Презентация Nano-enabled biological tissues онлайн

Содержание слайда: Nano-enabled Biological Tissues By Bradly Alicea http://www.msu.edu/~aliceabr/ Presented to PHY 913 (Nanotechnology and Nanosystems, Michigan State University). October, 2010.

Содержание слайда: Nanoscale Technology Enables Complexity at Larger Scales…….

Содержание слайда: Role of Scale (Size AND Organization)

Содержание слайда: Ingredient I, Biomimetics/ Biocompatibility Biomimetics: engineering design that mimics natural systems. Nature has evolved things better than humans can design them. * can use biological materials (silks) or structures (synapses). Biocompatibility: materials that do not interfere with biological function. * compliant materials used to replace skin, connective tissues. * non-toxic polymers used to prevent inflammatory response in implants.

Содержание слайда: Artificial Skin, Two Approaches

Содержание слайда: Artificial Skin – Response Characteristics Results for stimulation of electronic skin: Output signal from electronic skin, representation is close to pressure stimulus. * only produces one class of sensory information (pressure, mechanical). Q: does artificial skin replicate neural coding? * patterned responses over time (rate-coding) may be possible. * need local spatial information (specific to an area a few sensors wide). * need for intelligent systems control theory at micro-, nano-scale.

Содержание слайда: Silk as Substrate, Two Approaches

Содержание слайда: Ingredient II, Flexible Electronics Q: how do we incorporate the need for compliance in a device that requires electrical functionality? * tissues need to bend, absorb externally-applied loads, conform to complex geometries, dissipate energy. A: Flexible electronics (flexible polymer as a substrate).

Содержание слайда: E-skin for Applications Organic field effect transistors (OFETs): * use polymers with semiconducting properties. Thin-film Transistors (TFTs): * semiconducting, dielectric layers and contacts on non-Si substrate (e.g. LCD technology). * in flexible electronics, substrate is a compliant material (skeleton for electronic array).

Содержание слайда: Ingredient III, Nanopatterning Q: how do we get cells in culture to form complex geometries?

Содержание слайда: MWCNTs as Substrate for Neurons Multi-Wall CNT substrate for HC neurons: Nano Letters, 5(6), 1107-1110 (2005).

Содержание слайда: Bottom-up vs. Top-down Approaches

Содержание слайда: Top-down approach: Electrospinning Align nanofibers using electrostatic repulsion forces (review, see Biomedical Materials, 3, 034002 - 2008). Contact guidance theory: Cells tend to migrate along orientations associated with chemical, structural, mechanical properties of substrate.

Содержание слайда: Bottom-up approach: Molecular Self-assembly Protein and peptide approaches commonly used. Protein approach – see review, Progress in Materials Science, 53, 1101–1241 (2008).

Содержание слайда: Additional Tools: Memristor Memristor: information-processing device (memory + resistor, Si-based) at nanoscale. * conductance incrementally modified by controlling change, demonstrates short-term potentiation (biological synapse-like).

Содержание слайда: Additional Tools: Bioprinting Bioprinting: inkjet printers can deposit layers on a substrate in patterned fashion. * 3D printers (rapid prototypers) can produce a complex geometry (see Ferrari, M., “BioMEMS and Biomedical Nanotechnology”, 2006).

Содержание слайда: Conclusions Nano can play a fundamental role in the formation of artificial tissues, especially when considering: * emergent processes: in development, all tissues and organs emerge from a globe of stem cells. * merging the sensory (electrical) and biomechanical (material properties) aspects of a tissue. Advances in nanotechnology might also made within this problem domain. * scaffold design requires detailed, small-scale substrates (for mechanical support, nutrient delivery). * hybrid protein-carbon structures, or more exotic “biological” solutions (reaction-diffusion models, natural computing, Artificial Life)?