title: Precipitant induced porosity augmentation of polystyrene preserves the chondrogenicity of human chondrocytes.
abstract: Cells constantly sense and receive chemical and physical signals from neighboring cells, interstitial fluid, and extracellular matrix, which they integrate and translate into intracellular responses. Thus, the nature of the surface on which cells are cultured in vitro plays an important role for cell adhesion, proliferation, and differentiation. Autologs chondrocyte implantation is considered the treatment of choice for larger cartilage defects in the knee. To obtain a sufficient number of chondrocytes for implantation multiple passaging is often needed, which raises concerns about the changes in the chondrogenic phenotype. In the present study, we analyzed the effect at cellular and molecular level of precipitant induced porosity augmentation (PIPA) of polystyrene surfaces on proliferation and differentiation of human chondrocytes. Human chondrocytes were isolated from healthy patients undergoing anterior cruciate ligament reconstruction and cultured on PIPA modified polystyrene surfaces. Microscopical analysis revealed topographically arranged porosity with micron pores and nanometer pits. Chondrocytes cultured on PIPA surfaces revealed no difference in cell viability and proliferation, but gene- and protein expressions of collagen type II were pronounced in the first passage of chondrocytes when compared to chondrocytes cultured on control surfaces. Additionally, an analysis of 40 kinases revealed that chondrocytes expanded on PIPA caused upregulated PI3K/mTOR pathway activation and inhibition of mTORC1 resulted in reduced sGAG synthesis. These findings indicate that PIPA modified polystyrene preserved the chondrogenicity of expanded human chondrocytes at gene and protein levels, which clinically may be attractive for the next generation of cell-culture surfaces for ex vivo cell growth. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3073-3081, 2016.
authors.affiliation: Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark. nljorgensen@clin.au.dk.
authors.forename: Natasja L
authors.initials: NL
authors.lastname: Joergensen
authors.affiliation: Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Casper B
authors.initials: CB
authors.lastname: Foldager
authors.affiliation: Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Dang Q S
authors.initials: DQ
authors.lastname: Le
authors.affiliation: Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark.|Sports Trauma Clinic, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Lind
authors.affiliation: Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Helle
authors.initials: H
authors.lastname: Lysdahl
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D011232:Chemical Precipitation; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D020219:Chondrogenesis; D004146:Dioxanes / Q000737:chemistry*; D005786:Gene Expression Regulation; D006801:Humans; D011137:Polystyrenes / Q000737:chemistry*; D016062:Porosity; D011494:Protein Kinases / Q000378:metabolism; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D004146:Dioxanes; D011137:Polystyrenes; D011494:Protein Kinases; C025223:1,4-dioxane
keywords: cell-surface interaction; chondrocytes; surface modification; surface topography; tissue engineering