Form Matters: Stable Helical Foldamers Preferentially Target Human Monocytes and Granulocytes

Abstract

Some hybrid foldamers of various length, all containing the (4R,5S)-4-carboxy-5-methyloxazolidin-2-one (d-Oxd) moiety alternating with an l-amino acid (l-Val, l-Lys, or l-Ala), were prepared in order to study their preferred conformations and to evaluate their biological activity. Surprisingly, only the longer oligomers containing l-Ala fold into well-established helices, whereas all the other oligomers give partially unfolded turn structures. Nevertheless, they all show good biocompatibility, with no detrimental effects up to 64 μm. After equipping some selected foldamers with the fluorescent tag rhodamine B, a quantitative analysis was performed by dose- and time-response fluorescence-activated cell sorting (FACS) assays with human HeLa cells and primary blood lymphocytes, granulocytes, and monocytes. Among the cell types analyzed, the oligomers associated with monocytes and granulocytes with greatest efficacy, still visible after 24 h incubation. This effect is even more pronounced for foldamers that are able to form stable helices.

New Material Perspective for Waste Seashells by Covalent Functionalization

“…This material was used as a control instead of synthetic/geogenic CaCO 3 since (i) it had exactly the same elemental composition, (ii) the same particle size distribution is not obtainable with synthetic/geogenic CaCO 3 , and (iii) it has been reported that the synthetic/geogenic CaCO 3 has higher chemical stability and lower porosity than the biogenic one. , It was also decided not to use oyster powder as a control after the heat treatment that removes the organic matrix, as this process generates additional porosity . Subsequently, the coupling reaction of Rho-B piperazine (Figure , detailed procedure in SI) with oyster shell particles was set up following an optimized experimental procedure. , Our idea was to form a peptide bond between the free amine group of the Rho-B piperazine (using piperazine as a linker) and the exposed carboxyl groups of the protein, mostly due to the presence of glutamic and aspartic acid moieties.…”

“…25 Subsequently, the coupling reaction of Rho-B piperazine (Figure 2, detailed procedure in SI) with oyster shell particles was set up following an optimized experimental procedure. 26,27 Our idea was to form a peptide bond between the free amine group of the Rho-B piperazine (using piperazine as a linker) and the exposed carboxyl groups of the protein, mostly due to the presence of glutamic and aspartic acid moieties.…”