Transcript Final Poster Presentation 916 kb Friday, May 5

1
Desai , Nathan
1
Kleinhans ,
1
Linstroth ,
1
Soundarrajan
Dhaval
Lee
Malini
1
2
Advisor: Professor Naomi Chesler, Ph.D. , Client: Dr. Darin Y. Furgeson, Ph.D.
1Department
of Biomedical Engineering,
Elastin-like polypeptides (ELPs) are genetically engineered
biopolymers that serve as potential non-viral gene or drug
delivery agents for cancer treatments. ELP is purified from
bacteria resulting in a viscous ELP pellet. We modified an
existing rock tumbler design to develop a device to efficiently
resolublize ELP aggregate in Phosphate Buffered Saline
(PBS) solution. To ensure that our device is efficient and
produces a solution with uniform concentration we tested it
with both ELP and creamed honey. Further modifications to
our design may allow for the resolublization of larger
quantities of ELP.
Problem Definition
of Pharmacy
Design Criteria
• Efficiently
resolublize ELP harvested from 2 liters of bacteria
(1 liter of bacteria yields approximately 180 mg of ELP).
• Accommodate test tube (10.3 cm x 2.8 cm)
• Automated and require minimal manual labor.
• The final ELP solution should be uniform in concentration
with complete resolublization.
• The device should operate at room temperature.
Final Design
Device
• Lortone rock tumbler
• Drum rotates on its side
creamed honey and water.
-Number of beads
-Bead Type
-Quantity of honey and water
• Measured absorbance using spectrophotometer.
• Results indicate Zn beads contaminate solution.
• Absorbance values for stainless steel beads stabilized at a
faster rate than for glass beads.
Test 1 - 417mg
Honey, 2mL Water, 10
Zinc Beads
1.1
Test 2 - 404mg
Honey, 2mL Water, 20
Zinc Beads
1
Test 3 - 407mg
Honey, 2mL Water, 10
Glass Beads
0.9
0.8
Test 4 - 397mg
Honey, 2mL Water, 20
Glass Beads
0.7
Test 5 - 193mg
Honey, 1mL Water, 20
Stainless Steel Beads
0.6
0.5
0
2
4
6
8
Time (Minutes)
Test 6 - 204mg
Honey, 1mL Water, 40
Stainless Steel Beads
Figure 6: Absorbance data from testing prototype with creamed honey.
Future Work
Figure 2: Prototype fully assembled.
Designed from a model rock tumbler.
Harvesting ELP
Figure 3: Collapsed view of drum.
Figure 4: Test tube and holding
apparatus in drum.
Figure 1: Current procedure used to isolate ELP from E. coli bacteria. The ELP
gene is inserted into a plasmid and then transformed into E. coli cells. Once
transcribed, ELP is separated out through cell lysis and several temperature
controlled centrifugations. The ELP pellet, shown in red, is extremely viscous
and must be resolublized.
• Tested our device with
• Variables included:
1.2
The final design for our device is composed of a rotating
drum that contains an apparatus that holds a test tube at an
angle. Stainless steel beads are placed into the test tube to
aid in the resolublization process.
Background – Cancer has affected many people worldwide.
Current treatments for cancer include chemotherapy,
radiation therapy, hormonal therapy, and immunotherapy [1].
These treatments are invasive and harm normal tissue. ELPs
may serve as a less invasive gene and drug delivery agent
because they are non-immunogenic. They are also
hydrophobic and undergo inverse state transition, thereby
aggregating above a certain transition temperature due to
hydrophobic collapse [4].
Motivation – Since the solublization process in the harvesting
of ELP is time consuming and labor intensive, a device is
desired to convert the ELP aggregate into a soluble form.
This device should require minimal manual labor and should
solublize ELP rapidly.
Prototype Testing
Absorbance
Abstract
2School
References
Test Tube Apparatus
• High density
polyethylene
• Supported by three
peripheral bolts
• Angled hole
-Allows beads
maximum contact
with pellet
Stainless Steel Beads
• Solid to prevent flaking of outer coats
• Will not corrode
• Autoclavable
• Modify the design to accommodate multiple test tubes.
-Enlarge drum size.
-Add holes to test tube holding apparatus.
• Further testing with ELP and different sized stainless steel
beads
1. American Cancer Society. 02/06/2006. Copyright 2006. Retrieved on
02/17/2006 from< www.cancer.org>
2. Betre H, Setton LA, Meyer DE, Chilkoti A. Characterization for genetically
engineered elastin-like polypeptide for cartilaginous tissue repair.
Biomacromolecules. 2002 Sep-Oct, 3(5): 910-6.
3. Chilkoti A, Dreher MR, Meyer DE, Design of thermally responsive
recombinant polypeptide carriers for targeted drug delivery. Adv. Drug
Deliv Rev. 2002 Oct 18; 54(8): 1093-111. Review
4. Chilkoti A, Dreher MR, Meyer DE, Raucher D. Targeted drug delivery by
thermally responsive polymers. Adv Drug Deliv. Rev. 2002 Sep 13; 54(5):
613-30. Review
Figure 5: Drum components. From
bottom up: drum, test tube
apparatus, primary cover,
secondary cover, guiding nut. Test
tube is pictured over top left of
secondary cover.
Acknowledgments
Thanks to Darin Furgeson, Ph.D., and members of his lab for
their help in testing our device. We would also like to thank our
advisor, Naomi Chesler, Ph.D., for her continued support and
encouragement.