Transcript Dr. Putnam: Lab Projects

The Putnam Lab
Project Distributions
Delivery of Nucleic
Acid-Based
Therapeutics
Biomaterial Design
and
Synthesis
Outer Membrane
Vesicle
Engineering
siRNA
Controlled Release
plasmid DNA
Bioadhesives
Biolubricants
Vaccines
Adjuvants
Approach
polymeric libraries with serial changes in composition
molecular weight
backbone composition
side chain length/composition
(hydrophilicity/hydrophobicity)
side chain density
Multifactorial biomaterial
design and synthesis
side chain termini
composition/ratios
Refolding yield
100
80
Quantify efficacy of
each unique structure
60
40
20
500
1000 1500 2000 2500 3000 3500 4000 4500
Formulation number
Nuclear transport
Endosomal
Escape
Endosome
(pH ~ 5)
Biophysical and subcellular
characteristics
Nucleus
1. Transcription
Protein
2. Translation
Goal: Quantitative, mechanistic understanding of transfection
The Putnam Lab
Project Distributions
Delivery of Nucleic
Acid-Based
Therapeutics
Biomaterial Design
and
Synthesis
Outer Membrane
Vesicle
Engineering
siRNA
Controlled Release
plasmid DNA
Bioadhesives
Biolubricants
Vaccines
Adjuvants
Motivation
the human body is a monomer factory
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New polymeric biomaterials
from metabolic synthons
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Rational/targeted selection
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Investigate metabolic pathways
Identify interesting monomers
Akin to PLGA polyesters
Engineered polymer properties
Synthetically challenging
http://www.science.gmu.edu/~gsudama/csi803s97/met2.gif
Dihydroxyacetone (DHA)
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Glucose
Glucolytic metabolite
O
DHA
OH
OH
Pyruvic acid
Scheme 1: Glycolysis pathway
Dihydroxyacetone (DHA)

Glucolytic metabolite

FDA approved for use in oral
and topical administration (the
active ingredient in sunless
tanning lotions).
Glucose
DHA
Pyruvic acid
http://www.premiersalonsystems.com/
http://www.procyte.com/products/brand/asp/titanfoaming.shtml
Scheme 1: Glycolysis pathway
PEG-pDHA
Synthesis, characterization and application
O
HO
OH
HO
OH I
OH
O
O
OH II
O
a
O
O
O
OH
O
H3CO
b
O
OH III
O
O IV
O
O
+
O
H3CO
O
n
nH
V
c
Water soluble
block
O
m
Water insoluble
block
O O
H3CO
O
O
n
O
O
m
VI
d
O
H3CO
O
O
n
O
O
VII
m
Postoperative adhesions
Seroma closure
Fistula blockade
Chemo-emboli
Zawaneh, P.; Doody, A.; Zelikin, A.; Putnam, D. Biomacromolecules (2006)
DHA-based lipids
Synthesis
HYPOTHESIS
Release slower with
increasing lipid
chain length
DHA-based lipids
Release kinetics
C8
C10
C12
C14
C16
“Career path and research which have led you”
Project Distributions
Delivery of Nucleic
Acid-Based
Therapeutics
Biomaterial Design
and
Synthesis
Outer Membrane
Vesicle
Engineering
siRNA
Controlled Release
plasmid DNA
Bioadhesives
Biolubricants
Vaccines
Adjuvants
Outer membrane vesicles (OMVs)
natural vesicles for transfer of proteins and DNA
GOAL
Engineered vesicles to correctly fold
and stabilize proteins
Optimize antigen presentation to APCs
http://www.molbiol.umu.se/forskning/wai/
APPLICATIONS
Periplasmic
proteins are
entrapped within
the OMV lumen
Expression/stabilization/delivery of
conformational antigens
LPS
OM
PG Per
IM
Cyt
Kuehn and Kesty (2005) Genes Dev 19: 2645-55
Novel adjuvants to enhance existing
or poorly effective vaccines
Section 2

Joint project with Neurological Surgery

ChemoCoils and Brain Phantom
Creation and Validation of a Novel Drug Delivery Technique

Michael Shuler, Susan Pannullo, David Putnam, Jian Tan
ChemoCoils and Brain Phantom
Creation and Validation of a Novel Drug Delivery Technique
Cornell Cross-Campus
Neurological Surgery/Biomedical Engineering Project
Michael Shuler, Susan Pannullo, David Putnam, Jian Tan
July 2007
Reviewing the Problem
Malignant Gliomas
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Highly aggressive brain
cancers
Recur locally  need good
local control techniques
Only 1 validated/FDA
approved device:
chemotherapy wafers
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
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
Minimal survival benefit
Poor conformality to resection
cavity
Minimal brain penetration
Submaximal dose
Only one drug (BCNU) delivered
Drug delivery poorly
understood
Chemotherapy Coils and
Brain Phantom: The Project
Year 1
–
Development of an in vitro “Brain
Phantom” based upon Magnetic
Resonance Imaging of human
brain and brain tumor
–
Development of polymer coils
with appropriate mechanical,
chemical, and drug release
properties.
–
Test, using dyes and IMAGING,
the distribution, depth of
penetration, and duration of
chemical dyes from different
polymer formulations
Year 2
–
–
–
Refinement of delivery
system/drug mixtures
Animal trials
Clinical trials
Hypothesis
Maintaining contact with cavity wall will
improve treatment outcomes
Controlled Release Polymer
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Incorporate both p(CPP:SA) (poly
(carboxyphenoxypropane-sebacic acid) and
polyester of ε-caprolactone
Diameter and porosity are controlled by
electrospinning
Wafer: 14mm in diameter and 1mm thick
Mesh: interwoven fibers (<1μm); multiple
reporter “drugs”
Coil: order of 0.1mm size, mix of different coils
Pressure Model
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Brain experiences around 10mmHg of
pressure in brain cavity.
For our first experiments we will use a
simple water tank to create the pressure.
14cm
Alternate Pressure Model
Syringe to alter
pressure
Agarose Brain
Silicone
Encapsulation
Pressure
Probe
Mathematical Model

Simulate the transport of drugs from various
polymer constructs to the brain
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Assumption: transport of drug occurs by
diffusion and convection (due to edema) with
elimination (e.g. internationalization)
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Goal: to predict drug concentration and
deduce drug penetration in the artificial
tissue, then compare with our brain phantom
model
Section 3

Bill Olbricht

Microcatheters for drug delivery to the brain
Microcatheters for Convection-Enhanced Delivery
Diffusion only gets you so far.
Convection can get you further.
Remodeling ECM to enhance nanoparticle delivery
5 mm
Channel 1: Deliver enzymes that degrade ECM components (hyaluronan and
chondroitan sulfate proteoglycans) to increase permeability OR hyperosmolar
solutions that swell interstitium to increase permeability
Channel 2: Deliver drug-laden nanoparticles to reduce drug elimination during
transport in tissue and extend release time
Flexible microfluidic catheters
Section 4
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C. C. Chu

Materials for drug delivery
C. C. Chu

Biodegradable hydrogels as cytokine (IL-12)
carriers for immunotherapy of cancer.
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Estone carrier from polysaccharides.
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Biodegradable carriers of nitric oxide
derivatives for nitric oxide biofunctionality.
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Biodegradable hydrogels and microspheres as
anticancer drug (e.g., Doxorubicin, Paclitaxel)
carriers.
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Biodegradable hydrogels as gene carriers
1. Cytokine carriers for immunotherapy:
Interleukin 12 impregnated within Arginine-based biodegradable hydrogels.
• Burst release followed by sustained release
over 3 mo. wo/ bioactivity loss.
• 4 factors control IL-12 release – charge,
hydrophilicity, gel crosslinking density,
biomaterial biodegradation.
Dry
water
Nitroxyl radical release (%)
2. Biodegradable carriers for nitric oxide derivatives (NOD):
a. NOD conjugated with biodegradable biomaterials.
b. NOD Impregnated within biodegradable microspheres or nanofibers.
10
conjugated
2.5
2
6
1.5
1
2
0.5
0 0d
Phenylalanine-based
poly(ester amide)
microspheres w/
10 mg NO/g PEA
2d
4d
PGA, PLA, PEA
9d
3. Estrone carrier from polysaccharides:
a. Starch-estrone conjugate.
b. Dextran-estrone conjugate.
pH 8
pH 7.4
O
Polysaccharide – O – C – CH2 - Estrone
4. Biodegradable hydrogels and microspheres as anticancer drug carriers :
a. from poly(ester amide) gel and microspheres
b. from intelligent polysaccharide-synthetic hydrogels
80
70
Cumulative release (%)
60
50
40
30
20
NDF-1
NDF-3
10
NDF-5
0
0
10
20
30
40
50
60
70
80
90
100
Time (days)
Doxorubicin release
Poly(ester amide) gel
Intelligent Dextran-synthetic hydrogels