Nanomedical Devices

Nanotechnology

Devices or materials of size in the range of 1-1000 nm

Nanomedicine

Applications of nanotechnology in healthcare

Multidisciplinary Area of Nanomedicine (8)

Requires input from medicine and science, including:

• Medical physics

• Biophysics

• Biochemistry

• Human biology

• Engineering

• Mathematics

• Computer science

Promise of Nanomedicine

Potential to revolutionize medicine through:

• New methods for disease prevention, diagnosis, and therapy

• Rapid and easy Point-of-Care (POC) testing

• Home health status screening

• Personalized therapy tailored to individual patients (precision medicine)

Why therapies should be individualized?

Bc people bodies different thus they react differently - but in reality they treat people the same with different doses

Diameter of Human Hair

20,000 nm to 180,000 nm

Size of a Cell

Approximately 10,000 nm

Length of DNA in Human Chromosome #1

67,000 nm

Width of DNA Molecule

2.5 nm

Smallest Capillaries in the Body

Diameter ranges from 5,000 nm to 10,000 nm

Cellular Membrane K+ Channel Diameter

10 nm

Nuclear Membrane Channel Diameter

10 nm

Mitochondrial Membrane Channel Diameters

2 nm to 3 nm

Size of Nanodevices / Nanomaterials reference

Nanoshell

A spherical hollow shell made of an insulating material, such as silica (diameter 120 nm), surrounded by a thin conducting shell, typically a few nanometers thick, made of a material like gold

Altering Nanoshell Properties + example

By varying the thickness of the conducting shell, the electric and optical properties of nanoshells can be precisely adjusted
fx.: optimizing absorption of specific frequencies, like infra-red

Gold Nanoshell on Silica Core (2)

• Gold layer grows on silica core

• Biocompatible gold suitable for medical applications

Nanoshells functions (3)

• Photothermal Tumor Ablation

• Delivering Insulin in Diabetes

• Single Molecule Raman Spectroscopy

Photothermal Tumor Ablation (5)

• Nanoshells coated with receptor molecules bind to cancer cell receptors

• Nanoshells are injected into the bloodstream

• High-frequency infrared light (near IR) is shone through the skin

• Nanoshells absorb IR and convert it to heat, raising the tumor cells' temperature by 10-20°C

• The heat causes cancer cells to die

Photothermal Tumor Ablation Advantages (2)

• No toxic effects (unlike chemotherapy)

• No carcinogenic ionizing radiation (unlike radiotherapy or nuclear medicine)

Delivering Insulin in Diabetes (6)

• In diabetes mellitus (DM), too much glucose is in the blood and not enough in the cells

• Insulin moves glucose from the bloodstream into cells (muscle, fat, liver) for energy or storage

• Type 1 DM (low insulin production, requires daily injections) and Type 2 DM (insulin resistance)

• Porous nanoshells filled with insulin are placed on a "patch" below the skin

• A pen-sized IR laser is used over the skin to release insulin from the patch

• The patch may contain glucose sensors to release insulin when excess glucose is detected in the blood

Single Molecule Raman Spectroscopy (3)

• Raman spectroscopy uses scattered IR photons to determine molecular structure

• Nanoshells can increase the Raman signal by 10¹¹ times

• The system becomes sensitive enough to detect and determine the structure of a single molecule

  • fx.: chemical or biological toxins, viruses

Dendrimers definition (3)

• = Nanosized ‘Containers’

• globular-shaped polymers made of branched repeating units emanating from a central core

• must be compatible with body

Biodendrimers

Dendrimers that are biocompatible or biodegradable

Cavities within Dendrimers definition

Serve as binding sites for smaller molecules, allowing dendrimers to act as nanosized 'containers' or 'multifunctional platforms' for various functional molecules

Function of Dendrimers (4)

• Dendrimers have cavities (empty pockets or holes) formed by their branched structure

• These cavities can bind various molecules

  • fx.: those targeting cancer cells and others that detect if the cancer cells are dead

• The dendrimer's branched structure allows it to hold and release multiple functional molecules, making it useful for targeted drug delivery, diagnostics, and therapy

(photo - singular mol.)

Dendrimer Multifunctional ‘Platforms’ (photo!)

Fullerenes (3)

• Nanosized carbon structures in the shape of a hollow sphere, ellipsoid, tube, or ring

• Carbon is biocompatible, making fullerenes suitable for medical use

• If a substance is toxic to the body, it can be inserted into the carbon structure of fullerenes - preventing direct exposure and allowing targeted application + controlled delivery

  • fx.: gadolinium for MRI

Nanotubes

Cylindrical fullerenes

Fullerenes Medical Uses (3)

Fullerenes can be used as multifunctional platforms

• Nanotube Cold-Cathode X-ray Tubes

• Fullerenes with Gd in MRI

Nanotube Catheters (4)

• Very strong catheters

  • bc/ they are perfect crystals, thus hard to break

• Nanotube catheters have a Young’s modulus 5 times that of steel

• Lead to damages

Nanotube Cold-Cathode X-ray Tubes (3)

• Small nanotube cold-cathode based X-ray tubes can be placed inside the body

• Can replace radioactive sources used in brachytherapy

• Major advantage: can be switched on and off

Fullerenes with Gd in MRI (4)

• Fullerenes with Gd are 5 times more detectable as MRI contrast agents than current Gd agents

• Fullerene helps reduce the amount of injected Gd

• Gd is toxic, but fullerene helps reduce toxicity by encapsulating Gd

• Can kill neurons in brain

Nanopores (2)

• Nanopores drilled by a focused-ion beam in a 10 nm thick silicon nitride membrane

• Scale bar is 60 nm

Nanopores in DNA Analysis (4)

• in DNA sequencing

• DNA passes through the nanopore

• Different DNA bases cause different drops in current, allowing identification

• Could revolutionize genomics, enabling sequencing in seconds

Nanopores in DNA Analysis Diagram (3+photo)

• drops means that there is a block in channel

• in ionic solution

• the tube is a nanopore

Nanocrystals (3)

• = Nanoparticles

• Crystalline particle with at least one dimension less than 100 nm

dif. crystal show dif. colour

Quantum Dots (3)

• Semiconductor nanocrystals in the sub-10nm size range

• Have discrete energy levels (unlike larger solids)

• Used as single-frequency fluorescent biological labels instead of radioactive tracers

Magnetic Nanocrystals (2)

• Used as contrast agents in MRI

• Example: Superparamagnetic iron oxide (SPIO)

Fluorescence Imaging (4+5)

• Original Photo of Biomolecule

  • Initial image with possible autofluorescence from natural biomolecules

• Injection with Nanocrystals

  • Nanocrystals are injected to enhance imaging and bind to specific biomolecules

• Autofluorescence

  • Natural fluorescence emitted by biomolecules, which may interfere with labeled signals

• Quantum Dots

  • Fluorescent nanocrystals used as labels for biomolecules

  • emitting distinct fluorescence signals

Nanowires (3)

• Wires with a diameter in the order of nm

• Flexible and can be as slender as 50 nanometers in width

• About one-thousandth the width of a human hair

Nanowires in the Circulatory System (4)

• Smaller than the smallest capillary in the body

• Could be threaded through the circulatory system without blocking blood flow

• Do not interfere with gas or nutrient exchange through blood-vessel walls

• Too small to cause damage

Nanowires in Brain Studies and Therapy (5)

• Nanowires can be guided through the circulatory system to the brain

• They spread out, branching into smaller blood vessels

• Used to record electrical activity of single neurons or small groups of neurons

• More precise than PET or fMRI, helping to pinpoint damage from injury, stroke, or locate the cause of seizures

• Too small to cause damage

Nanowires in Parkinson's Disease Treatment (3)

• Nanowires can be used to stimulate affected brain areas with electrical pulses

• Current stimulation involves inserting wires through the skull, causing brain tissue scarring

• Nanowires threaded through blood vessels could provide the same benefits without the damaging side effects

Nanowires: Microfluidic Channels: Lab-on-a-Chip (photo)

Medical Nanorobots (2)

• Significant research underway

• Expected to irreversibly change medicine in 20-30 years

Drug Delivery Robots

A type of medical nanorobot focused on delivering drugs precisely to targeted areas

Medical Micro-Nanorobots

used in precision medicine for highly targeted treatments

Cell Repair Nanorobots (2)

• Nanorobots designed to repair or replace damaged cells

• Can potentially target specific cells or tissues to restore normal function

Artificial RBC ('Respirocyte') (7)

• Size: 1000 nm

• Can transport 236 times more O2 than natural RBCs

• Use serum glucose for energy supply

• Equipped with chemical, thermal, and pressure sensors, and an onboard nanocomputer

• Can be remotely reprogrammed via external acoustic signals

• Capable of operating indefinitely (compared to natural RBCs' 4-month lifespan)

• With respirocytes, an adult human could hold their breath underwater for four hours

Consumer Products with Nanoparticles (2)

• Nanoparticles are used in hundreds of consumer products

• Examples: cosmetics, sunscreens, sporting goods, clothing, electronics, baby products, and food packaging

Health Risks of Nanoparticles (5)

• Nanoparticles can cross biological membranes and reach cells, tissues, and organs that larger particles cannot

• Can enter the bloodstream through inhalation, ingestion, or skin penetration

• Once in the bloodstream, they are transported around the body and can be taken up by organs and tissues

• May enter cell mitochondria and the cell nucleus

• Potential risks include DNA mutation, mitochondrial damage, and cell death