The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ev...

Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes

Radical Polymerization and Copper(0) Mediated Polymerization): From Fundamentals to Bioapplications Cyrille Boyer,*,†,‡ Nathaniel Alan Corrigan,‡ Kenward Jung,‡ Diep Nguyen,‡ Thuy-Khanh Nguyen,‡ Nik Nik M. Adnan,†,‡ Susan Oliver,†,‡ Sivaprakash Shanmugam,‡ and Jonathan Yeow†,‡ †Australian Centre for Nanomedicine, and ‡Centre for Advanced Macromolecular Design (CAMD), School of Chemical Engineering, University of New South Wales, Sydney 2052, Australia

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

Materials Synthesis Athina Anastasaki,†,‡ Vasiliki Nikolaou,† Gabit Nurumbetov,† Paul Wilson,†,‡ Kristian Kempe,†,‡ John F. Quinn,‡ Thomas P. Davis,†,‡ Michael R. Whittaker,†,‡ and David M. Haddleton*,†,‡ †Chemistry Department, University of Warwick, Library Road, CV4 7AL, Coventry, United Kingdom ‡ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 399 Royal Parade, Parkville, Victoria 3152, Australia

Cu(0)-Mediated Living Radical Polymerization: A Versatile Tool for Materials Synthesis

Any design of nanoparticle vectors for cancer therapy or imaging must take into account the interaction of the nanoparticles with the tumor microenvironment. Size, charge, and shape have been shown to dominate this interaction.[1, 2] In vivo probing of solid tumors with particles of different sizes simultaneously has thus far been challenging due to the limitations of available nano-sized probes.[3–5] Fluorescent dextrans and other macromolecule probes have been used in studies with intravital microscopy, but heterogeneities across samples has prevented their use for the simultaneous imaging of a size series of probes within the same tumour.[5] MRI contrast agents are another attractive set of probes due to the minimally-invasive nature of the technology,[6, 7] but the lower spatial resolution of MRI limits the imaging of heterogeneity within tumors, and the technique does not allow for simultaneous imaging and tracking of a size series of probes within the same tumor.

A Nanoparticle Size Series for In Vivo Fluorescence Imaging

Smart drug delivery systems (DDSs) have attracted the attention of many scientists, as carriers that can be stimulated by changes in environmental parameters such as temperature, pH, light, electromagnetic fields, mechanical forces, etc. These smart nanocarriers can release their cargo on demand when their target is reached and the stimulus is applied. Using the techniques of nanotechnology, these nanocarriers can be tailored to be target-specific, and exhibit delayed or controlled release of drugs. Temperature-responsive nanocarriers are one of most important groups of smart nanoparticles (NPs) that have been investigated during the past decades. Temperature can either act as an external stimulus when heat is applied from the outside, or can be internal when pathological lesions have a naturally elevated termperature. A low critical solution temperature (LCST) is a special feature of some polymeric materials, and most of the temperature-responsive nanocarriers have been designed based on this feature. In...

Temperature-Responsive Smart Nanocarriers for Delivery Of Therapeutic Agents: Applications and Recent Advances

Timed-Release Polymer Nanoparticles

Oligonucleotide and Polymer Functionalized Nanoparticles for Amplification-Free Detection of DNA

Fine tuning the disassembly time of thermoresponsive polymer nanoparticles.

The disassembly of well-defined random copolymer nanoparticles to unimers at precise times can be programmed through the strong interaction with the surfactant, sodium dodecyl sulfate (SDS). The random copolymers consisted of thermoresponsive and self-degradable monomer units, rapidly self-assembled in water above the lower critical solution temperature of the thermoresponsive polymer component into SDS-stabilized polymer nanoparticles at a high weight fraction of polymer, a fully reversible process. Increasing the SDS concentration resulted in an increase in the nanoparticle size from ∼60 to ∼500 nm while maintaining a very narrow particle size distribution. These particles once formed were stable even under highly dilute conditions (i.e., an ∼10-fold dilution). Due to the self-catalyzed hydrolysis of the (N,N-dimethylaminoethyl acrylate) (DMAEA) to acrylic acid within the polymer, the nanoparticles rapidly disassembled back to unimers when the LCST of the hydrolyzed polymer was equal to or greater than the set solution temperature of 37 °C. The time to disassembly from nanoparticle to unimer was programmed through the amount of hydrophobic (butyl acrylate or styrene) units in the copolymer in combination with the amount of SDS. The higher hydrophopic content in the polymer resulted in longer disassembly times, while the higher SDS concentration reduced the disassembly time. Importantly, the self-catalyzed hydrolysis property of PDMAEA was not affected by SDS, allowing precise tunability of the time required for disassembly of the polymer nanoparticles. This active disassembly of nanoparticles provides a unique system that responds without an external trigger (e.g., light, heat, etc., ...) and could find applications where timed-release of compounds or timed activation of enzymes and other biocomponents is required.

Nguyen T. D. Tran

Papers

Timed-Release Polymer Nanoparticles

Oligonucleotide and Polymer Functionalized Nanoparticles for Amplification-Free Detection of DNA

Fine tuning the disassembly time of thermoresponsive polymer nanoparticles.

Programmable Disassembly of Polymer Nanoparticles through Surfactant Interactions