Nippon Sheet Glass Lecture- Dr. Jeffrey Brinker
Silica and Cells: A special relationship
We have shown that yeast, bacterial, and mammalian cells, when introduced into self-assembling solutions of phospholipids and soluble sol‐gel silica precursors, serve as living colloids directing the formation of unique biotic/abiotic interfaces and architectures (Science 2006, Nature Chem Biol. 2010). The result is a lipid‐associated cellular interface coherently incorporated within a surrounding lipid templated silica nanostructure. This structure allows us to understand and direct cellular behavior at the individual cell level, where we find, for example, that nanoconfinement results in cellular reprogramming, synchronization, and cell cycle arrest. The association of silica with cellular interfaces has been further explored in recent work, where we have discovered a process, Silica Cell Replication, wherein mammalian cells direct their exact replication in silica. The silica cell replicas preserve nm‐ to macro‐scale cellular features and dimensions on both the cell surface and interior after drying at room temperature ‐ and largely after calcination to 600 ̊C. The process appears to be self‐limiting and self‐healing, and remarkably generalizable to any cells of interest. Turning these lipid‐associated silica nanostructures inside out, we have also recently explored lipid bilayers supported on mesoporous silica nanoparticles (aka ‘protocells’) as a new nanoparticle delivery agent (Nature Materials 2011). The fluidity but stability of the mesoporous silica supported lipid bilayer provides a reconfigurable biomolecular surface that engages target cells multivalently, enhancing selective binding and internalization, while minimizing off‐target binding and immune response.