Calix[4]arene research points to multifunctional self-assembled molecules

Scientists from the Laboratory of Polymer Composite Materials and the Laboratory of Organic Compounds Research of Kazan Federal University have synthesized amphiphilic dendrimers based on a calix[4]arene platform with the ability to self-organize in aqueous solutions.

The research is conducted as part of the Russian Science Foundation grant "Imidazolium Janus-like dendrimers with macrocyclic nucleus: catalytic systems of multiple use in the 'flask' and in the flow regime for green chemistry", the head of which is Professor of the Department of Organic and Medical Chemistry Igor Antipin. The results are presented in articles published in the Royal Society of Chemistry journals Soft Matter and New Journal of Chemistry.

"Amphiphilic dendrimers attract the attention of scientists due to the fact that such molecules, in addition to the inherent branched tree-like structure of dendrimers, have the ability to self-organize in aqueous solutions with the formation of various nanostructures—from ordinary micelles to liposome-like dendrimersomes," said one of the participants of the study, Professor of the Department of Organic and Medical Chemistry Vladimir Burilov.

The scientists applied an original approach to build these systems. Used as a platform for the creation of amphiphilic dendrimers macrocyclic molecules callixarenes, according to the scientist, allowed not only to synthesize hyperbranched macromolecules, but also to give them the correct configuration in space.

"Our compounds synthesized using click-chemistry methods self-assemble in water to form structured nanosystems that resemble very porous balls, which can act as nanocontainers and can be used for targeted drug delivery in the human body, compression and storage of DNA. In addition, such nanosystems can be used in the catalysis of organic reactions," he emphasized.

The research team synthesized two varieties of amphiphilic dendrimers.

"The journal Soft Matter presents the results of our work on the synthesis of dendrimers based on thiacalix[4]arenes containing positively charged imidazolium groups on the surface. And the article published in the New Journal of Chemistry shows the preparation of amphiphilic dendrimers based on calix[4]arenes of the 1st and 2nd generation, i.e. possessing one or two branching points. Such dendrimers have polar hydroxyl and oxyethyl groups on the surface," informed Burilov.

The scientists have best studied the use of the amphiphilic dendrimers they obtained to stabilize palladium nanoparticles.

"Palladium is the number one metal in all catalytic reactions, it is used everywhere," emphasized Burilov. "Over time, palladium particles stick together and it loses its catalytic activity. Such palladium is called "palladium niello". When we use dendrimers, palladium nanoparticles are very evenly distributed on the "branches" of dendrimers, and there is no sticking, which means that the catalyst will retain its activity longer, and it can be used even in water."

Summarizing the above, Vladimir Burilov emphasized that the amphiphilic dendrimers synthesized at KFU can be used both as an effective organic matrix for the design of catalytically active hybrid materials and for use in biotechnology to create delivery vehicles for hydrophobic drugs or non-viral vectors.

More information:
Multi-functional imidazolium dendrimers based on thiacalix[4]arenes: self-assembly, catalysis and DNA binding
pubs.rsc.org/en/content/articl … g/2024/sm/d4sm00764f

Epichlorohydrin-based CuAAC dendrimers with a calix[4]arene core and polar hydroxyl/oxyethyl terminal groups: synthesis, aggregation and use in catalysis
pubs.rsc.org/en/content/articl … g/2024/nj/d4nj02942a

Provided by Kazan Federal University