nanomedicine, ie, it was investigated for both its diagnostic ability in vivo and its therapeutic hyperthermic effects in a standard A431 human tumor cell line. Following radiolabeling with (99m)Tc, the biodistribution and therapeutic hyperthermic effects of the nanosystem were studied noninvasively in vivo in tumor-bearing mice. A substantial decrease in tumor size correlated with an increase in both nanoparticle concentration and local temperature was achieved, confirming the possibility of using this multifunctional nanosystem as a therapeutic tool for epidermoid carcinoma

Radiochemical study and radiopharmacological evaluation of labeled peptide derivatives

It has been shown that gastrin releasing peptide receptors (GRP-Rs) are overexpressed in various types of cancer cells. Bombesin is an analogue of the mammalian GRP that binds with high specificity and affinity to GRP-Rs. Significant research efforts have been lately devoted to the design of radiolabeled 8 or 14 aminoacid bombesin (BN) peptides for the detection (with gamma or positron emitting radionuclides) and therapy (with β-emitting radionuclides) of cancer. The specific aim of the present study was to investigate further the radiolabeled peptide structure and to determine whether the total absence of a linker or the use of a diverse aminoacid sequence could influence the biodistribution profile of the new compounds for specific targeting of prostate cancer. Thus, two new derivatives with the structure Gly-Gly-Cys-X-BN[2-14], where linker X, is either zero ΒΝ(I) or Orn-Orn-Orn (Orn:Ornithine) ΒΝ(II) were designed and synthesized. The corresponding 99mTc-BN(I) and 99mTc-BN(II) derivatives were obtained with high radiochemical yield (>98%) and had almost identical retention times in RP-HPLC with the 185/187Re complexes, which were also characterized by ESI-MS. Metabolic stability was found high in human plasma, moderate in PC-3 cells and rather low in mouse liver and kidney homogenates for both BN derivatives studied. BN (I) was less stable than BN(II) in cell culture and liver homogenates. A satisfactory binding affinity to GRP-Rs, in the nanomolar range, was obtained for both BN derivatives, as well as for their Rhenium complexes, with BN (II) demonstrating the highest one. In vitro internalisation/externalisation assays indicated that ~6% of 99mTc-BN (I) and ~25% of 99mTc-BN (II) were internalized into PC-3 cells. In vivo evaluation in normal Swiss mice and in tumor bearing SCID mice showed that 99mTc-BN(II) presented tumor and pancreas uptake higher than 99mTc-BN(I). Small animal SPECT dynamic imaging, carried out after injection of 99mTc-ΒΝ(Ι) and 99mTc-BN(II) in mice bearing PC-3 tumors, resulted to PC-3 tumor delineation with low background activity especially for 99mTc-BN(II). Overall, this study performed for two new N3S-X-BN[2-14] derivatives indicated that hydrophilicity and charge affected strongly the in vitro and in vivo binding properties as well as the biodistribution pattern.Έχει αποδειχθεί υπερέκφραση πεπτιδικών υποδοχέων απελευθέρωσης γαστρίνης (GRP-Rs) σε διαφόρους τύπους καρκίνου. Η Μπομπεσίνη, ένα δεκατετραπεπτίδιο ανάλογο των πεπτιδίων απελευθέρωσης γαστρίνης (GRP), έχει απομονωθεί στα θηλαστικά και εμφανίζει υψηλή συγγένεια δέσμευσης και ειδικότητα με τους υποδοχείς απελευθέρωσης γαστρίνης (GRP-Rs). Πρόσφατα, σημαντικό ερευνητικό ενδιαφέρον έχει επιδειχθεί διεθνώς όσον αφορά στο σχεδιασμό αναλόγων Μπομπεσίνης (BN) 8 ή 14 αμινοξικών καταλοίπων επισημασμένων είτε με ραδιοϊσότοπα που εκπέμπουν γ και β+ σωματιδιακή ακτινοβολία είτε με ραδιοϊσότοπα που εκπέμπουν ηλεκτρόνια β- και α σωματιδιακή ακτινοβολία για διάγνωση και θεραπεία αντίστοιχα καρκινικών όγκων. Ο σκοπός της παρούσας μελέτης είναι να εξετάσει εάν η παρεμβολή ή μη ενός βασικού συνδετικού μορίου πεπτιδικής φύσεως μεταξύ του σχηματιζόμενου συμπλόκου του Τεχνητίου και της φαρμακολογικά δραστικής ομάδας του πεπτιδίου Μπομπεσίνης επηρεάζει τη φαρμακοκινητική συμπεριφορά των νέων ενώσεων, για εξειδικευμένη στόχευση καρκίνου του προστάτη. Στα πλαίσια της παραπάνω μελέτης έχουν συντεθεί με την μέθοδο πεπτιδικής σύνθεσης σε στερεά φάση και έχουν μελετηθεί δυο ανάλογα του τύπου: Gly-Gly-Cys-X-BN[2-14] όπου, είτε το συνδετικό μόριο δεν υπάρχει: Χ=0 ΒΝ(Ι), είτε αυτό είναι: X=Orn-Orn-Orn (Orn: α,δ-διαμινοβαλερικό οξύ ή 2,5 διαμινοπεντανοϊκό οξύ ή ορνιθίνη) ΒΝ(ΙΙ). Τα παράγωγα του Τεχνητίου, των δύο νέων πεπτιδικών (ΒΝ) μορίων, 99mTc-BN(Ι) και 99mTc-BN(ΙΙ), ελήφθησαν με ραδιοχημική καθαρότητα >98% και με σχεδόν ίδιους χρόνους έκλουσης από τη στήλη RP-HPLC με αυτούς των αντίστοιχων συμπλόκων του Ρηνίου 185/187Re-BN(Ι) και 185/187Re-BN(ΙΙ) τα οποία χαρακτηρίστηκαν με MS-ESI. Η μεταβολική σταθερότητα βρέθηκε υψηλή στο πλάσμα, μέτρια σε εναιώρημα καρκινικών κυττάρων του προστάτη (PC-3) και σχετικά χαμηλή σε ομογενοποίημα ήπατος και νεφρών. Το παράγωγο 99mTc-BN(I) ήταν λιγότερο σταθερό στο εναιώρημα κυττάρων και στο ομογενοποίημα ήπατος σε σχέση με το 99mTc-ΒΝ(ΙΙ). Ικανοποιητική κρίθηκε η συγγένεια δέσμευσης (της τάξης των nM) με τους GRP-Rs υποδοχείς, και των δύο παραγώγων, καθώς και των συμπλόκων τους με 185/187Re. Το BN(II) εμφανίζει την υψηλότερη συγγένεια. To ποσοστό της εσωτερικοποιημένης ραδιενέργειας στα καρκινικά κύτταρα PC-3 μετά την επώαση τους με το 99mTc-ΒΝ(Ι) ήταν ~6% και με το 99mTc-ΒΝ(ΙΙ) ~25%. Η in vivo αξιολόγηση σε φυσιολογικά πειραματόζωα τύπου Swiss και σε παθολογικά πρότυπα καρκίνου του προστάτη, σε πειραματόζωα τύπου SCID, έδειξε ότι το 99mTc-BN(II) παρουσίασε υψηλότερη συγκέντρωση στο πάγκρεας και στον όγκο σε σχέση με το 99mTc-BN(I). Με τη σπινθηρογραφική δυναμική μελέτη σε παθολογικά πρότυπα καρκίνου του προστάτη μετά τη χορήγηση με 99mTc-ΒΝ(Ι) και 99mTc-BN(II), ελήφθησαν ευκρινείς εικόνες του όγκου, ιδιαίτερα για το 99mTc-BN(II). Εν κατακλείδι, η διεξοδική μελέτη των δύο νέων παραγώγων N3S-X-BN[2-14] έδειξε ότι η υδροφιλικότητα και το φορτίο επηρεάζουν σημαντικά τις in vitro και in vivo ιδιότητες δέσμευσης και την φαρμακοκινητική των παραγώγων της Μπομπεσίνης

A Theranostic Imaging prototype based on SiPM detectors for nanoparticles imaging during hyperthermia

The combination of imaging and therapy has opened the very promising Theranostics domain with magnetic hyperthermia being a very promising domain. However, imaging systems should not interact with the magnetic field. In this work we have tested the recent C-series of SensL SiPM with 3mm pixel size, 4×4 arrays, coupled to different scintillators and irradiated with various gamma energies. The evaluation of the SiPM arrays shows that 1x1mm pixel size can be clearly resolved at PET energies for GAGG:Ce and CsI:Na and 1.5×1.5mm in SPECT imaging for CsI:Na. The best energy resolution was measured equal to 10.5% under 511keV irradiation for the 2×2mm GAGG:Ce; 16% under 511keV irradiation for the 1×1mm GAGG:Ce and 22% under 120keV irradiation for the 1×1mm CsI:Na. In addition, measurements with position sensitive photomultipliers have been carried out, to evaluate the effect of the magnetic field on the imaging performance of the system. While the effect of the magnetic field outside the coil is small, optimal images will be obtained if the imaging system is placed inside the coil, something that can be achieved only by using SiPMs

Design and development of a hybrid preclinical PET/SPECT/X-ray system

In this work we present the design and development of a prototype SPECT/PET/CT system, suitable for whole body small animal imaging, which is unique not only in national but also in regional level. The integrated SPECT/PET/CT system has three components and is mounted on a rotating gantry, which is designed specifically for such applications. The system is unique on national and regional level. The SPECT component has a 2mm spatial resolution, the PET components a 2.5mm spatial resolution and the X-ray component was recently purchased and is now mounted on the existing gantry and will be evaluated. The complete design of the system and evaluation results are presented

In vivo imaging techniques for bone tissue engineering

[EN] Bone is a dynamic tissue that constantly undergoes modeling and remodeling. Bone tissue engineering relying on the development of novel implant scaffolds for the treatment of pre-clinical bone defects has been extensively evaluated by histological techniques. The study of bone remodeling, that takes place over several weeks, is limited by the requirement of a large number of animals and time-consuming and labor-intensive procedures. X-ray-based imaging methods that can non-invasively detect the newly formed bone tissue have therefore been extensively applied in pre-clinical research and in clinical practice. The use of other imaging techniques at a pre-clinical level that act as supportive tools is convenient. This review mainly focuses on nuclear imaging methods (single photon emission computed tomography and positron emission tomography), either alone or used in combination with computed tomography. It addresses their application to small animal models with bone defects, both untreated and filled with substitute materials, to boost the knowledge on bone regenerative processes.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 645757. This study was co-supported through the Program of Industrial Scholarships of Stavros Niarchos Foundation and through IKY scholarships and co-financed by the European Union (European Social Fund ESF) and Greek national funds through the action entitled Reinforcement of Postdoctoral Researchers, in the framework of the Operational Program Human Resources Development Program, Education and Lifelong Learning of the National Strategic Reference Framework (NSRF) 2014-2020

Optimization of In Vivo Studies by Combining Planar Dynamic and Tomographic Imaging: Workflow Evaluation on a Superparamagnetic Nanoparticles System

Molecular imaging holds great promise in the noninvasive monitoring of several diseases with nanoparticles (NPs) being considered an efficient imaging tool for cancer, central nervous system, and heart- or bone-related diseases and for disorders of the mononuclear phagocytic system (MPS). In the present study, we used an iron-based nanoformulation, already established as an MRI/SPECT probe, as well as to load different biomolecules, to investigate its potential for nuclear planar and tomographic imaging of several target tissues following its distribution via different administration routes. Iron-doped hydroxyapatite NPs (FeHA) were radiolabeled with the single photon γ-emitting imaging agent [99mTc]TcMDP. Administration of the radioactive NPs was performed via the following four delivery methods: (1) standard intravenous (iv) tail vein, (2) iv retro-orbital injection, (3) intratracheal (it) instillation, and (4) intrarectal installation (pr). Real-time, live, fast dynamic screening studies were performed on a dedicated bench top, mouse-sized, planar SPECT system from t=0 to 1 hour postinjection (p.i.), and consequently, tomographic SPECT/CT imaging was performed, for up to 24 hours p.i. The administration routes that have been studied provide a wide range of possible target tissues, for various diseases. Studies can be optimized following this workflow, as it is possible to quickly assess more parameters in a small number of animals (injection route, dosage, and fasting conditions). Thus, such an imaging protocol combines the strengths of both dynamic planar and tomographic imaging, and by using iron-based NPs of high biocompatibility along with the appropriate administration route, a potential diagnostic or therapeutic effect could be attained

Targeted delivery of silver nanoparticles and alisertib: in vitro and in vivo synergistic effect against glioblastoma

Aim: Targeted biocompatible nanoplatforms presenting multiple therapeutic functions have great potential for the treatment of cancer. Materials & methods: Multifunctional nanocomposites formed by polymeric nanoparticles (PNPs) containing two cytotoxic agents – the drug alisertib and silver nanoparticles – were synthesized. These PNPs have been conjugated with a chlorotoxin, an active targeting 36-amino acid-long peptide that specifically binds to MMP‑2, a receptor overexpressed by brain cancer cells. Results: The individual and synergistic activity of these two cytotoxic agents against glioblastoma multiforme was tested both in vitro and in vivo. The induced cytotoxicity in a human glioblastoma–astrocytoma epithelial‑like cell line (U87MG) was studied in vitro through a trypan blue exclusion test after 48 and 72 h of exposure. Subsequently, the PNPs’ biodistribution in healthy animals and their effect on tumor reduction in tumor‑bearing mice were studied using PNPs radiolabeled with 99mTc. Conclusion: Tumor reduction was achieved in vivo when using silver/alisertib@PNPs–chlorotoxin.JRC.I.4-Nanobioscience