Preliminary evaluation of the radiotherapeutic efficacy of 131I-atorvastatin in rats with hepatocellular carcinoma

As one of the most critical types of cancer,hepatocellular carcinoma(HCC)affects many people worldwide.This study demonstrated the prospective use of atorvastatin,a drug that inhibits the mevalonate pathway,causing hypolipidemia,as a carrier to deliver the iodine-131(131I)isotope to liver tissues for HCC radiotherapy.The atorvastatin radioiodination method was optimized for utilizing the131I isotope.The radiochemical quality and the in vitro stability of the generated[131I]atorvastatin were investigated.In addition,the biodistribution experiments of[131I]atorvastatin were evaluated in both normal and HCC-induced rat models.[131I]atorvastatin was produced at a maximum radiochemical yield of 86.7±0.49%.The[131I]atorvastatin solution purified via high-performance liquid chromatography showed good in vitro stability for 12 h after tagging.Biodistribution analyses revealed remarkable liver targeting capacity of[131I]atorvastatin and good localization of131I in liver tissues.Overall,the encouraging biochemical profile and histopathologicalfindings have been reported,and preliminary investigations on the possible use of[131I]atorvastatin as a radiotracer and its impact on HCC radiotherapy in rats show promise.

Radiolabeling of lacosamide using highly purified rhenium-188 as a prospective brain theranostic agent

Rhenium-188 is prospectively effective for both diagnosis and radiotherapy as it appropriately emits gamma rays and beta particles.Lacosamide(LCM)is a newly approved antiepileptic medication for focal drug-resistant epilepsy.Rhenium-188 was separated with high elution yield and high purity using the new 188W/188Re generator based on the ZrSiW gel matrix.188Re-LCM was prepared with high radiochemical yield and high purity.Biodistribution of 188Re-LCM in normal Swiss albino mice was investigated to determine its utility as a potential brain therapy agent.The 188W/188Re generator was used to obtain 188Re based on the ZrSi188W gel matrix,and the chemical,radiochemical,and radionuclidic purity of the obtained 188Re was determined using inductively coupled plasma optical emission spectrometry(ICP-AES),a paper chromatography technique,and high-purity germanium(HPGe)detection,respectively,to assess its validity for LCM labeling.Various factors,such as the pH,reaction time,and LCM quantity,were therefore studied in order to improve the yield and purity of 188Re-LCM,as determined by various chromatographic techniques such as electrophoresis,thin layer chromatography(TLC),and highpressure liquid chromatography(HPLC).188Re was obtained with a high elution yield(75±3%)and a low 188W breakthrough(0.001±0.0001%).The maximum radiochemical yield of 188Re-LCM(87.5±1.8%)was obtained using 50 ll LCM(4 mM),250 ll stannous chloride(4.4 mM)at pH 4,100 ll 188Re(37 MBq),within 30 min,at room temperature(25±3C),as determined by TLC,electrophoresis,and HPLC techniques.Biodistribution analysis showed that 188Re-LCM was primarily localized in the brain(5.1%)with a long residence time(240 min).

Radiolabeling, docking studies, in silico ADME and biological evaluation of serotonin with 125I for 5-HTRs imaging

Serotonin is one of the significant signaling molecules used by several neural systems in the gut and brain. This study aimed to develop a novel and potent tracer for targeting, detecting, and imaging serotonin receptors(5-HTRs), which is a promising tool in the determination of the receptor’s function and relationship with the diseases related to serotonin and its receptor dysfunction. Serotonin was effectively labeled via a direct electrophilic substitutional reaction using an oxidizing agent such as iodogen with 125I in a neutral medium, and 125I-serotonin was achieved with a maximum labeling yield of 91 ± 0.63% with in vitro stability up to 24 h. Molecular modeling was conducted to signify 125I-serotonin structure and confirm that the radiolabeling process did not affect serotonin binding ability to its receptors. Biodistribution studies show that the maximum gastro intestinal tract uptake of 125I-serotonin was 17.8 ± 0.93% ID/organ after 30 min postinjection and the tracer’s ability to pass the blood–brain barrier. Thus, 125I-serotonin is a promising single photon emission computed tomography tracer in the detection of 5 HTRs.

Radioiodination and biological evaluation of valsartan as a tracer for cardiovascular disorder detection

A procedure for radioiodination of valsartan with iodine-125 is carried out via an electrophilic substitution of hydrogen atom with the iodonium cation I+. All reaction parameters were studied to optimize the labeling conditions of valsartan and to obtain a maximum radiochemical yield (RCY) of the 125I-Valsartan [125I-Val]. By using 3.7 MBq of Na125I, 50 μg of valsartan (0.2 mM) as substrate, 25 μg of Iodogen (0.15 mM) as oxidizing agent in ethanol at room temperature for 30 min, the radiochemical yield of 125I-Val was 98.6% The radiochemical yield was determined by electrophoresis using cellulose acetate moistened with 0.02 M phosphate buffer pH 7. The labeled compound was separated and purified by means of high-pressure liquid chromatography (HPLC). The biological distribution in normal mice indicates the suitability of radioiodinated valsartan to image any cardiovascular disorders.