In two other significant studies , the influence of sterols on transfection has also been emphasized. Various naturally occurring cholesterol analogs (phytosterols) have been shown to markedly enhance transfection efficiency for different ILs, including the widely recognized MC3 lipid. To test this, we conducted additional PMF fusion assays using LNP bilayers containing MC3:STEROL:DSPC (50:40:10 mol%), incorporating cholesterol, 𝛽-sitosterol, ergosterol, and stigmasterol to the LNP bilayer. These were tested against the plasma membrane model , as mentioned previously.