Subject groups/Research projects
Biological Evaluation of Ferromagnetic Fibre Networks for Bone Growth Stimulation
- Dr Roger Brooks (Orthopaedic Research Unit, Addenbrooke’s Hospital)
- Dr Rose Spear (Engineering Department, University of Cambridge)
- Study the response of human mesenchymal stem cells to stainless steels networks
Patients undergoing total joint replacement operations can experience complications during recovery due to failure of the implant to integrate with bone tissue. The use of bonded networks of ferromagnetic fibres as an anchoring technique for bone tissue in-growth has been proposed  to improve implant fixation. When the network is subjected to an external magnetic field, alignment of the fibres imposes mechanical strains to in-growing bone tissue. Such deformation is known to promote bone cell growth provided the strains lie in the beneficial range. Incorporation of human mesenchymal stem cells (hMSCs) into ferromagnetic stainless steel fibre networks, as an allogeneic“off-the shelf”product, could further prevent implant failure by stimulating osteogenesis within the networks.
Research rationale describing the steps included for a proposed clinical use of magneto-mechanically actuated hMSCs to promote implant anchoring.
My research is focused on the in vitro responses of hMSCs to 444 ferritic stainless steel. Cellular viability and proliferation as well as metabolic activity are examined using the CyQuant® and AlamarBlue® assays respectively. Scanning electron microscopy (SEM) and fluorescence imaging are used to investigate cellular morphology. Measurement of alkaline phosphatase (ALP) activity is used to determine early osteoblastic differentiation. Gene expression of osteogenic markers is investigated by real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR), while their phenotype is characterised by fluorescence activated cell sorting (FACS).
Future in vitro studies will focus on assessing whether hMSC differentiation and bone tissue in-growth can be influenced by magneto-mechanical strain induction within the fibre network.
Extracellular matrix formation and calcification of hMSC cultures grown on 316L and 444 fibre networks, as obtained by SEM imaging.
- A.E. Markaki and T.W. Clyne: "Magneto-mechanical stimulation of bone growth in a bonded array of ferromagnetic fibres", Biomaterials 25(2004), pp. 4805-4815.