Download - Lect 9-10 Surface II Photonics Biosensing Cell Surface Print

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MSE 598/494 Bio-inspired Materials and BiomaterialsMSE 598/494 Bio-inspired Materials and Biomaterials

Instructor: Ximin He

TA: Xiying Chen Email: [email protected]

2014-04-01

Lecture 9 & 10. Biomimetic Surfaces II

Bio-optics, Biosensing, Cell-Material Interface

What you will learn in the next 90 minutes?

Lecture 9. Color & Biophotonics

• Pigmentary & Structural color

• Natural structural colors: Butterfly wings, bird feather, plant

• Synthetic structural colors

• Photonic Materials: waveguide

Lecture 10. Biosensing & Cell-Surface Interaction

• Biosensing

– Photonic sensor: bioinspired photonic crystals

– Photonic bioassay

• Cell-Surface Interaction

– Cell membrane structure and cell-surface interaction

– Periodic patterns and other approaches

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2014-04-01

Lecture 9. Biomimetic Surfaces I

Color & Biophotonics

Dream of Color That Doesn’t Fade

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Nature evolved to produce striking colors

Scarab beetle

Color

• Pigmental color Feature?

single color, non-variable, easy to fade, low diversity

Mechanism?

Pigment molecules/Chemical chromophoresabsorb certain portions of the white light spectrum and the portions that are not absorbed manifest as the color we see.

Preparation?

• Synthetic dye,

• Extract pigment from natural materials

• Structural color?

Feature?

Mechanism?

Replicate?

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What is Structural Color?

• Variable

• Shiny, glossy, glare…

• Vivid, bright…

• Stable

What is Structural Color?

• Arises from surfaces with periodic structures in micro/nanoscales

• Depends on the structure

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Structural Color

• Definition: Colors that are produced structurally by the scattering and/or reflecting of light photons by micro/nanoscale sub-surface features (called bio-photonic nanostructures), fine enough to interfere with visible light, sometimes in combination with pigments.

• Structure’s features: basically repeating variation in material composition on the order of a few hundred nanometers, which matches the wavelengths of visible light.

quasiorderedarchitecture

light

Structural color

stronglyinteracts

PigmentsPigments

bright and saturated colors

Pigment: brown Structure makes them appear:blue, turquoise, and green, and often they appear iridescent

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Structural Color

• Mechanism: Through a material is scored with fine parallel lines, formed of one or

more parallel thin layers, or otherwise composed of microstructures on the scale of the colors' wavelength.

When light falls on a thin film, the partial waves reflected from the upper and lower surfaces travel different distances depending on the angle, so they interfere.

Butterfly Wing Anatomy

Venationcomprised of a very thin double membrane with rigidity supplied by a network of tubular veins which radiate from the base of the wings

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Butterfly Wing Anatomy

Scales- Wing membranes are transparent, but are partially or fully covered in a dust-like layer of tiny coloured scales (600 individual scales/mm2)

- Each scale comprises of a flat plate arising from a single cell on the wing surface

Butterfly Wing Anatomy (The most popular model structural color – morpho butterfly)

ScalesPigmentary scales:- mostly flat. - account for the basic colours, as result of the presence of melanins, pterins and other chemical pigments from foodplants- also known as "ground scales" as they effectively form a lower ground layer of colour and pattern on a butterfly's wingsStructural scales- "cover scales“- overlap pigmentary scales- semi-transparent so the colours of the pigmentaryscales can be seen through them

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Mechanism of structural color of morpho butterfly

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cuticlesscales

Morpho Butterfly

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Inspired by Morpho butterflies

Thin-film color reflectors

Features:

• Flexible

• Angle-Independent

• Structural Color Reflectors

Jung H. Shin, Adv. Mater. 2012

Thin-film color reflectors inspired by Morpho butterflies

Fabrication:

• a combination of directional deposition, silica microspheres with a wide size distribution, and a PDMS (polydimethylsiloxane) encasing

Jung H. Shin, Adv. Mater. 2012

Butterfly Wing

multilayered ridges on the dorsal ground scale

Artificial Reflector

SiO2

TiO2

Cr-covered

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BIOINSPIRED PHOTONIC MATERIALS

• Research: the construction of devices that can confine light with particular wavelengths and that can control the direction of light propagation, based on the study of surface nanostructures and control mechanisms of living creatures.

• Photonic crystals (PCs) are one kind of well-known artificial material with spatially ordered lattices that exhibit brilliant structural colors.

Photonic crystals (PCs)

Wavelength match PBGbeing reflected

Pass through

1. Photonic band gap (PBG)

A remarkable property, appears due to the periodic arrangement of the dielectric materials.

This property leads to light with certain wavelengths or frequencies located in the PBG being prohibited from propagating through the PCs

2. Viewing angle dependence• Different structural colors will be

observed when viewing at different orientations

• Mechanism: the diversity of lattice constants formed by the PC at different viewing angles.

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• Types of PCs: according to the arrangement of the dielectric periodic units - 1D PCs, 2D PCs, and 3D PCs (controlling the flow of light in all directions).

• Composed of: monodisperse silica nanospheres, polymer nanospheres, or composite nanospheres, with the diameter ranging from several hundred nanometers to several micrometers.

• Fabrication methods: top–down micromachining, bottom–up self-assembly, holographic lithography, laserguided stereolithography, and electrophoretic deposition, etc.

capillary forceevaporation

NP of different diameters


• Fabrication methods: Sedimentation: most convenient, versatile, but hard to control

(Browninan motion, gravitational settling, crystallization) “Lifting” method: self-assembly of colloidal crystals takes place at the air–

liquid interface

Colvin, V. L. Chem. Mater. 1999; Nagayama, K. Langmuir 1996

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Large-area Photonic Structures

• a potentially rapid and industrially scalable process in which colloidal particles are sandwiched as a thin film between two removable polymer sheets and drawn over a sharp edge

• edge-induced rotational shearing of a solid assembly of core–shell polymer particles

Green/Red opal sample viewed in reflected white-light

Applications of Photonic Structures - Macroscopic

• Macroscopic appearance

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Applications of Photonic Structures - nanoscale

Waveguide make use of the defects like vacancies, cracks, or boundaries in the 3D crystalline lattices during the self-assembly process a point defect in a photonic material acts as a cavity capable of trapping photons

a line defect can control and direct the propagation route of photons

• Mechanism: These defects disrupt the periodicity of the crystalline lattice and create specific optical states within the band gap. Therefore, light coupling to these states can be localized within the defect regions and propagate under control.

• Preparation: Lithography, etching, assembling, laser, etc. Chua, S. J. Adv. Mater. 2005

Kitaev, V. Adv. Mater. 2004Turberfield, A. J. Adv. Mater. 2006

Applications of Photonic Materials with Defects

1) Photonic crystal fibers: achieved by introducing single defects into photonic crystals that are used for guiding light through a 3D periodical lattice. Two main kinds:

Total internal reflection photonic crystal fibers: a core surrounded by an array of holes

Photonic band gap fibers: a hollow core, inside of which losses can greatly be reduced due to confinement of the light, thereby keeping scattering and absorption to a rather low level

2) Laser devices: the defect layer is composed of a fluorescent laser dye. Emission at the PBG is strongly prohibited and narrow luminescence peaks appear exactly at the wavelengths of the defect transmission states.

3) Optic communications, highly sensitive sensors, and high-power transmission, etc

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Plant’s Structural Color

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Pollia condensata fruit – alcohol preserved specimen in 1974

Tutejaa, A. et al. PNAS 2012

"This obscure little plant has hit on a fantastic way of making an irresistible shiny, sparkly, multi-coloured, iridescent signal to every bird in the vicinity, without wasting any of its precious photosynthetic reserves on bird food. Evolution is very smart!"

• Mechanism: The cellulose is laid down in layers that is able to interact with light. Each individual cell generates color independently, producing a pixelated effect. The color is produced by the reflection of light of particular wavelengths from layers of cellulose in the cell wall. Excellent stability.

• Thickness of the layers Wavelength of light to be reflected. (thinner layers and reflect blue; thicker layers green or red)

• Applications: to obtain smart multifunctional materials using sustainable routes with abundant and cheap materials like cellulose, to substitute toxic dyes and colorants in foods.

Non-iridescent or angle-independent structural colors

Bird feather barbs: complex nanostructures, made of the protein beta-keratin and air

Fundamental forms:

1) a tortuous network of air channels in keratin (like a porous sponge)

2) an array of spherical air bubbles in keratin (like Swiss cheese)

3) sometimes, more disordered and highly variable versions of the two forms

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Summary of Lect 9. Color & Biophotonics

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• Pigmental and Structural color

• Natural structural colors:

Butterfly wings,

bird feather,

plant



• Tunable Optical Devices

(Option for Lit Rev Presentation)

Tunable Optical Devices(Option for Lit Rev Presentation)

• Bioinspiration:

Chameleons can adjust absorption efficiency

through migration and redistribution of dye

Damselfish can modulate the distance between adjacent reflecting units by slightly stretching or shrinking its skin

leaf beetle charidotella egregia induces color changes by controlling the filling of pigments via injection or draining of a fluid

• Tunable Optical Devices:

Light/Temperature/Chemical/ Mechanical-Force /Electrical/ Magnetic-Field -Responsive Photonic Materials

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2014-04-01

Lecture 10. Biomimetic Surfaces II

Photonic Biosensing

Photonic Sensors

• Photonic sensors: • Use PCs to generate or transmit signals from the biological recognition event.

• New type of sensors, bringing about the possibility of fabricating simple, highly sensitive, and low-cost sensors and bioassays.

• Types: (1) Fluorescence-based PC film sensors: molecules are labeled with dyes or fluorescent

tags the status of the targeted molecules can be recognized by the fluorescence signals the sensitivity of the signal is improve by PC films, via the enhancement of excitation light with wavelength matching the PBG

(2) Label-free PC film sensors: the diffraction peaks are usually used as an indicator. Physical or chemical changes of the film (e.g., changes in the refractive index or the periodicity of the 3D lattice caused by reactions of the components) the Bragg diffraction peak exhibited by the PC film could easily be distinguished and detected by optical measurement. No need to track the status of the molecules with tags – “label free” method.

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Photonic Sensors

• Detection of anions, using ionic liquids inverse opal made from PCs template

• Signal can be directly recognized by the naked eye

33 Li, G. Adv. Mater. 2008

Soaking into anion aqueous solutions↓

Change of solubility of ions and refraction index↓

Color presented

Responsive Photonic Sensors

• Polymerized crystalline colloidal arrays (PCCA) by dissolving non-ionic polymerizable monomers within the CCA suspension and photopolymerizingthese species into a hydrogel which entraps the CCA lattice.

• Sensitive to - Pb2+, Ba2+ and K+ by copolymerizing a crown ether

- Glucose with glucose hydrogels

• Mechanism: the gel swelling mainly results from an increased osmotic pressure within the gel due to a Donnen potential arising from mobile counterions to the crown ether bound cations.

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Asher, et al.Nature 1997JACS 2000

Anal Chem 2003Clin. Chem 2004

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Photonic Bioassays - detecting multiple analytes in a single sample

35 Kwon, S. Nat. Mater. 2010, 9, 745.

high-throughput bioassays generated with an external magnetic field and a computer-controlled spatial light modulator as mask. Taking advantage of both spectral encoding and graphical encoding, various barcodes can be obtained

• Mechanism: For colloidal crystals with a certain diameter, the assembled close-packed periodical lattice a predetermined band gap the characteristic reflection peak/spectrum is definite corresponds to one code To realize multiple codes by using PCs with different reflection peaks.

• Optical signal (physical penomenon) is much more stable than fluorescent dyes or organic tags (chemical change).




2014-04-01

Lecture 10. Biomimetic Surfaces II

Cell-Surface Interactions

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Cell – Surface Interaction

• Surfaces play prominent roles in the behavior of cells attached to them.

• Cells in the body either reside on rigid surfaces (such as organ linings, bones, vascular pathways), or respond to cues provided by interaction with external surfaces – either surfaces of organs/tissues/other cells.

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• Modifications of cell-surface interactions through surface manipulations are considered a primary tool in diverse biomedical and research fields

• Synthetic and semi-synthetic surfaces are designed and created to mimic physiological environments for cell proliferation and manipulation of cell properties, with particular emphasis on the stem cell biology.

Surface Engineering for cell adhesion/transformations

Two main routes:

• Mechanical modification of surface feature

– Physical patterning (develops with progress in lithography and nano-capabilities) elucidates mechanisms of cell response to parameters such as surface elasticity or stiffness and topography, contributing to our understanding and control of cell biology.

• Chemical functionalization

– Effect of cell structure, metabolism, motility, and overall liability and proliferation

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Cell Membrane Structure

• Different membrane regions correspond to different functions such as absorption, secretion, fluid transport, mechanical attachment, and communication with other cells and extracellular matrix components.

• Microfilaments in the cytoplasm is connected with cell membrane via integrin.

• Microfilament networks is responsible for cellular adhesion and locomotion, and is called the cytoskeleton.

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Cell ↔ Surface

• Integrins are receptors and can bind to the RGD sequence (arginine, glycine, aspartic acid) of fibronectin or other adhesive proteins.

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(adhesive protein)

(extracellular surface)

(receptor)

• The adhesive proteins, in turn, can bind to solid substrates, extracellular matrix components, and other cells.

• This specific receptor is thus used to connect the cytoskeleton with extracellular adhesive sites, via the intermediate fibronection.

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Cell – Surface Interaction

• Long-range interacton formces result in brining a paticle into the secondary minimum at ~100Å

• Short-range interactions between a particle and a solid can only take place at distances < 20Å. Adhesive macromolacules in cellular membrane might be able to cross the energy barrier and establish acid-base or hydrogen bond interaction with solid substrate, depending on the surface energy of substrate.

G = GE+GVDW

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Dendrimer-controlled cell growth

• A dendrimer–gold-nanoparticle hybrid array, which can control the apparent dendrimer surface density, was used to investigate cell adhesion.

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PEG=polyethylene glycol

• The effect of the macromolecular architecture on the attachment and the morphological development of endothelial cells was studied.

• The dendrimer outperformed a linear counterpart, most likely modulated by the different interactions between dendrimer and proteins in cell media.

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Surface interactions affecting stem cell properties

• Stem cells: undifferentated cells capable of self-renewal and differentiation into varied cell species.

• Significance: The most promising therapeutic avenues for numerous diseases, pathological conditions, and injuries might revolutionize medicine.

• Microenvironment (elasticity, viscosity, ligand identity & density, spatial configuraion): a powerful tool for controlling the fate of SCs.

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Surface interactions affecting stem cell properties

• Research: being able to intimately control differentiation of the stem cells into a desired cell type (muscle, skin, blood vessels, bone or neurons) Structural features

Chemical composition of surface

• Periodic Pattern: shown to provide intimate guidance for SC adhesion, growth direction, and morphologies, as it affects: Organization of cells on surface

Induce distinct differentiation profiles

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A thermally reversible culture substratewith a topographically active surface of aligned nanofibers is able to induce cytoskeletal alignment and nucleus elongation

human mesenchymal stem cells (hMSC) on a thermally responsive hydroxybutyl chitosan (HBC)/collagen fibers

K. W. Leong, et al. Adv. Mater. 2007

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polymer brushes to control single cell

• Superior protein resistance of polymer brushes to control single cell adhesionand polarisation at the micron scale

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poly(oligo(ethylene glycol methacrylate)) (POEGMA)

W. Huck. et al. Biomaterials 2010

Other Approaches

• Microfluidic channel to induce cell shape change: the cylindrical rod shape of the fission yeast is organized and maintained by interactions between the microtubule, cell membrane, and actin cytoskeleton. Mutations affecting any components in this pathway lead to bent, branched, or round cell. The cytoskeleton controls cell polarity and thus dictates cell shape.

• Restricted nueron cell growth on a carbon nanotube template: nanotube area boundary indeed restricted cell growth, except where extended to adjacent neuronal cells.

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Terenna, et al. Curr. Bio. 2008 Images courtesy of Y. Hanein, Tel Aviv Univ, Israel

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Summary

Lecture 9. Color & Biophotonics

• Structural color

• Natural structural colors: Butterfly wings, bird feather, plant



• Tunable Optical Devices (Option for Lit Rev Presentation)

Lecture 10. Photonic Biosensing & Cell-Surface Interaction

• Photonic Sensor

– Photonic sensor: bioinspired photonic crystals

– Photonic bioassay

• Cell-Surface Interaction

– Cell membrane structure and cell-surface interaction

– Periodic patterns and other approaches (Option for Lit Rev Presentation)47

Homework of Lecture 9-10

1. Please state the mechanism of Structural Color taking a natural organism as example.

2. Please describe the how cell interact with an cell-adhesive surface and its influence on stem cell’s growth.

• Due by 04/08/2014

• Hand in hard copy of homework at the TA, Xiying Chen, at the beginning of the 04/08 class

• Please contact [email protected] for questions.