Programmed disassembly of supramolecular nanoparticles stabilized by heteroternary CB[8] host-guest interactions

Controlled release is an important determinant of the in-vivo performance of drug delivering nanoparticles (NPs). Therefore the control over and understanding of the release mechanism, e.g. by disassembly or degradation of the carrier, is essential for the optimization of NP formulations. This paper presents a supramolecular toolbox approach for the formation and UV-induced disassembly of supramolecular nanoparticles (SNPs) which are either exclusively stabilized by cucurbit[8]uril (CB[8])/methyl viologen (MV)/azobenzene (Azo) interactions or CB[8]/MV/naphthol (Np) interactions, or by a combination of both. Photoisomerization of the Azo units enables UV-triggered disassembly of the CB[8]/MV/Azo host-guest complex. Depending on the valency of the electron-rich guest moieties (Np or Azo), either SNPs with a UV-responsive shell or a UV-responsive core were formed by assembling SNPs using a mixture of Azo and Np bearing guest molecules. In contrast, non-responsive SNPs or SNPs which disintegrate at both the core and the shell were formed by using exclusively CB[8]/MV/Np or CB[8]/MV/Azo interactions, respectively. (C) 2015 Elsevier B.V. All rights reserved.