title: Synthesis of polyacid nanogels: pH-responsive sub-100 nm particles for functionalisation and fluorescent hydrogel assembly.
abstract: Nanogels are crosslinked polymer particles with a swollen size between 1 and 100 nm. They are of major interest for advanced surface coatings, drug delivery, diagnostics and biomaterials. Synthesising polyacid nanogels that show triggered swelling using a scalable approach is a key objective of polymer colloid chemistry. Inspired by the ability of polar surfaces to enhance nanoparticle stabilisation, we report the first examples of pH-responsive polyacid nanogels containing high -COOH contents prepared by a simple, scalable, aqueous method. To demonstrate their functionalisation potential, glycidyl methacrylate was reacted with the -COOH chemical handles and the nanogels were converted to macro-crosslinkers. The concentrated (functionalised) nanogel dispersions retained their pH-responsiveness, were shear-thinning and formed physical gels at pH 7.4. The nanogels were covalently interlinked via free-radical coupling at 37 °C to form transparent, ductile, hydrogels. Mixing of the functionalised nanogels with polymer dots enabled covalent assembly of fluorescent hydrogels.
authors.affiliation: School of Materials, University of Manchester, Manchester, M13 9PL, UK. amirhossein.milani@manchester.ac.uk.
authors.forename: Amir H
authors.identifier: http://orcid.org/0000-0001-6243-9738
authors.initials: AH
authors.lastname: Milani
authors.affiliation: School of Materials, University of Manchester, Manchester, M13 9PL, UK. amirhossein.milani@manchester.ac.uk.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Saunders
authors.affiliation: School of Materials, University of Manchester, Manchester, M13 9PL, UK. amirhossein.milani@manchester.ac.uk.
authors.forename: Nam T
authors.initials: NT
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK.
authors.forename: Liam P D
authors.initials: LPD
authors.lastname: Ratcliffe
authors.affiliation: Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Daman J
authors.initials: DJ
authors.lastname: Adlam
authors.affiliation: Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Freemont
authors.affiliation: Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, UK and NIHR Manchester Musculoskeletal Biomedical Research Unit, Manchester Academic Health Science Centre, Manchester, UK.
authors.forename: Judith A
authors.initials: JA
authors.lastname: Hoyland
authors.affiliation: Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Armes
authors.affiliation: School of Materials, University of Manchester, Manchester, M13 9PL, UK. amirhossein.milani@manchester.ac.uk.
authors.forename: Brian R
authors.identifier: http://orcid.org/0000-0003-1410-2967
authors.initials: BR
authors.lastname: Saunders