The incidence of malignant melanoma is rising faster than that of any other cancer in the United States. Due to its high expression on the surface of melanomas, MC1R has been investigated as a target for selective imaging and therapeutic agents against melanoma. Eight ligands were screened against cell lines engineered to over-express MC1R, MC4R or MC5R. Of these, compound 1 (4-phenylbutyryl-His-Dphe-Arg-Trp-NH2) exhibited high (0.2 nM) binding affinity for MC1R, and low (high nM) affinities for MC4R and MC5R. Subsequently functionalization of the ligand at the C-terminus with an alkyne for use in Cu-catalyzed click chemistry was shown not to affect the binding affinity. Finally, formation of the targeted-polymer, as well as the targeted micelle formulation, also resulted in constructs with low nM binding affinity.

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Control of the two strongest upconversion emission lines in NaYF4:Yb3+, Er3+ nanoparticles is demonstrated by varying the excitation repetition rate. This technique may enable new multiplexed sensing modalities based on multicolor luminescent nanoparticles, currently contemplated for biomedical imaging and diagnostics.

Nearly monodisperse lanthanide-doped magnetite nanoparticles were obtained by thermally decomposing a mixture of Fe(acac)(3) and Ln(acac)(3) (acac = acetylacetonate; Ln = Sm, Eu, Gd) in the presence of passivating surfactants. Magnetic studies revealed room-temperature ferromagnetic behaviors of these doped nanoparticles, distinctly different from those of the undoped parent magnetite or the doped nanoparticles prepared by a coprecipitation method.