The fusion mechanism of small polymersomes formed by rod-coil diblock copolymers.

The fusion mechanism of polymersomes self-assembled by rod-coil copolymers is intrinsically different from that of liposomes due to the effect of chain topology on conformational entropy and molecular packing. The influences of membrane tension, coil-block length, rod-block length, mutual compatibility between the solvent and the rod-coil block, and π-π interaction strength on the fusion pathway are explored by dissipative particle dynamics. The fusion process of spontaneously formed polymersomes generally consists of four stages.

Self-assembled polymersomes formed by symmetric, asymmetric and side-chain-tethered coil-rod-coil triblock copolymers.

Self-assembly behaviors of coil-rod-coil copolymers in selective solvents are explored by dissipative particle dynamics. The morphological phase diagram as a function of rod length and coil length shows five distinct types of aggregates, including spherical micelles, worm-like micelles, disk-like aggregates, honeycomb structures, and polymersomes. Small polymersomes are formed at rather poor alignment associated with monolayered rod domains.

Effect of grafting architecture on the surfactant-like behavior of clay-poly(NiPAAm) nanohybrids.

A new class of clay-polymer nanohybrids was synthesized by grafting poly(N-isopropylacrylamide) (PNiPAAm) on the edge of nanoscale silicate platelets (NSPs) through covalently bonded linkers to form various architectures. The inherent ionic character of NSPs and the organic moieties of isopropyl amide in PNiPAAms impart surface active properties to the nanohybrids. Surface tension and particle size measurements were used to determine the critical micelle concentrations (CMCs) of the nanohybrids.

Effects of molecular architectures and solvophobic additives on the aggregative properties of polymeric surfactants.

The aggregative behavior of the polymeric surfactants with various molecular architectures in dilute solutions is studied by dissipative particle dynamics. The effects of the solvophobic/solvophilic length, polymeric architecture (linear, star, dendritic, and cyclic type), chain rigidity, and solvophobic additives on the critical micelle concentration (CMC) and the aggregative patterns are systematically investigated. It is found that molecular architectures have a noteworthy impact on the aggregative properties.

SAR studies of 3-cyclopropanecarbonyloxy-2-cyclohexen-1-one as inhibitors of 4-hydroxyphenylpyruvate dioxygenase.

Various 3-cyclopropanecarbonyloxy-2-cyclohexen-1-one 1 derivatives have been synthesized and tested as inhibitors of 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) from pig liver. The inhibition results indicated that well-positioned dicarbonyl groups as well as the cyclopropyl group of 1 were essential for potent inhibition. Substitution at the 2-position of the ring system has a significant effect on inhibitor potency, while the 5-position can undergo substantial variations and retain inhibitor potency.