High-Yield 99mTc Labeling of Gold Nanoparticles Carrying Atropine and Adrenaline.

This work focuses on the synthesis, purification, and analytical characterization of novel multifunctional Au NPs radiolabeled with 99mTc. These mixed-ligand shell Au NPs represent pharmacologically relevant samples for potential application in theragnostics. A ligand using a plain linker with a rather long chain consisting of 10 CH2 groups and a thiol moiety along with the PADA chelator has been used for both the attachment to the Au NP surface and for the 99mTc(CO)3+ complexation. We have combined this with our approach of stabilizing Au NP without any PEG or other stabilizing groups. Thus, monoligand shell Au NPs were radiolabeled by different strategies (prelabeling and postlabeling). Additionally, pharmacologically relevant Au NPs were synthesized carrying both a biofunctionalization with either atropine or adrenaline and the 99mTc radiolabel. All samples were obtained in very good yields (up to 80% of the total activity loaded onto the column) and completely/particularly purified using desalting columns. Detailed analytical characterization of the Au NPs before and after radiolabeling has proven the NPs' robustness throughout the process. Their intact functionalization, shape, and stability was confirmed by transmission electron microscopy (TEM), ultraviolet/visible (UV/vis) spectroscopy, dynamic light scattering (DLS), and infrared (IR) spectroscopy. The presented strategy represents a versatile building block system that can be adapted to a variety of bioactive molecules and may be of high relevance for theragnostic applications.

Stabilizing Superacid Anions: The New [H(S4 O13 )2 ]3- Anion in the Crystal Structure of Li3 [H(S4 O13 )2 ].

The unique hydrogenium-bis-tetrasulfate anion [H(S4 O13 )2 ]3- in the crystal structure of Li3 [H(S4 O13 )2 ] (monoclinic, P21 /n (No. 14), Z=2, a=552.46(4) pm, b=939.70(6) pm, c=1876.6(1) pm, ß=97.492(3)°, V=965.9(1)⋅106  pm3 ) is the longest protonated polysulfate chain ever observed. Very strong symmetrical hydrogen bonds are a bold feature of the crystal structure. The protonation of a very weak base such as [S4 O13 ]2- and accordingly the stabilization of the first base of the superacid H2 S4 O13 is a significant success towards the still elusive polysulfuric acids.