title: Preparation of thermoresponsive polymer brush surfaces and their interaction with cells.
abstract: Poly(N-isopropylacrylamide) (PIPAAm) brush surfaces with different layer thickness on polystyrene substrates were prepared by surface-initiated atom transfer radical polymerization (ATRP). Surface characteristics of PIPAAm brushes and their influence on adhesion and detachment of bovine carotid artery endothelial cells (ECs) were controlled by PIPAAm layer thickness. Surface hydrophilicity increased with PIPAAm layer thickness at 37 degrees C because PIPAAm brush surfaces with higher thickness provide more extended chain conformations with relatively high chain mobility, and accompanying polymer chain hydration. These surface property alterations lead to negligible cell adhesion through minimal matrix protein adsorption and also modified surface modulus. By adjusting polymerization reaction conditions and time, polymer layers supporting confluent cultures of ECs were possible. Confluent EC monolayers spontaneously detached as contiguous cell sheets from PIPAAm brush surfaces at reduced temperatures. Thermoresponsive cell adhesion and detachment behavior were analyzed from the standpoint of surface physicochemical characteristics. Thermoresponsive surfaces prepared by surface-initiated ATRP techniques allow surface selection in preparing cell sheets from attachment-dependent cells having relatively strong adhesive property for tissue engineering applications.
authors.affiliation: Department of Pharmacy, Kyoritsu University of Pharmacy, 1-5-14 Shibakoen, Minato, Tokyo 105-0011, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Mizutani
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.forename: Hideko
authors.initials: H
authors.lastname: Kanazawa
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D002448:Cell Adhesion; D048430:Cell Shape; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D005609:Free Radicals / Q000737:chemistry; D015394:Molecular Structure; D013499:Surface Properties; D013696:Temperature
chemical_list: D000180:Acrylic Resins; D005353:Fibronectins; D005609:Free Radicals; C052970:poly-N-isopropylacrylamide