facile-synthesis-worm-like-micelles-visible-light-mediated-dispersion

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

The University of New South Wales

We present the synthesis and characterisation of naphthalimide-flavin redox sensor 1 (NpFR1), a novel flavin molecule that is almost non-fluorescent in reduced form, but oxidation gives rise to a 125-fold increase in fluorescence. Confocal microscopy experiments confirm that is sensitive to redox changes within living cells.

A novel flavin derivative reveals the impact of glucose on oxidative stress in adipocytes.

We report a versatile synthetic method for the in situ self-assembly of magnetic-nanoparticle-functionalized polymeric nanomorphologies, including spherical micelles and rod-like and worm-like micelles and vesicles. Poly(oligoethylene glycol methacrylate)-block-(methacrylic acid)-block-poly(styrene) (POEGMA-b-PMAA-b-PST) triblock copolymer chains were simultaneously propagated and self-assembled via a polymerization-induced self-assembly (PISA) approach. Subsequently, the carboxylic acid groups in the copolymers were used to complex an iron ion (Fe(II)/Fe(III)) mixture. Iron oxide nanoparticles were then formed in the central block, within the polymeric nanoparticles, via alkaline coprecipitation of the iron(II) and (III) salts. Nanoparticle morphologies, particle sizes, molecular weights, and chemical structures were then characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), size exclusion chromatography (SEC), and (1)H NMR measurements. TEM micrographs showed that the average size of the magnetic nanoparticles was ∼7 nm at the hydrophobic/hydrophilic nexus contained within the nanoparticles. In addition, XRD was used to confirm the formation of iron oxide nanoparticles. Importantly, the polymeric nanoparticle morphologies were not affected by the coprecipitation of the magnetic nanoparticles. The hybrid nanoparticles were then evaluated as negative MRI contrast agents, displaying remarkably high transverse relaxivities (r2, greater than 550 mM(-1) s(-1) at 9.4 T); a result, that we hypothesize, ensues from iron oxide nanoparticle clustering at the hydrophobic-hydrophilic interface. This simple synthetic procedure is highly versatile and produces nanocarriers of tunable size and shape with high efficacy as MRI contrast agents and potential utility as theranostic delivery vectors.

An efficient and highly versatile synthetic route to prepare iron oxide nanoparticles/nanocomposites with tunable morphologies.

Copper-Mediated Living Radical Polymerization (Atom Transfer Radical Polymerization and Copper(0) Mediated Polymerization): From Fundamentals to Bioapplications.

The polymerization of the photocleavable monomer, o-nitrobenzyl methacrylate (NBMA), is investigated using photoinduced electron/energy transfer reversible addition-fragmentation chain transfer polymerization. The polymerizations under visible red (λ max = 635 nm, 0.7 mW cm(-2) ) and yellow (λ max = 560 nm, 9.7 mW cm(-2) ) light are performed and demonstrate rational evidence of a controlled/living radical polymerization process. Well-defined poly(o-nitrobenzyl methacrylate) (PNBMA) homopolymers with good control over the molecular weight and polymer dispersity are successfully synthesized by varying the irradiation time and/or targeted degree of polymerization. Chain extension of a poly(oligo(ethylene glycol) methyl ether methacrylate) macro-chain transfer agent with NBMA is carried out to fabricate photocleavable amphiphilic block copolymers (BCP). Finally, these self-assembled BCP rapidly dissemble under UV light suggesting the photoresponsive character of NBMA is not altered during the polymerization under yellow or red light. Such photoresponsive polymers can be potentially used for the remote-controlled delivery of therapeutic compounds.

Polymerization of a Photocleavable Monomer Using Visible Light.

Back Cover: Polymers featuring photoresponsive groups have been exploited as promising drug delivery systems. Light as spatially and temporally controllable external stimulus can be readily tuned and focused to trigger changes in the structure of polymer chains to provide "on-command" drug delivery. A benign synthesis route for a novel controlled polymerization, known as photoinduced electron/energy transfer-reversible addition-fragmentation (PET-RAFT) polymerization, is presented. Further details can be found in the article by A. Bagheri, J. Yeow, H. Arandiyan, J. Xu, C. Boyer,* and M. Limon page 905.

Jonathan Yeow

Centre for Advanced Macromolecular Design (CAMD),
Australian Centre for NanoMedicine (ACN),
School of Chemical Engineering

The University of New South Wales

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Jonathan Yeow

Centre for Advanced Macromolecular Design (CAMD),Australian Centre for NanoMedicine (ACN),School of Chemical Engineering

The University of New South Wales

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Centre for Advanced Macromolecular Design (CAMD),
Australian Centre for NanoMedicine (ACN),
School of Chemical Engineering