Synovial fluid protein adsorption on polymer-based artificial hip joint material investigated by MALDI-TOF mass spectrometry imaging

•Protein adsorption was investigated for UHMWPE hip joint material using synovial fluid as lubricant.•High abundance proteins and especially apolipoproteins subunits were identified on gamma-irradiated and Vitamin E doped UHMWPE using SDS PAGE and mass spectrometry imaging.•Mass spectrometry imaging revealed a homogeneous protein distribution on planar polymer surfaces.•Morphological changes of UHMWPE material, i.e. rough surfaces, lead to enhanced protein cluster formation.

UHMW-PE (ultra-high molecular weight polyethylene), most frequently used material in acetabular cup replacement, is affected by the interaction with its surrounding synovial fluid. It is assumed that protein layer formation is of high importance for lubrication, however alters polymer characteristics. This study investigates in vitro protein adsorption on gamma-irradiated and Vitamin E doped UHMW-PE using synovia as modeling system. SDS-PAGE and MALDI-TOF mass spectrometry imaging showed adsorption of high abundance proteins in a mass range between 2 and 200 kDa. Protein layer formation was observed on planar UHMW-PE material, whereas morphologically modified UHMW-PE regions were highly affected by protein aggregation.

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