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9. Photoswitchable gating of non-equilibrium enzymatic feedback in chemically communicating polymersome nanoreactors

Author

Rifaie-Graham, Omar, primary, Yeow, Jonathan, additional, Najer, Adrian, additional, Wang, Richard, additional, Sun, Rujie, additional, Zhou, Kun, additional, Dell, Tristan N., additional, Adrianus, Christopher, additional, Thanapongpibul, Chalaisorn, additional, Chami, Mohamed, additional, Mann, Stephen, additional, de Alaniz, Javier Read, additional, and Stevens, Molly M., additional

Published
2022
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12. Potent Virustatic Polymer–Lipid Nanomimics Block Viral Entry and Inhibit Malaria Parasites In Vivo

Author

Najer, Adrian, primary, Blight, Joshua, additional, Ducker, Catherine B., additional, Gasbarri, Matteo, additional, Brown, Jonathan C., additional, Che, Junyi, additional, Høgset, Håkon, additional, Saunders, Catherine, additional, Ojansivu, Miina, additional, Lu, Zixuan, additional, Lin, Yiyang, additional, Yeow, Jonathan, additional, Rifaie-Graham, Omar, additional, Potter, Michael, additional, Tonkin, Renée, additional, Penders, Jelle, additional, Doutch, James J., additional, Georgiadou, Athina, additional, Barriga, Hanna M. G., additional, Holme, Margaret N., additional, Cunnington, Aubrey J., additional, Bugeon, Laurence, additional, Dallman, Margaret J., additional, Barclay, Wendy S., additional, Stellacci, Francesco, additional, Baum, Jake, additional, and Stevens, Molly M., additional

Published
2022
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13. Photoswitchable gating of non-equilibrium enzymatic feedback in chemically communicating polymersome nanoreactors

Author

Rifaie-Graham, Omar, Yeow, Jonathan, Najer, Adrian, Wang, Richard, Sun, Rujie, Zhou, Kun, Dell, Tristan, Adrianus, Christopher, Thanapongpibul, Chalaisorn, Mann, Stephen, de Alaniz, Javier Read, and Stevens, Molly

Abstract

The circadian rhythm generates out-of-equilibrium metabolite oscillations controlled by feedback loops under light/dark cycles. Here we describe a non-equilibrium nanosystem comprising a binary population of enzyme-containing polymersomes capable of light-gated chemical communication, controllable feedback and coupling to macroscopic oscillations. The populations consist of esterase-containing polymersomes functionalized with photo-responsive Donor-Acceptor Stenhouse Adducts (DASA) and light-insensitive semi-permeable urease-loaded polymersomes. The DASA-polymersome membrane becomes permeable under green light, switching on esterase activity and decreasing the pH, which in turn initiates production of alkali in the urease-containing population. A pH-sensitive pigment that absorbs green light when protonated provides a negative feedback loop for deactivating the DASA-polymersomes. Simultaneously, increased alkali production deprotonates the pigment, re-activating esterase activity by opening the membrane gate. We utilise light-mediated fluctuations of pH to perform non-equilibrium communication between the nanoreactors and use the feedback loops to induce work as chemomechanical swelling/deswelling oscillations in a crosslinked hydrogel. We envision possible applications in artificial organelles, protocells, and soft robotics.

Published
2022
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15. Big Is Beautiful: Enhanced saRNA Delivery and Immunogenicity by a Higher Molecular Weight, Bioreducible, Cationic Polymer

Author

Blakney, Anna K., primary, Zhu, Yunqing, additional, McKay, Paul F., additional, Bouton, Clément R., additional, Yeow, Jonathan, additional, Tang, Jiaqing, additional, Hu, Kai, additional, Samnuan, Karnyart, additional, Grigsby, Christopher L., additional, Shattock, Robin J., additional, and Stevens, Molly M., additional

Published
2020
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22. Visible Light Mediated Polymerization-Induced Self-Assembly: New Insights and Opportunities

Author

Yeow, Jonathan

Subjects
Photopolymerization, RAFT polymerization, PET-RAFT polymerization, Polymerization-Induced Self-Assembly, Polymeric nanoparticles
Abstract

In recent years, polymeric nanoparticles (PNPs) have found diverse applications in fields such as diagnostics, catalysis and drug delivery. However, current methods to synthesize PNPs can be limited by the scalability of the synthesis and/or the reproducibility of particle size and shape. Polymerization-Induced Self-Assembly (PISA) is a technique that uses a living polymerization process to drive the self-assembly of PNPs to occur during the polymerization. Compared to conventional methods, the PISA process allows for PNP synthesis at much higher polymer concentrations (up to 50 wt%) in addition to providing more reproducible access to nanoparticles of different morphologies. Normally, the PISA process is conducted under thermally initiated reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization conditions. In contrast, this dissertation explores the application of various visible light photopolymerization techniques to drive the PISA process (Photo-PISA). In particular, this work investigates the advantages of visible light initiated photopolymerization techniques which generally proceed under mild conditions and enable a fine degree of external control over the polymerization by variations in irradiation wavelength, intensity and time. This body of work demonstrates that the Photo-PISA approach can perform PNP synthesis under mild room temperature conditions and in environmentally friendly solvents. A high degree of temporal control over the nanoparticle shape is observed which facilitates the isolation of specific morphologies. Interestingly, manipulation of extrinsic parameters such as the irradiation wavelength and/or intensity can be used to favor the formation of different morphologies. In addition, by performing Photo-PISA at room temperature, worm-like micelles can be readily isolated by monitoring the reaction viscosity during the polymerization. When the photocatalyst, ZnTPP is employed to initiate the Photo-PISA process, it can also be encapsulated into the nanoparticle after the polymerization and act as a light activated drug for applications in photodynamic therapy. Finally, under certain conditions, it is demonstrated that the Photo-PISA process can be exploited to perform PNP synthesis without the usual deoxygenation procedures. This allows for self-assembled PNPs to be synthesized at ultralow volumes and in parallel with a view towards applications in high throughput synthesis and structure-activity screening.

Published
2017
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23. Pair Correlation Rnicroscopy Reveals The Role Of Nanoparticle Shape In Intracellular Transport And Site Of Drug Release

Author

Hinde, Elizabeth, Thammasiraphop, Kitiphume, Duong, Hien T. T., Yeow, Jonathan, Karagoz, Bunyamin, Boyer, Cyrille, Gooding, J. Justin, and Gaus, Katharina

Abstract

Nanoparticle size, surface charge and material composition are known to affect the uptake of nanoparticles by cells. However, whether nanoparticle shape affects transport across various barriers inside the cell remains unclear. Here we used pair correlation microscopy to show that polymeric nanoparticles with different shapes but identical surface chemistries moved across the various cellular barriers at different rates, ultimately defining the site of drug release. We measured how micelles, vesicles, rods and worms entered the cell and whether they escaped from the endosomal system and had access to the nucleus via the nuclear pore complex. Rods and worms, but not micelles and vesicles, entered the nucleus by passive diffusion. Improving nuclear access, for example with a nuclear localization signal, resulted in more doxorubicin release inside the nucleus and correlated with greater cytotoxicity. Our results therefore demonstrate that drug delivery across the major cellular barrier, the nuclear envelope, is important for doxorubicin efficiency and can be achieved with appropriately shaped nanoparticles.

Published
2017

32. Visible Light Mediated Polymerization-Induced Self-Assembly: New Insights and Opportunities

Author

Boyer, Cyrille, Centre for Advanced Macromolecular Design, Faculty of Engineering, UNSW, Yeow, Jonathan, Centre for Advanced Macromolecular Design, Faculty of Engineering, UNSW, Boyer, Cyrille, Centre for Advanced Macromolecular Design, Faculty of Engineering, UNSW, and Yeow, Jonathan, Centre for Advanced Macromolecular Design, Faculty of Engineering, UNSW

Abstract

In recent years, polymeric nanoparticles (PNPs) have found diverse applications in fields such as diagnostics, catalysis and drug delivery. However, current methods to synthesize PNPs can be limited by the scalability of the synthesis and/or the reproducibility of particle size and shape. Polymerization-Induced Self-Assembly (PISA) is a technique that uses a living polymerization process to drive the self-assembly of PNPs to occur during the polymerization. Compared to conventional methods, the PISA process allows for PNP synthesis at much higher polymer concentrations (up to 50 wt%) in addition to providing more reproducible access to nanoparticles of different morphologies. Normally, the PISA process is conducted under thermally initiated reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization conditions. In contrast, this dissertation explores the application of various visible light photopolymerization techniques to drive the PISA process (Photo-PISA). In particular, this work investigates the advantages of visible light initiated photopolymerization techniques which generally proceed under mild conditions and enable a fine degree of external control over the polymerization by variations in irradiation wavelength, intensity and time. This body of work demonstrates that the Photo-PISA approach can perform PNP synthesis under mild room temperature conditions and in environmentally friendly solvents. A high degree of temporal control over the nanoparticle shape is observed which facilitates the isolation of specific morphologies. Interestingly, manipulation of extrinsic parameters such as the irradiation wavelength and/or intensity can be used to favor the formation of different morphologies. In addition, by performing Photo-PISA at room temperature, worm-like micelles can be readily isolated by monitoring the reaction viscosity during the polymerization.When the photocatalyst, ZnTPP is employed to initiate the Photo-PISA process, it can a

Published
2017

37. An Efficient And Highly Versatile Synthetic Route To Prepare Iron Oxide Nanoparticles/Nanocomposites With Tunable Morphologies

Author

Karagoz, Bunyamin, Yeow, Jonathan, Esser, Lars, Prakash, Shyam M., Kuchel, Rhiannon P., Davis, Thomas P., and Boyer, Cyrille

Abstract

We report a versatile synthetic method for the in situ self-assembly of magnetic-nanoparticle-fimctionalized 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 H-1 NMR measurements. TEM micrographs showed that the average size of the magnetic nanoparticles was similar to 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 (r(2), 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.

Published
2014

41. Macromol. Rapid Commun. 11/2016

Author

Bagheri, Ali, primary, Yeow, Jonathan, additional, Arandiyan, Hamidreza, additional, Xu, Jiangtao, additional, Boyer, Cyrille, additional, and Lim, May, additional

Published
2016
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50. Pair correlation microscopy reveals the role of nanoparticle shape in intracellular transport and site of drug release

Author

Hinde, Elizabeth, Thammasiraphop, Kitiphume, Duong, Hien T. T., Yeow, Jonathan, Karagoz, Bunyamin, Boyer, Cyrille, Gooding, J. Justin, and Gaus, Katharina

Abstract

Nanoparticle size, surface charge and material composition are known to affect the uptake of nanoparticles by cells. However, whether nanoparticle shape affects transport across various barriers inside the cell remains unclear. Here we used pair correlation microscopy to show that polymeric nanoparticles with different shapes but identical surface chemistries moved across the various cellular barriers at different rates, ultimately defining the site of drug release. We measured how micelles, vesicles, rods and worms entered the cell and whether they escaped from the endosomal system and had access to the nucleus via the nuclear pore complex. Rods and worms, but not micelles and vesicles, entered the nucleus by passive diffusion. Improving nuclear access, for example with a nuclear localization signal, resulted in more doxorubicin release inside the nucleus and correlated with greater cytotoxicity. Our results therefore demonstrate that drug delivery across the major cellular barrier, the nuclear envelope, is important for doxorubicin efficiency and can be achieved with appropriately shaped nanoparticles.

Published
2017
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