title: Adhesive forces and surface properties of cold gas plasma treated UHMWPE.
abstract: Cold atmospheric plasma (CAP) treatment was used on ultra-high molecular weight polyethylene (UHMWPE), a common articulating counter material employed in hip and knee replacements. UHMWPE is a biocompatible polymer with low friction coefficient, yet does not have robust wear characteristics. CAP effectively cross-links the polymer chains of the UHMWPE improving wear performance (Perni et al., Acta Biomater. 8(3) (2012) 1357). In this work, interactions between CAP treated UHMWPE and spherical borosilicate sphere (representing model material for bone) were considered employing AFM technique. Adhesive forces increased, in the presence of PBS, after treatment with helium and helium/oxygen cold gas plasmas. Furthermore, a more hydrophilic surface of UHMWPE was observed after both treatments, determined through a reduction of up to a third in the contact angles of water. On the other hand, the asperity density also decreased by half, yet the asperity height had a three-fold decrease. This work shows that CAP treatment can be a very effective technique at enhancing the adhesion between bone and UHMWPE implant material as aided by the increased adhesion forces. Moreover, the hydrophilicity of the CAP treated UHMWPE can lead to proteins and cells adhesion to the surface of the implant stimulating osseointegration process.
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Science, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK.
authors.forename: Emily Callard
authors.initials: EC
authors.lastname: Preedy
authors.affiliation: Cardiff School of Engineering, Cardiff University, Queen's Buildings, The Parade, Cardiff CF24 3AA, Wales, UK.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Brousseau
authors.affiliation: Cardiff School of Engineering, Cardiff University, Queen's Buildings, The Parade, Cardiff CF24 3AA, Wales, UK.
authors.forename: Sam L
authors.initials: SL
authors.lastname: Evans
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Science, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK ; Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, NE47-377, Cambridge, MA 02139, USA.
authors.forename: Stefano
authors.initials: S
authors.lastname: Perni
authors.affiliation: Cardiff School of Pharmacy and Pharmaceutical Science, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK ; Cardiff School of Engineering, Cardiff University, Queen's Buildings, The Parade, Cardiff CF24 3AA, Wales, UK ; Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, NE47-377, Cambridge, MA 02139, USA.
authors.forename: Polina
authors.initials: P
authors.lastname: Prokopovich
keywords: A.C., alternative current; AFM; AFM, atomic force microscopy; Adhesion forces; CAP, cold atmospheric plasma; Cold atmospheric plasma-treatment; ECM, extracellular matrix; Material modification; PBS, phosphate buffer solution; PCTFE, polychlorofluoroethylene; Surface topography; TJA, total joint arthroplasty; TJR, total joint replacement; UHMWPE; UHMWPE, ultra-high molecular weight polyethylene; XLPE, highly cross-linked polyethylene; sccm, standard cubic centimetre per minute; slm, standard litre per minute