TY - JOUR AB - Recently, small interfering RNA (siRNA)/cationic liposome complexes (siRNA lipoplexes) have become a crucial research tool for studying gene function. Easy and reliable siRNA transfection with a large set of siRNAs is required for the successful screening of gene function. Reverse (Rev)‑transfection with freeze‑dried siRNA lipoplexes is validated for siRNA transfection with a large set of siRNAs in a multi‑well plate. In our previous study, it was shown that Rev‑transfection with siRNA lipoplexes freeze‑dried in disaccharides or trisaccharides resulted in long‑term stability with a high level of gene‑knockdown activity. In the present study, the effects of amino acids used as cryoprotectants in the freeze‑drying of siRNA lipoplexes on gene knockdown via Rev‑transfection were assessed. A total of 15 types of amino acids were used to prepare freeze‑dried siRNA lipoplexes, and it was found that the freeze‑drying of siRNA lipoplexes with amino acid concentrations >100 mM strongly suppressed targeted gene expression regardless of the amino acid type; however, some amino acids strongly upregulated or downregulated gene expression in the cells transfected with negative control siRNA. Amongst the amino acids tested, the presence of asparagine showed specific gene‑knockdown activity, forming large cakes after freeze‑drying and retaining a favorable siRNA lipoplex size after rehydration. These findings provide valuable information regarding amino acids as cryoprotectants for Rev‑transfection using freeze‑dried siRNA lipoplexes for the efficient delivery of siRNA into cells. AD - Department of Molecular Pharmaceutics, Hoshi University, Tokyo 142‑8501, Japan AU - Tang,Min AU - Hattori,Yoshiyuki DA - 2021/09/01 DO - 10.3892/br.2021.1448 IS - 3 JO - Biomed Rep KW - cationic liposome small interfering RNA reverse transfection amino acids freeze‑drying PY - 2021 SN - 2049-9434 2049-9442 SP - 72 ST - Effect of using amino acids in the freeze‑drying of siRNA lipoplexes on gene knockdown in cells after reverse transfection T2 - Biomedical Reports TI - Effect of using amino acids in the freeze‑drying of siRNA lipoplexes on gene knockdown in cells after reverse transfection UR - https://doi.org/10.3892/br.2021.1448 VL - 15 ER -