Silicon-based cell-like biomaterials for studying multiscale emergent behaviors
Abstract
Phospholipid bilayers, ion channels, and cytoskeletal systems promote communication and cooperation among single cells, and can produce emergent properties in tissue assemblies. These emergent properties occur at many length scales, from the subcellular level (e.g. the cytoskeletal patterns in a neural axon) to the whole animal (e.g. skin patterns in octopus). In particular, single cells make use of dynamic internal structures to control their shape and movement. With appropriate energy inputs, these internal structures can be assembled into organized and coordinated systems for force generation and movement, allowing cells to adapt to their environment. The proposed research effort involves the construction of synthetic mimics of cells, such as liposomes, and the employment of them for the investigation of emergent properties in cellular and synthetic systems across multiple length scales. Specifically, silicon-supported liposome structures will be constructed by integrating intrinsically stretchable and deformable silicon nanostructures with phospholipids in a liposome system. The silicon nanostructures will have a Young~s modulus (i.e. measure of stiffness in a solid material) at a level comparable to natural biomaterials, such as collagen, and will serve as a mimic of the cytoskeletal network of living cells. Additionally, the photothermal properties of the nanostructured silicon network are expected to allow for light-induced heat from the silicon-supported liposomes, which will cause depolarization of the lipid bilayers and yield transient membrane ionic current. Light-induced electrical activity in silicon-supported liposomes will be assessed as will the ability of the induced current in the silicon-supported liposomes to induce liposomal morphogenesis (growth, fusion, division). Individual silicon-supported liposomes will also be inserted into existing mouse skeletal muscle cell monolayers and actuated to investigate tissue-level emergent biological behaviors. It is hypothesized that the silicon-supported liposomes can elicit intercellular bioelectric signals by altering ion channel activities, and that such signals can cause either a local or global cellular response. To enable emergent behavior, the engineered cellular constructs that contain silicon-supported liposomes will be illuminated with light patterned in two- or even three-dimensions. Calcium flow and morphology variation will then be visualized using fluorescence and bright field optical microscopes, respectively. Building on that mechanism, a unique class of underwater adhesive devices will be demonstrated wherein both cellular components and silicon-based liposomes are needed for the tissue-level mechanical response. In parallel to the studies using the silicon-supported liposomes for optical control of engineered cellular materials, multiple methods will be explored for assembling the silicon-supported liposomes into macroscopic silicon-based meta-materials (i.e. smart materials engineered to have properties not yet found in nature). The optical (e.g. light scattering and transmission) and mechanical (e.g. adhesive force and work, tensile strength, compressive strength) properties of the silicon-based meta-materials will be determined. Also, error correction capability will be assessed to determine if there are new mechanisms of error correction and defect management within the silicon-based materials and devices. Finally, local light-induced deformation will be investigated within the silicon-based metamaterials to determine whether that occurs as well as subsequent long-range and cooperative reordering, which are additional emergent features that would create the potential for programmable meta-material response, and controllable and optically tuned surfaces. The proposed research, if successful, would address multiple functional and biological questions about silicon-based biomaterials, and provide a novel platform for
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 23, 2016
- Source ID
- N000141612958
Entities
People
- Bozhi Tian
Organizations
- Office of Naval Research
- United States Navy
- University of Chicago