Porous PCL scaffolds using gas foaming/salt leaching method

Hi! I am trying to create porous PCL scaffolds using gas foaming/salt leaching method. Unfortunately, I've met with some difficulties...just wondering if anyone has used this technique before and could shed some light on my doubts.

PCL solution was formed by dissolving PCL pellets in chloroform to the concentration of 15%. Sodium bicarbonate salt (acting as porogen leaching and effervescence salt) was then added in a variety of ratios to the PCL solutions. Ethanol was used as a non-solvent to precipitate out the PCL to form a gel paste, which was then placed into a mold. The next step would be to immerse the mold in citric acid to react away the salt and create effervescence which is supposed to help expand the pore size within the PCL scaffold. Herein lies the problem:

1) Although the sodium bicarbonate salt was supposed to be mixed homogeneously within the PCL solution, it was observed to all settle down to the bottom of the mold/petri dish after awhile. So essentially there's a bottom layer of settled salt and a top layer with no salt at all. (Any recommendations on how to improve on this step?)

2) When the carbon dioxide was formed, it "forced" its way out of the mold through the surface, creating large holes at the sides and on the top layer. This action essentially broke the integrity of the PCL mold/scaffold.

3) After effervescence was completed, what was left was only a thin layer of PCL (I have no idea why this is so)

Because of all these factors, I am unable to create the desired scaffold. Could anyone kindly provide me with some directions / point out any possible mistakes in my steps? Greatly appreciated!

Out of curiosity I searched for (PCL scaffold DMSO). DMSO, dimethylsulfoxide is very safe, and has the potential to be very dangerous as it can be used as a chemical delivery device, DMSO can transport chemicals through your skin and directly into your blood stream. I'm wondering if your gel phase can be improved with DMSO, but I don't know, it was just a thought.

Found a patent that mentions it:
Cell scaffold matrices with incorporated therapeutic agents
[www.pharmcast.com]

Then found this, so not sure if DMSO is helpful in your case.
(PLGA) solution in dimethylsulfoxide (a good solvent for PLGA but a poor one for PCL).
[www.sciencedirect.com]

You might want to find a forum more suited to ask your question.

Good luck.

Edited 1 time(s). Last edit at 09/11/2014 09:48AM by A2.

This is really cool, could you post photos of your results so far and the sources for your procedure?

This book recommends a freeze drying/salt leaching method specifically for PCL.
Scaffolding in Tissue Engineering