Yumei Shen

Synthesis, Biodistribution, and Microsingle Photon Emission Computed Tomography (SPECT) Imaging Study of Technetium-99m Labeled PEGylated Dendrimer Poly(amidoamine) (PAMAM)-Folic Acid Conjugates

Three conjugates based on dendrimer PAMAM generation five were synthesized and radiolabeled successfully. To investigate their tumor targeting, the in vitro and in vivo stability, cell uptake, in vivo biodistribution, and micro-SPECT imaging were evaluated, respectively. The conjugate of (99m)Tc labeled PEGylated dendrimer PAMAM folic acid conjugate ((99m)Tc-G5-Ac-pegFA-DTPA) shows much higher uptake in KB cancer cells and accumulated more in the tumor area than that of the other two conjugates. The uptake in KB cells depends on the incubation time. The results of in vivo biodistribution agree with the data obtained from micro-SPECT imaging. These studies show that PEGylation of PAMAM dendrimer folic acid conjugate improves the tumor targeting. Folate-conjugated dendrimer maybe developed to be potential radiopharmaceuticals and targeted drug delivery systems.

Radiosynthesis and micro-SPECT imaging of 99mTc-dendrimer poly(amido)-amine folic acid conjugate

Acetylated (Ac) dendrimer poly(amido)-amine (PAMAM) generation 5 (G5) reacted with folic acid (FA), followed by reacting with 2-(p-isothiocyanatobenzyl)-6-methyl-diethylenetria minepentaacetic acid (1B4M DTPA) to form the conjugate of Ac-G5-FA-1B4M DTPA which was further radiolabeled with (99m)Tc. The radiochemical yield is up to 98.9% with excellent in vitro/in vivo stability, rapid blood clearance and certain tumor accumulation which was further confirmed by micro-SPECT imaging study.

Synthesis and in vitro anti-proliferative activity of β-elemene monosubstituted derivatives in HeLa cells mediated through arrest of cell cycle at the G1 phase

Beta-elemene monosubstituted amine, ether and rhenium coordinated complex were synthesized. Their structures were characterized by IR, (1)H NMR, (13)C NMR, HRMS or EA. Their IC(50) on HeLa cell lines, cell cycle and protein expression of G(1) phase (Cyclin D(1), Rb, P-Rb) were detected respectively by the method of WST-1, Flow Cytometry and Western Blot. The Results showed that the in vitro anti-proliferative activity of beta-elemene monosubstituted amine and Re(CO)(3)-beta-elemene derivatives in human cervix epitheloid carcinoma HeLa cells were improved significantly compared with both of ether derivatives and parent beta-elemene. These derivatives could reduce Rb phosphorylation and cyclin D(1) protein expression to arrest the cell cycle at G(1) phase.

Design, synthesis, and evaluation of cyclofenil derivatives for potential SPECT imaging agents

To develop technetium- and rhenium-labeled nonsteroidal estrogen imaging agents for estrogen receptor (ER) positive breast tumors, two groups of rhenium and technetium cyclofenil derivatives were synthesized and characterized. The binding affinities of the rhenium complexes for ERs were determined. The tricarbonyl rhenium complex showed the highest binding affinity for ERs (81.2 for ERβ, 16.5 for ERα). Tricarbonyl technetium cyclofenil complexes were obtained in high radiochemical purity and radiochemical yields. The results of studies of their octanol/water partition and in vitro stability are presented. These results demonstrate that these radiolabeled cyclofenil derivatives may be considered as potential breast cancer imaging agents.

Synthesis and 188Re Radiolabelling of Dendrimer Polyamide Amine (PAMAM) Folic Acid Conjugate

Folic acid receptors (FR) are usually over expressed in many cancer cells and are considered as potential targeted therapy agent. Generation of five polyamido amine (PAMAM) dendrimer folic acid conjugate was synthesised and radiolabelled with (188)Re, furthermore the in vitro/in vivo stability was evaluated accordingly. The labelling yield of the conjugate G5-FA-DTPA-(188)Re was 67.1% and its radiochemical purity exceeded 95%. The conjugate also showed high in vitro stability and potential value for further structure modifications and evaluations.

Practical Synthesis of FEt-penta-cyclofenil and Its Derivatives for Potential PET Imaging

Generally, FEt-penta-cyclofenil and its derivatives have greater relative binding affinity to estradiol receptors than estradiol. (4-Fluoroethoxyphenyl)–(4′-hydroxyphenyl) methylenecyclopentane and its derivatives were synthesized for potential radioactive image agents, and their structures were characterized by ultraviolet, infrared, 1H NMR, 19F NMR, and high-resolution mass spectrometry.

Radioactive synthesis and biodistribution study of β-elemene–99mTc(CO)3 conjugates

Abstractβ-Elemene, (5S,7R,10S)-(−)-(1-methyl-1-vinyl-2,4-diisopropenylcyclohexane), is an anticancer agent from traditional Chinese herbal medicine. Three novel 99mTc(CO)3–β-elemene conjugates were synthesized successfully, and compared with β-elemene exhibited improved water solubility. A biodistribution and micro single photon emission computed tomography image study showed there is a visible accumulation in Lewis lung cancer tumors.