NMR insights into dendrimer-based host-guest systems

Applications of various NMR techniques to investigate the host behaviors of different dendrimers were reviewed. Chemical shift titration experiments give information on the types of interactions between dendrimer and guests, and can be used to calculate the binding parameters of the host-guest systems including number of binding sites and binding affinities. NOE analysis provides precise spatial conformations such as the localizations and orientations of the guests within the dendrimer/guest complexes. Diffusion NMR reveals the size of the dendrimer/guest complexes and can be used to predict the supramolecular structure of the dendrimer/surfactant aggregates. Relaxation measurement reflects the mobility and rigidity of the guest molecules bound with dendrimers. Besides, the combination of NOE, diffusion, and STD NMR experiments is successfully used for high-throughput screening dendrimer-binding drugs. NMR techniques also provide precise size information of palladium nanoparticles loaded within dendrimers.