Lupeol-3-carbamate Derivatives: Synthesis and Biological Evaluation as Potential Antitumor Agents.

In the following study, a series of new lupeol-3-carbamate derivatives were synthesized, and the structures of all the newly derived compounds were characterized. The new compounds were screened to determine their anti-proliferative activity against human lung cancer cell line A549, human liver cancer cell line HepG2, and human breast cancer cell line MCF-7. Most of the compounds were found to show better anti-proliferative activity in vitro than lupeol.

Anthraquinodimethane-Based Molecular Switches Tethered by Four-Arm Star-like Polymers.

Molecular switches that reversibly change their structures and physical properties are important for applications such as sensing and information processing at molecular scales. In order to avoid the intermolecular aggregation that is often detrimental to the stimuli-responses of molecular switches, previous studies of molecular switches have been often conducted in dilute solutions which are difficult for applications in solid-state devices. Here we report molecular design and synthesis that integrates anthraquinodimethane as molecular switching units into polymers with amenable processibility in solid states.

Lewis Pair-Mediated Surface-Initiated Polymerization.

We present the first example of surface-initiated polymerization mediated by Lewis pairs for the synthesis of polymer brushes on planar substrates. The method enables the rapid grafting polymerization from the self-assembled monolayer or surface-attached macroinitiators, furnishing linear polymer brushes and bottle-brush brushes. Both homopolyester and block copolyester brushes can be synthesized via this versatile approach.

Controlled Growth of Metal-Organic Frameworks on Polymer Brushes.

Polymer brushes are for the first time used to induce the synthesis of metal-organic frameworks (MOFs). The semi-fixed polymer chains provide a confined environment, which allows a mild growth of MOFs in between polymer chains to give surface-attached spherical MOF nanoparticles, in contrast to the larger MOF cubes/plates formed simultaneously in solution. Polymer brushes bearing carboxylate acid functionalities are indispensable for the formation of surface bound MOFs, while no MOF nanoparticles are observed on neutral polymer brushes.

Indocyanine green-functionalized bottle brushes of poly(2-oxazoline) on cellulose nanocrystals for photothermal cancer therapy.

Deriving from the most abundant and renewable material, cellulose nanocrystals (CNCs) have drawn increasing attention in nanomedicine as well as other biomedical fields due to their excellent physicochemical properties and unique rod-like geometry. In this work, we report an efficient procedure to create biocompatible poly(2-oxazoline)s with a defined bottle brush architecture on CNCs through UV-induced photopolymerization and subsequent living cationic ring-opening polymerization. Characterization of the poly(2-oxazoline) modified CNCs indicates an improved thermal stability with the crystalline structure as well as the rod-like contour intact.

Polymer brushes on planar TiO2 substrates.

A facile and universal method is presented for the preparation of polymer brushes on amorphous TiO2 film. Homogeneous and stable poly(methyl methacrylate), polystyrene, poly(4-vinylpyridine), and poly(N-vinyl imidazole) (PNVI) brushes up to 550 nm are directly created onto TiO2 via UV-induced photopolymerization of corresponding monomers. Kinetic studies reveal a linear increase in thickness with the polymerization time.