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.

Organic solids and polymers that absorb in the near-infrared (NIR) region (1000-2000 nm) represent a class of emerging materials and show a great potential for use in photonics and telecommunications. The radical anions of stacked aromatic imides, fused phorphyrin arrays, polythiophenes, sandwich-type lanthanide bisphthalocyanines, semiquinones, and mixed-valence dinuclear metal complexes are a few known examples of NIR-absorbing organic materials. Most of these NIR-absorbing materials are also electrochemically active or electrochromic (EC). This brief review covers several types of NIR-absorbing organic materials and discusses their potentials for applications in EC variable optical attenuators (VOAs).

Novel cross-linkable, highly fluorinated poly(arylene ether ketones/sulfones) have been prepared by copolycondensation reactions of perfluorinated aromatic ketone/sulfone with 4,4′-(hexafluoroisopropylidene)diphenol and a tetrafluorostyrol-containing bisphenol (i.e., 1,1-bis(4-hydroxyphenyl)ethyl-1-phenyl 2,3,5,6-tetrafluorostyrol ether). The reactions were conducted at low temperature in the presence of calcium hydride and cesium fluoride. The resulting polymers have number-average molecular weights in the range of 25 000-36 000, excellent solubilities in common organic solvents, high glass transition temperatures (T g ) in the region of 150-185 °C, and good thermal stabilities (T d up to 480 °C). Tough, flexible, and transparent thin films of these polymers can be readily prepared by both solution casting and spin-coating. By adjusting the feed ratio of monomers, the refractive index and cross-linking density of the polymers can be readily controlled. Cross-linking of these polymers has been demonstrated by both thermal heating and UV irradiation. The cross-linked polymer thin films exhibit low optical loss (∼0.5 dB/cm) and low birefringence (∼2 × 10 -3 ) at 1550 nm, demonstrating that they are promising candidates for optical waveguide materials.