title: Photo-cross-linkable thermoresponsive star polymers designed for control of cell-surface interactions.
abstract: Star polymers with thermoresponsive arms, consisting of 2-(2-methoxyethoxy)ethyl methacrylate (MEO₂MA) and oligo(ethylene glycol) methacrylate with ~4 ethylene oxide units (OEOMA₃₀₀, M(n) = 300), were synthesized via atom transfer radical polymerization (ATRP). 25% of the arms contained benzophenone chain-end functionality at the star periphery. A mixture of linear poly(MEO₂MA-co-OEOMA₃₀₀)-Br macroinitiators without and with benzophenone end-group macroinitiators were (MI and Bzp-MI, respectively) cross-linked with ethylene glycol dimethacrylate to form star polymers. Formation of star polymers was monitored by GPC, and the presence of benzophenone functionality in the stars was confirmed by ¹H NMR. The UV-vis spectroscopy revealed that the star polymers exhibit the low critical solution temperature (LCST) at 27 °C, slightly lower than LCST of either MI or Bzp-MI. Commercially available tissue culture grade polystyrene surface was modified by depositing a thin film of functionalized stars and UV cross-linking (λ = 365 nm). The star polymers covalently attached onto surfaces allowed a control of cell shrinkage and attachment in response to temperature changes.
authors.affiliation: Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
authors.forename: Sangwoo
authors.initials: S
authors.lastname: Park
authors.forename: Hong Yul
authors.initials: HY
authors.lastname: Cho
authors.forename: Jeong Ae
authors.initials: JA
authors.lastname: Yoon
authors.forename: Yungwan
authors.initials: Y
authors.lastname: Kwak
authors.forename: Abiraman
authors.initials: A
authors.lastname: Srinivasan
authors.forename: Jeffrey O
authors.initials: JO
authors.lastname: Hollinger
authors.forename: Hyun-jong
authors.initials: HJ
authors.lastname: Paik
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Matyjaszewski
mesh_terms: D000818:Animals; D001577:Benzophenones / Q000737:chemistry; D002448:Cell Adhesion / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000737:chemistry*; D005027:Ethylene Oxide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000737:chemistry; D051379:Mice; D008858:Microscopy, Phase-Contrast; D015394:Molecular Structure; D041681:NIH 3T3 Cells; D055668:Photochemical Processes; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011137:Polystyrenes / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D001577:Benzophenones; D003432:Cross-Linking Reagents; D008689:Methacrylates; D011108:Polymers; D011137:Polystyrenes; C539356:2-(2-methoxyethoxy)ethyl methacrylate; C047723:benzophenone; C004919:ethylene dimethacrylate; D005027:Ethylene Oxide