Transcript Cell-What-is-research

Teacher: Audrey Gonzalez CCISD
Professor Mentor: Zhengdong Cheng, PhD
Artie McFerrin Department of Chemical Engineering
What type of engineering is conducted in the lab?
Chemical Engineering
 What is the research?
Soft condensed matter: colloids, droplets,
and cells

Gas in
liquid
Droplets
Liquid
in liquid
Cell
B.S., University
of Science &
Technology of
China, Hefei,
China, 1990
M.S., Institute
of High Energy
Physics,
Beijing, China,
1993
Ph.D.,
Princeton
University,
1999
Postdoc, Exxon
Mobil 99-2000,
Harvard
University, Ma,
2002-2004
Assistant
professor,
Chemical
Engineering,
Texas A&M
Univ. 2004



(1) Colloidal Crystal Growth:
Understanding colloid structure in order to
Engineer Materials for Optical Computers
(2) Discotic colloids:
Using colloids to make replications of disk
like shapes like those in RBCs, TMV, and
Histones
(3) Cell encapsulation:
Creating protective “bubble” to encapsulate
cells to release therapeutic substances for
humans

Colloidal crystals are 3 -D
periodic structures formed
from small particles suspended
in solution

Band gaps can be created
within the structure of crystal
to create a “circuit” for light to
travel through in order to
engineer optical computers


Crystals can be created by
using a suspension of
polymers (PNIPAM)
If there is a high volume
fraction in suspension there
are more crystals
0 min
25 min
4 min
89 min
11 min
152 min
How do you structure colloidal
crystals?
One method is to use the Belousov-Zhabotinsky reaction. This
reaction is used to convert its chemical energy to mechanical
energy to order crystal structure.
BZ reaction
facilitated
annealing of
colloidal
crystals
Crystal with Grain
Boundaries
Single Crystal
Biosa G, Bastianoni S, Rustici M
Chemical waves
CHEMISTRY-A EUROPEAN JOURNAL 12
(13): 3430-3437 APR 14 2006

RBCs
Disk shapes like those found in RBCs , TMV,
Histones, and Lipoprotien E4 found in Alzheimers
can be replicated to better understand their
function
Histones
Lipoprotein E4
Tobacco
Mosaic
Virus
• Wax with
1%
STADIS450
• Flow Rate
: 4ml/h
• Voltage:
2.8 kV
Tang, K. Q.; Gomez, A., J. Colloid Interface Sci. 1996, 184,500.
Step 2
Step 1
Step 3
Step 5
Step 4
Uniform wax emulsion
Place wax emulsion in
freezing temperature to
form discs



Encapsulating cells of interest with
therapeutic agent with a “bubble-like” semipermeable membrane
Implant cell capsules into human
Cells release therapeutic substance such as
insulin for diabetics.


Method: Electrospray
Make “bubbles” of Alginic acid solution with
Turgitol (surfactant) then drop into a solution
of Calcium Chloride
One method is using Microfluidics
Cells are joined together with semi-permeable
membrane, “bubble”.
Soft lithography (G.M. Whitesides, Harvard Univ.)
Encapsulation of
bacteria for
screening purposes.
Small diameter
agarose bead
(20µm), with a
single bacteria
encapsulated into.
http://www.nisco.ch/19.htm
1. Using the Electrospray to create wax
discs
Why?
To replicate form of RBCs and study flow of disk shaped
objects
 2. Make Agarose encapsulations and coat using layer by
layer coating to form a protective layer around
encapsulation
Why?
Coating is to create optimum mechanical strength that
will allow for cell to survive in vivo and at the same time
be able to secrete essential hormones needed by body


(1) Colloidal Crystal Growth:

(2) Discotic colloids:
Making colloidal crystals for optical
computers by creating ordered structure
through BZ reaction
Making colloidal disks via electrospray to
study shape and flow of RBCs and
Lipoproteins in Alzheimers disease

(3) Cell encapsulation:
Encapsulating cells to release therapeutic
substances for humans using electrospray and
microfluidics




Dr. Zhengdong Chengdong
Grad student : Andres Mejia
Undergrad student : Lucas Kinard
NSF