Module 2
Nanomedicine:
A Paradigm Shift in Healthcare
Nanomedicine Changing the Healthcare
Clinical
Symptoms
Early
Diagnosis
Preventive
Treatment
Follow the disease
response to
therapy
management
tailored to the
patient
Screening
Functional and quantitative
imaging localizing the
disease
Minimally
invasive
treatment
How Conventional Medicine Works for a Disease
• Identification of a “diseased state”
by a patient who doesn’t “feel right”
and then goes or is taken to a clinic
• Simple measurements
• Follow-up clinical tests
• Functional imaging (e.g. x-rays, CAT
scans, MRI scans; PET)
• Occasional “molecular” tests (gene
relocations, amplified gene copies,
etc.) to establish genetically
determined diseases
• Comparison of individual results
with “normal ranges” of “normal”
individuals.
• Surgical repair of injuries
(“reconstructive surgery” or
removal or diseased tissues or
organs
• Chemical drugs delivered locally
(e.g. ointments to skins, injection
of drugs into tissues or organs,
etc.)
• Chemical drugs delivered
systemically (e.g. chemotherapy,
etc.)
• Stabilization of the patient so
that the patient can repair
himself/herself
https://nanohub.org/resources/3095/about
3
Issues with conventional medicine
Waiting for a patient to feel symptoms means
• Disease detection is not early
• By the time symptoms are felt, tissue and/or
organ destruction has already begin and may
be irreversible
• Many diseases have similar symptoms making
diagnoses based on symptoms at best a
guessing game
Cost: Trained people and modern drugs
• Diagnostic technologies, if available, are still
relatively primitive; or if expensive, are not
readily available
• Drugs and other treatments are either
completely or only crudely targeted to the
diseased cells leading to extensive damage to
normal bystander cells
4
http://www.bniembarcadero.com/wp-content/uploads/wallet_hospital_400w.jpg
Nanomedicine: A Paradigm Shift in Healthcare
Clinical Symptoms
Screening
Early
Diagnosis
Challenge?
• Understanding root causes of disease
• Linking symptoms to molecular origins
• Bring bench side science to clinics
Image source: wiki
Preventive
Treatment
Pan et. al. Eur J Radiol. 2009, 70(2):274-85.
Pan et. al. Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2010 Sep 21.
The ‘Holy Grail’ in Nanomedicine Research
What are we
really after?
•A suitable marker and a high affinity ligand
• Preferably peptides, peptidomimmetics)
• Affinity: nano molar
1. Finding the target
2. Detect early
3. Quantify the disease site
4. Release the drug
5. Follow the drug response
6. Perform all of the above
with a “safer” cargo
•A carrier that is extremely robust
• “Soft”- preferably self-assemblies of polymer
or lipids
•Sensitive imaging
modality
•An imaging
technique that
can provide
quantitative
information
•Deliver
therapeutics
affecting the
normal cells little
or none
Can we
really
package
everything
in a
sensitive,
efficacious
yet “safer”
way?
6
The World of “Nano”
A nanometre (Greek: νάνος, nanos, "dwarf";
μέτρον, metrοn) is a unit of length in the
metric system, equal to one billionth of a
meter (i.e., 10-9 m or one millionth of a
millimeter).
Real world scenario:
•Humans are 10,000,000 times smaller than
the earth.
•A 100 nm sized particle, is 10,000,000 times
smaller than a human.
At scales on the order of 100’s of nm, novel materials properties emerge, enabling the
development of new class of materials. It can create opportunities for paradigm shifting
results, creating new preventive, diagnostic and therapeutic approaches to cancer
Nanomedicine: A Blast from Past?
How old is nanotechnology in human history?
Lead sulfide
crystals (5 nm)
Silver nano-colloids were used by Persians, Babylonian
and Greek civilizations as antiobiotics
Blonde hair
The astounding qualities of “nano”-gold were
understood by the ancients, who devoted massive
amounts of time and energy to alchemy and labeled a
primitive form of Nanogold the “Elixir of Life.”
It's over 4000 years old. Goes back in ancient Egyptian and Persian times
8
Engineered Nanoparticles for Theranostic
Application
Homing Ligands
CONTRAST
TARGETING
MRI: Mn, Cu, Fe
Optical/Photoacoustics
Imaging (PAT): Au, Cu
Computed tomography
(CT) and Spectral CT: I, Bi,
Au, Yb
Fibrin: Monoclonal
antibody (NIB5F3), peptide
Angiogenesis (Integrin):
Ab, peptide,
peptidomimmetics
Self-assembled
polymeric
Phospholipids
architecture
20-200 nm
Other functionalization
THERAPEUTICS
Drugs or Prodrugs for Controlled Delivery
Anticancer agents; Radiosensitizers;
Radioprotectors; Fibrinolytic agents etc.
High payload
(40 wt% to 70 wt%)
Pan D. 2013 Molecular Pharmaceutics, March, Editorial , Special Issue
Application areas:
Cancer
Cardiovascular
inflammatory
Basic Concept of Building a Nano-device
Step A: Choice of Core Materials
Gold, Metal Oxides, Quantum Dots
Metal Sulfides, Silica, water, air, fluorocarbon….
Multi-component nanomedicinal devices are typically formed in
reverse order of controlling events, namely from the inside out.
10
Basic Concept of Building a Nano-device
Step B: Incorporating water insoluble drugs
or therapeutic genes
AND
Contrast Agents OR both
Drugs: anti cancer ….
Contrast agents
Making the device “theranostic”
11
Basic Concept of Building a Nano-device
Step C: Addition of a coating
Coating:
Synthetic or natural
Polymer
Lipidic
Silica
Making the device biocompatible
12
Basic Concept of Building a Nano-device
Step D: Introduction of homing agents
Targeting agents:
Antibody
Small molecule ligands
Peptides
Peptidomimmetics
Aptamers
Targets
Molecular disease markers
Cell surface receptors
(folate)
Integrins (transmembrane
protein in ECM)
Enzymes
Fibrin (thrombus-Factor Ia)
Signaling molecules
Cells (e. g., lymphocytes,
stem cells)
Making the device home-able
13
Basic Concept of Building a Nano-device
Step E: Introduction of contrast agents and
(or) soluble drugs
Contrast agents:
• Paramagnetic metal (MRI)
• Heavy metals (CT)
• K-edge metals (Spectral CT)
• Small molecule fluorescence
dyes (Optical)
• Radioisotopes for nuclear
(PET, SPECT)
Step D and E can be in reverse order
Making the device brighter
14
Basic Concept of Building a Nano-device
End product: A Multi-component, Multi-functional “smart” Nanoparticulate system
to visualize, characterize and measure biological processes in living systems
•PET
•SPECT
•Optical
•Ultrasound
•MRI
•Computed
Tomography
•Photoacoustic
Tomography
•Antibodies
•Proteins
•Peptides
•Small molecule
Anticancer drugs
Anti inflammatory
Radioisotopes
DNA, genes
Therapeutic
agent
Core
materials
Contrast
materials
PTD
Polyarginine
Carrier
peptide
Homing
agent
•Phospholipids
•Polyethyleneglycol
(PEG)
•Carbohydrate
•Amphiphilic polymers
Gold
Metal oxides
Metal
sulphide
Silica
Shell/
coating
Linker
Flexibility
Hydrophilicity
Charge
Length
15
The Importance of “Bionics”: Invention
Inspired by Nature
UC Berkley
Bionics is the application of biological
methods and systems found in nature
to the study and design of
engineering systems and modern
technology.
“Biommicry (or Biomimetics) is a new
science that studies nature’s models
and then imitates or takes inspiration
from these designs and processes to
solve human problems.”
…… Janine M. Benyus
“Biomimicry Innovation Inspired by Nature”
Collage illustrates gecko adhesion, from toes to nanostructures
Adhesive that is the first to master the easy attach and easy release of the
reptile's padded feet
http://lclark.edu/~autumn
16
Examples of Nano-platforms
Dendrimer
Nano Car (James Tour, Rice U)
Nano Necklace
Nano Wire
JC Charlier, Belgium
Gold NanoCages
Younan Xia, WUSTL
NanoGold
Nanoprobes, Inc.
Liposomes
Virus NP
M Manchester, MG Finn
Scripps Research
Nano Vault
Sarah H. Tolbert , UCLA
NanoDots
(Quantum Dots)
Iron Oxide NP
NanoTube
FeCo
MWNT
Nanobox
David Gracias, JHU
Perfluorocarbon
Wickline, Lanza
CTRAIN/Kereos, Inc
Nano Bialys
Pan (CTRAIN, Washu)
“soft” Metal Nanocolloids
Pan (CTRAIN, Washu)
Golden Carbon nanotube
Jin-Woo Kim, U Arkansa
17
Size Scales of Nanotechnology
Polymeric
Micelles
“Nano-Bialys”
Liposomes
20-60 nm
120-260 nm
100-400 nm
Size
18
Understanding the Properties Before
Using In Vivo
NCL assay cascade
Physical
Characterization:
– Size
– Size distribution
– Molecular weight
– Morphology
– Surface area
– Porosity
– Solubility
– Surface charge density
– Purity
– Sterility
– Surface chemistry
– Stability
– No of ligands, CAs, drugs
In Vivo:
In Vitro:
– Binding
– Pharmacology
– Blood contact properties
– Cellular uptake
– Cytotoxicity
– Absorption
– Pharmacokinetics
– Serum half-life
– Tissue distribution
– Excretion
– Safety
Plasma PK profile/
Tissue distribution
(Liver, lungs, kidney,
heart, spleen)
Size Dictates in vivo Distribution of
Nanoparticles in the Lymph Nodes!
Sentinel lymph node (SLN) imaging is highly
relevant in the context of breast cancer staging
and may replace fine needle biopsy (FNB)
2
1
http://www.surgicalprobe.com/
1
MORE GOLD
NON INVASIVE
IMAGING
Real Time
IMAGING?
Realizing the Importance of Particle Diameter
for In Vivo PA Imaging
0
0
5
5
10
10
0
0
15
15
5
5
5
0.6
10
10
10
0.4
15
15
15
0.2
20
k20 5 min
Ctrl
0
5
GNBs
10
15 0
5
l
10
0
5
5
10
10
15
15
20
0
5
0
pGNBs
n
m20 60 min
Ctrl
10
15 0
5
10
0.8
lGNBs
15
a
20 Ctrl
0
0
lGNBs
15
5
10
20 5 min
15 0
5
c
b 20 20 min
10
15
0
5
10
15
Angiogenesis
Biological process of forming new blood vessels
22
Angiogenesis
In order for a tumor to grow beyond 2 mm^3, it must have a
steady supply of amino acids, nucleic acids, carbohydrates, oxygen,
and growth factors for metastasis and continued growth.
Tumors must stimulate angiogenesis, the growth of new blood
vessels from preexisting ones so as to obtain these nutrients.
Cascade of Events in Angiogenesis
The endothelial cell's machinery begins to produce
Newly
formed
blood
tubes
are
stabilized
by
The
Matrix
endothelial
metalloproteinases
cells vessel
begin
(MMP)
to
divide
are
produced
new
molecules
including
enzymes.
These
enzymes
Specialized
Sprouting
endothelial
molecules
called
cells
roll
adhesion
up
to
form
a
Individual
blood
vessel
tubes
connect
to cells,
form
specialized
muscle
cells
(smooth
muscle
(proliferate)
to
dissolve
the
and
tissue
migrate
in
front
out
through
of
the
sprouting
the
dissolve
tiny
holes
in
the
sheath-like
covering
molecules
blood
vessel
called
tube.
integrins
(avb3,
avb5)
The angiogenic
growth
factors
bind
toserve
specific
located on the endothelial cells
blood
vessel
loops
that
can
circulate
blood.
pericytes)
that
provide
structural
support.
Blood receptors
Diseased
or
injured
tissues
produce
and
release
growth
dissolved
vessel
tip
holes
in
order
of
to
the
accommodate
existing
vessel
it.
towards
(basement
membrane)
surrounding
all
existing
growth
factors
bind
to their
receptors,
the endothelial
cells angiogenic
become activated.
asOnce
grappling
hooks
to help
pull
thenearby
sprouting
(EC)
of
preexisting
blood
vessels
flow
then begins.
the
diseased
tissue
(tumor).
blood
vessels.
Signals
arevessel
sent
from
the
cell's surface
the nucleus.
factors
(proteins)
thattodiffuse
into the nearby tissues
new
blood
sprout
forward.
Angiogenic Switch
Angiogenic Switch
Balance is important in every aspect of life !
Antiangiogenesis Targets for Therapy
and Imaging
• Neovasculature
• Proteases that breakdown the ECM (e.g. MMPs)
• Growth factors that stimulate endothelial cell
proliferation (e.g. VEGF, PDGF, bFGF, IL-8)
• Integrins that allow adhesion of endothelial cells (e.g.
avb3)
• Endothelial cell apoptosis (e.g. TNF…)
• Pre-existing Vasculature
• Various Vasculature Targeting Agents
Timeline of Anti-angiogenic Therapy
• 1971: The field began in early 1970s with Judah
Folkman’s hypothesis that tumor growth would be
halted if it were deprived of a blood supply
• 1989: Dr. Napolene Ferra identified and isolate VEGF
• 1996: Dr. Jeffery Isner published first clinical trials
regarding VEGF
• 2004: FDA approves first antiangiogenic drug to treat
colorectal cancer (Avastin)
Is it possible to detect neo-angiogenic vessels ?
The specificity of αvβ3-integrin –NP was
demonstrated by inhibiting αvβ3 transfected K293 cell binding to
vitronectin. Effective affinity = 50 pM (per
particle).
Integrin avb3-Targeted
300 copies/Nanoparticle
Gold NanoBeacons (GNB)
2010 FASEB J, 25, 875-882
Early angiogenic vessels
Sprouting
No full circulation yet
Nanobeacons for Photoacoustic Imaging
(A)
(1) Probe sonication;
(2) Homogenization
(20,000 psi, 4°C, 4
min)
(B)
FASEB J, 25, 875-882
Nanosci and Nanotech 2010, 10(12):8118-23.
(C)Kd < 10 nM
ACS Nano. 2012 Feb 28;6(2):1260-7.
Angew Chem Int Ed 48,4170 (2009)
How Early We Are Able to Detect?
Early detection of immature, nascent angiogenic vessels with Photoacoustics Imaging!
MATRIGEL MOUSE MODEL
720 nm
720 nm
14 days
avb3-GNB
FASEB J, 25, 875-882
720 nm
Atherosclerotic Plaque and Angiogenesis
In vivo T1 sagittal section spin-echo image
to display long axis of aorta from aortic
arch to diaphragm of cholesterol-fed rabbit
Circulation 2010, 122, A20216
“Find, fight and follow” angiogenesis in a
Vx-2 tumor rabbit model with MRI
THERAPY
Comparison of MR Contrast Enhanced Images
presented as 2D Slice and 3D Volume
Treated
30µg/kg x 3 times (3, 6, 9 days)
NO THERAPY
Un-treated
Circulation. 2009, 120, S322.
Biomaterials, 2012, 33 (33), 8632–8640