4582-21-2Relevant articles and documents
Hierarchical nanostructures in semifluorinated norbornene block copolymers
Pulamagatta,Pankaj,Beiner,Binder
, p. 958 - 965 (2011)
Structure and dynamics of two microphase-separated norbornene block copolymers containing one comb-like component are investigated by X-ray scattering, relaxation spectroscopy as well as differential scanning calorimetry. It is shown that two self-assembling processes on different length scales coexist for these copolymers leading to hierarchically structured systems. Microphase separation of both block copolymer components appears on a scale of 20-25 nm while norbornene main and long semifluorinated side chains of the comb-like block nanophase separate within their domains on a scale of about 3 nm. This hierarchical structure is accompanied by a complex relaxation behavior which is characterized by two glass transitions. The glass temperature of the block with long bulky side chains is expectedly lower due to internal plasticization. An additional relaxation process showing typical features of a dynamic glass transition is related to an independent dynamics in small nanodomains formed by long aggregated side chains similar to the findings for many other comb-like polymers. Indications for the disappearance of the nanophase separation of main and semifluorinated side chains at high temperatures are discussed.
Natural Triterpenoid- and Oligo(Ethylene Glycol)-Pendant-Containing Block and Random Copolymers: Aggregation and pH-Controlled Release
Li, Ying,Gao, Yuxia,Wang, Bo,Hao, Jie,Hu, Jun,Ju, Yong
supporting information, p. 2723 - 2729 (2018/09/06)
In this research, a series of random and block amphiphilic copolymers of norbornene derivatives containing biocompatible natural triterpenoid and oligo(ethylene glycol) pendants were synthesized by ring-opening metathesis polymerization. These copolymers were heat and pH responsive, and could self-assemble into core–shell spherical micelles in aqueous solution. Their hydrodynamic diameters corresponded to pH values and monomer sequences. By evaluating the loading and release capacity of hydrophobic molecules, it was found that 1) the higher the content of the hydrophobic triterpenoid, the higher the loading capacity; 2) the release speed could be trigged by the pH because of the deprotonation of the carboxyl groups on the triterpenoid. Additionally, the copolymers exhibited low cytotoxicity toward L929 cells, which makes them potential nanocarrier candidates for controlled drug delivery.
Cyclopentanedi- and tricarboxylic acids as squalene synthase inhibitors: Syntheses and evaluation
Shen, Wang,Garvey, David S.,Cohen, Jerry,Stein, Herman,Rosenberg, Saul H.
, p. 891 - 896 (2007/10/03)
Based on earlier lead squalene synthase inhibitor A-87049 (3) and zaragozic acids, a series of cyclopentanedi- and tricarboxylic acids were synthesized and evaluated against the enzyme. Some exhibited good potency and SAR revealed the importance of conformation and substitution pattern of these synthetic inhibitors.
