Browsing by Author "El-Kolaly, MT"

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Formulation and preclinical evaluation of 99mTc–gemcitabine as a novel radiopharmaceutical for solid tumor imaging
(SPRINGER, 2014) Ibrahim, AB; Sakr, TM; Khoweysa, OMA; Motaleb, MA; El-Kolaly, MT
The aim of this study is the formulation of a new radiopharmaceutical for imaging solid tumor bearing. Gemcitabine is a nucleoside analogue used as chemotherapeutic agent. Gemcitabine was formulated and radiolabeled with one of the most important diagnostic radioactive isotopes (technetium-99m) to be investigated in solid tumor imaging. The labeling parameters such as gemcitabine amount, stannous chloride amount, pH of the reaction mixture, and reaction time were optimized. 99mTc–gemcitabine was prepared at pH 9 with a maximum labeling yield of 96 ± 0.3 % without any notable decomposition at room temperature over a period of 8 h. The preclinical evaluation and biodistribution in solid tumor bearing mice showed that 99mTc–gemcitabine had solid tumor selectivity, preclinical high biological accumulation in tumor cells and high retention. Tumor/normal muscle (T/NT) ratios increased with time showing high T/NT ratio (T/NT = 4.9 ± 0.27 at 120 min post injection) and high Tumor/Blood ratio (3.4 ± 0.06), suggesting 99mTc–gemcitabine as a novel solid tumor imaging agent
Preliminary assessment of radioiodinated fenoterol and reproterol as potential scintigraphic agents for lung imaging
(SPRINGER, 2015) Swidan, MM; Sakr, TM; Motaleb, MA; Abd El-Bary, A; El-Kolaly, MT
Radioiodinated fenoterol and reproterol were prepared by electrophilic radioiodination reaction using chloramin-T as oxidizing agent with radiochemical yields of 97.7 ± 0.7 and 95.2 ± 0.3 %, respectively, and in vitro stability up to 72 h. Biodistribution study performed in male Albino Swiss mice showed maximum radioactivity accumulation in lungs tissue to the extent of 52 ± 1.03 and 50.6 ± 1.2 % ID/g at 15 and 30 min post injection (p.i.) for radioiodinated fenoterol and reproterol, respectively, with low accumulation in heart and blood. The clearance pathway of both iodo-compounds was through renal and hepatobiliary routes. The selectivity of iodo-compounds to lung was examined by in vivo receptor blocking study. Radioiodinated fenoterol and reproterol are not a blood products and so they are more safer than the currently available 99mTc-MAA, and their lungs uptake is higher than that of the recently discovered 125/123I-IPMPD, 99mTc(CO)5I, 99mTc-DHPM and 125/123I-paroxetine. So, radioiodinated fenoterol and reproterol could be introduced as a new compromising radiopharmaceuticals for lung perfusion scintigraphy more safe than the currently available 99mTc-MAA and more potential than the recently discovered 125/123I-IPMPD, 99mTc(CO)5I, 99mTc-DHPM and 125/123I-paroxetine
Radioiodinated anastrozole and epirubicin as potential targeting radiopharmaceuticals for solid tumor imaging
(SPRINGER, 2015) Ibrahim, AB; Sakr, TM; Khoweysa, OMA; Motaleb, MA; Abd El-Bary, A; El-Kolaly, MT
This study describes the preparation of radioiodinated anastrozole and epirubicin and their biological evaluation as potential solid tumor imaging gents. Radioiodinated anastrozole and epirubicin were successfully prepared via direct electrophilic substitution reaction at ambient temperature. The radiochemical yields for radioiodinated anastrozole and epirubicin were maximized to 92.9 ± 0.1 and 98.8 ± 0.1 %, respectively by studying different reaction parameters such as substrate amount, chloramine-T, pH of the reaction mixture, reaction temperature and reaction time. They showed in vitro stability up to 4 and 24 h, respectively. The preclinical evaluation and biodistribution in mice bearing solid tumor showed high retention and biological accumulation in solid tumor cells (12.4 and 25.3 % injected activity/g tissue) and high T/NT ratio equal to 4.7 ± 0.1 and 5.2 ± 0.1 at 2 and 1 h post-injection, respectively. Data described before could recommend radioiodinated anastrozole and radioiodinated epirubicin as potential targeting radiopharmaceuticals for solid tumor imaging