title: Effect of the hydrophobic basal layer of thermoresponsive block co-polymer brushes on thermally-induced cell sheet harvest.
abstract: Thermoresponsive poly(benzyl methacrylate)-b-poly(N-isopropylacrylamide) (PBzMA-b-PIPAAm) block co-polymer brush surfaces were prepared by surface-initiated two-step reversible addition-fragmentation chain transfer radical (RAFT) polymerization. PBzMA brushes were fabricated on azoinitiator-immobilized glass substrates in the presence of dithiobenzoate (DTB) compound as a RAFT agent. The amount of grafted polymer was regulated by initial monomer concentrations. The second thermoresponsive blocks were added to the RAFT-related DTB groups located at PBzMA termini through the propagation of PIPAAm chains, resulting in formation of PBzMA-b-PIPAAm brushes. Surface characteristics of the block co-polymer brushes and its influence on thermally regulated cellular behavior were investigated using bovine carotid artery endothelial cells (BAECs), compared with PIPAAm brush surfaces. Cell adhesion/detachment behavior on thermoresponsive polymer brush surfaces significantly depended on their individual polymer architectures and chemical compositions of grafted polymers. Low-temperature treatment at 20°C, below the phase-transition temperature of PIPAAm, induced the spontaneous detachment of adhering cells from the PBzMA-b-PIPAAm brush surfaces with a higher rate than that from PIPAAm brush surfaces. In addition, the cell-repellent effect of the hydrophobic basal layer successfully accelerated for harvesting BAEC sheets from the block co-polymer brush surfaces. Unique features of thermoresponsive block co-polymer brush architectures can be applied to control cell-adhesion strength for enhancing cell adhesion or accelerating cell detachment.
authors: a Department of Materials Science and Technology , Graduate School of Industrial Science and Technology, Tokyo University of Science , 2641 Yamazaki , Noda , Chiba , 278-8510 , Japan.
authors: Naoki
authors: N
authors: Matsuzaka
authors: Hironobu
authors: H
authors: Takahashi
authors: Masamichi
authors: M
authors: Nakayama
authors: Akihiko
authors: A
authors: Kikuchi
authors: Teruo
authors: T
authors: Okano
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D002339:Carotid Arteries / Q000502:physiology; D002417:Cattle; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000295:instrumentation* / Q000379:methods; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology; D005898:Glass; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D015394:Molecular Structure; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry*; D013388:Succinimides / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D017155:Wettability
chemical_list: D000180:Acrylic Resins; D011109:Polymethacrylic Acids; D013388:Succinimides; C098156:polybenzylmethacrylate; C052970:poly-N-isopropylacrylamide; C011240:dithiobis(succinimidylpropionate)