Steroid-Based Liquid Crystalline Polymers: Responsive and Biocompatible Materials of the Future

Steroid-based liquid crystal polymers and co-polymers have come a long way, with new and significant advances being made every year. This paper reviews some of the recent key developments in steroid-based liquid crystal polymers and co-polymers. It covers the structure–property relationship between cholesterol and sterol-based compounds and their corresponding polymers, and the influence of chemical structure and synthesis conditions on the liquid crystalline behaviour. An overview of the nature of self-assembly of these materials in solvents and through polymerisation is given. The role of liquid crystalline properties in the applications of these materials, in the creation of nano-objects, drug delivery and biomedicine and photonic and electronic devices, is discussed.

Topological Glycopolymers as Agglutinator and Inhibitor: Cyclic versus Linear

Carbohydrates play an important role in biological processes for their specific interactions with proteins. Cyclic glycopolymers are promising to mimic the topology of natural macrocycle-biomacromolecules due to their unique architecture of lacking chain ends. To systematically study the effect of glycopolymer architecture on the interactions with protein, the cyclic glycopolymers bearing galactose side-chain (cyclic PMAG_n ) with three degrees of polymerization (n = 14, 24, 47) are prepared for the first time. The cyclic PMAG_n exhibits unique properties in agglutinating and inhibiting proteins in subsequent studies by comparison with the linear precursor with the same molecular weights. More impressively, the cyclic PMAG_n highlight the improved performance of cyclic architecture. For example, the cyclic PMAG_n shows superior inhibition abilities to suppress amyloid formation from amyloid β protein fragment 1-42 aggregation and block the specific interaction between bacteria and galactose-modified surface compared to that of respective linear counterpart. This interesting finding suggests that the architecture of cyclic glycopolymers may be capable of optimizing the ability to bind or inhibit proteins in biological processes.

A sulfur(vi) fluoride exchange click chemistry approach towards main chain liquid crystal polymers bearing sulfate ester groups

Here we report a sulfur(vi) fluoride exchange click chemistry approach towards the synthesis of main chain liquid crystal polymers.

Self-organization of cholesterol-side-chain liquid crystalline polymers by tailoring the main chain structure and flexible spacer length

Liquid crystal polymers with cholesterol side-chains formed different smectic A phases under the influence of the main-chain structure and flexible spacer length.

Cooperation of Amphiphilicity and Smectic Order in Regulating the Self-Assembly of Cholesterol-Functionalized Brush-Like Block Copolymers

Nanoparticle morphology significantly affects the application of nanometer-scale materials. Understanding nanoparticle formation mechanisms and directing morphological control in nanoparticle self-assembly processes have received wide attention. Herein, a series of brush-like amphiphilic liquid crystalline block copolymers, PChEMA _m- b-POEGMA _n, containing cholesteryl mesogens with different hydrophobic/hydrophilic block ratios were designed and synthesized. The self-assembly behaviors of the resulting PChEMA _m- b-POEGMA _n block copolymers in different solvents (tetrahydrofuran/H₂O, 1,4-dioxane/H₂O, and N, N-dimethylformamide) were investigated in detail. Desirable micellar aggregates with well-organized architectures, including short cylindrical micelles, nanofibers, fringed platelets, and ellipsoidal vesicles with smectic micellar cores, were observed in 1,4-dioxane/H₂O with an increasing hydrophobic block ratio. Although both amphiphilicity and smectic order governed the self-assembly, these two factors were differently balanced in the different solvents. This unique supramolecular system provides a new strategy for the design of advanced functional nanomaterials with tunable morphologies.

Self-assembly of amphiphilic macrocycles containing polymeric liquid crystal grafts in solution

Amphiphilic macrocycles containing polymeric liquid crystal side-chains are synthesized facilely, and the topological effects on their solution self-assembly behaviors are investigated, compared with their linear analogues.

Cyclic polymers with pendant triphenylene discogens: convenient synthesis and topological effect on thermotropic liquid crystal behavior and fluorescence enhancement

Cyclic topological constraint suppresses columnar ordering while showing remarkably enhanced fluorescence as a supplement of aggregation-induced emission (AIE).