Tracey Hanna-University of Florida
Chemical Engineering, Junior
Mentor: Carlee Ashley
Principal Investigator: Dr. C. Jeffrey Brinker
Optimization of Drug Loading and Release
Rates from Protocells for Targeted Delivery
in vitro to Human Cancer
¾A stable protocell at a pH of 7.4
(bloodstream) is desirable. A large
amount of release in the lysosome of
the cell-pH of 4-is also desirable.
Release of the drug doxorubicin with
respect to pH of just silica core
versus protocell shows that as pH
increases release rate decreases.
Doxorubicin
Goal:
1.4
Silica
¾Optimize
drug loading and release rates of
protocells by using microemulsion templated silica
cores over aerosol synthesized cores
Fraction Released
1.2
Protocell
1
0.8
0.6
0.4
0.2
0
pH 4
Aerosol
pH 5
pH 6
pH 7
Rough Microemulsion
Percent V iable
100
90
Aerosol DOX
80
Aerosol CAM
70
Emulsion DOX
60
Emulsion CAM
50
40
30
20
10
0
0
50
100
150
200
Time (hours)
Approach:
¾Characterize
microemulsion silica particles using TEM and
confocal
¾Observe loading efficiencies and release rates of
doxorubicin, camptothecin and calcein in both types of
protocells while:
zAltering pH
zModifying the surface of the silica
¾Conducting viability tests of hepatocytes and Hep3B cells
exposed the the protocells loaded with chemotheraputic
agents
250
300
350
400
¾Viability studies using flow
cytometry show a steeper viability
dropoff initially for the mircoemulsion
protocells, indicating a “burst” release
most likely due to the large pore size
of microemulsion templated silica
cores.
Results and Conclusions:
¾Microemulsion
particles have about the same cargo
capacity as the aerosol particles, but can be loaded and
released at faster rates
¾Faster release rates lead to faster cell death, but not
necessarily sustained release
¾The drugs are not associating or reacting with the silica
particles
¾The protocell must be tailored to be small enough to
maintain circulation in the body, but with large enough pores
to load and release cargo effectively
Macro‐Scale and Nano‐Scale Characterization of Synthetic
Osteoporotic Femurs Research:
• Study the material properties of osteoporotic bone at the nano‐scale level and understand the mechanical properties and fracture mechanics of bone.
Significance:
• Understanding the material properties of bone at the molecular level is a means of predicting fracture occurrence and potentially reduce or eliminate osteoporosis.
• Preventing nontraumatic fractures in oseoporotic patients could significantly reduce morbidity and health‐care expenditures associated with these fractures. Robert Mercer
Mentor: Aaron Reinhardt
PI: Dr. Taha
Approach:
• Use nanoindentation techniques to retrieve material properties such as hardness, stiffness, and elastic modulus.
• Use a material testing system (MTS) to test for macro‐scale properties in compression, bending, and torsion.
Accomplishments:
• Osteoporotic cortical bone have significantly different material properties then ostepenic cortical bone.
• Nanoindentation is an effective way to retrieve material properties of specimens
• Successfully developed a method to test different implants in synthetic femurs at the marco‐level.
Spray Pyrolysis of Under-valent Manganese Oxide
Catalysts for Use in Air Breathing Batteries
Results:
Manuel Molina Villalba
University of Pennsylvania 2011
Mentor: Daniel Konopka
P.I.: Dr. Plamen Atanassov
•Performance differences
were attributed to
morphological Differences of
the commercial carbon blacks
Used that were used as
precursors
Research Goal:
O
HO
•Develop a protocol for synthesizing
carbon supported MnOx particles for use
OHin ORR catalysis of Zn-Air battery
MnO
cathode in alkaline media
Carbon
•Compare carbon supports derived
•MnOx supported on Monarch
from different commercial carbon blacks
1000 performed better than that
on Vulcan XC-72R in RDE tests
Approach:
2
2
x
•Use the spray pyrolysis technique to synthesize
MnOx particles from a salt precursor solution
(KMnO4)
•Wash spray product to remove ions
•Post-treat in 10V%H2/N2 at 400˚C
•Characterize: SEM, EDS, RDE
Conclusions:
•Morphological properties such as
primary particle size, structure and
specific surface area affect the cap
conductivity of the carbon black
•The differences in performance of
the catalysts can be attributed to
a reduced internal resistance
Tassie Andersen
Chemistry, Sophomore
Carnegie Mellon University
Mentor: Adam Wise
PI: Dr. Jeffrey Brinker Measurement of Single‐Cell Photosynthesis
Goal‐
Integrate photosynthetic cells into a silica matrix in order to:
•Make single‐cell photosynthesis measurements
•Characterize the metabolic products of single cells
•Work towards creating an artificial symbiotic system
Cyanobacteria and yeast integrated into silica matrix
Lysosensor Blue/yellow image of pH gradient created by photosynthesis in film
Approach/ Methods:
Conclusions:
•Cell‐directed assembly and cell‐directed integration in silica gels using algae cells
•Viability testing of algae cells in films
•Quantitative analysis of photosynthesis of cyanobacteria in silica matrix using pH sensing dyes
•Cyanobacteria can be integrated into Sol E films in a similar manner to yeast cells
•In film the cells continue to perform photosynthesis demonstrating a high level of functionality
•Photosynthetic and heterotrophic cells can be integrated in the same matrix
Matthew Bosch
Biomedical Engineering, Senior
The University of Texas at Austin
Mentor: Shisheng Xiong
PI: Dr. C. Jeffrey Brinker
Transformation of Monolayer
Nanoparticle Array to 2D
Anisotropic Nanorod Structure
Induced By Phase Transformation
D‐spacing decreases
Image A
Goal:
•Create 2D anisotropic nanorod structures from monolayer
nanoparticle (NP) array
D‐spacing increases
Significance:
•Much simpler than pre-existing methods to create nanorod structure
•Ability to pattern nanorod structures in any arrangement that is
preferred
•Potential future applications include nano-circuitry devices, highthroughput fabrication, and novel Surface Enhanced Raman Scattering
(SERS) substrate
HCP
CCP
Nanowire
Nanorod
Image B
70 nm
5 nm
Approach:
Results and Conclusions:
•Mechanical Deformation (Image A)
– Transfer NP film to elastic polymer
– Increasing d-spacing in one direction (by uni-axial stretching)
while decreasing d-spacing in normal direction to create
nanorods from 2D monolayer array
•Curved Water Subphase
–Patterning hydrophobic/hydrophilic substrate
–Placement of NP/Toluene and polymer water interface
–Evaporation of water droplet structure transformation
•Mechanical Deformation
–Au NP/PMMA monolayer film sensitive to E-beam irradiation
NP/Polymer Monolayer
Confined water droplet
Anisotropic
NP/Polymer
monolayer
►Au NPs retract perpendicularly from PMMA edge where ebeam caused mechanical instability in polymer matrix (Image B)
►Individual Au NPs fuse into single nanowire structures
–PbS Quantum Dots/Polystyrene monolayer film sensitive to chloroform
vapor annealing
►Film undergoes structural changes demonstrated in Image A
until nanorod structure, does not further fuse at room temp.
►Forced retraction of free-standing edge of films
•Curved Water Subphase
–Demonstrated ability to pattern Au NP films into any desired
shape and size
–Must analyze nano-structure to determine if formation of
nanowires
Elijah Champagne
University of Louisiana @
Lafayette
Chemical Engineering, Senior
REU (Summer 2009)
Mentor: Svitlana Pylypenko
PI: Plamen Atanassov
Templated
Electrocatalysts for
Oxidation in Fuel Cells
Goals:
Approach:
1.Synthesize templated electrocatalyst for ethanol oxidation
1.Synthesize electrocatalysts using templated silica structure to increase
surface area of electrocatalyst and mass transport.
2.Demonstrate the benefits of templated structure
2.Vary metal loadings on templated structure
3.Identify benefits of addition of Ru/Sn
3.Use
cyclic voltammetry
Synthesized
Materials : to compare performance of electrocatalyts
10% Pt/TC
10%PtSn(80:20)/TC;
45%PtSn(80:20)/TC
10%PtRu(50:50)/TC;
45%PtRu(50:50)/TC
Commercial Materials:
60% PtRu (50:50)/Vulcan XC72
A.Intrinsic catalytic activity
•Bi-functionality (oxidation of intermediate products [CO])
Results:
Conclusions:
1.Better nanoparticle size and dispersion achieved with lower metal
weight materials. This results in better metal and platinum
utilizations
TEM
Backscatter
SEM
•PtSn materials: enhancement in adsorption/dehydrogenation and
CO oxidation
•PtRu materials: enhancement in CO oxidation but poor
adsorption/dehydrogenation
XRD
CV
Surface Analysis of Thermoresponsive
Microwave-Polymerized pNIPAM
Films
Goal:
„
„
„
Test poly(N-isopropyl
acrylamide (pNIPAM) made by
microwave polymerization for
potential use in tissue
engineering applications
Approach:
„
„
„
Polymerize NIPAM using fast,
inexpensive microwave method1
Spin coat microwavepolymerized pNIPAM film on
surfaces
Test pNIPAM film in terms of:
Results:
„
Microwave-polymerized films >2100 Å
thicker than other methods tested2 and
show 88% less cell adhesion (vs.
ppNIPAM), although cell release is still
achieved at 99%
Fig. 1. Bovine aortic endothelial cell
adhesion on microwave-polymerized
film (left) and ppNIPAM (right).
Film Thickness (Å)
„
Daniel Cox
Senior, Biological Engineering
University of Missouri
Mentor: Kristin Wilde
PI: Heather Canavan
4000
20x magnification
3500
3000
2500
2000
1500
1000
500
2118 Å
Micro 1-3
Micro 4
ppNIPAM
spNIPAM
0.35% pNIPAM
in acetone
Thermoresponse (goniometry)
Fig. 2. Film thickness for 5 sample types. Note: pNIPAM from Micro 4
run dissolved in 200 mL acetone (vs. 50 mL for Micro 1-3 runs).
„ Thickness (interferometry)
„ Cell
1. Fischer, F. and Freitag,
R. J.adhesion
Chem. Educ.and
2006,detachment
83: 447-450.
Special Thanks to:
2. ppNIPAM and spNIPAM.
See
Reed,
J.
et
al.,
J.
Appl. Biomater. Biom. 2008, 6: 81-88.
(mammalian cell culture)
„
0
Acknowledgements: Steven Candelaria, Marta Cooperstein, Laura Pawlikowski,
and Jamie Reed
Reactivity of Ethanol on PdZn Catalysts
Benjamin Galloway- University of Pennsylvania
Mentor: Dr. Barr Halevi
PI: Dr. Abhaya Datye
Goal - to test the various
components of the PdZn/C
catalyst and examine their effects
on ethanol steam reforming
TPR- Temperature
Programmed Reaction
•Continuously flow reactant
gas
• Temperature ramp is
more gradual
•Major Products
RESULTS FOR
PDZN 1:1
the support and Pd:Zn ratio in a several
environments
1.
2.
3.
EtOH
EtOH & H2O
EtOH & H2
TPD- Temperature Programmed
Desorption
•Set amount of material allowed to
adsorb onto catalyst surface
•Ramp temperature up quickly
•Can see individual reaction events
CO2 Production
Pd/C
PdZn 1:1
Composition
Pd/C
PdZn/C 2:1
PdZn 1:1
Support
Carbon
ZnO
Role of Support
Pd/C
Pd/ZnO/C
Pd/ZnO
TPD‐ EtOH
x
x
x
TPD‐ Etoh and H2O
x
x
x
TPR‐ EtOH
x
x
x
TPR‐ EtOH and H2O
x
x
x
TPR‐ EtOH and H2
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
TPR ResultsPdZn/C 1:1
PdZn 1:1
TPD Results1. Support made
little difference in
activation energy
2. Composition
actually changes
Ea drastically
Experimental Approach- test the role of
1.
In a more
steady state
system
dehydrogenati
on to
acetaldehyde
(CH3CHO) is
primary
product with or
0
without a
coreactant
x
EtOH
CH3CH2OH
H2
CH3CHO
CO
500
Hector Moreno
Princeton University
Mentor: Arjun Thapa
PI: Eva Chi
Biosensor Detection of
Protein Aggregate Toxicity
Results:
Research Goal:
Achieved 100% disruption with Triton X-100
To develop a novel biosensor for the detection
of Aβ aggregate-induced membrane disruption
Observed partial disruption with Aβ protein
Tested interaction with different lipid compositions
← Lipid Bilayer
After
Fluorescein Dye →
Disruption
Approach:
Coat porous silica microspheres with lipid bilayers
and load with Fluorescein dye
Membrane Disruption - AB Protein
500
450
Detect membrane disruption through fluorescence
measurements
400
Quantitatively measure the disruption induced by
Triton X-100 and Aβ aggregates
350
Qualitatively observe membrane disruption
300
0
50
100
150
200
Time (min)
•Dye Leakage (normalized)
•Control (no protein added)
Summer 2009
OXIDATIVE STRESS AS A MEASURE
OF CELL VIABILITY, 2009
Goal
Measure Oxidative Stress levels of cells exposed to protocells to
confirm non-specific uptake of DOTAP and DOPG
phospholipids, which leads to cell apoptosis.

Ingrid Spielman
Johns Hopkins University
Approach


Characterize oxidative stress levels associated with cells
integrated into Sol Gel films

Use MitoSOX to quantify superoxide reactive oxidative species in
mitochondria of cells through flow cytometry and confocal imaging
Modify protocols of similar work done by Andre Nel on the
assessment of oxidative stress found in cells exposed to
nanoparticles (NP)
Results
Conclusion
1. Reproduce Andre Nel work of NP toxicity to macrophages

80
60
Control
TiO2 (-)
40
PS (+)
2. Oxidative stress studies of
Hep3B cells exposed to protocells to
determine none-specific NP uptake
20

0
PS TiO2 Cells
H2O2
PS NH2
PS COOH
SiO2
Unlabeled
Propidium Iodide

MitoSOX
H2O2
PS NH2
PS COOH
SiO2
Unlabeled

Presence of NP
3. Baseline levels of Oxidative Stress of Yeast in SOLE films
Pixel Intensity
y/
Volume
Propidium Iodide for Yeast
Viability
6000
H2O2
6000
MitoSOX Fluorescence in
Yeast
None
H2O2
None
4000
4000
2000
2000
0
0
CDI
No Film
CDI
No Film

Mentor: Carlee Ashley,
Xingmao Jiang
PI: Jeff Brinker
Oxidative Stress was
successfully measured in mouse
macrophages, reproducing the
results of the Andre Nel
research g
group.
Cells with Polystyrene
y y
NPs
By modifying methods used by the Andre Nel group
for measuring cell oxidative stress we were able to look
at other cell lines, such as the Hep3B cancerous cells.
We show that while DOTAP and DOPG coated silica
particles induce non
non-specific
specific protocell uptake in Hep3B
cells, both DOPC and DPPC coated silica particles do
not, making them favored candidates for protocell drug
delivery.
Studying Oxidative stress is limited by our ability to
quantif fluorescence le
quantify
levels,
els mainl
mainly measured through
flow cytometry. A cell is naturally found in a 3D
scaffolding environment and therefore, a way to study
oxidative stress in films was desired
Initial studies of oxidative stress in SOLE films was
made
d using
i yeast,
t a simple
i l system
t
for
f quick
i k protocol
t l
calibration. We find that oxidative stress does not
increase in cells integrated in a SOLE film. Further
protocol modification must be made before looking at
other cell lines.
DESIGN OF OXIDE MICROPARTICLES
WITH NANO-POROSITY DERIVED FROM
MICROEMULSION TEMPLATING
GOAL
Rachel Strubhar-Masick
Mentor: Nick Caroll
PI: Dr. Dimiter Petsev
APPROACH
Create microparticles with alkoxides using the
sol gel method with microemulsion templating
Particles with high porosity and surface area
and electrochemical properties
Oxide
Properties and Potential Uses
SnO2
Electrochemical properties for fuel
cells
TiO2
Catalysis
Using the sol gel method with self induced
evaporation with and microemulsion
Microemulsion allows for bimodal porosity.
Large pores for better transport properties,
and small pores allow for larger surface area
Characterization of the particles include
SEM for micrograph, XRD for pore order
and size, BET for surface area
CONCLUSIONS
RESULTS
SnO2
• Nitric Acid
• Isopropanol and Water
• 6 – 8 pH
• Calcination process needs to be explored
for application
BET Surface
Area:
75 – 300 m2/g
TiO2
• Particles, after calcination, are very
crystalline and dense
• Sol needs to be perfected
Joshua Yearsley
Rutgers University
Goal: Find the effects of valve geometry on vacuum actuation requirements in monolithic “normally closed” PDMS microfluidic devices
Actuation Vacuum (‐torr)
Approach: Fabricate and test different valve angles across a wide range of widths at fixed height
500
450
400
350
300
250
200
150
100
50
0
Findings: Terminal geometry did not matter as much as aspect ratio, which dominated the required Change in Valve Angle actuation pressures moreso than 315 Theta 90 Theta valve geometry
Aspect ratio = L / W of overlapped area
PI: Chris Apblett
Sandia National Laboratory
Mentor: Benjamin Schudel
University of Illinois
Aspect Ratio <= 0.90
Future Exploration: Focus on devices with variation based on aspect ratio rather than width
Old Design New Design
Aspect Ratio >= 0.90
0
100
200
300
Channel Width (um)
400
Proposed channel design for more precise vacuum requirements