For the acquisition of the OrbiSIMS depth profiles, a 20 keV Ar3000 + analysis beam of 20 µm diameter, was used as primary ion beam. The distribution is shown in Figure . OrbiSIMS profiles were acquired from 3 replicates from the same LNP batch. Ar3000 + with duty cycle set to 4.2% and GCIB current was 220 pA. The Q-Exactive depth profile was run on the area of 400 µm × 400 µm using random raster mode with crater size 498 × 498 μm. The cycle time was set to 400 μs. Optimal target potential was set to -57 V in negative polarity and +57 V in positive polarity. Argon gas flooding was in operation in order to aid charge compensation, pressure in the main chamber was maintained at 9.0 × 10 -7 mbar. The spectra were collected in positive polarity, in mass range m/z 75-1125. The injection time was set to 500 ms and each area analysed lasted 1000 scans, the total ion dose per measurement was 2.62 × 10 14 ions/cm 2 . The static limit of primary ion dose, commonly used for primary beams which result in the build-up of sample damage (10 12 ions/cm 2 ) is reached at the third scan.