Glycoside-Mediated\nEnhancement of Stability in Aluminum\nOxyhydroxide Nanoadjuvants during Freeze-Drying

Aluminum-based adjuvants have been indispensable to vaccine\npotency.\nHowever, their effectiveness is difficult to maintain after freeze-drying,\nwhich limits the storage and application of aluminum-adjuvanted vaccines.\nIn this study, the impact of freeze-drying on aluminum oxyhydroxide\nnanorods (AlOOH NRs) was investigated. Freeze-drying led to aggregation\nand resulted in the loss of the surface hydroxyl content of aluminum\nadjuvants. To alleviate freeze-drying-induced damage, the potency\nof different alkyl glycosides as protectants was further evaluated.\nIt was demonstrated that the structural balance of the head and tail\nof a glycoside was more conducive to protecting AlOOH NRs from aggregation\nand loss of surface hydroxyl groups. These results underline the proper\nselection of protectants to protect adjuvants against functional defects\ncaused by freeze-drying, which is important for the stability and\nefficacy of vaccines and biopharmaceutical products.