Hello dear,

1. The sterilization methods commonly used for polymers, including chitosan, comprise exposure to steam, ethylene oxide and gamma ray radiation . These methods lead to changes in molecules of vital structures of the microorganisms.

2.If you start your hydrogel preparation with a non sterile biomaterial there is no effective way of eliminating bacteria especially for hydrogels. You can always try adding antibiotics/antimyctotics in your culture media and increasing the frequency of media change to restrict the bacterial/fungal growth but you cannot eliminate it 100%. If you are following John's suggestion, make sure that you eliminated all that excess loads of antibiotics before seeding your cells.

So I would suggest you to start with a sterile material and do all your hydrogel preparation under aseptic conditions .

Always use the recommended concentrations of antibiotics/antimycotics in your culture media and increase the frequency of your media change.

All the best !!

Safia Arbab

Hi Safia

Thank you for the suggestions. I really appreciate that. Actually, I thought of sterilization of the solvents for chitosan and preparing the solutions under aseptic conditions. The problem is that chitosan powder can not be sterilized (to the best of my knowledge) Also, I can not use antibiotics because I want to do the minimum fungal inhibitory concentration (MIC) test for chitosan on specific fungi. So, I assume that the best way is to use ethylene oxide.

Kind Regards,

Elham

By using suitable filter

Membrane, I guess.