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Prof. STEVE HOWDLE's Outputs (59)

Supercritical RROP: Exploring the radical ring-opening polymerisation of 2-methylene-1,3,6-trioxocane in supercritical CO2 as a green solvent (2024)
Journal Article
Mehner, F., Hopkins, B., Reynolds-Green, M., Keddie, D. J., Howdle, S. M., & Gaitzsch, J. (2024). Supercritical RROP: Exploring the radical ring-opening polymerisation of 2-methylene-1,3,6-trioxocane in supercritical CO2 as a green solvent. Polymer, 309, Article 127373. https://doi.org/10.1016/j.polymer.2024.127373

Radical ring opening polymerisation (RROP) of cyclic ketene acetals (CKAs) is an attractive technique to synthesize branched, (bio)degradable polyesters. However, CKAs as monomers of RROP suffer from hydrolysis lability, making aqueous heterogeneous... Read More about Supercritical RROP: Exploring the radical ring-opening polymerisation of 2-methylene-1,3,6-trioxocane in supercritical CO2 as a green solvent.

Sustainable, upscaled synthesis of pinene-derived (meth)acrylates and their application as high Tg monomers in styrene/acrylic-based bioderived copolymer coatings (2024)
Journal Article
Pin-Nó, M., L. Jacob, P., Taresco, V., Kastelijn, M., Nabuurs, T., Surti, C., Bilney, J., Daly, J., J. Keddie, D., M. Howdle, S., & A. Stockman, R. (2024). Sustainable, upscaled synthesis of pinene-derived (meth)acrylates and their application as high Tg monomers in styrene/acrylic-based bioderived copolymer coatings. RSC Sustainability, 2(9), 2515-2523. https://doi.org/10.1039/D4SU00210E

n improved synthesis of the pinene-derived monomers (3-pinanyl acrylate 1 and 3-pinanyl methacrylate 2), replacing hazardous and/or expensive reagents from established methods with cheaper, more innocuous and sustainable reagents, is reported; the mo... Read More about Sustainable, upscaled synthesis of pinene-derived (meth)acrylates and their application as high Tg monomers in styrene/acrylic-based bioderived copolymer coatings.

A facile one step route that introduces functionality to polymer powders for laser sintering (2024)
Journal Article
Krumins, E., Crawford, L. A., Rogers, D. M., Machado, F., Taresco, V., East, M., …Howdle, S. M. (2024). A facile one step route that introduces functionality to polymer powders for laser sintering. Nature Communications, 15(1), Article 3137. https://doi.org/10.1038/s41467-024-47376-4

Laser Sintering (LS) is a type of Additive Manufacturing (AM) exploiting laser processing of polymeric particles to produce 3D objects. Because of its ease of processability and thermo-physical properties, polyamide-12 (PA-12) represents ~95% of the... Read More about A facile one step route that introduces functionality to polymer powders for laser sintering.

Glycerol- and diglycerol-based polyesters: Evaluation of backbone alterations upon nano-formulation performance (2024)
Journal Article
Axioti, E., Dixon, E. G., Reynolds-Green, M., Alexander, E. C., Brugnoli, B., Keddie, D. J., …Taresco, V. (2024). Glycerol- and diglycerol-based polyesters: Evaluation of backbone alterations upon nano-formulation performance. Colloids and Surfaces B: Biointerfaces, 236, Article 113828. https://doi.org/10.1016/j.colsurfb.2024.113828

Despite the success of polyethylene glycol-based (PEGylated) polyesters in the drug delivery and biomedical fields, concerns have arisen regarding PEG's immunogenicity and limited biodegradability. In addition, inherent limitations, including limited... Read More about Glycerol- and diglycerol-based polyesters: Evaluation of backbone alterations upon nano-formulation performance.

Glycerol-based sustainably sourced resin for volumetric printing (2024)
Journal Article
Krumins, E., Lentz, J. C., Sutcliffe, B., Sohaib, A., Jacob, P. L., Brugnoli, B., …Taresco, V. (2024). Glycerol-based sustainably sourced resin for volumetric printing. Green Chemistry, 26(3), 1345-1355. https://doi.org/10.1039/d3gc03607c

Volumetric Additive Manufacturing (VAM) represents a revolutionary advancement in the field of Additive Manufacturing, as it allows for the creation of objects in a single, cohesive process, rather than in a layer-by-layer approach. This innovative t... Read More about Glycerol-based sustainably sourced resin for volumetric printing.

Synthesis of core-shell polymer particles in supercritical carbon dioxide via iterative monomer addition (2023)
Journal Article
Kortsen, K., Reynolds-Green, M., Hopkins, B., McLellan, A., Derry, M. J., Topham, P. D., …Howdle, S. M. (2023). Synthesis of core-shell polymer particles in supercritical carbon dioxide via iterative monomer addition. Chemical Communications, 59(98), 14536-14539. https://doi.org/10.1039/d3cc04969h

A new, robust methodology for the synthesis of polystyrene-poly(methyl methacrylate) (PS-PMMA) core-shell particles using seeded dispersion polymerisation in supercritical carbon dioxide is reported, where the core-shell ratio can be controlled predi... Read More about Synthesis of core-shell polymer particles in supercritical carbon dioxide via iterative monomer addition.

Self-assembled chitosan-sodium usnate drug delivery nanosystems: Synthesis, characterization, stability studies, in vitro cytotoxicity and in vivo biocompatibility against 143 B cells (2023)
Journal Article
Brugnoli, B., Mariano, A., Simonis, B., Bombelli, C., Sennato, S., Piozzi, A., …Francolini, I. (2023). Self-assembled chitosan-sodium usnate drug delivery nanosystems: Synthesis, characterization, stability studies, in vitro cytotoxicity and in vivo biocompatibility against 143 B cells. Carbohydrate Polymer Technologies and Applications, 6, Article 100373. https://doi.org/10.1016/j.carpta.2023.100373

Polymers are among the most studied materials as drug carriers, due to their tunable chemical structure and ability to self-assemble to give different types of nanostructures. In this study, chitosan (CS) nanoparticles (NPs) were investigated as carr... Read More about Self-assembled chitosan-sodium usnate drug delivery nanosystems: Synthesis, characterization, stability studies, in vitro cytotoxicity and in vivo biocompatibility against 143 B cells.

Synthesis of Multifunctional Polymersomes Prepared by Polymerization-Induced Self-Assembly (2023)
Journal Article
Phan, H., Cavanagh, R., Jacob, P., Destouches, D., Vacherot, F., Brugnoli, B., …Couturaud, B. (2023). Synthesis of Multifunctional Polymersomes Prepared by Polymerization-Induced Self-Assembly. Polymers, 15(14), Article 3070. https://doi.org/10.3390/polym15143070

Polymersomes are an exciting modality for drug delivery due to their structural similarity to biological cells and their ability to encapsulate both hydrophilic and hydrophobic drugs. In this regard, the current work aimed to develop multifunctional... Read More about Synthesis of Multifunctional Polymersomes Prepared by Polymerization-Induced Self-Assembly.

Modification of Linear Polyethylenimine with Supercritical CO2: From Fluorescent Materials to Covalent Cross-Links (2023)
Journal Article
Mees, M. A., McAllister, T. D., Curia, S., Howdle, S. M., & Hoogenboom, R. (2023). Modification of Linear Polyethylenimine with Supercritical CO2: From Fluorescent Materials to Covalent Cross-Links. Macromolecules, 56(7), 2841-2851. https://doi.org/10.1021/acs.macromol.2c02443

Along with their DNA binding ability, the secondary amines in linear polyethylenimine (L-PEI) units can also act as a reaction platform to introduce new functionalities. This renders the possibility to make a plethora of copolymers without the burden... Read More about Modification of Linear Polyethylenimine with Supercritical CO2: From Fluorescent Materials to Covalent Cross-Links.

Evaluation of two terpene-derived polymers as consolidants for archaeological wood (2023)
Journal Article
Cutajar, M., Braovac, S., Stockman, R. A., Howdle, S. M., & Harding, S. E. (2023). Evaluation of two terpene-derived polymers as consolidants for archaeological wood. Scientific Reports, 13(1), Article 3664. https://doi.org/10.1038/s41598-023-29785-5

The evaluation of two terpene-derived polymers, termed TPA6 and TPA7, as possible consolidants for archaeological wood was carried out. The overall objective of this work was to expand the non-aqueous treatment toolkit which is available for the cons... Read More about Evaluation of two terpene-derived polymers as consolidants for archaeological wood.

Oxidation of Monoterpenes to Form Diols and Triols: A Versatile Toolbox for Polymer Synthesis (2023)
Journal Article
Fowler, H. R., O'Brien, D. M., Keddie, D. J., Alexander, C., Irvine, D. J., Stockman, R. A., …Taresco, V. (2023). Oxidation of Monoterpenes to Form Diols and Triols: A Versatile Toolbox for Polymer Synthesis. Macromolecular Chemistry and Physics, 224(8), Article 2200446. https://doi.org/10.1002/macp.202200446

Polyols and polyacrylates have a wide range of applications in polymer synthesis as monomers, initiators, or building blocks in a variety of polymerization reaction types. With an ever-growing need to reduce the global dependency on fossil fuels, fin... Read More about Oxidation of Monoterpenes to Form Diols and Triols: A Versatile Toolbox for Polymer Synthesis.

Comparative hydrodynamic characterisation of two hydroxylated polymers based on α-pinene- or oleic acid-derived monomers for potential use as archaeological consolidants (2022)
Journal Article
Cutajar, M., Machado, F., Cuzzucoli Crucitti, V., Braovac, S., Stockman, R. A., Howdle, S. M., & Harding, S. E. (2022). Comparative hydrodynamic characterisation of two hydroxylated polymers based on α-pinene- or oleic acid-derived monomers for potential use as archaeological consolidants. Scientific Reports, 12(1), Article 18411. https://doi.org/10.1038/s41598-022-21027-4

The Oseberg Viking ship burial is one of the most extensive collections of Viking wooden artefacts ever excavated in Norway. In the early twentieth century, many of these artefacts were treated with alum in order to preserve them, inadvertently leadi... Read More about Comparative hydrodynamic characterisation of two hydroxylated polymers based on α-pinene- or oleic acid-derived monomers for potential use as archaeological consolidants.

N-Hydroxyethyl acrylamide as a functional eROP initiator for the preparation of nanoparticles under “greener” reaction conditions (2022)
Journal Article
Lentz, J. C., Cavanagh, R., Moloney, C., Falcone Pin, B., Kortsen, K., Fowler, H. R., …Howdle, S. M. (2022). N-Hydroxyethyl acrylamide as a functional eROP initiator for the preparation of nanoparticles under “greener” reaction conditions. Polymer Chemistry, 13(42), 6032-6045. https://doi.org/10.1039/d2py00849a

N-Hydroxyethyl acrylamide was used as a functional initiator for the enzymatic ring-opening polymerisation of ϵ-caprolactone and δ-valerolactone. N-Hydroxyethyl acrylamide was found not to undergo self-reaction in the presence of Lipase B from Candid... Read More about N-Hydroxyethyl acrylamide as a functional eROP initiator for the preparation of nanoparticles under “greener” reaction conditions.

Sustainable ABA triblock methacrylate copolymers incorporating both high and low Tg terpene-derived monomers (2022)
Journal Article
Atkinson, R. L., Elsmore, M., Smith, S., Reynolds-Green, M., Topham, P. D., Toolan, D. T., …Howdle, S. M. (2022). Sustainable ABA triblock methacrylate copolymers incorporating both high and low Tg terpene-derived monomers. European Polymer Journal, 179, Article 11567. https://doi.org/10.1016/j.eurpolymj.2022.111567

We report the synthesis of novel terpene-based monomers: nopinyl acrylate and methacrylate, from naturally abundant β-pinene. A very high Tg value was observed for poly(nopinyl methacrylate) when synthesised by free radical polymerisation, and well-d... Read More about Sustainable ABA triblock methacrylate copolymers incorporating both high and low Tg terpene-derived monomers.

Antimicrobial ‘inks’ for 3D printing: block copolymer-silver nanoparticle composites synthesised using supercritical CO2 (2022)
Journal Article
Larder, R. R., Krumins, E., Jacob, P. L., Kortsen, K., Cavanagh, R., Jiang, L., …Howdle, S. M. (2022). Antimicrobial ‘inks’ for 3D printing: block copolymer-silver nanoparticle composites synthesised using supercritical CO2. Polymer Chemistry, 13(25), 3768-3779. https://doi.org/10.1039/d2py00398h

Silver nanoparticles (AgNP) are widely exploited for their effective antimicrobial activity against a range of pathogens. Their high efficacy in this regard has seen the global demand for AgNP in consumer products steadily increase in recent years, n... Read More about Antimicrobial ‘inks’ for 3D printing: block copolymer-silver nanoparticle composites synthesised using supercritical CO2.

Passerini chemistries for synthesis of polymer pro-drug and polymersome drug delivery nanoparticles (2022)
Journal Article
Travanut, A., Monteiro, P. F., Smith, S., Howdle, S. M., Grabowska, A. M., Kellam, B., …Alexander, C. (2022). Passerini chemistries for synthesis of polymer pro-drug and polymersome drug delivery nanoparticles. Journal of Materials Chemistry B, 10, 3895-3905. https://doi.org/10.1039/d2tb00045h

New materials chemistries are urgently needed to overcome the limitations of existing biomedical materials in terms of preparation, functionality and versatility, and also in regards to their compatibility with biological environments. Here, we show... Read More about Passerini chemistries for synthesis of polymer pro-drug and polymersome drug delivery nanoparticles.

Exploiting the tuneable density of scCO2 to improve particle size control for dispersion polymerisations in the presence of poly(dimethyl siloxane) stabilisers (2022)
Journal Article
Kortsen, K., Fowler, H. R., Jacob, P. L., Krumins, E., Lentz, J. C., Souhil, M. R., …Howdle, S. M. (2022). Exploiting the tuneable density of scCO2 to improve particle size control for dispersion polymerisations in the presence of poly(dimethyl siloxane) stabilisers. European Polymer Journal, 168, Article 111108. https://doi.org/10.1016/j.eurpolymj.2022.111108

The dispersion polymerisation of methyl methacrylate (MMA) is a widely employed method for producing discrete, spherical PMMA particles from traditional solvents, which cover a broad particle size range. With environmental impact becoming an ever mor... Read More about Exploiting the tuneable density of scCO2 to improve particle size control for dispersion polymerisations in the presence of poly(dimethyl siloxane) stabilisers.

Greener extraction-chemical modification-polymerization pipeline of vernolic acid from Ethiopian ironweed plant (2022)
Journal Article
d'Almeida Gameiro, M., Jacob, P. L., Kortsen, K., Ward, T., Taresco, V., Stockman, R. A., …Howdle, S. M. (2022). Greener extraction-chemical modification-polymerization pipeline of vernolic acid from Ethiopian ironweed plant. Journal of Polymer Science, https://doi.org/10.1002/pol.20220050

Epoxidized oils are commonly used in the plastics industry as additives in the formulation of polyvinyl chloride (PVC) and as monomers in the coating industry. They are produced from petrochemical feedstocks or by chemical epoxidation of natural oils... Read More about Greener extraction-chemical modification-polymerization pipeline of vernolic acid from Ethiopian ironweed plant.

Sustainable terpene triblock copolymers with tuneable properties for pressure sensitive adhesive applications (2022)
Journal Article
Elsmore, M., Atkinson, R., Irvine, D., Howdle, S., & De Focatiis, D. (2022). Sustainable terpene triblock copolymers with tuneable properties for pressure sensitive adhesive applications. Polymer Testing, 109, Article 107530. https://doi.org/10.1016/j.polymertesting.2022.107530

A series of triblock copolymers in a hard-soft-hard block configuration with varying hard block α-pinene methacrylate content and molecular weight and butyl acrylate soft segment have been synthesised and investigated for viability in pressure sensit... Read More about Sustainable terpene triblock copolymers with tuneable properties for pressure sensitive adhesive applications.

Green enzymatic synthesis and processing of poly (cis-9,10-epoxy-18-hydroxyoctadecanoic acid) in supercritical carbon dioxide (scCO2) (2021)
Journal Article
Sagnelli, D., Vestri, A., Curia, S., Taresco, V., Santagata, G., Johansson, M. K., & Howdle, S. M. (2021). Green enzymatic synthesis and processing of poly (cis-9,10-epoxy-18-hydroxyoctadecanoic acid) in supercritical carbon dioxide (scCO2). European Polymer Journal, 161, Article 110827. https://doi.org/10.1016/j.eurpolymj.2021.110827

There is significant potential for industrial use of renewables for a wide range of materials demanded by society. Plants, trees and algae are increasingly attracting attention as sustainable sources for functionalised and polymerizable building bloc... Read More about Green enzymatic synthesis and processing of poly (cis-9,10-epoxy-18-hydroxyoctadecanoic acid) in supercritical carbon dioxide (scCO2).

Synthesis of model terpene-derived copolymers in supercritical carbon dioxide for cosmetic applications (2021)
Journal Article
Bennett, T. M., Portal, J., Jeanne-Rose, V., Taupin, S., Ilchev, A., Irvine, D. J., & Howdle, S. M. (2021). Synthesis of model terpene-derived copolymers in supercritical carbon dioxide for cosmetic applications. European Polymer Journal, 157, Article 110621. https://doi.org/10.1016/j.eurpolymj.2021.110621

There is currently a strong drive within the cosmetics industry to replace petroleum based solvents and polymers with renewable alternatives. Copolymers of 2-ethylhexyl acrylate (2EHA) and maleic anhydride (MA) are interesting model candidates to be... Read More about Synthesis of model terpene-derived copolymers in supercritical carbon dioxide for cosmetic applications.

RAFT polymerisation of renewable terpene (meth)acrylates and the convergent synthesis of methacrylate-acrylate-methacrylate triblock copolymers (2021)
Journal Article
Atkinson, R. L., Monaghan, O., Elsmore, M. T., Topham, P. D., Toolan, D. T. W., Derry, M. J., …Howdle, S. M. (2021). RAFT polymerisation of renewable terpene (meth)acrylates and the convergent synthesis of methacrylate-acrylate-methacrylate triblock copolymers. Polymer Chemistry, 12(21), 3177-3189. https://doi.org/10.1039/d1py00326g

Terpenes are ideal candidates for sustainable polymer feedstocks, due to their natural abundance and availability from existing waste streams. Previously, we have shown that a range of terpene(meth)acrylate monomers can be synthesised from the most c... Read More about RAFT polymerisation of renewable terpene (meth)acrylates and the convergent synthesis of methacrylate-acrylate-methacrylate triblock copolymers.

Synthesis of water-soluble surfactants using catalysed condensation polymerisation in green reaction media (2021)
Journal Article
Goddard, A. R., Apebende, E. A., Lentz, J. C., Carmichael, K., Taresco, V., Irvine, D. J., & Howdle, S. M. (2021). Synthesis of water-soluble surfactants using catalysed condensation polymerisation in green reaction media. Polymer Chemistry, 12(20), 2992-3003. https://doi.org/10.1039/d1py00415h

Sustainable and biobased surfactants are required for a wide range of everyday applications. Key drivers are cost, activity and efficiency of production. Polycondensation is an excellent route to build surfactant chains from bio-sourced monomers, but... Read More about Synthesis of water-soluble surfactants using catalysed condensation polymerisation in green reaction media.

Amylose/cellulose nanofiber composites for all-natural, fully biodegradable and flexible bioplastics (2020)
Journal Article
Xu, J., Sagnelli, D., Faisal, M., Perzon, A., Taresco, V., Mais, M., …Blennow, A. (2021). Amylose/cellulose nanofiber composites for all-natural, fully biodegradable and flexible bioplastics. Carbohydrate Polymers, 253, Article 117277. https://doi.org/10.1016/j.carbpol.2020.117277

Thermoplastic, polysaccharide-based plastics are environmentally friendly. However, typical shortcomings include lack of water resistance and poor mechanical properties. Nanocomposite manufacturing using pure, highly linear, polysaccharides can overc... Read More about Amylose/cellulose nanofiber composites for all-natural, fully biodegradable and flexible bioplastics.

On-line polymerisation monitoring in scCO2: a reliable and inexpensive sampling method in high pressure applications (2020)
Journal Article
Kortsen, K., Pacheco, A. A., Lentz, J. C., Taresco, V., & Howdle, S. M. (2021). On-line polymerisation monitoring in scCO2: a reliable and inexpensive sampling method in high pressure applications. Journal of Supercritical Fluids, 167, Article 105047. https://doi.org/10.1016/j.supflu.2020.105047

A versatile and reliable on-line sampling system for polymerisation reactions in supercritical fluids was developed. By withdrawing a small volume of a high-pressure reaction mixture and expanding it in a controlled volume, reliable kinetic data were... Read More about On-line polymerisation monitoring in scCO2: a reliable and inexpensive sampling method in high pressure applications.

Synthesis of Passerini-3CR Polymers and Assembly into Cytocompatible Polymersomes (2020)
Journal Article
Travanut, A., Monteiro, P. F., Oelmann, S., Howdle, S. M., Grabowska, A. M., Clarke, P. A., …Alexander, C. (2021). Synthesis of Passerini-3CR Polymers and Assembly into Cytocompatible Polymersomes. Macromolecular Rapid Communications, 42(6), Article 2000321. https://doi.org/10.1002/marc.202000321

© 2020 The Authors. Published by Wiley-VCH GmbH The versatility of the Passerini three component reaction (Passerini-3CR) is herein exploited for the synthesis of an amphiphilic diblock copolymer, which self-assembles into polymersomes. Carboxy-funct... Read More about Synthesis of Passerini-3CR Polymers and Assembly into Cytocompatible Polymersomes.

Synthesis of two-phase polymer particles in supercritical carbon dioxide (2020)
Journal Article
Haddleton, A., Bennett, T. M., Chen, X., Atkinson, R. L., Taresco, V., & Howdle, S. M. (2020). Synthesis of two-phase polymer particles in supercritical carbon dioxide. Polymer Chemistry, 11(31), 5029-5039. https://doi.org/10.1039/d0py00729c

The synthesis of particles with discrete phases using traditional emulsion polymerisation is a well-established process. Phase-separated particles have a wide range of applications, such as in coatings, drug delivery, impact modification and as suppo... Read More about Synthesis of two-phase polymer particles in supercritical carbon dioxide.

Clean synthesis of linear and star amphiphilic poly(ε-caprolactone)-block-poly(ethyl ethylene phosphonate) block copolymers: assessing self-assembly and surface activity (2020)
Journal Article
Baheti, P., Rheinberger, T., Gimello, O., Bouilhac, C., Wurm, F. R., Lacroix-Desmazes, P., & Howdle, S. M. (2020). Clean synthesis of linear and star amphiphilic poly(ε-caprolactone)-block-poly(ethyl ethylene phosphonate) block copolymers: assessing self-assembly and surface activity. Green Chemistry, 22(10), 3248-3261. https://doi.org/10.1039/d0gc00819b

2‐Methyltetrahydrofuran (2‐MeTHF) as a versatile green solvent for the synthesis of amphiphilic copolymers via ROP, FRP, and RAFT tandem polymerizations (2020)
Journal Article
Englezou, G., Kortsen, K., Pacheco, A. A. C., Cavanagh, R., Lentz, J. C., Krumins, E., …Taresco, V. (2020). 2‐Methyltetrahydrofuran (2‐MeTHF) as a versatile green solvent for the synthesis of amphiphilic copolymers via ROP, FRP, and RAFT tandem polymerizations. Journal of Polymer Science, 58(11), 1571-1581. https://doi.org/10.1002/pol.20200183

2‐methyltetrahydrofuran (2‐MeTHF) is a readily available, inexpensive, neoteric, bio‐based solvent. It has been adopted across a wide range of chemical processes including the batch manufacture of fine chemicals, enzymatic polycondensations and ring... Read More about 2‐Methyltetrahydrofuran (2‐MeTHF) as a versatile green solvent for the synthesis of amphiphilic copolymers via ROP, FRP, and RAFT tandem polymerizations.

Starch/Poly(glycerol-adipate) Nanocomposites: A Novel Oral Drug Delivery Device (2020)
Journal Article
Vestri, A., Pearce, A. K., Cavanagh, R., Styliari, I. D., Sanders, C., Couturaud, B., …Sagnelli, D. (2020). Starch/Poly(glycerol-adipate) Nanocomposites: A Novel Oral Drug Delivery Device. Coatings, 10(2), Article 125. https://doi.org/10.3390/coatings10020125

Biocompatible and bio-based materials are an appealing resource for the pharmaceutical industry. Poly(glycerol-adipate) (PGA) is a biocompatible and biodegradable polymer that can be used to produce self-assembled nanoparticles (NPs) able to encapsul... Read More about Starch/Poly(glycerol-adipate) Nanocomposites: A Novel Oral Drug Delivery Device.

Enzymatic One-Pot Synthesis of Renewable and Biodegradable Surfactants in Supercritical Carbon Dioxide (scCO2) (2020)
Journal Article
d’Almeida Gamiero, M., Goddard, A. . R., Taresco, V., & Howdle, S. M. (2020). Enzymatic One-Pot Synthesis of Renewable and Biodegradable Surfactants in Supercritical Carbon Dioxide (scCO2). Green Chemistry, 22(4), 1308-1318. https://doi.org/10.1039/c9gc04011k

We seek to expand the opportunities to exploit glycerol, a largely untapped renewable feedstock, by exploiting enzymatic catalysis in supercritical carbon dioxide (scCO2). This work highlights a promising and clean approach to bio-renewable amphiphil... Read More about Enzymatic One-Pot Synthesis of Renewable and Biodegradable Surfactants in Supercritical Carbon Dioxide (scCO2).

Starch/Poly (Glycerol-Adipate) Nanocomposite Film as Novel Biocompatible Materials (2019)
Journal Article
Sagnelli, Cavanagh, Xu, Swainson, Blennow, Duncan, …Howdle. (2019). Starch/Poly (Glycerol-Adipate) Nanocomposite Film as Novel Biocompatible Materials. Coatings, 9(8), Article 482. https://doi.org/10.3390/coatings9080482

Starch is one of the most abundant polysaccharides on the earth and it is the most important source of energy intake for humans. Thermoplastic starch (TPS) is also widely used for new bio-based materials. The blending of starch with other molecules m... Read More about Starch/Poly (Glycerol-Adipate) Nanocomposite Film as Novel Biocompatible Materials.

Polyacrylates Derived from Biobased Ethyl Lactate Solvent via SET-LRP (2019)
Journal Article
Bensabeh, N., Moreno, A., Roig, A., Monaghan, O. R., Ronda, J. C., Cádiz, V., …Percec, V. (2019). Polyacrylates Derived from Biobased Ethyl Lactate Solvent via SET-LRP. Biomacromolecules, 20(5), 2135-2147. https://doi.org/10.1021/acs.biomac.9b00435

The precise synthesis of polymers derived from alkyl lactate ester acrylates is reported for the first time. Kinetic experiments were conducted to demonstrate that Cu(0) wire-catalyzed single electron transfer-living radical polymerization (SET-LRP)... Read More about Polyacrylates Derived from Biobased Ethyl Lactate Solvent via SET-LRP.

New renewably-sourced polyesters from limonene-derived monomers (2018)
Journal Article
Thomsett, M. R., Moore, J. C., Buchard, A., Stockman, R. A., & Howdle, S. M. (2019). New renewably-sourced polyesters from limonene-derived monomers. Green Chemistry, 21(1), 149-156. https://doi.org/10.1039/c8gc02957a

The functionalisation of limonene has enabled the synthesis of two renewably-sourced monomers for the formation of terpene-derived polyesters. Three methods for the synthesis of the novel hydroxy-acid 6 are reported and their green-credentials scruti... Read More about New renewably-sourced polyesters from limonene-derived monomers.

Sustainable synthesis and precise characterisation of bio-based star polycaprolactone synthesised with a metal catalyst and with lipase (2018)
Journal Article
Baheti, P., Gimello, O., Bouilhac, C., Lacroix-Desmazes, P., & Howdle, S. M. (2018). Sustainable synthesis and precise characterisation of bio-based star polycaprolactone synthesised with a metal catalyst and with lipase. Polymer Chemistry, 9(47), 5594-5607. https://doi.org/10.1039/c8py01266k

Bio-based building blocks and sustainable synthesis pathways were used to synthesise star-shaped polymers composed of a D-sorbitol core and polycaprolactone arms by ring opening polymerisation (ROP). The use of volatile organic solvents was avoided a... Read More about Sustainable synthesis and precise characterisation of bio-based star polycaprolactone synthesised with a metal catalyst and with lipase.

Antimicrobial peptide encapsulation and sustained release from polymer network particles prepared in supercritical carbon dioxide (2018)
Journal Article
Parilti, R., Caprasse, J., Riva, R., Alexandre, M., Vandegaart, H., Bebrone, C., …Jérôme, C. (2018). Antimicrobial peptide encapsulation and sustained release from polymer network particles prepared in supercritical carbon dioxide. Journal of Colloid and Interface Science, 532, 112-117. https://doi.org/10.1016/j.jcis.2018.07.125

© 2018 Antimicrobial peptide loaded poly(2-hydroxyethyl methacrylate) particles were synthesized in supercritical carbon dioxide via one-pot free-radical dispersion polymerisation of 2-hydroxyethyl methacrylate and a cross-linker. Discrete particles... Read More about Antimicrobial peptide encapsulation and sustained release from polymer network particles prepared in supercritical carbon dioxide.

Sulindac encapsulation and release from functional poly(HEMA) microparticles prepared in supercritical carbon dioxide (2018)
Journal Article
Parilti, R., Riva, R., Howdle, S. M., Dupont-Gillain, C., & Jerome, C. (2018). Sulindac encapsulation and release from functional poly(HEMA) microparticles prepared in supercritical carbon dioxide. International Journal of Pharmaceutics, 549(1-2), 161-168. https://doi.org/10.1016/j.ijpharm.2018.07.060

Sulindac loaded poly(HEMA) cross-linked microparticles were synthesized via one-pot free radical dispersion polymerisation in supercritical carbon dioxide (scCO2) in presence of photocleavable diblock stabilisers based on polyethylene oxide (PEO) and... Read More about Sulindac encapsulation and release from functional poly(HEMA) microparticles prepared in supercritical carbon dioxide.

A facile route to bespoke macro- and mesoporous block copolymer microparticles (2018)
Journal Article
He, G., Bennett, T. M., Alauhdin, M., Fay, M. W., Liu, X., Schwab, S. T., Sun, C.-G., & Howdle, S. M. (in press). A facile route to bespoke macro- and mesoporous block copolymer microparticles. Polymer Chemistry, 9(27), https://doi.org/10.1039/c8py00707a

We report a facile and versatile strategy for the bespoke fabrication of macro- and mesoporous block copolymer microparticles. A clean synthetic route, RAFT dispersion polymerisation in supercritical carbon dioxide (scCO2), is used to generate block... Read More about A facile route to bespoke macro- and mesoporous block copolymer microparticles.

Synthesis and control of crosslinked poly(acrylic acid) based viscosity modifiers using dense phase carbon dioxide as a solvent (2018)
Journal Article
Alexander, W., Wickson, J., Duncan, J., Carmichael, K., Irvine, D., & Howdle, S. (2018). Synthesis and control of crosslinked poly(acrylic acid) based viscosity modifiers using dense phase carbon dioxide as a solvent. Journal of Supercritical Fluids, 139, 38-44. https://doi.org/10.1016/j.supflu.2018.05.003

We investigate the clean synthesis of a cross-linked poly(acrylic acid) viscosity modifier using supercritical CO2 to replace more hazardous volatile organic solvents that are typically used for this process. The polymers were analysed by aqueous swe... Read More about Synthesis and control of crosslinked poly(acrylic acid) based viscosity modifiers using dense phase carbon dioxide as a solvent.

Can a combination of poly(ethylene glycol) and dense phase carbon dioxide improve processing of polylactide? A high pressure rheology investigation (2017)
Journal Article
Pepper, K., Masson, T., De Focatiis, D. S., & Howdle, S. M. (in press). Can a combination of poly(ethylene glycol) and dense phase carbon dioxide improve processing of polylactide? A high pressure rheology investigation. Journal of Supercritical Fluids, 133(1), https://doi.org/10.1016/j.supflu.2017.10.014

High temperature melts or use of organic solvents are not practicable approaches for encapsulating protein based or thermally labile drugs into degradable polymers. Here, we demonstrate that poly(ethylene glycol) (PEG) in combination with supercritic... Read More about Can a combination of poly(ethylene glycol) and dense phase carbon dioxide improve processing of polylactide? A high pressure rheology investigation.

One-pot synthesis of micron-sized polybetaine particles: innovative use of supercritical carbon dioxide (2017)
Journal Article
Bassett, S. P., Birkin, N. A., Jennings, J., Champman, E., O'Reilly, R. K., Howdle, S. M., & Willcock, H. (in press). One-pot synthesis of micron-sized polybetaine particles: innovative use of supercritical carbon dioxide. Polymer Chemistry, 8, https://doi.org/10.1039/C7PY00455A

Polybetaines exhibit unique properties combining anti-polyelectrolyte and low protein fouling behaviour, as well as biocompatibility. To date, the synthesis of polybetaine particles >50 nm has proved to be extremely challenging with standard emulsion... Read More about One-pot synthesis of micron-sized polybetaine particles: innovative use of supercritical carbon dioxide.

Mild synthesis of poly(HEMA)-networks as well-defined nanoparticles in supercritical carbon dioxide (2017)
Journal Article
Parilti, R., Alaimo, D., Grignard, B., Boury, F., Howdle, S., & Jerome, C. (2017). Mild synthesis of poly(HEMA)-networks as well-defined nanoparticles in supercritical carbon dioxide. Journal of Materials Chemistry B, 5, https://doi.org/10.1039/C7TB00740J

Free-radical dispersion polymerisation of 2-hydroxyethyl methacrylate was carried out in supercritical carbon dioxide (scCO2) in the presence of stabilisers based on polyethylene oxide (PEO) and poly(heptadecafluorodecyl acrylate) (PFDA). Different a... Read More about Mild synthesis of poly(HEMA)-networks as well-defined nanoparticles in supercritical carbon dioxide.

Bioreducible cross-linked core polymer micelles enhance in vitro activity of methotrexate in breast cancer cells (2017)
Journal Article
Gulfam, M., Matini, T., Monteiro, P. F., Riva, R., Collins, H., Spriggs, K., …Alexander, C. (2017). Bioreducible cross-linked core polymer micelles enhance in vitro activity of methotrexate in breast cancer cells. Biomaterials Science, 5, https://doi.org/10.1039/c6bm00888g

Polymer micelles have emerged as promising carriers for controlled release applications, however, several limitations of micelle-based drug delivery have also been reported. To address these issues, we have synthesized a functional biodegradable and... Read More about Bioreducible cross-linked core polymer micelles enhance in vitro activity of methotrexate in breast cancer cells.

Synthesis of polymeric microcapsules by interfacial-suspension cationic photopolymerisation of divinyl ether monomer in aqueous suspension (2017)
Journal Article
Benedetti, M., Congdon, T. R., Bassett, S. P., Alauhdin, M., Howdle, S. M., Haddleton, D. M., …Schiller, T. L. (2017). Synthesis of polymeric microcapsules by interfacial-suspension cationic photopolymerisation of divinyl ether monomer in aqueous suspension. Polymer Chemistry, 8(6), 972-975. https://doi.org/10.1039/c6py01782g

© 2017 The Royal Society of Chemistry. Polymeric microcapusles have been synthesised with a markedly more hydrophillic monomer than previously reported, triethylene glycol divinyl ether, using cationic photopolymerisation in an aqueous environment. C... Read More about Synthesis of polymeric microcapsules by interfacial-suspension cationic photopolymerisation of divinyl ether monomer in aqueous suspension.

Amphiphilic block copolymers from a renewable Ɛ-decalactone monomer: prediction and characterization of micellar core effects on drug encapsulation and release (2016)
Journal Article
Kakde, D., Taresco, V., Bansal, K. K., Magennis, E. P., Howdle, S. M., Mantovani, G., …Alexander, C. (in press). Amphiphilic block copolymers from a renewable Ɛ-decalactone monomer: prediction and characterization of micellar core effects on drug encapsulation and release. Journal of Materials Chemistry B, 44, https://doi.org/10.1039/C6TB01839D

Here we describe a methoxy poly(ethyleneglycol)-b-poly(ε-decalactone) (mPEG-b-PεDL) copolymer and investigate the potential of the copolymer as a vehicle for solubilisation and sustained release of indomethacin (IND). The indomethacin loading and rel... Read More about Amphiphilic block copolymers from a renewable Ɛ-decalactone monomer: prediction and characterization of micellar core effects on drug encapsulation and release.

Synthesis, characterization and evaluation of in vitro toxicity in hepatocytes of linear polyesters with varied aromatic and aliphatic co-monomers (2016)
Journal Article
Kakde, D., Powell, L. G., Bansal, K. K., Howdle, S., Irvine, D., Mantovani, G., …Alexander, C. (2016). Synthesis, characterization and evaluation of in vitro toxicity in hepatocytes of linear polyesters with varied aromatic and aliphatic co-monomers. Journal of Controlled Release, 244(B), https://doi.org/10.1016/j.jconrel.2016.08.003

Polyesters are extensively used in drug delivery because of their controllable biodegradation properties and perceived favorable cytocompatibility. However, new ester-based materials are continually being sought which can be produced from readily acc... Read More about Synthesis, characterization and evaluation of in vitro toxicity in hepatocytes of linear polyesters with varied aromatic and aliphatic co-monomers.

Improved particle size control for the dispersion polymerization of methyl methacrylate in supercritical carbon dioxide (2016)
Journal Article
McAllister, T. D., Farrand, L. D., & Howdle, S. M. (in press). Improved particle size control for the dispersion polymerization of methyl methacrylate in supercritical carbon dioxide. Macromolecular Chemistry and Physics, https://doi.org/10.1002/macp.201600131

Dispersion polymerization is a well-established method of producing polymer particles that are easily handled and processed. With careful choice of reaction conditions this technique can yield well defined, spherical particles for a wide range of app... Read More about Improved particle size control for the dispersion polymerization of methyl methacrylate in supercritical carbon dioxide.

Effect of supercritical CO2 on the copolymerization behavior of cyclohexene oxide/CO2 and copolymer properties with DMC/salen-Co(III) catalyst system (2016)
Journal Article
Meng, Q.-Y., Pepper, K., Cheng, R.-H., Howdle, S. M., & Liu, B.-P. (in press). Effect of supercritical CO2 on the copolymerization behavior of cyclohexene oxide/CO2 and copolymer properties with DMC/salen-Co(III) catalyst system. Journal of Polymer Science Part A: Polymer Chemistry, https://doi.org/10.1002/pola.28162

The copolymerization of cyclohexene oxide (CHO) and carbon dioxide (CO2) was carried out under supercritical CO2 (scCO2) conditions to afford poly (cyclohexene carbonate)(PCHC) in high yield. The scCO2 provided not only the C1 feedstock but also prov... Read More about Effect of supercritical CO2 on the copolymerization behavior of cyclohexene oxide/CO2 and copolymer properties with DMC/salen-Co(III) catalyst system.

Controlled polymerisation and purification of branched poly(lactic acid) surfactants in supercritical carbon dioxide (2016)
Journal Article
Goddard, A. R., Pérez-Nieto, S., Passos, T. M., Quilty, B., Carmichael, K., Irvine, D. J., & Howdle, S. M. (in press). Controlled polymerisation and purification of branched poly(lactic acid) surfactants in supercritical carbon dioxide. Green Chemistry, https://doi.org/10.1039/c6gc00745g

Product degradability, sustainability and low-toxicity are driving demand for the synthesis of biobased polymers and surfactants. Here we report the synthesis of novel surface active polymers using cyclic esters (D,L-lactide) and temperature sensitiv... Read More about Controlled polymerisation and purification of branched poly(lactic acid) surfactants in supercritical carbon dioxide.

Towards sustainable polymeric nano-carriers and surfactants: facile low temperature enzymatic synthesis of bio-based amphiphilic copolymers in scCO2 (2016)
Journal Article
Curia, S., & Howdle, S. M. (2016). Towards sustainable polymeric nano-carriers and surfactants: facile low temperature enzymatic synthesis of bio-based amphiphilic copolymers in scCO2. Polymer Chemistry, https://doi.org/10.1039/C6PY00066E

We demonstrate that useful bio-based amphiphilic polymers can be produced enzymatically at a mild temperature, in a solvent-free system and using renewably sourced monomers, by exploiting the unique properties of supercritical CO2 (scCO2). We present... Read More about Towards sustainable polymeric nano-carriers and surfactants: facile low temperature enzymatic synthesis of bio-based amphiphilic copolymers in scCO2.

How does dense phase CO2 influence the phase behaviour of block copolymers synthesised by dispersion polymerisation? (2015)
Journal Article
Jennings, J., Bassett, S., Hermida-Merino, D., Portale, G., Bras, W., Knight, L., …Howdle, S. (2015). How does dense phase CO2 influence the phase behaviour of block copolymers synthesised by dispersion polymerisation?. Polymer Chemistry, https://doi.org/10.1039/C5PY01823D

Block copolymers synthesised in supercritical CO2 dispersion undergo in situ self-assembly which can result in a range of nanostructured microparticles. However, our previous study revealed that copolymers with different block combinations possessed... Read More about How does dense phase CO2 influence the phase behaviour of block copolymers synthesised by dispersion polymerisation?.

Green process for green materials: viable low-temperature lipase-catalysed synthesis of renewable telechelics in supercritical CO2 (2015)
Journal Article
Curia, S., Barclay, A., Torron, S., Johansson, M., & Howdle, S. (2015). Green process for green materials: viable low-temperature lipase-catalysed synthesis of renewable telechelics in supercritical CO2. Philosophical Transactions A: Mathematical, Physical and Engineering Sciences, 373(2057), https://doi.org/10.1098/rsta.2015.0073

We present a novel near ambient temperature approach to telechelic renewable polyesters by exploiting the unique properties of supercritical CO2 (scCO2). Bio-based commercially available monomers have been polymerised and functional telechelic materi... Read More about Green process for green materials: viable low-temperature lipase-catalysed synthesis of renewable telechelics in supercritical CO2.

High-pressure rheological analysis of CO2-induced melting point depression and viscosity reduction of poly(ε-caprolactone) (2015)
Journal Article
Curia, S., De Focatiis, D. S., & Howdle, S. M. (2015). High-pressure rheological analysis of CO2-induced melting point depression and viscosity reduction of poly(ε-caprolactone). Polymer, 69, https://doi.org/10.1016/j.polymer.2015.05.026

High-pressure rheology has been used to assess the effects of supercritical carbon dioxide (scCO2) on the melting point (Tm) and viscosity of poly (ε-caprolactone) (PCL) over a range of temperatures and pressures up to 300 bar over a wide range of sh... Read More about High-pressure rheological analysis of CO2-induced melting point depression and viscosity reduction of poly(ε-caprolactone).

Facile one-spot synthesis of highly branched polycaprolactone (2014)
Journal Article
Nguyen, N. T., Thurecht, K. J., Howdle, S. M., & Irvine, D. J. (2014). Facile one-spot synthesis of highly branched polycaprolactone. Polymer Chemistry, 5(8), https://doi.org/10.1039/C3PY01725G

Reported is the first solvent-free (bulk) synthesis of degradable/bioresorbable, highly branched polymers via tin octanoate Sn(Oct2) catalysed controlled ring opening co-polymerisation (ROP) of mono and di-functional lactone monomers that proceed to... Read More about Facile one-spot synthesis of highly branched polycaprolactone.

Bacteria clustering by polymers induces the expression of quorum sense controlled phenotypes (2013)
Journal Article
Lui, L. T., Xue, X., Sui, C., Brown, A., Pritchard, D. I., Halliday, N., …Alexander, C. (2013). Bacteria clustering by polymers induces the expression of quorum sense controlled phenotypes. Nature Chemistry, 5(12), https://doi.org/10.1038/nchem.1793

Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environment. Quorum sensing is one mean by which bacteria use chemical reactions to modulate pre-infection behaviour such as surface attachment. Polymers that can... Read More about Bacteria clustering by polymers induces the expression of quorum sense controlled phenotypes.

Interconnectivity and permeability of supercritical fluid-foamed scaffolds and the effect of their structural properties on cell distribution (2013)
Journal Article
Reinwald, Y., Johal, R. K., Ghaemmaghami, A. M., Rose, F. R., Howdle, S. M., & Shakesheff, K. M. (2014). Interconnectivity and permeability of supercritical fluid-foamed scaffolds and the effect of their structural properties on cell distribution. Polymer, 55(1), 435-444. https://doi.org/10.1016/j.polymer.2013.09.041

This study aims to investigate interconnectivity and permeability of scCO2-foamed scaffolds and the influence of structural scaffold properties on cell distribution. Supercritical fluid technology was utilized to fabricated scaffolds from 37 kDa, 53... Read More about Interconnectivity and permeability of supercritical fluid-foamed scaffolds and the effect of their structural properties on cell distribution.

Uniform cell colonization of porous 3-D scaffolds achieved using radial control of surface chemistry (2011)
Journal Article
Intranuovo, F., Howard, D., White, L. J., Johal, R. K., Ghaemmaghami, A. M., Favia, P., …Alexander, M. R. (2011). Uniform cell colonization of porous 3-D scaffolds achieved using radial control of surface chemistry. Acta Biomaterialia, 7(9), 3336-3344. https://doi.org/10.1016/j.actbio.2011.05.020

Uniform cellular distribution is a prerequisite to forming tissue within porous scaffolds, but the seeding process often results in preferential adhesion of cells at the periphery. We develop a vapour phase coating strategy which is readily applicabl... Read More about Uniform cell colonization of porous 3-D scaffolds achieved using radial control of surface chemistry.