Macromolecular Rapid Communications

Front Cover: Bio-nanocomposite fibers made from a Laponite cross-linked poly (ethylene oxide) hydrogel stretch to extreme lengths and crystallize polymer chains. The fibers provide a matrix for cell proliferation, with cells aligning themselves along the fiber axis. Further information can be found in the article by A. K. Gaharwar, P. J. Schexnailder, A. Dundigalla, J. D. White, C. R. Matos-Pérez, J. L. Cloud, S. Seifert, J. J. Wilker, G. Schmidt^*on page 50.

The cell uptake and trafficking properties of a series of non-covalent, coiled-coil based polymer–drug conjugates are studied. These therapeutics consist of a biocompatible, synthetic polymer carrier modified with peptide sequences that selectively heterodimerize with a complementary peptide sequence carrying a cargo molecule. From cytotoxicity and FACS experiments insight into the cell uptake and trafficking behavior of these nanomedicines was obtained.

Polymeric nanoparticles consisting of a hydrophobic core and a PEGylated corona bearing an NHS-ester at its periphery are synthesized. The integrity of the activated esters is evidenced during the different synthetic steps. The reactivity towards amine moieties is demonstrated both qualitatively and quantitatively by the reaction of the nanoparticles with a fluorescent dye.

Electrochemical template synthesis is a powerful technique for the fabrication of a large variety of single component and multi-segmented conducting polymer-based nanowires with precise control over lengths and diameters. This feature article provides an overview on the most significant works in this area and gives an insight into future developments for engineering multifunctional nanowires for a wide range of applications.

Oligomers of aniline have recently emerged as flexible building blocks for various nanostructures and as an important mediator in orchestrating nanostructure formation for conducting polymers. In this Feature Article, the role of oligomeric species in the synthesis, assembly, and applications of such nanomaterials are highlighted.

A fibrous material generated from a nanoplatelet cross-linked poly(ethylene oxide) hydrogel with extreme extensibility. The fibers provide a matrix for cell proliferation, with growth on the fiber surfaces and cells aligning themselves along the fiber axis.

A new photoinduced controlled radical polymerization which is mainly based on photochemical generation of activator in the atom transfer radical polymerization was described. The system can be initiated by in situ generation of copper (I) complex from higher oxidation state species by light without using any reducing agent at room temperature. This strategy may open a new pathway for the synthesis of many nano-structured materials such as well-defined components of coatings, gels and hydrogels, molecular hybrids, biomaterials, and electronic materials.

The extent of branching is lower for controlled radical polymerization (CRP) than for conventional free radical polymerization (FRP) because in CRP, the transient life time of the radicals, namely, the time that it takes for a radical to be deactivated by the CRP agent, is similar or even shorter than the characteristic time for the chain transfer to polymer processes. This reduces the likelihood of chain transfer to polymer events.

Poly(N-isopropylacrylamide) (PNIPAM) oligomer containing one adamantyl (AD) and two β-cyclodextrin (β-CD) moieties at the chain terminals, AD-PNIPAM-(β-CD)₂, was synthesized by atom transfer radical polymerization (ATRP) and successive click reactions. In aqueous solution, AD-PNIPAM-(β-CD)₂ spontaneously forms supramolecular thermoresponsive hyperbranched polymers via molecular recognition.

The synthesis of well defined PEO based star-shaped polymers in water is described. Both conventional free radical polymerization and atom transfer radical polymerization techniques were successful for the preparation of uniform star polymers in water using different kinds of arm precursors and cross-linking agents.

A generalized silica coating scheme is used to functionalize and protect micron size monomer-filled capsules and polymer-protected catalyst particles for use in small size-scale self-healing applications. The silica layer adds functionality and protection that allows the capsules and particles to be dispersed at high concentrations with little loss of reactivity. These components are incorporated into epoxy to demonstrate self-healing capability in bulk polymers.

Liquid crystalline (LC) polymers were processed by miniemulsion and subsequent crosslinking into nanometer-sized LC elastomer (LCE) colloids. The shape changing ability of the LCEs was used to induce an overall shape change of the spherical particles into strongly anisotropic nanocolloids.

Greatly enhanced energy density in P(VDF-CTFE) is realized through interface effects induced by a photo cross-linking method. The cross-linked P(VDF-CTFE)s possess high breakdown field as well as remarkably elevated polarization, both of which contribute to the enhanced energy density as high as 22.5 J·cm⁻³. Patterned thin films with various shapes and sizes are fabricated by photolithography, which sheds new light on the integration of PVDF-based electroactive polymers into micro organic electronic devices.

Back Cover: The image schematically depicts the electrochemically template method, a powerful technique used for the fabrication of a large variety of single and multi-component nanowires with precise control over diameters and lengths. The background shows a TEM picture of hybrid nanowires, made of metallic and conducting polymer segments. Further details can be found in the article by V. Callegari and S. Demoustier-Champagne^*on page 25.