title: Osteoblast adhesion on poly(L-lactic acid)/polystyrene demixed thin film blends: effect of nanotopography, surface chemistry, and wettability.
abstract: Biomaterial surface characteristics are critical cues that regulate cell function. We produced a novel series of poly(l-lactic acid) (PLLA) and polystyrene demixed nanotopographic films to provide nonbiological cell-stimulating cues. The increase in PLLA weight fraction (phi) in blend solutions resulted in topography changes in spin-cast films from pit-dominant to island-dominant morphologies having nanoscale depth or height (3-29 nm). Lower molecular weight PLLA segregated to the top surface of demixed films, as observed by X-ray photoelectron spectroscopy and secondary ion mass spectroscopy (SIMS). For phi > or = 0.5, the topmost film layer was predominantly filled with PLLA (>96% by SIMS at 20-A depth). Nanotextured substrata stimulated osteoblastic cell adhesion to a greater degree than did flat PLLA (phi = 1), and this effect was more pronounced for nanoisland (phi = 0.7 and 0.9) relative to nanopit topographies (phi = 0.5). Demixed films having relatively lower water contact angles generally enhanced cell adhesion and spreading. Our results reveal that cell adhesion is affected by surface chemistry, topography, and wettability simultaneously and that nanotextured surfaces may be utilized in regulating cell adhesion.
authors.affiliation: Division of Musculoskeletal Sciences, Department of Orthopaedics and Rehabilitation, Center for Biomedical Devices and Functional Tissue Engineering, College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033, USA.
authors.forename: Jung Yul
authors.initials: JY
authors.lastname: Lim
authors.forename: Joshua C
authors.initials: JC
authors.lastname: Hansen
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Siedlecki
authors.forename: Robert W
authors.initials: RW
authors.lastname: Hengstebeck
authors.forename: Juan
authors.initials: J
authors.lastname: Cheng
authors.forename: Nicholas
authors.initials: N
authors.lastname: Winograd
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Donahue
mesh_terms: D000268:Adhesiveness; D001672:Biocompatible Materials / Q000737:chemistry*; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000295:instrumentation*; D002478:Cells, Cultured; D006801:Humans; D007477:Ions; D019344:Lactic Acid / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry*; D013058:Mass Spectrometry; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: D001672:Biocompatible Materials; D007477:Ions; D046911:Macromolecular Substances; D011091:Polyesters; D011108:Polymers; D011137:Polystyrenes; D014867:Water; D019344:Lactic Acid; C033616:poly(lactide)