Tutorial

What is Alchite?

Creating Alginate Gels

Supplies:

• scale (that measures in grams)
• graduated cylinders
• disposable bowls
• stirring tool, e.g. whisk, fork, centrifuge
• tweezers
• pipette
• syringe
• 2% sodium alginate
• 2% calcium chloride
• water
• flourescein isothiocynate (FITC-BSA) protein
• hot plate
• saline solution

Steps:

1. It is often cheaper to buy solid sodium alginate and calcium chloride in their solid form and then dissolve it in water. If you are starting out with solid alginate and calcium chloride, then you will need to create solutions. Start by weighing 2 g of sodium alginate and measuring out 100 mL of water.
2. Preheat hot plate.
3. Pour the alginate and water into a bowl and add about  7 mg of FITC-BSA. Stir mixture while it is being heated on the hot plate until particles of alginate powder are no longer visible and a uniform solution has formed.
4. Weigh 2 g of calcium chloride and 100 mL of water, and dump them into another bowl.
5. Stir the mixture while it is being heated until the solution is uniform.
6. Extract alginate solution using a pipette.
7. Add alginate to the calcium chloride solution. To create small beads, lightly squeeze the pipette to allow droplets of alginate to fall into the calcium chloride. To create long strands, extract the alginate solution with a pipette, transfer it into the syringe, then place the needle of the syringe in the calcium chloride and inject it.
8. Wait about one minute for the reaction to complete.
9. Take out the newly formed calcium alginate gels using tweezers and place them in a bath of saline solution. Let it sit for a few minutes.

Creating alchite strings

The supplies and procedure for this process is identical to the one above, just with additional chitosan. This is specifically for alginate strings, not beads.

Supplies (in addition to those in previous procedure):

• 2% chitosan
• 1% acetic acid

Steps (continued from previous procedure):

     11. Create chitosan solution by dissolving the chitosan in a solution of acetic acid.
     10. Submerge the alginate string in bath of chitosan solution. Let it sit for a few minutes.



Comparing the Release Rates of Chitosan-Coated Alginate vs Bare Alginate
This is the main component of the team's research.

Supplies:

• spectrometer
• aluminum foil
• sample of alginate coated in chitosan
• sample of alginate not coated in chitosan
• cuvettes

Steps:

1. Transfer each sample of alginate into a cuvette.
2. Place the cuvettes in the spectrometer.
3. Cover the spectrometer with the foil (this will prevent unwanted light from penetrating the cuvette and messing with your measurements).
4. Record the absorbance of each sample over a period of 15 minutes, 1 hour, 2 hours, 4 hours, and 8 hours.*

*You should see that the spectrometer records a much higher intensity for the alginate not coated in chitosan because it diffuses its contents much more rapidly than the alginate coated in chitosan.