Cells are inherently sensitive to local mesoscale, microscale, and nanoscale patterns of chemistry and topography. We are developing approaches to control cell behavior through the nanoscale engineering of materials surfaces including monolayer protected metal, nanotubes and other nanotopographies/ nanochemistries. Far-reaching implications are emerging for applications including medical implants, cell supports, and materials that can be used as instructive three-dimensional environments for tissue regeneration.
The Stevens group has substantial experience in designing materials for tissue engineering based on explorations of the cell-material interface will enable the rational design of bio-functionalised materials with extracellular influences introduced in optimised forms. Fundamental cell-material interface mechanisms are explored across the length scales from the cell to the tissue level with state of the art bioengineering and materials science.
Elucidating the events within the cell-material interface informs us so that the surface chemistry of designed materials can be engineered accordingly. One conceptual framework of doing so involves treating the cell and the material surface as chemical systems. This approach minimizes the sophisticated complexity encountered when viewing these systems from a systems biology perspective. Our publication in Nature Chemistry, 2011 [Mager, LaPointe and Stevens, 2011
] focuses on using such an approach to tailor a material for a specific application.
Protein adsorption is a fundamentally important process for biomaterials as it can influence the performance and functionality of biomaterials on the nanoscale. Computational models are being used in collaboration with Prof Irene Yarovsky (RMIT) to model non-homogeneous complex molecular systems at functionalised nanostructured interfaces, which have elucidated specific adsorption behaviour of proteins on nanostructured surfaces [Hung, Mwenifumbo, Mager, Kuna, Stellacci, Yarovski and Stevens, 2011
; Hung, Mager, Hembury, Stellacci, Stevens and Yarovsky, 2012
], whilst solvent molecules arranged at nanostructured surfaces have also been elucidated, which was published in Nature Materials [Kuna, Voïtchovsky, Singh, Jiang, Mwenifumbo, Ghorai, Stevens, Glotzer and Stellacci, 2009
• The Stevens group has developed a number of techniques to better understand and exploit the cell surface, which is an extremely sophisticated yet complicated dynamic construct. There are thousands of lipids, proteins and carbohydrates located on or within the lipid bilayer that are organised and arranged across multiple length scales and understanding and engineering the chemistry occurring at the interface between the cell surface and a biomaterial is an enormous task. The Stevens group uses numerous approaches that address the challenges facing this field, where many of these topics have been published in Science [Stevens and George, 2005
] and Nature Chemistry [Mager, LaPointe and Stevens, 2011
• The Stevens group uses a number of innovative methods to investigate the material influences on cell behaviour and differentiation. The topographical cues and surface properties presented by underlying or surrounding material substrates need to be identified to determine how they instruct adjacent cells, such as embryonic stem cells, osteoblasts and osteoclasts. An example of this includes one recent study showing how embryonic stem cell colonies respond to substrates formed of silica colloidal crystal microspheres with varying topographical cues [Ji, LaPointe, Evans, Stevens, 2012