what is going on in the lab?

Teacher: Audrey Gonzalez CCISD Professor Mentor: Zhengdong Cheng, PhDArtie 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

Liquid in liquid

Gas in liquid

Droplets

Cell

(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

89 min 152 min

0 min 4 min 11 min

25 min

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.

Crystal with Grain Boundaries

Single Crystal

BZ reaction facilitated

annealing of colloidal crystals

How do you structure How do you structure colloidal crystals? colloidal crystals?

Biosa G, Bastianoni S, Rustici MChemical waves CHEMISTRY-A EUROPEAN JOURNAL 12 (13): 3430-3437 APR 14 2006

Disk shapes like those found in RBCs , TMV, Histones, and Lipoprotien E4 found in Alzheimers can be replicated to better understand their function

RBCs

Histones

Lipoprotein E4TobaccoMosaicVirus

• Wax with 1% STADIS-450• Flow Rate : 4ml/h• Voltage: 2.8 kV

Tang, K. Q.; Gomez, A., J. Colloid Interface Sci. 1996, 184,500.

Step 1 Step 2

Step 3Step 4

Step 5

Uniform wax emulsion Place wax emulsion in freezing temperature to form discs

Encapsulating cells of interest with therapeutic agent with a “bubble-like” semi-permeable membrane

Implant cell capsules into humanCells release therapeutic substance

such as insulin for diabetics.

Method: ElectrosprayMake “bubbles” of Alginic acid

solution with Turgitol (surfactant) then drop into a solution of Calcium Chloride

One method is using MicrofluidicsCells 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: Making colloidal crystals for optical computers by creating ordered structure through BZ reaction

(2) Discotic colloids: 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 ChengdongGrad student : Andres MejiaUndergrad student : Lucas KinardNSF