Immunogenicity of Structurally Perturbed Hen Egg Lysozyme Adsorbed to Silicone Oil Microdroplets in Wild-Type and Transgenic Mouse Models.

Silicone oil microdroplets may act as adjuvants, promoting unwanted immune responses against both foreign and self-proteins. Proteins often unfold upon adsorption to silicone oil microdroplets, but it is unclear how such unfolding might affect the immune response. In this study, we found that hen egg lysozyme (HEL) readily adsorbed to silicone oil microdroplets and perturbed the conformation of HEL.

Silicone Oil Microdroplets Can Induce Antibody Responses Against Recombinant Murine Growth Hormone in Mice.

Therapeutic protein products can cause adverse immune responses in patients. The presence of subvisible particles is a potential contributing factor to the immunogenicity of parenterally administered therapeutic protein formulations. Silicone oil microdroplets, which derive from silicone oil used as a lubricating coating on barrels of prefilled glass syringes, are often found in formulations.

In Vivo Analysis of the Potency of Silicone Oil Microdroplets as Immunological Adjuvants in Protein Formulations.

Subvisible particles in a therapeutic protein product may act as adjuvants to promote unwanted immune responses against the protein. Silicone oil is used as a lubricant in prefilled syringes, and microdroplets of silicone oil are often detected in protein formulations expelled from prefilled syringes. In order to test the adjuvant potency of silicone oil microdroplets, antibody responses in mice to subcutaneous injections of formulations of ovalbumin (OVA) that contained silicone oil microdroplets were measured.