DESIGN ENGINEERING:
CELL ENCAPSULATION
Presented by:
Audrey Gonzalez and Carlos Montalvo (CCISD)
Faculty mentor:
Dr. Zhengdong Cheng of the Artie McFerrin Chemical
Engineering Department
BEING BRIDGED INTO
CLASSROOM PROJECT
CELL ENCAPSULATION
CORE ELEMENT OF RESEARCH
•Encapsulating
cells of interest
with therapeutic
agent in a semipermeable
membrane
•Implant
cell
capsules into
human
•Cells
release
therapeutic
substance such
as insulin for
diabetics
DR. CHENG’S LAB: FOCUSED ON
CHEMISTRY OF ENCAPSULATION
Encapsulation is made
from Alginic acid which is
insoluble in water/organic
solvents and is
biocompatible
The Alginic acid
encapsulation is then
covered by the
polymer PNIPAM that
exhibits controlled
variations of
permeability
MAKING ENCAPSULATIONS IN THE LAB
1. Make a solution of
calcium cholride and water
and setup camera
2. Make a solution of alginic
acid, water, and turgitol
and place in syringe pump
3. Set up syringe pump
and voltage source
4. Test electrospray and
begin making
encapsulations
4D, 5A, 6A, (IPC 7A), 12A, 12C)
Physics concepts: interpreting
graphs, measurements (time, density,
mass, volume, buoyant forces, grams
released per unit time), semi-permeable
membrane, design engineering (TEKS 1A,
2A, 2B, 2C, 2E, 3B, 4A, 4B, 4C, 4D)
AP Biology concepts: Biomedicine (time
release), cell encapsulation, cell processes
(osmosis/diffusion, semi-permeability), biochemistry
(hydrophobic/philic bilayer, chem/phys properties of
membrane, chem/phys changes to encapsulation,
properties of water), immune system role
TEXAS ESSENTIAL KNOWLEDGE AND SKILLS
Chemistry Concepts: properties of
water, solubility, chemical/physical
properties and changes, density and
buoyancy, atoms (TEKS 1A, 2A, 2B, 2C, 4A, 4B, 4C,
CONCEPTS
AND TEKS
COVERED
IN
PROJECT
CLASSROOM PROJECT
Timeline:
Cumulative project (7 weeks)
Actual design, build, analysis phase (2 weeks)
Objective:
Lab groups will be defending a cell encapsulation
design to a local pharmaceutical representative
using knowledge based on research of given
materials and data measurements.
CLASSROOM PROJECT

Proposal: A local pharmaceutical company is
looking for a new way to encapsulate a drug.
The actual encapsulation must be1. protective of the medicine inside
2. time released
3. selectively-permeable
WHO CARES?
WHAT IS THE RELEVANCE?
We need drugs on the market that are safe and
work properly.
WHAT IS THE RELEVANCE?
Diabetics



About 176,500 people
aged 20 years or younger
have diabetes.
As of 2005, 20.8 million
people have diabetes
The estimated economic
cost of diabetes in 2002
was $132 billion. Of this
amount, $92 billion was
due to direct medical
costs.
www.cdc.gov/diabetes
WHAT IS THE RELEVANCE?
The
pharmaceutical
industry is a
billion dollar
industry that has
become a necessity
in our allopathic
culture today.
DESIGN PHASE
Students will be given
5 different semiResearch:
permeable
 physical and chemical
materials to test
properties of membrane
 Size restriction
-Do they affect semi A design proposal will permeability or density?
be submitted for
(Chemistry)
approval
 Bioencapsulations/Immu
nosuppression of (AP

Biology)

Advantages and
disadvantages of time
released (AP
bio/chemistry/physics)
MEASUREMENT PHASE
Before building:
 Time that it takes for
small measured amount
of Tums to diffuse
through each membrane
 Using ratios decide time
for an entire packet of
Tums quikpak to dissolve
 Based on research decide
if long or short
diffusion is better
 Rank membranes and
choose material(s)
Coffee filter
burlap
fiberglass
nylon
Pantyhose
MEASUREMENT PHASE
Testing of encapsulation:
 Mass before/after
 Volume
 Density: sink, float, or suspended in
water
Find buoyant forces (physics)
 Measure mass released per unit
time (extrapolate at 2*t, 4*t, 6*t)
 Selectively permeable?

ANALYSIS PHASE: AFTER TESTING AND
DATA REVIEWED, DEFENSES WILL BEGIN

Groups must clearly
and concisely defend
their encapsulation
product, design and
material, to a local
pharmaceutical rep
THE PROJECT
This
encapsulation is
made out of a
double layer of
nylon material
that is
surrounding an
embroidery hoop.
The “therapeutic
agent” that is
encapsulated is a
Tums quikpak.
Time for Tums to diffuse out of encapsulation 2.14 min
This encapsulation is made of a double layer of filter paper
surrounding an embroidery hoop and is encapsulating a Tums
quikpak.
Time for Tums to diffuse out 3.53 min
RUBRIC FOR GRADING
Research on
material:
accurate info taken
from reliable sources
Data Collection:
data taken several
times in careful and
reliable manner
Design plan:
plan is neat with
clear measurements
and labeling
Construction of
materials:
materials used in a
way that made them
even better
Science
knowledge: defense
is clearly articulated
and accurate info is
given to defend model
Modification/testin
g: clear evidence of
troubleshooting, why
this material above
others
Function:
structure functions
as an encapsulation
should
Aesthetics:
structure is neat and
attractive and follows
plans accurately
Pre and post-test
ACKNOWLEDGEMENTS
•Dr. Zhengdong Cheng
•Grad student Andres Mejia
•Undergrad Lucas Kinard
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Dr. Cheryl Page
Dr. Karen Butler-Purry
Dr. Robin Autenrieth
Jacque Hodge
Joy Monroe
Dr. Andy Conkey
Dr. Arun Srinivasa
Dr. Jennifer Welch
All E3 participants
Dr. Chance Lewis
JOYS OF TEACHING
Ma and Pa video
http://www.youtube.com/watch?v=Bfq5kju627c