ESI MS/MS Study of Calix[4]arene Derivatives and their Metal Complexes

The peptidocalixarenes 1-3 bearing tryptophan, phenylglycine and leucil units at the lower rim and their complexes with alkali-metal (Li+, Na+, K+, Rb+, Cs+) and selected lanthanide cations (La3+, Ce3+, EU3+, Yb3+) were analyzed by ESI MS. The influences of the solvent (acetonitrile, methanol, addition of formic acid or sodium acetate) and the calixarene:cation molar ratio on signal intensities were investigated. Comprehensive MS/MS analyses were performed of all singly and doubly charged ions of 1-3 and their complexes, and fragmentation pathways were proposed. An inductive cleavage was observed during dissociation of protonated ions, while the presence of alkali-metal or lanthanide cations caused homolytic cleavage and formation of radical cations. The results of MS analysis were in accordance with those obtained by other techniques (spectrophotometric, potentiometric, and conductometric titrations). The MS/MS experiments could be used as fast and sensitive method for prediction of relative stabilities of calixarene complexes with metal ions

Adamantane in Drug Delivery Systems and Surface Recognition

The adamantane moiety is widely applied in design and synthesis of new drug delivery systems and in surface recognition studies. This review focuses on liposomes, cyclodextrins, and dendrimers based on or incorporating adamantane derivatives. Our recent concept of adamantane as an anchor in the lipid bilayer of liposomes has promising applications in the field of targeted drug delivery and surface recognition. The results reported here encourage the development of novel adamantane-based structures and self-assembled supramolecular systems for basic chemical investigations as well as for biomedical application

Mannosylated Liposomes with Built-in Peptidoglycan Based Immunomodulators for Subunit Vaccine Formulations

The aim of the present study is preparation of mannosylated liposomes with built-in small molecule immunopotentiators for targeted, receptors mediated, delivery of antigens. The liposomes were mannosylated in two ways, by covalent attachment of p-aminophenyl-α-D-mannopyranoside to the preformed liposomes and by incorporation of synthetic mono-, di- and tetramannosyl-lipoconjugates into the lipid bilayer of liposomes. Four different mannosylated liposome formulations with incorporated model antigen, ovalbumin (OVA), and immunomodulators, PGM and Ad2TP2, were prepared and characterized. The influence of mannosylated liposome formulations on the antigen-specific humoral immune response was investigated. It has been shown that mannosylated liposomal formulations did not enhance the humoral immune response and production of anti-OVA antibodies but they significantly affected the type of OVA specific immune reaction and directed it towards Th1 type. This work is licensed under a Creative Commons Attribution 4.0 International License

Application of functionalized lanthanide-based nanoparticles for the detection of okadaic acid-specific immunoglobulin G

Marine biotoxins are widespread in the environment and impact human health via contaminated shellfish, causing diarrhetic, amnesic, paralytic, or neurotoxic poisoning. In spite of this, methods for determining if poisoning has occurred are limited. We show the development of a simple and sensitive luminescence resonance energy transfer (LRET)-based concept which allows the detection of anti-okadaic acid rabbit polyclonal IgG (mouse monoclonal IgG1) using functionalized lanthanide-based nanoparticles. Upon UV excitation, the functionalized nanoparticles were shown to undergo LRET with fluorophore-labeled anti-okadaic acid antibodies which had been captured and bound by okadaic acid-decorated nanoparticles. The linear dependence of fluorescence emission intensity with antigen−antibody binding events was recorded in the nanomolar to micromolar range, while essentially no LRET signal was detected in the absence of antibody. These results may find applications in new, cheap, and robust sensors for detecting not only immune responses to biotoxins but also a wide range of biomolecules based on antigen−antibody recognition systems. Further, as the system is based on solution chemistry it may be sufficiently simple and versatile to be applied at point-of-care