Li Wenxin

Preparation of 99mTc-C60(OH)x and its biodistribution studies

The biological behavior of fullerene derivatives shows their considerable potential for medical applications. In order to provide a C(60) derivative for biodistriburtion studies, the (99m)Tc-labeling of C(60)(OH)(x) was optimized. Gamma counting and single photon emission computed tomography (SPECT) were used to assess the biodistribution of the (99m)Tc-labeled compound in mice and rabbits. Biodistribution studies in mice and imaging of rabbits indicated that (99m)Tc-C(60)(OH)(x) was widely distributed in all tissues. A significant percentage of total activity was retained for 48 h, particularly in the kidneys, bone, spleen, and liver. All tissues displayed a slow clearance over 48 h, except for bone, which showed slightly increasing localization within 24 h.

Radioiodination of C60 Derivative C60(OH)xOy

In this paper water-soluble fullerene derivative C60(OH)xOy was radioiodinated with the iodogen method. The labeling yield was determined by radio-TLC. The effects of pH value, reaction time, temperature and amount of the iodogen on the labeling yield were studied. The labeled product was purified by Sephadex G-25 column chromatography and then the stability of 125I-C60(OH)xOy was examined . The results showed that the radiochemical purity of 125I-C60(OH)xOy solution with benzylalcohol remained 82.7% after 43 hours.

Preparation of (188Re) Re-AEDP and its biodistribution studies

The synthesis of the Re (V) complex and preparation of 188Re-AEDP are described using 188Re which was obtained from the alumina-based 188W/188Re generator. Dependence of the radiolabeling yields of 188Re-AEDP on reducing agent concentration, AEDP concentration, pH and addition of carrier was examined. In the case of optimum conditions, the radiolabeling yields of 188Re-AEDP were 92-93% for carrier-free 188Re and 95-98% for carrier-added 188Re. The stability of 188Re-AEDP at pH approximately 6 was studied and it is found that the carrier has a significant effect on the stability of 188Re-AEDP. The biodistribution of carrier-free and carrier-added 188Re-labelled compounds in rats was also measured. The results show that 188Re (carrier-added)-AEDP is a potential bone palliation radiopharmaceutical due to its high skeletal uptake, rapid blood clearance and relatively low soft tissue absorption.

Highly sensitive biosensors based on water-soluble conjugated polymers

Conjugated, conductive polymers are a kind of important organic macromolecules, which has found applications in a variety of areas. The application of conjugated polymers in developing fluorescent biosensors represents the merge of polymer sciences and biological sciences. Conjugated polymers are very good light harvesters as well as fluorescent polymers, and they are also “molecular wires”. Through elaborate designs, these important features, i.e. efficient light harvesting and electron/energy transfer, can be used as signal amplification in fluorescent biosensors. This might significantly improve the sensitivity of conjugated polymer-based biosensors. In this article, we reviewed the application of conjugated polymers, via either electron transfer or energy transfer, to detections of gene targets, antibodies or enzymes. We also reviewed recent efforts in conjugated polymer-based solid-state sensor designs as well as chip-based multiple target detection. Possible directions in this conjugated polymer-based biosensor area are also discussed.

Mass yield distributions of target fragments from the reactions of iron with 135 MeV/nucleon 12C and 80 MeV/nucleon 16O ions

Abstract: Cross sections for the production of target fragments in the reactions of iron with 135 MeV/nucleon 12C and 80 MeV/nucleon 16O ions have been measured by off-line γ-ray spectroscopy. Through these data, the mass yield distributions have been obtained. The result of the experiment for the reaction with 135 MeV/nucleon 12C ions is compared with theoretical calculations using the fusion-fragmentation model and the GEMINI code for sequential binary decay, following a calculation with the fireball model.

Terahertz Spectroscopy of Furosemide

Low frequency vibrational modes of furosemide were measured with terahertz time domain spectroscopy at room temperature. The different crystalline forms of furosemide were also measured. A clear difference between their spectra was observed. This makes the identification of polymorphs of furosemide easy and quick.