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Öğe 18FDG conjugated magnetic nanoparticle probes: Synthesis and in vitro investigations on MCF-7 breast cancer cells(2013) Ozkaya F.; Unak P.; Medine E.I.; Sakarya S.; Unak G.; Timur S.18FDG conjugated magnetic iron oxide nanoparticles (MNPs) were synthesized as PET-MR hybrid imaging agent. Synthesized and characterized NPs were then applied to MCF-7 human breast cancer cells. 18FDG conjugated MNPs exhibited the cell incorporation ratio up to 30 %. As well as the characterization studies, apoptotic effects were observed depending on the cellular incorporations by the time. In conclusion, synthesized structures could have a potential as hybrid imaging agent in PET-MR imaging systems besides apoptotic effect on cancer cells. © 2012 Akadémiai Kiadó, Budapest, Hungary.Öğe 99m Tc(I) carbonyl-radiolabeled lipid based drug carriers for temozolomide delivery and bioevaluation by in vitro and in vivo(De Gruyter, 2019) Arl K.; Uçar E.; Içhedef Ç.; Yurt Kllçar A.; Medine E.I.; Parlak Y.; Saylt Bilgin B.E.; Aydln B.; Gümüşer F.G.; Teksöz S.In preclinical research radiolabeled nanoparticles have been attracting interest as a new class of imaging probes. Assuming good stability of solid lipid nanoparticles (SLNs) under physiological conditions, radiolabeled SLNs can be used for imaging and measuring uptake in target tissue. Present study was performed to evaluate biological behavior of temozolomide (TMZ) loaded solid lipid nanoparticles (SLN-TMZ) in vivo and in vitro. Lipid nanoparticles were prepared by emulsification and low-temperature solidification method. ? potential, morphology and particle size of nanoparticles were determined. Biological behavior of 99m Tc(CO) 3 + radiolabeled SLN-TMZ were investigated in vitro on U87/Daoy cell lines and in vivo on female Wistar Albino rats. Obtained results of in vitro incorporation, in vivo biodistribution and gamma imaging studies on radiolabeled SLN-TMZ show that the radiolabeled solid lipid nanoparticles could have potential as a drug delivery system for TMZ. © 2019 Walter de Gruyter GmbH, Berlin/Boston 2019.Öğe 99mTc labeled plumbagin: estrogen receptor dependent examination against breast cancer cells and comparison with PLGA encapsulated form(Springer Netherlands, 2016) Yurt Kilcar A.; Tekin V.; Biber Muftuler F.Z.; Medine E.I.Plant origin products having anticancer properties come into prominence due to widespread of cancer. Plumbagin has various biological activities like anticancer activity. Estrogen receptor (ER) specificity of plumbagin (PL) and radiolabeled PL investigated by in vitro studies on ER+ and ER- adenocarcinoma cells. Additionally, PLGA encapsulation was carried out to reduce toxicity of plumbagin and encapsulation effect was investigated. Plumbagin radiolabeled with 100 % in yields and had ER specificity. Furthermore, PLGA encapsulation effected positively on properties of plumbagin; reduced toxicity, increased stability and ER specificity. A promising agent for the diagnosis of ER+ breast cancer is suggested. © 2015, Akadémiai Kiadó, Budapest, Hungary.Öğe 99mTc-exorphin-glucuronide in tumor diagnosis: Preparation and biodistribution studies in rats(2006) Ertay T.; Ünak P.; Özdogan O.; Biber F.Z.; Zihnioglu F.; Medine E.I.; Durak H.A glucuronide derivative of exorphin C called exorphin C glucuronide was obtained by enzymatic synthesis and labeled with 99mTc using glucoheptonate (GH) as bifunctional chelating agent. Labeling efficiency was 99.7±0.03%. Biodistribution studies were performed on normal and mammary tumor bearing albino Wistar rats. In addition, scintigraphic imaging with 99mTc-GH-exorphin C glucuronide (99mTc-GEG) was performed. The radiopeptide-glucuronide is rapidly cleared via the urinary system showing lower liver uptake. Results demonstrated that 99mTc-GEG can be used as a vehicle to target tumors. © 2006 Akadémiai Kiadó.Öğe 99mTc-glucoheptonate-guanine: Synthesis, biodistribution and imaging in animals(2008) Unak P.; Teksoz S.; Biber Muftuler F.Z.; Medine E.I.; Acar C.; Yurekli Y.The aim of the current study was to design a nucleotide-based radiopharmaceutical which could be labeled with 99mTc and to investigate its radiopharmaceutical efficiency and stability. GHA (glucoheptonate) was used as bifunctional chelate. GHA was labeled with 99mTc by SnCl2 reduction method first, and then G (guanine) was conjugated with 99mTc-GHA at 90°C. In order to determine its radiopharmaceutical stability, thin layer radio chromatography (TLRC) and electrophoresis were employed. In addition, the results were confirmed using high performance liquid radio chromatography (HPLRC). Scintigraphic imaging was performed on rats with mammary tumors, while tissue distribution was determined on Albino Wistar rats. Labeling yield was found to be over 95% and the labeled complex maintained its stability during the study period. The lipophilicity of the 99mTc-GHG was measured and the partition coefficient (logP) of the labeled compound calculated. The results demonstrated that the uptake of 99mTc-GHG (99mTc- glucoheptonate-guanine) reached its maximum at 3 hours p.i. in stomach and intestines. Main way of excretion was renal. Hepatobiliary excretion was also observed. In conclusion, 99mTc-GHG may be useful as a nucleotide-based radiopharmaceutical for in vivo applications. © 2008 Springer Science+Business Media, LLC.Öğe Affinity based laccase immobilization on modified magnetic nanoparticles: Biosensing platform for the monitoring of phenolic compounds(Taylor and Francis Inc., 2015) Babadostu A.; Guldu O.K.; Demirkol D.O.; Medine E.I.; Unak P.; Timur S.The authors report an electrochemical phenol biosensor based on the immobilization of laccase (Lac) on the surface of copper capped magnetic core-shell (Fe3O4-SiO2) nanoparticles (MNPs). After synthesis, MNP surfaces were functionalized by silanization and then, modified with histidine (His) and copper, respectively. The performance of the MNP-His/Cu/Lac biosensor has been investigated at -0.05 V versus Ag/AgCl. The proposed biosensor allowed to detect catechol and phenol in the range of 0.01-0.4 mM and 0.025-0.2 mM, respectively. Finally, phenol analysis in culture medium of P. putida adapted to phenol was successfully demonstrated with appreciable recovery values. © 2015 Copyright Taylor & Francis Group, LLC.Öğe Bioevaluation of 99mTc(CO) 3-Guanine in vitro and in vivo(2012) Içhedef C.; Şenocak K.; Ertay T.; Teksöz S.; Medine E.I.; Bekiş R.; Ünak P.The aim of this study is to examine biological behaviour of radiolabeled guanine with [Tc(CO) 3] + core in vitro and in vivo. In vitro biological behavior of 99mTc(CO) 3-Gua was evaluated on Lung (A-549), Breast (MCF-7), Colonic (Caco) carcinoma cell lines and normal human bronchial epithelial (NHBE). 99mTc(CO) 3-Gua compound showed high uptake on A-549 cell line when compared to NHBE cell line. Biodistribution characteristics of 99mTc(CO) 3-Gua was evaluated using New Zeland Rabbits. Scintigraphic results showed that a high level of radioactivity was observed in the lungs and liver shortly after administration of the 99mTc(CO) 3-Gua and excretion takes place via both renal and hepatobiliary route. It was concluded that 99mTc(CO) 3-Gua could be used as a nucleotide radiopharmaceutical for imaging purposes. © 2012 Akadémiai Kiadó, Budapest, Hungary.Öğe Biosensing Applications of Modified Core-Shell Magnetic Nanoparticles(2012) Ozdemir C.; Akca O.; Medine E.I.; Demirkol D.O.; Unak P.; Timur S.Fe 3O 4 magnetic nanoparticles (MNPs) were synthesized and silanized to form a core-shell (Fe 3O 4-SiO 2) structure. Afterwards, surface modification with amino silane was carried out to produce amino groups on the MNPs for the biomolecule immobilization. In order to test the performance of amino functional MNPs as immobilization platform in biosensing applications, glucose oxidase was immobilized on the surface via glutaraldehyde. Obtained Bio-MNPs were then fixed onto the carbon paste electrode by the aid of magnetic force and used as the working electrode during the amperometric measurements at -0. 7 V versus Ag/AgCl. After optimization of some parameters affecting the biosensor performance, analytical characterization was carried out. Linearity was found in the range of 0. 25-2. 0 mM glucose and defined by the equation of y = 8. 366x + 1. 819, (R 2 = 0. 996). Proposed biosensor was then applied for the glucose analysis in various beverages. Finally, data were compared with a commercial enzyme assay kit based on spectrophotometric Trinder reaction as a reference method. © 2011 Springer Science+Business Media, LLC.Öğe Examination of the Association between 3,4-Divanillyltetrahydrofuran Lignan (Urtica dioica Origin) and Prostate Cancer Cells by 131I Radiolabeling(Mary Ann Liebert Inc., 2021) Tekin V.; Guldu O.K.; Medine E.I.; Muftuler F.Z.B.Background: Prostate cancer is the most common type of cancer for men in many countries. One of the various prostate cancer therapy methods is hormone therapy, and explaining the association between androgen hormones and prostate cancer is a critical role for successful prostate cancer treatment. Materials and Methods: In the current study, the behavior of 3,4-divanillyltetrahydrofuran (DTH) was examined against prostate cancer cells, which have androgen sensitivity differences [LNCaP (+), PC3 (-)]. For this aim, DTH was obtained by extraction of Urtica dioica roots. The molecular structure of isolated compound was confirmed as DTH by liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy analyses. To evaluate the association of androgen sensitivity, DTH was radiolabeled with 131I, and cell uptake assay was performed by using 131I-radiolabeled DTH. Also, cytotoxicity (WST-1) assay of DTH was performed against LNCaP and PC3 cells to determinate the toxic effects of DTH on different androgen mechanisms. Results: The results of assays on cells have shown that DTH lignan behaves different like being more toxic to LNCaP cells than PC3 cells, depending on androgen sensitivity. Conclusion: The results may contribute both the research topics of phytolignan prostate cancer and androgen-sensitive prostate cancer. © 2021, Mary Ann Liebert, Inc., publishers.Öğe In vitro determination of wound healing potential of axonge(HMP Communications, 2017) Bilgi A.; Muftuler F.Z.B.; Akman L.; Medine E.I.; Bilgi P.T.; Guldu O.K.; Gokulu S.G.; Tekin V.; Terek M.C.Background: Research on treatment alternatives that improve wound healing is an ever-evolving area in medicine, and a wound healing agent that carries minimal pain, discomfort, and scarring for patients with burn wounds, venous and decubitis ulcers, traumatic wounds, and many others is needed. The phases of wound healing include homeostasis, inflammation, migration, proliferation, and maturation. Adeps suillus (axonge) is known as a therapeutic agent for skin diseases and mainly consists of triglycerides. Objective: In the current study, the proliferation effect of axonge was determined on human normal epidermal keratinocyte (HaCaT) cells and human normal foreskin fibroblast cell line (BJ) cells. Materials and Methods: Experimental steps included preparation of HaCaT and BJ cell lines, axonge's stable tetrazolium salt-based proliferation assay, and evaluation of the wound healing effect of axonge on HaCaT and BJ cells. Results: Axonge concentrations of 3.12 µg/mL, 6.25 µg/mL, 12.5 µg/mL, 25 µg/mL, and 50 µg/mL showed no cytotoxic effect on both HaCaT and BJ cells for 24, 48, and 72 hours. Considering the wound area of HaCaT cells, after 6 hours the wound healing effect of the axonge group reached almost 70% and then stopped. According to the results of the study on BJ cells, after 6 hours axonge wound closure was found to be 50% while the control group was only 10%. Conclusion: On the basis of this study, the authors determined that axonge might have potential for use in wound healing. © 2017 HMP Communications. All rights reserved.Öğe In vitro evaluation of radiolabeled (125I) methanol extracts of yarrow in cell lines of MCF-7, PC-3, A-549 and Caco-2(2013) Yurt Kilcar A.; Cekic B.; Biber Muftuler F.Z.; Unak P.; Medine E.I.Nowadays, cancer is still the second leading cause of death all over the world. Therefore, natural products which have anticancer and antitumor properties are come into prominence. Achillea family is known with anticancer and antitumor activity. Yarrow which has over a hundred bioactive compounds is a member of Achillea family. In current study; components of yarrow which was obtained after methanol extraction and purification were radiolabeled with 125I and effects of these radiolabeled components on the cells were examined with using Caco-2, MCF-7, A-549, PC-3 cell lines. As a result of these studies, seven peaks were obtained and the highest radiolabeling yield was calculated for 125I radiolabeled Peak 7 (95.00 ± 7.07, n = 4). To screen the biological properties of these radiolabeled peaks at determined cell lines, our ongoing effort was to evaluate incorporation percentage with time dependent. Furthermore, 125I-Peak 7 had highest incorporation ratio for whole cell lines and its incorporation percentage was increased with time dependent. Results of these in vitro studies were compatible with previous in vivo studies and traditional use of yarrow plants. © 2012 Akadémiai Kiadó, Budapest, Hungary.Öğe In Vitro/In Vivo Evaluation of Radiolabeled [99mTc(CO)3]+-Hydroxyurea and Fluorescein Isothiocyanate-Hydroxyurea(Mary Ann Liebert Inc., 2016) Yilmaz B.; Teksoz S.; Kilcar A.Y.; Ucar E.; Ichedef C.; Medine E.I.; Ari K.The aim of current study is to examine hydroxyurea (HU), which is an antineoplastic drug used for the treatment of leukemia, sickle-cell disease, HIV, psoriasis, thrombocythemia, and various neoplastic diseases in two aspects. The active ingredient hydroxyurea was obtained by purification of the capsule form drug, commercially named as HYDREA. Then, [99mTc(CO)3]+core radiolabeling with HU was performed as first aspect. Quality control studies of 99mTc(CO)3-HU complex were performed by thin-layer radiochromatography and high-performance liquid radiochromatography methods. The results demonstrated that the radiolabeling yield was quite high (98.43% ± 2.29%). Also, 99mTc(CO)3-HU complex has good stability during the 24-hour period. Biological behavior of 99mTc(CO)3-HU complex is evaluated by biodistribution studies on Wistar Albino rats. Fluorescein isothiocyanate (FITC) labeling of HU was performed as second aspect. Fluorometric evaluation of binding efficacy and fluorescence imaging studies on MCF7 and Hela cell lines were carried out. It was thought that the knowledge achieved in this study would contribute to using 99mTc(CO)3-HU complex as an imaging agent, which inhibits the DNA synthesis selectively, by inhibiting ribonucleotide reductase enzyme. It was observed that FITC-HU has noteworthy incorporation on both cell lines. © Copyright 2016, Mary Ann Liebert, Inc. 2016.Öğe The influence of stereoisomerism on the biological behavior of 99mTc labeled penicillamine(2009) Acar C.; Teksoz S.; Ünak P.; Biber Müftüler F.Z.; Medine E.I.The aim of this study is to investigate stereoisomeric behavior of penicillamine and the effect of temperature on labeling. In addition, it was explored how stereoisomerism affected biological behavior of them. In the present work, D- and L-enantiomers of penicillamine(D-PA, L-PA) were labeled with 99mTc using SnCl2 as reducing agent and their radiopharmaceutical potentials were investigated. Quality control procedures were carried out using thin layer radiochromatography (TLRC), electrophoresis and high performance liquid radiochromatography (HPLRC). HPRLC chromatograms showed two peaks for 99mTc-D-PA, while a single peak was observed for 99mTc-L-PA at room temperature. However, the single peak was observed at 90 °C for both isomers. Labeling yields of each isomer were found to be over 98%. Biological activity of these complexes was determined on male Albino Wistar rats by biodistribution studies. While the biodistribution result of 99mTc-D-PA showed high uptake in the liver, maximum uptake of 99mTc-L-PA was observed in the kidneys. Both two complexes were cleared rapidly from the blood, mainly by the renal system. Since the activity concentration of 99mTc-D-PA at the 30th minute in the kidneys and the liver reached a maximum value and at the 120th minute, it was removed by renal and hepatobiliary excretion. As a result, it can be concluded that stereoisomerism affect not only the chemical behavior, but also differs their biological behavior of these compounds. © 2009 Akadémiai Kiadó, Budapest, Hungary.Öğe Investigation of in vitro efficiency of magnetic nanoparticle-conjugated 125I-uracil glucuronides in adenocarcinoma cells(2011) Medine E.I.; Ünak P.; Sakarya S.; Özkaya F.Modification of the magnetic properties of a drug can be used to direct the drug to the desired site, enhancing its therapeutic effectiveness and reducing side effects. In this study, surface-modified magnetic nanoparticles were immobilized with uracil glucuronide derivatives and then labeled with I-125. The morphology, structure, and composition of the magnetic particles were examined by TEM, SEM, VSM, and XRD. The particles sizes were about 50 nm. The labeling yield was 93.8% for uracil-O-glucuronide-immobilized magnetic particles and 95.0% for uracil-N-glucuronide-immobilized magnetic particles. The cell incorporation rates of N- and O-glucuronides were higher than those of uracil. The incorporation rates of uracil-, O-glucuronide-, and N-glucuronide-conjugated magnetic particles were all high. The cell incorporation rates of ligand-conjugated magnetic particles increased under a magnetic field. © 2011 Springer Science+Business Media B.V.Öğe Investigation of therapeutic efficiency of bleomycin and bleomycin-glucuronide labeled with 131I on the cancer cell lines(Mary Ann Liebert Inc., 2013) Ediz M.; Avcibaşi U.; Ünak P.; Müftüler F.Z.B.; Medine E.I.; Yurt Kilçar A.; Demiroglu H.; Gümüşer F.G.; Sakarya S.The aim of this study is to determine the incorporations of radiolabeled bleomycin (131I-BLM) and bleomycin-glucuronide (131I- BLMGLU) on PC-3 (human prostate carcinoma cell line), Caco-2 (human colon adenocarcinoma cell line), Hutu-80 (Human Duodenum adenocarcinoma cell line), and A549 (Human lung adenocarcinoma epithelial cell line) cancerous cell lines. For this purpose, BLM and BLMGLU enyzmatically synthesized were labeled with 131I, quality control studies were done and the incorporation yields of 131I-BLM and 131I-BLMGLU on these cell lines were measured. Quality-control studies showed that the radiolabeling yields were obtained as 95% and 90% for 131I-BLM and 131I-BLMGLU, respectively. Also, as a result of the cell culture studies, it was found that 131I-BLM and 131I-BLMGLU had higher incorporation on PC-3 cells than that of other cell lines. In addition to this, it was reported that the incorporation yield of 131I-BLMGLU was higher than that 131I-BLM. At the end of the study, cytotoxicities of BLM and BLMGLU on PC-3 cancerous cell line were inspected and fluorescent images of BLM and BLMGLU were taken on PC-3 cells by using fluorescein isothiocyanate. In conclusion, cell culture studies demonstrated that the incorporation values of 131I-BLMGLU on the four cell lines were about five to six times higher than 131I-BLM. Radiolabeled glucuronide derivatives can be used in cancer therapy and tumor imaging, depending on the properties of radioiodine for the ß-glucuronidase-rich tissues because glucuronidation leads to rapid and higher incorporation on adenocarcinoma cells. © Mary Ann Liebert, Inc.Öğe Isolation and immobilization of his-tagged alcohol dehydrogenase on magnetic nanoparticles in one step: Application as biosensor platform(Taylor and Francis Inc., 2014) Guldu O.K.; Ece S.; Evran S.; Medine E.I.; Demirkol D.O.; Unak P.; Timur S.His-tagged Alcohol dehydrogenase was produced as a recombinant protein in E. coli. Afterwards, isolation and immobilization of the enzyme was carried in one-step via copper modified magnetic nanoparticles (MNPs) by the effect of interactions between Cu and histidine. The resulting enzyme bound MNPs was then attached to the surface of carbon paste electrode by the magnetic force and used as an electrochemical biosensor for the alcohol sensing applications. © 2014 Taylor and Francis Group, LLC.Öğe Multifunctional molecular imaging probes for estrogen receptors: 99mTc labeled diethylstilbestrol (DES) conjugated, cuinp quantum dot nanoparticles (DESCIP)(Springer Netherlands, 2017) Moharrami P.; Unak P.; Guldu O.K.; Medine E.I.; Gumuser G.; Bilgin E.S.; Aras O.A theranostic nanoparticle was synthesized based on diethylstilbestrol conjugated with phosphate, copper, and indium (DESCIP) and labelled with 99mTc which can be used for SPECT imaging of ER-enriched cancers. In vitro biological activity of 99mTc-DESCIP was examined in breast adenocarcinoma cells (MCF-7), prostatic carcinoma cells (PC-3), and pulmonary epithelial cells (A-549). In vivo lymph node imaging was performed in normal and receptor blocked female New Zealand rabbits. Results demonstrated that 99mTc-DESCIP and DESCIP has potential for imaging ER-enriched tumors such as breast and prostate tumors, and their metastases in the lung, as well as improving management for their therapies. © 2017, Akadémiai Kiadó, Budapest, Hungary.Öğe A new approach for in vitro imaging of breast cancer cells by anti-metadherin targeted PVA-pyrene(Wiley-VCH Verlag, 2010) Medine E.I.; Odaci D.; Gacal B.N.; Gacal B.; Sakarya S.; Unak P.; Timur S.; Yagci Y.Poly(vinyl alcohol)-pyrene-anti-metadherin (PVA-Py-(Anti-MTDH)), a novel antibody based water soluble probe containing both fluorescent and target sites in the structure for in vitro imaging of breast cancer cells is reported here. Since breast cancer cells have an excess of MDTH protein expressed on the surface, a PVA-Py prepared by "Click chemistry" approach is targeted by Anti-MTDH antibody and applied to the MCF-7 cell line. After characterization, the designed architecture was evaluated in terms of cell incorporation efficiency and compared with a non-targeted structure (PVA-Py). Atomic force microscopy (AFM) and fluorescence microscopy images of cells after incubation of the probe molecules were also obtained to monitor the interaction of the probes with the cancerous cells. (Figure Presented). © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.Öğe Nonionic, water self-dispersible "hairy-Rod" poly(p -phenylene)-g-poly(ethylene glycol) copolymer/carbon nanotube conjugates for targeted cell imaging(2012) Yuksel M.; Colak D.G.; Akin M.; Cianga I.; Kukut M.; Medine E.I.; Can M.; Sakarya S.; Unak P.; Timur S.; Yagci Y.The generation and fabrication of nanoscopic structures are of critical technological importance for future implementations in areas such as nanodevices and nanotechnology, biosensing, bioimaging, cancer targeting, and drug delivery. Applications of carbon nanotubes (CNTs) in biological fields have been impeded by the incapability of their visualization using conventional methods. Therefore, fluorescence labeling of CNTs with various probes under physiological conditions has become a significant issue for their utilization in biological processes. Herein, we demonstrate a facile and additional fluorophore-free approach for cancer cell-imaging and diagnosis by combining multiwalled CNTs with a well-known conjugated polymer, namely, poly(p-phenylene) (PP). In this approach, PP decorated with poly(ethylene glycol) (PEG) was noncovalently (?-? stacking) linked to acid-treated CNTs. The obtained water self-dispersible, stable, and biocompatible f-CNT/PP-g-PEG conjugates were then bioconjugated to estrogen-specific antibody (anti-ER) via -COOH functionalities present on the side-walls of CNTs. The resulting conjugates were used as an efficient fluorescent probe for targeted imaging of estrogen receptor overexpressed cancer cells, such as MCF-7. In vitro studies and fluorescence microscopy data show that these conjugates can specifically bind to MCF-7 cells with high efficiency. The represented results imply that CNT-based materials could easily be fabricated by the described approach and used as an efficient "fluorescent probe" for targeting and imaging, thereby providing many new possibilities for various applications in biomedical sensing and diagnosis. © 2012 American Chemical Society.Öğe Preparation and characterization of radiolabeled magnetic nanoparticles as an imaging agent(2012) Içhedef C.; Teksöz S.; Ünak P.; Medine E.I.; Ertay T.; Bekiş R.Magnetic nanoparticles were prepared by a reduction-precipitation method and coated with an amino silane coupling agent. Guanine (Gua) was conjugated to the magnetic nanoparticles (MNPs) using glutaraldehyde as a cross-linker. Common techniques (Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and vibrating electron microscopy) were used to assess the properties of the particles. Structural investigations showed that amino silane-coated MNPs had a particle size of about 40-60 nm in diameter with a spherical morphology. The guanine-conjugated MNPs were radiolabeled with 99mTc(I)-tricarbonyl core ( 99mTc(CO) 3-MNP-Gua) with a labeling yield of 72 ± 4 %. Pure radiolabeled magnetic particles were obtained by washing them with saline solution, and the radiochemical purity of 99mTc(CO) 3-MNP-Gua was 98 ± 2 % in the final solution. The biologic distribution of guanine MNPs was assessed in New Zealand rabbits using a gamma camera. In the in vivo experiment, a high level of radioactivity was observed in the lungs and liver soon after intravenous administration of 99mTc(CO) 3-MNP-Gua. © 2012 Springer Science+Business Media B.V.
