Have you heard of “The unbreakable cryobag”?

2021-12-21T05:00:00.000Z

Cryopreservation of product bags is an essential process in all stem cell therapy laboratories, but this road occasionally gets rough. Here is a story that I know many of stem cell therapy professionals can relate to.

“I was assigned to perform a transplant of 4 cryopreserved 70mL bags. I arrived at the clinical site and prepared for the transplant. We started the transplant; the thaw and infusion process was going smoothly with no issues. While I was thawing the 4th bag, I noticed the cryo bag was slowly leaking into the sterile bag that it was wrapped in”

Being in a situation like this is unfavorable at all; besides the potentially lost product, this situation stresses everyone involved.

What can we do about cryobag breakage?

To address this and similar situations, we started a study to compare different cryo bags. The study compared two plastic types of cryobags by exposing them to thermal and physical stress. The study clearly showed that some plastics have more tolerance to stress than others.

Reduction of cryobag breakage

Below are some practices that can reduce the cryobag breakage rate:

1. Switch to a fluorinated ethylene propylene (FEP) or comparable plastic type cryobags. Although pricy, such crybags reduce the incidents of bag breakage, hence, saving more products for patient’s infusion.
2. Before cryopreservation, examine the filled cryobags and make sure their ports are not to long; long lines get bended when placed inside the canister which could result in line breakage.

1. Chose an appropriately sized canister to reduce the cryobag movement inside the canister when the canister is handled.
2. Handle carefully when transferring the cryobag from the cryo freezer to the final storage point and avoid any physical stress.
3. Bundle the information recording and verification tasks to limit the times the cryobag is handled.
4. At thaw, gradually increase the temperature of the cryobag. If possible, use the 3-stage thaw process when moving the cryobags out of liquid nitrogen (LN2) freezer: LN2 storage to dry ice temperature to water bath temperature
5. If transporting the cryobags to an external facility, make sure the cryobag is secured in place with minimal movement, label the container as fragile, and notify the currier to pay extra attention.

While switching cryobags require an additional validation work, the rest of the practices can be implemented with little to no change required.

Here is more to my story:

“Following the protocol, I notified the attending physician of the incident; after examining the leaking cryobag they decided not to use it. The patient did well with 3 cryobag transplant with no issues, and I returned with the broken cryobag for further assessment”.

I hope you learn something from my little story, and start making changes proactively.

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