Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Polyion complex (PIC) formation is one of the most powerful techniques for obtaining molecular self-assemblies in aqueous media, and useful for material syntheses particularly in the biomedical field. In this review article, recent progress on PIC vesicles (PICsomes) is summarized. PICsomes are characterized by their simple preparation, semipermeability and environment-sensitivity. Very recently, the methods to control structural uniformity and size of the vesicles have been established, and the potential utility of PICsomes has been expanded by crosslinking their PIC layers. In addition, the unique dynamic nature of PICs is also described.
The morphology and the electronic conductive properties of self-assembled monolayers formed by helical oligopeptides suitably functionalized with electro- and photoactive units were investigated by electrochemical, spectroscopic and atomic force microscopy techniques. The versatility of peptide building blocks was also highlighted by the formation of bicomponent self-assembled monolayers exploiting interchain dipole–dipole interactions.
The recent progress of research on polymer reactions utilizing dynamic covalent exchanges of alkoxyamine units—adducts of styryl and stable nitroxide radicals—is reviewed. Various types of macromolecular design, polymer reactions based on dynamic covalent exchanges of alkoxyamine units and their related research are described. Various examples of polymer reactions of main-chain-type, side-chain-type, crosslinked and star-shaped poly(alkoxyamine)s are systematically shown. The progress of the polymer reactions can be confirmed by diverse characterization techniques, such as spectroscopic, chromatographic, microscopic and scattering methods.
Theranostic agents based on nanovectors (liposomes, naposomes, micelles, polymeric micelles and micelles built around a solid core) able to carry, simultaneously, a drug and a contrast agent and externally modified with targeting peptides are described.
A number of biomaterials have been proposed, including hydrophilic, phase-separated and zwitterionic polymers. It has not been clearly elucidated which mechanisms are responsible for biocompatibility on a molecular level. Water interactions have been recognized as a fundamental part of the biological response to contact with biomaterials. We have proposed the ‘intermediate water’ concept; the water exhibited both clear peak for cold crystallization in differential scanning calorimetry chart and a strong peak at 3400 cm−1 in a time-resolved infrared spectrum. We found the localized hydration structure consisting of the three hydrated water in poly(2-methoxyethyl acrylate) (PMEA).
Isolated molecules of cyclic polymers were directly observed by atomic force microscopy. Interdiffusion of cyclic polystyrene/cyclic deuterated polystyrene bilayer films were investigated as functions of temperature and molecular weight by dynamic secondary ion mass spectroscopy.
