DNA-encoded library (DEL) technology features a time- and cost-effective interrogation format for the discovery of therapeutic candidates in the pharmaceutical industry. To develop DEL platforms, the implementation of water-compatible transformations...
The selective activation of the immune system using nanoparticles as a drug delivery system is a promising field in cancer therapy. Block copolymers from HPMA and laurylmethacrylate‐co‐hymecromone‐methacrylate allow the preparation of multifunctionalized core‐crosslinked micelles of variable size. To activate dendritic cells (DCs) as antigen presenting cells, the carbohydrates mannose and trimannose are introduced into the hydrophilic corona as DC targeting units. To activate DCs, a lipophilic adjuvant (L18‐MDP) is incorporated into the core of the micelles. To elicit an immune response, a model antigen peptide (SIINFEKL) is attached to the polymeric nanoparticle—in addition—via a click reaction with the terminal azide. Thereafter, the differently functionalized micelles are chemically and biologically characterized. While the core‐crosslinked micelles without carbohydrate units are hardly bound by DCs, mannose and trimannose functionalization lead to a strong binding. Flow cytometric analysis and blocking studies employing mannan suggest the requirement of the mannose receptor and DC‐SIGN for effective micelle binding. It could be suppressed by blocking with mannan. Adjuvant‐loaded micelles functionalized with mannose and trimannose activate DCs, and DCs preincubated with antigen‐conjugated micelles induce proliferation of antigen‐specific CD8+ T cells.
The one-pot sulfonylation/aminoalkylation
of styrene derivatives
furnishing substituted γ-sulfonylamines was accomplished through
a photoredox-catalyzed four-component reaction. Besides one molecule
of water and the sodium counterion of the sulfinate, all atoms of
the starting materials are transferred to the final product, rendering
this process highly atom-efficient. The operationally simple protocol
allows for the simultaneous formation of three new single bonds (C–S,
C–N, and C–C) and therefore grants rapid access to structurally
diverse products.
DNA-encoded library (DEL) technology has emerged as a time- and cost-efficient technique for the identification of therapeutic candidates in the pharmaceutical industry. Although several reaction classes have been successfully validated...
An operationally simple, open-air, and efficient light-mediated Minisci C–H alkylation method is described, based on the formation of an electron donor–acceptor (EDA) complex between nitrogen-containing heterocycles and redox-active esters.
A versatile protocol for light induced catalytic activation of thioglycosides using iodine as an inexpensive and readily available photocatalyst was developed. Oxygen serves as a green and cost‐efficient terminal oxidant and irradiation is performed with a common household LED‐bulb. The scope of this glycosylation protocol was investigated in the synthesis of O‐glycosides with yields up to 95 %.
Two hitherto unknown neo-clerodane-type diterpenoids along with twelve known compounds have been isolated from Conyza pyrrhopappa Sch.Bip. ex A.Rich, a medicinal plant traditionally used across tropical Africa to relieve fever. The structures of isolates have been elucidated by a combination of spectroscopic techniques. The crude extract and the isolated compounds were evaluated in the Hela-S3 cell line and in a panel of microorganisms (bacteria and fungi) at concentrations up to 50 µg/mL. The new compounds were inactive while the pentamethylated flavonoids showed low to significant activity against the cancer cell line used. However, none of the samples showed any activity against the tested microorganisms at this concentration. The present manuscript is the first investigation of the cytotoxicity of phytochemicals and extract from C. pyrrhopappa.
Dendritic cells (DCs) are a compelling target in cancer immunotherapy as they initialize strong antigen‐specific immune responses. Drug delivery systems (DDSs) such as liposomes provide the opportunity to deliver antigens and immunostimulatory molecules to DCs, which in turn initiate an antigen‐specific immune response. To address predominantly DCs, DDSs need to be equipped with targeting moieties. This study evaluates liposomes, bearing the oligosaccharide trimannose on their surface, for their ability to address DCs in vitro and in vivo. Trimannose as a saccharidic structure is known to be recognized by receptors on the surface of DCs. To obtain trimannosylated liposomes, azide‐bearing trimannose is coupled to alkyne‐functionalized hyperbranched polyglycerol (hbPG) with a bis(hexadecyl)glycerol (BisHD) anchor in a Cu(I)‐catalyzed alkyne‐azide cycloaddition (CuAAC). To enable tracking of the liposomes in vivo, the trimannosylated BisHD‐hbPG lipids are radiolabeled with 18F in a CuAAC. Subsequently, liposomes are produced via the thin‐film hydration method followed by extrusion. The behavior of the trimannosylated liposomes is evaluated in in vitro cell binding assays and in vivo µPET and ex vivo biodistribution studies in healthy C57BL/6 mice and the results are compared to similar liposomes not bearing trimannose on their surface.
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