10.6084/m9.figshare.7751111.v1 Marie Rouquette Marie Rouquette Karine Ser-Le Roux Karine Ser-Le Roux Mélanie Polrot Mélanie Polrot Claudie Bourgaux Claudie Bourgaux Jean-Philippe Michel Jean-Philippe Michel Fabienne Testard Fabienne Testard Frédéric Gobeaux Frédéric Gobeaux Sinda Lepetre-Mouelhi Sinda Lepetre-Mouelhi Towards a clinical application of freeze-dried squalene-based nanomedicines Taylor & Francis Group 2019 Nanomedicines nanoparticles squalenoylation freeze-drying lyophilisation nanoprecipitation 2019-02-21 08:23:53 Journal contribution https://tandf.figshare.com/articles/journal_contribution/Towards_a_clinical_application_of_freeze-dried_squalene-based_nanomedicines/7751111 <p>Squalene-adenosine (SQAd) nanoparticles (NPs) were found to display promising pharmacological activity similar to many other nanomedicines, but their long-term stability was still limited, and their preparation required specific know-how and material. These drawbacks represented important restrictions for their potential use in the clinic. Freeze-drying nanoparticles is commonly presented as a solution to allow colloidal stability, but this process needs to be adapted to each nanoformulation. Hence, we aimed at developing a specific protocol for freeze-drying SQAd NPs while preserving their structural features. NPs were lyophilised, resuspended and analysed by dynamic light scattering, atomic force microscopy and small-angle scattering. Among four different cryoprotectants, trehalose was found to be the most efficient in preserving NPs physico-chemical characteristics. Interestingly, we identified residual ethanol in NP suspensions as a key parameter which could severely affect the freeze-drying outcome, leading to NPs aggregation. Long-term stability was also assessed. No significant change in size distribution or zeta potential could be detected after three-month storage at 4 °C. Finally, freeze-dried NPs innocuity was checked <i>in vitro</i> on cultured hepatocytes and <i>in vivo</i> on mice. In conclusion, optimisation of freeze-drying conditions resulted in safe lyophilised SQAd NPs that can be easily stored, shipped and simply reconstituted into an injectable form.</p>