title: Engineering of a novel adjuvant based on lipid-polymer hybrid nanoparticles: A quality-by-design approach.
abstract: The purpose of this study was to design a novel and versatile adjuvant intended for mucosal vaccination based on biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) modified with the cationic surfactant dimethyldioctadecylammonium (DDA) bromide and the immunopotentiator trehalose-6,6'-dibehenate (TDB) (CAF01) to tailor humoral and cellular immunity characterized by antibodies and Th1/Th17 responses. Such responses are important for the protection against diseases caused by intracellular bacteria such as Chlamydia trachomatis and Mycobacterium tuberculosis. The hybrid NPs were engineered using an oil-in-water single emulsion method and a quality-by-design approach was adopted to define the optimal operating space (OOS). Four critical process parameters (CPPs) were identified, including the acetone concentration in the water phase, the stabilizer [polyvinylalcohol (PVA)] concentration, the lipid-to-total solid ratio, and the total concentration. The CPPs were linked to critical quality attributes consisting of the particle size, polydispersity index (PDI), zeta-potential, thermotropic phase behavior, yield and stability. A central composite face-centered design was performed followed by multiple linear regression analysis. The size, PDI, enthalpy of the phase transition and yield were successfully modeled, whereas the models for the zeta-potential and the stability were poor. Cryo-transmission electron microscopy revealed that the main structural effect on the nanoparticle architecture is caused by the use of PVA, and two different morphologies were identified: i) A PLGA core coated with one or several concentric lipid bilayers, and ii) a PLGA nanoshell encapsulating lipid membrane structures. The optimal formulation, identified from the OOS, was evaluated in vivo. The hybrid NPs induced antibody and Th1/Th17 immune responses that were similar in quality and magnitude to the response induced by DDA/TDB liposomes, showing that the adjuvant properties of DDA/TDB are maintained in the PLGA hybrid matrix. This study demonstrates the complexity of formulation design for the engineering of a hybrid lipid-polymer nanoparticle adjuvant.
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Rose
authors.affiliation: Department of Infectious Disease Immunology, Chlamydia Vaccine Research, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
authors.forename: Jeanette Erbo
authors.initials: JE
authors.lastname: Wern
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Pall Thor
authors.initials: PT
authors.lastname: Ingvarsson
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Marco
authors.initials: M
authors.lastname: van de Weert
authors.affiliation: Department of Infectious Disease Immunology, Chlamydia Vaccine Research, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Andersen
authors.affiliation: Department of Infectious Disease Immunology, Chlamydia Vaccine Research, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
authors.forename: Frank
authors.initials: F
authors.lastname: Follmann
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark. Electronic address: camilla.foged@sund.ku.dk.
authors.forename: Camilla
authors.initials: C
authors.lastname: Foged
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry*; D015195:Drug Design; D006017:Glycolipids / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D000276:Adjuvants, Immunologic; D006017:Glycolipids; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C507803:trehalose 6,6'-dibehenate; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C015831:dimethyldioctadecylammonium; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: Adjuvant; Dimethyldioctadecylammonium (DDA); Drug delivery; Nanomedicine; Nanoparticles; PLGA; Quality-by-design (QbD); Trehalose 6,6-dibehenate; Vaccine