Disregarded determinant role of transfection medium in chitosan mediated siRNA delivery

It is well known that the chitosan (CS) properties such as molecular weight (Mw) and deacetylation degree (DD) are crucial for siRNA delivery. In the present study, we have unintentionally found that the transfection medium has much more substantial effect, which has not been reported before. Specifically, the transfection efficiency was considerably increased in Hank's Balanced Saline Solution (HBSS), with various Mw (30-150 kD) and DD (85-95%) combinations in different cell types. In addition, even though the CS/siRNA nanoparticles physical parameters such as diameter size and polydisperse index were disturbed by cell culture medium or serum, a relatively high knockdown efficiency could still be obtained in HBSS. Moreover, the highly efficient silencing in HBSS even did not require pre-mixing to formulate the CS/siRNA nanoparticles. In conclusion, our findings have confirmed a neglected but crucial important factor of transfection medium in the chitosan mediated siRNA delivery. (C) 2022 The Authors. Published by Elsevier Ltd.

Automated summary

This study reveals the significant impact of transfection medium on chitosan-mediated siRNA delivery, with even disturbed physical parameters of nanoparticles still achieving high knockdown efficiency.