title: Investigating the biological response of human mesenchymal stem cells to titanium surfaces.
abstract: BACKGROUND
  We have investigated the behaviour of a newly characterised population of haemarthrosis fluid-derived human mesenchymal stem cells (HF-hMSCs) with titanium (Ti) surfaces.
  
  
  METHODS
  HF-hMSCs were seeded onto round cannulated interference (RCI; Smith and Nephew) screws or control Ti discs and cultured under pro-osteogenic conditions.
  
  
  RESULTS
  Electron microscopy showed the attachment and spreading of HF-hMSCs across both Ti surfaces during the early stages of osteogenic culture; however, cells were exclusively localised to the basal regions within the vertex of the Ti screws. In the later stages of culture, an osteoid matrix was deposited on the Ti surfaces with progressive culture expansion and matrix deposition up the sides and the top of the Ti Screws. Quantification of cellular content revealed a significantly higher number of cells within the Ti screw cultures; however, there was no difference in the cellular health. Conversely, alizarin red staining used as both a qualitative and quantitative measure of matrix calcification was significantly increased in Ti disc cultures compared to those of Ti screws.
  
  
  CONCLUSIONS
  Our results suggest that the gross topography of the metal implant is able to create microenvironment niches that have an influence on cellular behaviour. These results have implications for the design of advanced tissue engineering strategies that seek to use cellular material to enhance biological remodelling and healing following tissue reconstruction.
authors.affiliation: Centre for Oral Health Research, School of Dental Sciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4BW, UK. matthew.german@ncl.ac.uk.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: German
authors.affiliation: Institute of Genetic Medicine, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Times Square, Newcastle upon Tyne, NE1 4EP, UK. charles.osei-bempong@ncl.ac.uk.
authors.forename: Charles
authors.initials: C
authors.lastname: Osei-Bempong
authors.affiliation: North East England Stem Cell Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Times Square, Newcastle upon Tyne, NE1 4EP, UK. callieanknuth@gmail.com.
authors.forename: Callie A
authors.initials: CA
authors.lastname: Knuth
authors.affiliation: Department of Orthopaedics, Freeman Hospital, Newcastle upon Tyne NHS Hospitals Foundation Trust, Freeman Road, High Heaton, Newcastle upon Tyne, NE7 7DN, UK. david.deehan@nuth.nhs.uk.
authors.forename: David J
authors.initials: DJ
authors.lastname: Deehan
authors.affiliation: North East England Stem Cell Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Times Square, Newcastle upon Tyne, NE1 4EP, UK. lrao1@liverpool.ac.uk.|Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, The University of Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK. lrao1@liverpool.ac.uk.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Oldershaw
mesh_terms: D000328:Adult; D001863:Bone Screws; D000069343:Bone-Implant Interface / Q000502:physiology*; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010012:Osteogenesis / Q000502:physiology; D014025:Titanium / Q000378:metabolism*
chemical_list: D014025:Titanium