Soft Matter Approaches to Drug Delivery Shapes and Stem Cell Differentiation

From viruses to tissue matrices, biology is filled with examples that motivate mimicry with a goal toward clarifying biological principles. Several distinct systems will be described from our explorations of ‘nano'-shape, flexibility, and ligands in bio-function and recognition. First, filamentous viruses inspire development of worm-like polymer micelles that reveal nano-therapeutics deliver better if non-spherical in shape [1]. Second, crosslinked tissue matrices are measured and then imitated in their elasticity with polymeric hydrogels, demonstrating the potent influence of matrix elasticity on basic processes such as stem cell differentiation [2] while motivating novel Mass Spec approaches to in-cell protein structure [3]. Lastly – as ideas and systems are tested in vivo and the innate immune system is confronted – progress will be shown on species specific ‘Marker of Self' ligands that inhibit and passivate phagocytes on contact [4]. The results collectively illustrate the potential for a productive interplay between materials biophysics and biomolecular engineering.

References: [1] Geng et al. Nature Nanotech. 2: 249 (2007). [2] Engler et al. Cell 126: 677 (2006). [3] Johnson et al. Science 317: 663 (2007). [4] Tsai et al. J Cell Biol 180: 989 (2008).