title: Poly(ethylene glycol) microparticles produced by precipitation polymerization in aqueous solution.
abstract: Methods were developed to perform precipitation photopolymerization of PEG-diacrylate. Previously, comonomers have been added to PEG when precipitation polymerization was desired. In the present method, the LCST of the PEG itself was lowered by the addition of the kosmotropic salt sodium sulfate to an aqueous solution. Typical of a precipitation polymerization, small microparticles or microspheres (1-5 μm) resulted with relatively low polydispersity. However, aggregate formation was often severe, presumably because of a lack of stabilization of the phase-separated colloids. Microparticles were also produced by copoymerization of PEG-diacrylate with acrylic acid or aminoethylmethacrylate. The comonomers affected the zeta potential of the formed microparticles but not the size. The carboxyl groups of acrylic-acid-containing PEG microparticles were activated, and scaffolds were formed by mixing with amine-containing PEG microparticles. Although the scaffolds were relatively weak, human hepatoma cells showed excellent viability when present during microparticle cross-linking.
authors.affiliation: Department of Biomedical Engineering and Center for Materials Innovation, Washington University, St. Louis, Missouri, USA.
authors.forename: Megan M
authors.initials: MM
authors.lastname: Flake
authors.forename: Peter K
authors.initials: PK
authors.lastname: Nguyen
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Scott
authors.forename: Leah R
authors.initials: LR
authors.lastname: Vandiver
authors.forename: Rebecca Kuntz
authors.initials: RK
authors.lastname: Willits
authors.forename: Donald L
authors.initials: DL
authors.lastname: Elbert
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival; D011232:Chemical Precipitation; D006801:Humans; D008863:Microspheres; D010316:Particle Size; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry / Q000627:therapeutic use; D058105:Polymerization; D012996:Solutions; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D012996:Solutions; D011092:Polyethylene Glycols