On the Role of Block Copolymers in Self-Assembly of Dense Colloidal Polymeric Systems

Micellar catalysts with a switchable core are attractive materials in organic synthesis. However, little is known about the role of the shell forming block on the performance of the catalyst. Thermoresponsive block copolymers based on poly(N-isopropylacrylamide-co-vinyl-4,4-dimethylazlactone) attached to different permanently hydrophilic blocks, namely poly(ethylene glycol), poly(N,N-dimethylacrylamide), and poly(2,3-dihydroxypropyl acrylate), were successfully synthesized via reversible addition/fragmentation chain transfer radical polymerization (RAFT). Post-polymerization attachment of an amino-functionalized L-prolineamide using the azlactone ring-opening reaction afforded functionalized thermoresponsive block copolymers. Temperature-induced aggregation of the functionalized block copolymers was studied using dynamic light scattering. It was shown that the chemical structure of the permanently hydrophilic block significantly affected the size of the polymer self-assemblies. The functionalized block copolymers were subjected to an aldol reaction between p-nitrobenzaldehyde and cyclohexanone in water. Upon temperature-induced aggregation, an increase in conversion was observed. The enantioselectivity of the polymer-bound organocatalyst improved with an increasing hydrophilic/hydrophobic interface as a result of the different stability of the polymer aggregates.

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The role of cooling rate in crystallization-driven block copolymer self-assembly

Chemical Science ◽

10.1039/d1sc05937h ◽

2021 ◽

Author(s):

Shaofei Song ◽

Jingjie Jiang ◽

Ehsan Nikbin ◽

Jane Howe ◽

Ian Manners ◽

...

Keyword(s):

Block Copolymer ◽

Block Copolymers ◽

Cooling Rate ◽

Self Assembly ◽

Selective Solvents

Self-assembly of crystalline-coil block copolymers (BCPs) in selective solvents is often carried out by heating the mixture until the sample appears to dissolve and then allowing the solution to cool...

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The cyclodextrin inclusion complex-containing biodegradable polymeric systems as drug carrier

Journal of Science and Technology Issue on Information and Communications Technology ◽

10.31130/jst-ud2019-084e ◽

2019 ◽

Vol 17 (6) ◽

pp. 61

Author(s):

Trâm Trương Lê Bích

Keyword(s):

Block Copolymers ◽

Self Assembly ◽

Laser Scanning ◽

Drug Carrier ◽

Drug Carriers ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Hep G2 ◽

Polymeric Systems ◽

Vis Spectroscopy

This article shows that the supramolecular micelle assemblies from PCL-b-P4VP block copolymers with α-CD via self-assembly of inclusion complexes in an aqueous solution. Dox encapsulation and the release at different pH of supramolecular micelle assemblies from poly (ε-caprolactone-block-4-vinylpyridine) (PCL-b-P4VP) block copolymers with α-CD showed excellent cytocompatibility. Dox was successfully loaded into the micelles with a loading content of 14.4% and loading efficiency of 28.9% by using UV-Vis spectroscopy (UV). The Dox loaded micelles showed lower cytotoxicity than free drugs, and could efficiently deliver and release the drug into human hepatocellular carcinoma (Hep-G2) cells as confirmed by confocal laser scanning microscopy (CLSM). These properties make the polymer micelles attractive as drug carriers for pharmaceutical applications.

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Self-Assembly of Hydrogels From Elastin-Mimetic Block Copolymers

MRS Proceedings ◽

10.1557/proc-724-n8.1 ◽

2002 ◽

Vol 724 ◽

Author(s):

Elizabeth R. Wright ◽

R. Andrew McMillan ◽

Alan Cooper ◽

Robert P. Apkarian ◽

Vincent P. Conticello

Keyword(s):

Block Copolymers ◽

Self Assembly ◽

Triblock Copolymers ◽

Variable Temperature ◽

Inverse Temperature ◽

Temperature Transition ◽

Scanning Calorimetry ◽

Design Synthesis ◽

Inverse Temperature Transition ◽

Functional Biomaterials

AbstractTriblock copolymers have traditionally been synthesized with conventional organic components. However, triblock copolymers could be synthesized by the incorporation of two incompatible protein-based polymers. The polypeptides would differ in their hydrophobicity and confer unique physiochemical properties to the resultant materials. One protein-based polymer, based on a sequence of native elastin, that has been utilized in the synthesis of biomaterials is poly (Valine-Proline-Glycine-ValineGlycine) or poly(VPGVG) [1]. This polypeptide has been shown to have an inverse temperature transition that can be adjusted by non-conservative amino acid substitutions in the fourth position [2]. By combining polypeptide blocks with different inverse temperature transition values due to hydrophobicity differences, we expect to produce amphiphilic polypeptides capable of self-assembly into hydrogels. Our research examines the design, synthesis and characterization of elastin-mimetic block copolymers as functional biomaterials. The methods that are used for the characterization include variable temperature 1D and 2D High-Resolution-NMR, cryo-High Resolutions Scanning Electron Microscopy and Differential Scanning Calorimetry.

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Self-Assembly of Rod-Coil Block Copolymers.

10.21236/ada366979 ◽

1999 ◽

Cited By ~ 1

Author(s):

S. A. Jenekhe ◽

X. L. Chen

Keyword(s):

Block Copolymers ◽

Self Assembly

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Directive Effect of Chain Length in Modulating Peptide Nano-assemblies

Protein and Peptide Letters ◽

10.2174/0929866527666200224114627 ◽

2020 ◽

Vol 27 (9) ◽

pp. 923-929

Author(s):

Gaurav Pandey ◽

Prem Prakash Das ◽

Vibin Ramakrishnan

Keyword(s):

Electron Microscopy ◽

Amino Acids ◽

Light Scattering ◽

Chain Length ◽

Self Assembly ◽

The Self ◽

Ionic Charge ◽

Self Assembling ◽

Biophysical Techniques

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.

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