title: Aqueous worm gels can be reconstituted from freeze-dried diblock copolymer powder.
abstract: Worm-like diblock copolymer nanoparticles comprising poly(glycerol monomethacrylate) (PGMA) as a stabilizer block and poly(2-hydroxypropyl methacrylate) (PHPMA) as a core-forming block were readily synthesized at 10% w/w solids via aqueous dispersion polymerization at 70 °C using Reversible Addition-Fragmentation chain Transfer (RAFT) chemistry. On cooling to 20 °C, soft transparent free-standing gels are formed due to multiple inter-worm interactions. These aqueous PGMA-PHPMA diblock copolymer worms were freeze-dried, then redispersed in water with cooling to 3-5 °C before warming up to 20 °C; this protocol ensures molecular dissolution of the copolymer chains, which aids formation of a transparent aqueous gel. Rheology, SAXS and TEM studies confirm that such reconstituted gels comprise formed PGMA-PHPMA copolymer worms and they possess essentially the same physical properties determined for the original worm gels prior to freeze-drying. Such worm gel reconstitution is expected to be highly beneficial in the context of various biomedical applications, since it enables worm gels to be readily prepared using a wide range of cell growth media as the continuous aqueous phase.
authors.affiliation: Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, Yorkshire S3 7HF, UK. s.p.armes@shef.ac.uk.
authors.forename: M K
authors.initials: MK
authors.lastname: Kocik
authors.forename: O O
authors.initials: OO
authors.lastname: Mykhaylyk
authors.forename: S P
authors.initials: SP
authors.lastname: Armes
mesh_terms: D005612:Freeze Drying; D005782:Gels / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012212:Rheology; D053838:Scattering, Small Angle; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D005782:Gels; D011108:Polymers