Fig. 2

Addition of PAA as a stabilizer produces stable nanoalum particles. a The particle size of Alhydrogel, Alhydrogel mixed with PAA prior to sonication and microfluidization, and PAA:nanoalum were determined by dynamic light scattering (DLS) or laser diffraction. b Increasing the amount of PAA at the start of the process or increasing the number of passes through the microfluidizer results in smaller PAA:nanoalum particles. c PAA:nanoalum retains the original particle size for at least 3 months at 5, 25, or 37 °C as determined by DLS. d Cryo-TEM images of Alhydrogel on the left and PAA:nanoalum on the right reveal a highly aggregated and mono-dispersed state, respectively. Scale bars, 100 nm. c Cryo-TEM images of Alhydrogel on the left and PAA:nanoalum on the right reveal a highly aggregated and mono-dispersed state, respectively. d PAA:nanoalum retains the original particle size for at least 3 months at 5, 25, or 37 °C as determined by DLS. e Unlike Alhydrogel, PAA:nanoalum particle size is stable for at least three free-thaw cycles. Data are representative of three experiments with three replicates each. The means and standard deviations are shown