{ "abstract": "Background: Subunit vaccines offer excellent safety profiles but often suffer from limited immunogenicity, requiring potent adjuvants to elicit robust protection. We hypothesized that combining a positively charged biopolymer, trimethyl chitosan (TMC), with a nanoemulsion (NE) would create a synergistic delivery system to enhance immune responses. This study aimed to formulate a TMC-loaded nanoemulsion (TMC-NE) and evaluate its potential as a safe, effective adjuvant for subunit vaccines. Methods: TMC was synthesized via the quaternization of chitosan. Its modification and cyto-compatibility were verified by FT-IR, Zeta potential analysis, and cytotoxicity assays. Based on the pseudo-ternary phase diagram, a stable oil-in-water blank nanoemulsion (NE) was prepared. Subsequently, TMC-loaded nanoemulsion (TMC-NE) was prepared with TMC aqueous solution as the aqueous phase. The formulation was characterized for its droplet size, polydispersity index (PDI), and viscosity, and its safety in vivo was evaluated in mice. Using ovalbumin (OVA) as the model antigen, the immune adjuvant activity of TMC-NE was evaluated in mice by intramuscular injection, and compared with the NE and a commercial similar adjuvant M902. Humoral and cellular immune responses were analyzed by measuring serum IgG antibody levels and splenic lymphocyte proliferation, as well as the expression of cytokines IL-4 and IFN-γ. Results: Chitosan was successfully quaternized, yielding TMC with low cytotoxicity. The formulated TMC-NE was clear and transparent, with a mean droplet size of 25.41 ± 2.13 nm, a PDI of 0.231, and suitable viscosity. In vivo, TMC-NE showed no significant tissue toxicity. Immunization studies revealed that TMC-NE stimulated IgG antibody levels comparable to the M902 adjuvant and significantly higher than the blank NE. Furthermore, TMC-NE significantly increased the expression of IL-4 and IFN-γ and promoted lymphocyte proliferation and T lymphocyte levels, indicating the induction of both humoral and cellular immune responses. Conclusions: The TMC-loaded nanoemulsion (TMC-NE) is characterized as a safe and effective antigen delivery system with potent immune adjuvant properties. These findings strongly support its prospective application as a novel vaccine adjuvant.", "abstract_shown": true, "affiliations": [ "School of Intelligent Pharmaceutical Manufacturing & New Chemical Engineering Materials, Taizhou Poly-technic College, Taizhou, Jiangsu, China", "School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China", "Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Bi-ological Engineering and Technology, Ministry of Agriculture, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China" ], "article_type": "Research Article", "arxiv": null, "author_total": 9, "authors": [ { "affs": [ 0 ], "name": "Zhuyun Liu", "orcid": "0000-0003-2747-4647" }, { "affs": [ 0 ], "name": "Weilu Guo" }, { "affs": [ 0 ], "name": "Lei Wang" }, { "affs": [ 1 ], "name": "Pengcheng Zhao" }, { "affs": [ 0 ], "name": "Shanshan Yang" }, { "affs": [ 0 ], "name": "Donghua Zhai" }, { "affs": [ 2 ], "name": "Baochao Fan" }, { "affs": [ 0 ], "name": "Lizhong Wang" }, { "affs": [ 2 ], "name": "Bin Li" } ], "bibtex": "https://research.draconitic.com/paper/6k7r4c6gw4a3n.bib", "cited_by": 0, "doi": "10.1371/journal.pone.0359159", "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13712623/", "id": "6k7r4c6gw4a3n", "issns": [ "1932-6203" ], "landing_url": "https://doi.org/10.1371/journal.pone.0359159", "language": "en", "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Biochemistry" ], [ "heading", "Biology and Life Sciences" ], [ "heading", "Colloids" ], [ "heading", "Computer and Information Sciences" ], [ "heading", "Data Management" ], [ "heading", "Data Visualization" ], [ "heading", "Emulsions" ], [ "heading", "Enzyme-Linked Immunoassays" ], [ "heading", "Immune Response" ], [ "heading", "Immunoassays" ], [ "heading", "Immunologic Adjuvants" ], [ "heading", "Immunologic Techniques" ], [ "heading", "Immunology" ], [ "heading", "Infectious Disease Control" ], [ "heading", "Infectious Diseases" ], [ "heading", "Lipids" ], [ "heading", "Materials" ], [ "heading", "Materials Science" ], [ "heading", "Medical Conditions" ], [ "heading", "Medicine and Health Sciences" ], [ "heading", "Mixtures" ], [ "heading", "Oils" ], [ "heading", "Phase Diagrams" ], [ "heading", "Physical Sciences" ], [ "heading", "Preventive Medicine" ], [ "heading", "Public and Occupational Health" ], [ "heading", "Research Article" ], [ "heading", "Research and Analysis Methods" ], [ "heading", "Surfactants" ], [ "heading", "Vaccination and Immunization" ], [ "heading", "Vaccines" ], [ "openalex", "3003|Advanced Drug Delivery Systems" ], [ "plos", "/Biology and life sciences/Biochemistry/Lipids/Oils" ], [ "plos", "/Biology and life sciences/Immunology/Immune response" ], [ "plos", "/Biology and life sciences/Immunology/Vaccination and immunization/Immunologic adjuvants" ], [ "plos", "/Computer and information sciences/Data management/Data visualization/Phase diagrams" ], [ "plos", "/Medicine and health sciences/Immunology/Immune response" ], [ "plos", "/Medicine and health sciences/Immunology/Vaccination and immunization/Immunologic adjuvants" ], [ "plos", "/Medicine and health sciences/Medical conditions/Infectious diseases/Infectious disease control/Vaccines" ], [ "plos", "/Medicine and health sciences/Public and occupational health/Preventive medicine/Vaccination and immunization/Immunologic adjuvants" ], [ "plos", "/Physical sciences/Materials science/Materials/Mixtures/Colloids/Emulsions" ], [ "plos", "/Physical sciences/Materials science/Materials/Surfactants" ], [ "plos", "/Research and analysis methods/Immunologic techniques/Immunoassays/Enzyme-linked immunoassays" ] ], "openalex": "W7223980515", "pdf_url": "https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0359159&type=printable", "pmcid": "PMC13712623", "pmid": "42945266", "published": "2026-10-27", "publisher": "Public Library of Science", "ris": "https://research.draconitic.com/paper/6k7r4c6gw4a3n.ris", "sources": [ { "first_seen": "2026-10-30T12:17:17Z", "native_id": "10.1371/journal.pone.0359159", "source": "plos", "url": "https://doi.org/10.1371/journal.pone.0359159" }, { "first_seen": "2026-10-31T12:23:10Z", "native_id": "PMC13712623", "source": "pmc", "url": "https://doi.org/10.1371/journal.pone.0359159" } ], "subjects": [ { "field": "biochemistry", "origin": "heading:Biochemistry", "subfield": "general" }, { "field": "biology", "origin": "plos:immunology", "subfield": "immunology" }, { "field": "chemistry", "origin": "plos:materials science", "subfield": "materials-polymers" }, { "field": "medicine", "origin": "heading:Public and Occupational Health", "subfield": "epidemiology-public-health" }, { "field": "medicine", "origin": "heading:Infectious Diseases", "subfield": "infectious-disease" } ], "title": "Preparation and immunopotentiating activity of a novel oil-in-water nanoemulsion adjuvant based on trimethyl chitosan", "title_text": "Preparation and immunopotentiating activity of a novel oil-in-water nanoemulsion adjuvant based on trimethyl chitosan", "type": "peer-reviewed", "updated_at": "2026-10-31T12:23:10Z", "url": "https://research.draconitic.com/paper/6k7r4c6gw4a3n", "venue": "PLOS One", "versions": [] }