Subject groups/Research projects
Evaluation of Materials Intended for Implants and Biomedical Applications
Dr Spear's research expertise is in chemical reactions and biological interactions – proteins and cells – with biomedical materials. As a Research Associate in the Life Science Division of the Engineering Department at the University of Cambridge, her experiments have focused in two areas 1. protein deposition on stainless steel implant surfaces [1, 2] and 2. cellular responses to ferromagnetic metallic scaffolds intended for applications in magneto-mechanical stimulation of bone tissue [3-5].
Protein deposition on stainless steel fibre networks
Current work with human osteoblasts  and mesenchymal stromal cells  is focused on the effect of protein deposition on cell behaviour within stainless steel fibre networks. The overall aim for this project is to understand the how protein deposition affects the process of magneto-mechanical strain transduction to cells in these magneto-active fibre networks.
Magneto-mechanical stimulation of human bone cells in ferritic stainless steel fibre networks
Current investigations study the responses of human mesenchymal stromal cells and osteoblasts within magneto-active fibre networks following the application of cyclic magnetic fields. The project uses cellular (metabolic activity, proliferation, flow cytometry characterisation of antigen expression), molecular biology (qPCR) and imaging techniques (immunostaining, confocal, scanning electron microscopy) to understand cellular responses to magneto-mechanical strain.
Acute inflammatory responses of human peripheral blood monocytes
Early work focused on acute inflammatory responses of human peripheral blood monocytes to stainless steel surfaces. Experiments with fully dense discs showed that 444 ferromagnetic stainless steel surfaces do not cause a significant inflammatory response from human monocytes in short-term cultures compared with 316L stainless steel surfaces . Additional studies considered the inflammatory response – as indicated by tumour necrosis factor-alpha and lactate dehydrogenase release – to three-dimensional networks of ferromagnetic fibre networks [5,6]. The results indicated that fibre networks composed of 444 ferritic stainless steel produce comparable responses to control networks composed of 316L austenitic stainless steel. These ferritic fibre networks were able to support human peripheral blood monocytes in short-term in vitro cultures without inducing significant inflammatory or cytotoxic effects .
- R.L. Spear, B. Srigengan, S. Neelakantan, W. Bosbach, R. A. Brooks, A.E. Markaki (2015), "Physical and Biological Characterisation of Ferromagnetic Fibre Networks: Effect of Fibrin Deposition on Short-term In Vitro Responses of Human Osteoblasts", Tissue Engineering Part A, 21(3-4), pp. 463-474. doi:10.1089/ten.tea.2014.0211.
- R.L. Spear, Antonia Symeonidou, Jeremy N. Skepper, Roger A. Brooks and Athina E. Markaki
(2015), "Fibrin affects short-term in vitro responses of human mesenchymal stromal cells to magneto-active fibre networks", submitted to Biomaterials and Biomedical Engineering.
- 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.
- V.N. Malheiro, R.L. Spear, R.A. Brooks, A.E. Markaki (2011), “Osteoblast and Monocyte Responses to 444 Ferritic Stainless Steel intended for a Magneto-Mechanically Actuated Fibrous Scaffold”, Biomaterials, 32(29), pp. 6883-6892.
- R.L. Spear, R.A. Brooks and A.E. Markaki (2013), "Short-term In vitro Responses of Human Peripheral Blood Mononuclear Cells to Ferritic Stainless Steel Fibre Networks", Journal of Biomedical Materials Research: Part A. 101A(5), pp. 1456-1463.
For several years, Dr Spear has contributed to the volunteer outreach efforts of the British Science Association throughout Cambridgeshire, leading events in public spaces such as shopping centres, cinemas and festivals.
You can view a list of Dr Spear's publications in the Engineering Department Publications Database.