Lecture by Richard Feynman (1959) There is a plenty of room at the bottom

Transcription

1 NanoBiotechnology

2 Lecture by Richard Feynman (1959) There is a plenty of room at the bottom We could arrange the atoms one-by-one in a way we want them High-resolution microscopes would allow a direct look at single molecules in biological systems It is very easy to answer many of these fundamental biological questions; you just look at the thing! Unfortunately, the present microscope sees at a scale which is just a bit too crude. Make the microscope one hundred times more powerful, and many problems of biology would be made very much easier.

3 Nanotechnology Creation of useful materials, devices, and systems through the manipulation of matter on a nanometer scale. - Generally nanotechnology deals with structures sized between 1 to 100 nanometer in at least one dimension. Ability to design systems with defined structure and function on the nanometer scale. Involves developing materials, devices within that size, and analytical tools (methodology), which can be used for analysis and measurement on a molecular scale Interdisciplinary area : Biology, Physics, Chemistry, Material science, Electronics, Chemical Engineering, Information technology

4 Nanotechnology Plays by Different Rules Normal scale Nanoscale - Nanoscale research is to reach a better understanding of how matter behaves on this small scale. - The factors that govern larger systems do not necessarily apply at the nanoscale. - Because nanomaterials have large surface areas relative to their volumes, phenomena like friction and sticking are more important than they are in larger systems.

5 Analytical methods and Nano-sized materials Analytical tools : Atomic force microscopy(afm), Electron microscopy (EM) Nano-sized materials Unusual and different property - Semiconductor nanocrystals: Size-dependent optical property - Nanoparticles: Magnetic nanoparticles (Ferromagnetic, superparamagnetic), Gold nanoparticles, Carbon nanotubes, Graphene - Superparamegnetism: In the absence of an external magnetic field, magnetization is in average zero

6 Graphene Allotrope of carbon in the form of a two-dimensional, atomic-scale, hexagonal lattice Extraordinary properties. - About 200 times stronger than steel by weight - Conducts heat and electricity with great efficiency - Nearly transparent Potential applications: -Semiconductor, electronics, battery energy, and composites Andre Geim and Konstantin Novoselov at the Univ. Manchester won the Nobel Prize in Physics in Groundbreaking experiments regarding the two-dimensional material graphene

7 Scanning probe microscopy image Graphene-Based Nanomaterials

8 Examples of nano-sized materials

9 Future implications of nanotechnology Nanotechnology may be able to create many new materials and devices with a vast range of applications, such as in medicine, biomaterials, electronics, and energy production. Nanotechnology raises many of the same issues as with any introduction of new technology, including concerns about the toxicity and environmental impact of nano-sized materials, and their potential effects on global economics.

10 Nano-Biotechnology Integration of nano-sized/structured materials, nano-scale analytical tools, and nano-devices with biological sciences for development of new biomaterials and analytical tool-box as well as for understanding life science Use of bio-inspired molecules or materials Typical characteristics of Biological events/materials - Self assembly - Highly efficient : high energy yield - Very specific : extremely precise Bio-molecules Proteins, DNA, RNA, Aptamers, Peptides, Antibody, Virus

11 Nano-Bio Convergence Bio-inspired device and system Bio-Technology Nano-Technol Molecular Imaging Molecular Switch DNA barcode Biochip / Biosensor Nanotherapy / Delivery Bionano-machine / Nano-Robot

12 Applications and Perspectives of Nanobiotechnology Development of new tools and methods - More sensitive - More specific - Multiplexed - More efficient and economic Implementation - Diagnosis and treatment of diseases - Rapid and sensitive detection (Biomarkers, Imaging) - Targeted delivery of therapeutics (higher therapeutic efficacy, low side-effects - Drug development - Drug target discovery - Understanding of biology

13 Examples Nano-Biodevices Nano-Biosensors Drug and gene delivery using nanoparticles Imaging with nanoparticles Analysis of a single molecule/ a single cell

14 Issues to be considered Synthesis or selection of nano-sized/ structured materials: bottom-up or top-down Functionalization with biomolecules or for biocompatibility Integration with devices and/or analytical tools Assessment : Reproducibility, Toxicity Mass production and practical implementation

15 The size of things

16 NanoBiotech was initiated by the development of SPM(Scanning Probe Microscopy) that enables imaging at atomic level in 1980 Scanning Tunneling Microscopy (STM) Atomic Force Microscopy (AFM)

17 Scanning Tunneling Microscopy (STM) Instrument for imaging surfaces at the atomic level. Developed in 1981 by Gerd Binnig and Heinrich Rohrer (at IBM Zürich) Nobel Prize in Physics in Resolution : 0.1 nm lateral resolution and 0.01 nm (10 pm) depth resolution. Used not only in ultra-high vacuum but also in air, water, and various other liquid or gas ambients, and at temperatures ranging from near zero kelvin to over 1000 C. Operating principle: Concept of quantum tunneling. - When a conducting tip is brought very near to the surface to be examined, a bias (voltage difference) applied between the two can allow electrons to tunnel through the vacuum between them. - The resulting tunneling current is a function of tip position, applied voltage, and local density of states (LDOS) of the sample. - Information is acquired by monitoring the current as the tip's position scans across the surface, and is usually displayed in image form. - Needs extremely clean and stable surfaces, sharp tips, excellent vibration control, and sophisticated electronics

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19 AFM (Atomic Force Microscope) One of the foremost tools for imaging, measuring, and manipulating matters at the nanoscale. A cantilever with a sharp tip (probe) at its end that is used to scan the specimen surface When the tip is brought into a close proximity of a sample surface, force between the tip and sample leads to a deflection of the cantilever according to the Hooke s law (F= -kx) Deflection is measured using a laser spot reflected from the top surface of the cantilever into an array of photodiode Depending on the situation, forces that are measured in AFM include mechanical contact force, van der Waals forces, capillary forces, chemical bonding, electrostatic forces, magnetic forces (magnetic force microscope, MFM), Casimir forces, solvation forces.

20 Principle and mode of AFM

21 Modes of AFM Contact mode: - Tip is "dragged" across the surface of the sample and the contours of the surface are measured either using the deflection of the cantilever directly or, more commonly, using the feedback signal required to keep the cantilever at a constant position. - Because the measurement of a static signal is prone to noise and drift, low stiffness cantilevers (i.e. cantilevers with a low spring constant, k) are used to achieve a large enough deflection signal while keeping the interaction force low. - Close to the surface of the sample, attractive forces can be quite strong, causing the tip to "snap-in" to the surface. - Thus, contact mode AFM is almost done at a depth where the overall force is repulsive, that is, in firm "contact" with the solid surface.

22 Tapping mode (Intermittent contact mode) In ambient conditions, most samples develop a liquid meniscus layer. Keeping the probe tip close enough to the sample for short-range forces to become detectable while preventing the tip from sticking to the surface presents a major problem for contact mode in ambient conditions. Dynamic contact mode (also called intermittent contact) was developed to bypass this problem. Currently, tapping mode is the most frequently used AFM mode when operating in ambient conditions or in liquids Cantilever is driven to oscillate up and down at or near its resonance frequency. Amplitude of this oscillation usually varies from several nm to 200 nm. Frequency and amplitude of the driving signal are kept constant, leading to a constant amplitude of the cantilever oscillation as long as there is no drift or interaction with the surface. Interaction of forces acting on the cantilever when the tip comes close to the surface, Van der Waals forces, dipole-dipole interactions, electrostatic forces, etc. cause the amplitude of the cantilever's oscillation to change (usually decrease) as the tip gets closer to the sample. This amplitude is used as the parameter that goes into the electronic servo that controls the height of the cantilever above the sample

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24 Non-contact mode - Tip of the cantilever does not contact the sample surface. - The cantilever is instead oscillated at either its resonant frequency (frequency modulation) or just above (amplitude modulation) where the amplitude of oscillation is typically a few nanometers (<10 nm) down to a few picometers. - The van der Waals forces, which are strongest from 1 nm to 10 nm above the surface, or any other long-range force that extends above the surface acts to decrease the resonance frequency of the cantilever. - This decrease in resonant frequency combined with the feedback loop system maintains a constant oscillation amplitude or frequency by adjusting the average tip-to-sample distance. - Measuring the tip-to-sample distance at each data point : to construct a topographic image of the sample surface

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26 Imaging profiles

27 VEECO TESPA VEECO TESPA-HAR NANOWORLD SuperSharpSilicon Tip length : 10 m Radius : 15~20 nm Tip length :10 m (last 2 m 7:1) Radius : 4~10 nm Tip length :10 m Radius : 2 nm

28 Resolution of protein structure by AFM Image of ATP synthase composed of 14 subunits

29 Molecular imaging Biomedical & Biological Sciences : - Ultra-sensitive imaging of biological targets under non-invasive in-vivo conditions - Fluorescence, positron emission tomography, Magnetic resonance imaging Ultra-sensitive imaging - Cancer detection, cell migration, gene expression, localization of proteins, angiogenesis, apotosis - MRI : Powerful imaging tool as a result of non-invasive nature, high spatial resolution and tomographic capability Resolution is highly dependent on the molecular imaging agents Signal enhancement by using contrast agents : iron oxide nanoparticles

30 Semiconductor Nanocrystals Quantum Dots Properties and Biological Applications

31 Synthesis of CdSe/ZnS (Core/Shell) QDs CdSe/ZnS 5.5 nm (red) Step 1 CdO + Se CdSe Step 2 Solvent : TOPO, HAD, TOP Surfactant : TDPA, dioctylamine ZnS ZnEt 2 + S(TMS) 2 CdSe Growth temperature 140 (green) 200 (red) 20 nm Bawendi et al. J. Am. Chem. Soc. (1994)

32 Optical Properties of Quantum Dots a) Multiple colors with size b) Photostability c) Wide absorption and narrow emission d) High quantum yield Quantum Yield 60 ~ 70 % Single source excitation

33 Coating of QD Surface for Biocompatibility Encapsulation with the hydrophobic core of a micelle NH 2 NH 2 + N NH 2 P O CdSe O P O P O P O P O P O P Coating with PC Coating of the outer Shell with ZnS P O ZnS CdSe O P O P O P O P O P O P P O O P ZnS O P NH 2 CdSe O P O P + N O P O P + N + N + N NH 2 NH 2 NH 2 CdSe QDs CdSe/ZnS core-shell Quantum Dots encapsulated in phospholipid micelles NH 2 PEG-PE (n-poly(ethylenglycol) phosphatidylethanolamine): micelle-forming hydrophilic polymer-grafted lipids comparable to natural lipoproteins PEG : low immunogenic and antigenic, low non-specific protein binding PC : Phosphatidylcholine Dubertret et al. Science (2002)

34 In vitro imaging Y QD QD-Antibody conjugates + Organelle Antigen Y QD 3T3 cell nucleus stained with red QDs and microtubules with green QDs Organelle - Multiple Color Imaging - Stronger Signals Wu et al. Nature Biotech

35 In vivo imaging Live Cell Imaging Quantum Dot Injection Cell Motility Imaging Red Quantum Dot locating a tumor in a live mouse 10um Green QD filled vesicles move toward to nucleus (yellow arrow) in breast tumor cell Alivisatos et al., Adv. Mater.,

36 Bio-inspired systems Inherent capabilities of molecular recognition and self-assembly Attractive template for constructing and organizing the nano-structures Proteins, toxin, coat proteins of virus etc.

37 α -Hemolysin: Self-assembling transmembrane pore A self-assembling bacterial exo-toxin produced by some pathogens like Staphylococcus aureus as a way to obtain nutrients lysis of red blood cells α-hemolysin monomers bind to the outer membrane of the cells. Monomers oligomerize to form a water-filled heptameric transmembrane channel that facilitates uncontrolled permeation of water, ions, and small organic molecules. Rapid discharge of vital molecules, such as ATP, dissipation of the membrane potential and ionic gradients, and irreversible osmotic swelling leading to the cell wall rupture (lysis), can cause death of the host cell.

38 - Mushroom-like shape with a 50 A beta-barrel stem - Narrowest part (1.4 nm in diameter) of channel at the base of stem

39 Biotechnological applications : Stochastic sensors A molecular adaptor is placed inside its engineered stem, influencing the transmembrane ionic current induced by an applied voltage Reversible binding of analytes to the molecular adaptor transiently reduces the ionic current - Magnitude of the current reduction : type of analyte - Frequency of current reduction intervals: Analyte concentration Stochastic system: systems that are unpredictable due to the influence of a random variable

40 Construction of stochastic sensors

41 a : Histidine captured metal ions (Zn+2, Co+2, mixture ) b: CD captures anions (promethazine, imipramine, mixture) c : biotin ligand

42 Cyclodextrins Family of compounds made up of sugar molecules bound together in a ring : cyclic oligosaccharides). Comprising hydrophobic inside and hydrophilic outside, they can form complexes with hydrophobic compounds. Enhance the solubility and bioavailability of such compounds. Useful for pharmaceutical as well as dietary supplement applications in which hydrophobic compounds shall be delivered.

43 DNA sequencing Transmembrane pore can conduct big (tens of kda) linear macromolecules like DNA or RNA Eelectrophoretically-driven translocation of a 58-nucleotide DNA strand through the transmembrane pore of alpha-hemolysin Changes in the ionic current by the chemical structure of individual strands Nucleotide sequence directly from a DNA or RNA strand A single nucleotide resolution

44 DNA sequencing by nanopore

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46 Understanding Cancer and Related Topics Understanding Nanodevices Developed by: Jennifer Michalowski, M.S. Donna Kerrigan, M.S. Jeanne Kelly Brian Hollen Explains nanotechnology and its potential to improve cancer detection, diagnosis, and treatment. Illustrates several nanotechnology tools in development, including nanopores, quantum dots, and dendrimers. These PowerPoint slides are not locked files. You can mix and match slides from different tutorials as you prepare your own lectures. In the Notes section, you will find explanations of the graphics. The art in this tutorial is copyrighted and may not be reused for commercial gain. Please do not remove the NCI logo or the copyright mark from any slide. These tutorials may be copied only if they are distributed free of charge for educational purposes.

47 What Is NanoBiotechnology? Water molecule Nanodevices Nanopores Dendrimers Nanotubes Quantum dots Nanoshells White blood cell A period Tennis ball

48 Designing Nano-devices for Use in the Body Too Small Too Big

49 Manufacturing Nanodevices Top-down approach: Molding or etching materials into smaller components Bottom-up approach :Assembling structures atom-by-atom or molecule-by-molecule, useful in manufacturing devices used in medicine. X-ray beam Crystal Scattered X-rays Detector Atoms in crystal Crystal Nanodevices White blood cell

50 Nanodevices Are Small Enough to Enter Cells Cell (10,000~ 20,000 nm) Nanodevices Nanodevices Water molecule White blood cell

51 Nano-devices can improve cancer detection and diagnosis at early stages NanoBiotechnology Imaging Physical Exam, Symptoms

52 Nanodevices can improve sensitivity Normal cells Precancerous cells Nanodevices could potentially enter cells Normal cells and determine which cells are cancerous or precancerous. Precancerous cells

53 Nanodevices can preserve patients samples Traditional Tests Cells from patient Cells altered Active state lost Nanotechnology Tests Cells from patient Cells preserved Active state preserved Additional tests

54 Nanodevices can make cancer tests faster and more efficient Patient A Patient B Many diagnostic tests simultanelusly

55 Cantilevers can make cancer tests faster and moreefficient Cancer cell Antibodies with proteins Antibodies Bent cantilever Water molecule White blood cell Nanodevices Cantilevers

56 Nanopores Single-stranded DNA molecule Nanopore A T C G Nanopore A Singlestranded DNA molecule T Nanopore Single-stranded DNA molecule Water molecule Nanodevices Nanopores White blood cell

57 Quantum Dots Ultraviolet light off Ultraviolet light on Quantum dot bead Quantum dots Quantum dots emit light Water molecule Nanodevices Quantum dots White blood cell

58 Quantum dots can find cancer signatures Cancer cells Quantum dot beads Healthy cells Cancer cells Quantum dot beads Healthy cells

59 Improving cancer treatment Traditional Treatment Nanotechnology Treatment Drugs Toxins Nanodevices Cancer cells Cancer cells Toxins Noncancerous cells Noncancerous cells Dead cancer cells Dead cancer cells Dead noncancerous cells Intact noncancerous cells

60 Nanoshells Near-infrared light off Near-infrared light on Nanoshell Gold Nanoshell absorbs heat Water molecule Nanodevices Nanoshells White blood cell

61 Nanoshells as cancer therapy Nanoshells Nanoshells Cancer cells Cancer cells Healthy cells Healthy cells Near-infrared light Dead cancer cells Intact healthy cells

62 Nanodevices as a link between detection, diagnosis, and treatment Traditional Cancer Treatment NanoBiotechnology Cancer Treatment Cancer cell Cancer cell Drug Nanodevice Imaging Reporting Detection Targeting

63 Dendrimers Cancer cell Dendrimer Water molecule Nanodevices Dendrimer White blood cell

64 Dendrimers : Highly Branched Dendritic Macromolecules

65 Poly (amido amine) Dendrimers Characteristics Monodisperse macromolecule Globular (Spherical) Facile surface bio-functionalization Similar molecular size to biomolecules (Glucose oxidase nm) Applications 4.5 nm G4 Poly(amidoamine) Dendrimer Vehicles for delivery of genes and drugs Biomimetic catalysts (Peptides-, Glycodendrimers) Medical applications (MRI contrast enhancer) Molecular carriers for chemical catalysts (Core, Peripheral)

66 Dendrimers as cancer therapy Manipulate dendrimers to release their contents only in the presence of certain trigger (molecules or light) caged molecules Therapeutic agent Cancer detector Reporter Cell death monitor Water molecule Nanodevices Dendrimer White blood cell

67 NanoBiotechnology in Diagnosis and Patient Care Today 2020