{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T13:42:23Z","timestamp":1778074943130,"version":"3.51.4"},"reference-count":48,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,11,8]],"date-time":"2025-11-08T00:00:00Z","timestamp":1762560000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100007149","name":"Bureau of Land Management","doi-asserted-by":"publisher","award":["L24AC00526"],"award-info":[{"award-number":["L24AC00526"]}],"id":[{"id":"10.13039\/100007149","id-type":"DOI","asserted-by":"publisher"}]},{"name":"USDA-NIFA Hatch formula funds","award":["IND90022882"],"award-info":[{"award-number":["IND90022882"]}]},{"name":"McKinley Family Foundation"},{"name":"Frederick N. Andrews Fellowship"},{"name":"Presidential Excellence Award"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background\/Objectives: Subunit vaccines composed of purified proteins and adjuvants offer excellent safety, but often generate short-lived immunity due to rapid antigen clearance and limited antigen-presenting cell engagement. Sustained, localized delivery of antigen and adjuvant may improve the magnitude and durability of the immune response without compromising safety. This study evaluated an in-situ polymerizing type I oligomeric collagen (Oligomer) scaffold to localize antigen\/adjuvant at the injection site and prolong antigen presentation. Methods: Mice were immunized intramuscularly with ovalbumin (OVA) and CpG oligonucleotide adjuvant delivered alone or co-formulated with Oligomer. Antibody response and inflammation at the injection site were assessed post-booster at early (Day 32) and late (Day 68) time points. Antigen retention and dendritic cell trafficking to draining lymph nodes were evaluated using fluorescently labeled OVA. Results: The Oligomer scaffold retained vaccine antigen at the injection site without eliciting a material-mediated foreign body response. Co-delivery of OVA and CpG within the scaffold enhanced germinal center activity, increased follicular helper T cells and germinal center B cells, and skewed CD4+ T cells toward a Th1 phenotype. Humoral responses were greater and more durable, with higher OVA-specific IgG, IgG1, and IgG2a titers and an increased number of bone marrow antibody-secreting cells persisting through Day 68. Antigen-positive dendritic cells, including both resident and migratory subsets, were elevated in draining lymph nodes, indicating enhanced antigen transport. No anti-mouse collagen I antibodies were detected, confirming the maintenance of collagen self-tolerance. Conclusions: The Oligomer delivery platform functioned as a localized, immunotolerant vaccine depot, sustaining antigen availability and immune cell engagement. This spatiotemporal control enhanced germinal center responses and generated a more robust, durable humoral immune response, supporting its potential to improve subunit vaccine efficacy while maintaining an excellent safety profile.<\/jats:p>","DOI":"10.3390\/vaccines13111146","type":"journal-article","created":{"date-parts":[[2025,11,10]],"date-time":"2025-11-10T08:57:55Z","timestamp":1762765075000},"page":"1146","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["In-Situ Self-Assembling Oligomeric Collagen Scaffold Enhances Vaccine Retention and Vaccine-Induced Humoral Immunity"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0798-4132","authenticated-orcid":false,"given":"Juan F.","family":"Hernandez-Franco","sequence":"first","affiliation":[{"name":"Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-3173-6258","authenticated-orcid":false,"given":"Sushma","family":"Gude","sequence":"additional","affiliation":[{"name":"Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rachel A.","family":"Morrison","sequence":"additional","affiliation":[{"name":"Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4510-5124","authenticated-orcid":false,"given":"Daniela","family":"Castillo Perez","sequence":"additional","affiliation":[{"name":"Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sherry L.","family":"Voytik-Harbin","sequence":"additional","affiliation":[{"name":"Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA"},{"name":"Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2738-9189","authenticated-orcid":false,"given":"Harm","family":"HogenEsch","sequence":"additional","affiliation":[{"name":"Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA"},{"name":"Purdue Institute of Inflammation, Immunology and Infectious Diseases, Purdue University, West Lafayette, IN 47907, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2307","DOI":"10.1016\/S0140-6736(24)00850-X","article-title":"Contribution of vaccination to improved survival and health: Modelling 50 years of the Expanded Programme on Immunization","volume":"403","author":"Shattock","year":"2024","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1597","DOI":"10.1038\/nm.3409","article-title":"Key roles of adjuvants in modern vaccines","volume":"19","author":"Reed","year":"2013","journal-title":"Nat. Med."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Prasad, A.K. (2023). Vaccine adjuvants: Mechanisms of action. Vaccine Development: From Concept to Clinic, The Royal Society of Chemistry.","DOI":"10.1039\/9781839162572-00001"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"772","DOI":"10.1016\/j.immuni.2024.03.015","article-title":"Vaccine adjuvants: Tailoring innate recognition to send the right message","volume":"57","author":"Lavelle","year":"2024","journal-title":"Immunity"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1038\/nature09737","article-title":"Programming the magnitude and persistence of antibody responses with innate immunity","volume":"470","author":"Kasturi","year":"2011","journal-title":"Nature"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2882","DOI":"10.1016\/j.vaccine.2014.02.027","article-title":"Adjuvant-carrying synthetic vaccine particles augment the immune response to encapsulated antigen and exhibit strong local immune activation without inducing systemic cytokine release","volume":"32","author":"Ilyinskii","year":"2014","journal-title":"Vaccine"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1201","DOI":"10.1038\/nbt.3371","article-title":"In vivo characterization of the physicochemical properties of polymer-linked TLR agonists that enhance vaccine immunogenicity","volume":"33","author":"Lynn","year":"2015","journal-title":"Nat. Biotechnol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1945","DOI":"10.1016\/j.vaccine.2019.02.033","article-title":"Formulation of aluminum hydroxide adjuvant with TLR agonists poly(I:C) and CpG enhances the magnitude and avidity of the humoral immune response","volume":"37","author":"Lu","year":"2019","journal-title":"Vaccine"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1111\/imr.12751","article-title":"Plasma cell differentiation during the germinal center reaction","volume":"288","author":"Ise","year":"2019","journal-title":"Immunol. Rev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1016\/j.cell.2019.03.016","article-title":"B Cell responses: Cell interaction dynamics and decisions","volume":"177","author":"Cyster","year":"2019","journal-title":"Cell"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1016\/j.coi.2017.06.008","article-title":"Germinal center enhancement by extended antigen availability","volume":"47","author":"Cirelli","year":"2017","journal-title":"Curr. Opin. Immunol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"263ra160","DOI":"10.1126\/scitranslmed.3009980","article-title":"Rational design of small molecules as vaccine adjuvants","volume":"6","author":"Wu","year":"2014","journal-title":"Sci. Transl. Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"E6639","DOI":"10.1073\/pnas.1606050113","article-title":"Sustained antigen availability during germinal center initiation enhances antibody responses to vaccination","volume":"113","author":"Tam","year":"2016","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1016\/j.cell.2019.04.012","article-title":"Slow delivery immunization enhances HIV neutralizing antibody and germinal center responses via modulation of immunodominance","volume":"177","author":"Cirelli","year":"2019","journal-title":"Cell"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1038\/s41578-021-00372-2","article-title":"Designing spatial and temporal control of vaccine responses","volume":"7","author":"Roth","year":"2022","journal-title":"Nat. Rev. Mater."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.addr.2020.06.019","article-title":"Controlling timing and location in vaccines","volume":"158","author":"Irvine","year":"2020","journal-title":"Adv. Drug Deliv. Rev."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4362","DOI":"10.1016\/j.vaccine.2013.07.019","article-title":"Control of antigen-binding to aluminum adjuvants and the immune response with a novel phosphonate linker","volume":"31","author":"Lu","year":"2013","journal-title":"Vaccine"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1038\/s41591-020-0753-3","article-title":"Engineered immunogen binding to alum adjuvant enhances humoral immunity","volume":"26","author":"Moyer","year":"2020","journal-title":"Nat. Med."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Gregory, A.E., Titball, R., and Williamson, D. (2013). Vaccine delivery using nanoparticles. Front. Cell. Infect. Microbiol., 3.","DOI":"10.3389\/fcimb.2013.00013"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Luzuriaga, M.A., Shahrivarkevishahi, A., Herbert, F.C., Wijesundara, Y.H., and Gassensmith, J.J. (2021). Biomaterials and nanomaterials for sustained release vaccine delivery. Wiley Interdiscip. Rev. Nanomed. Nanobiotechnol., 13.","DOI":"10.1002\/wnan.1735"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1800","DOI":"10.1021\/acscentsci.0c00732","article-title":"Injectable hydrogels for sustained codelivery of subunit vaccines enhance humoral immunity","volume":"6","author":"Roth","year":"2020","journal-title":"ACS Cent. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e2301495","DOI":"10.1002\/adhm.202301495","article-title":"Broad and durable humoral responses following single hydrogel immunization of SARS-CoV-2 subunit vaccine","volume":"12","author":"Ou","year":"2023","journal-title":"Adv. Healthc. Mater"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1039","DOI":"10.1080\/17425247.2018.1522301","article-title":"Dissolving microneedles for intradermal vaccination: Manufacture, formulation, and stakeholder considerations","volume":"15","author":"Rodgers","year":"2018","journal-title":"Expert Opin. Drug Deliv."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.copbio.2018.03.003","article-title":"Bionanotechnology for vaccine design","volume":"52","author":"Frey","year":"2018","journal-title":"Curr. Opin. Biotechnol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"690","DOI":"10.1002\/bip.21431","article-title":"Polymerization and matrix physical properties as important design considerations for soluble collagen formulations","volume":"93","author":"Kreger","year":"2010","journal-title":"Biopolymers"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2711","DOI":"10.1038\/s41598-021-81771-x","article-title":"Regenerative tissue filler for breast conserving surgery and other soft tissue restoration and reconstruction needs","volume":"11","author":"Puls","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1039\/C5BM00443H","article-title":"Acellular and cellular high-density, collagen-fibril constructs with suprafibrillar organization","volume":"4","author":"Blum","year":"2016","journal-title":"Biomater. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"368","DOI":"10.1016\/j.actbio.2021.08.007","article-title":"Mechanobiological wound model for improved design and evaluation of collagen dermal replacement scaffolds","volume":"135","author":"Sohutskay","year":"2021","journal-title":"Acta Biomater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"E388","DOI":"10.1152\/ajpendo.00066.2020","article-title":"Oligomeric collagen as an encapsulation material for islet\/beta-cell replacement: Effect of islet source, dose, implant site, and administration format","volume":"319","author":"Stephens","year":"2020","journal-title":"Am. J. Physiol. Endocrinol. Metab."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1295","DOI":"10.2217\/rme-2019-0084","article-title":"Design and biofabrication of dermal regeneration scaffolds: Role of oligomeric collagen fibril density and architecture","volume":"15","author":"Sohutskay","year":"2020","journal-title":"Regen. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3278","DOI":"10.1039\/D3BM00091E","article-title":"Engineered collagen polymeric materials create noninflammatory regenerative microenvironments that avoid classical foreign body responses","volume":"11","author":"Morrison","year":"2023","journal-title":"Biomater. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"700","DOI":"10.4049\/jimmunol.2000703","article-title":"Effective and safe stimulation of humoral and cell-mediated immunity by intradermal immunization with a cyclic dinucleotide\/nanoparticle combination adjuvant","volume":"206","author":"Mosley","year":"2021","journal-title":"J. Immunol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"499","DOI":"10.1586\/erv.10.174","article-title":"CpG DNA as a vaccine adjuvant","volume":"10","author":"Bode","year":"2011","journal-title":"Expert Rev. Vaccines"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1623","DOI":"10.1084\/jem.186.10.1623","article-title":"CpG oligodeoxynucleotides act as adjuvants that switch on T helper 1 (Th1) immunity","volume":"186","author":"Chu","year":"1997","journal-title":"J. Exp. Med."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1038\/334255a0","article-title":"Regulation of antibody isotype secretion by subsets of antigen-specific helper T cells","volume":"334","author":"Stevens","year":"1988","journal-title":"Nature"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1742","DOI":"10.1126\/science.8456301","article-title":"Immune response in mice that lack the interferon-gamma receptor","volume":"259","author":"Huang","year":"1993","journal-title":"Science"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1038\/nri.2016.150","article-title":"Regulation of muscle growth and regeneration by the immune system","volume":"17","author":"Tidball","year":"2017","journal-title":"Nat. Rev. Immunol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"20729","DOI":"10.1073\/pnas.1915950117","article-title":"Heterogeneous origins and functions of mouse skeletal muscle-resident macrophages","volume":"117","author":"Wang","year":"2020","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"787","DOI":"10.1038\/nri2868","article-title":"Vaccine delivery: A matter of size, geometry, kinetics and molecular patterns","volume":"10","author":"Bachmann","year":"2010","journal-title":"Nat. Rev. Immunol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1016\/j.jconrel.2021.01.035","article-title":"Engineered drug delivery devices to address Global Health challenges","volume":"331","author":"Sadeghi","year":"2021","journal-title":"J. Control. Release"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1056","DOI":"10.1080\/21645515.2015.1117714","article-title":"PLGA particulate delivery systems for subunit vaccines: Linking particle properties to immunogenicity","volume":"12","author":"Silva","year":"2016","journal-title":"Hum. Vaccines Immunother."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"8385","DOI":"10.1016\/j.biomaterials.2014.05.067","article-title":"Time course study of the antigen-specific immune response to a PLGA microparticle vaccine formulation","volume":"35","author":"Wang","year":"2014","journal-title":"Biomaterials"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2584","DOI":"10.4161\/hv.26136","article-title":"Biodegradable particles as vaccine antigen delivery systems for stimulating cellular immune responses","volume":"9","author":"Joshi","year":"2013","journal-title":"Hum. Vaccines Immunother."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1038\/nbt.3071","article-title":"Injectable, spontaneously assembling, inorganic scaffolds modulate immune cells in vivo and increase vaccine efficacy","volume":"33","author":"Kim","year":"2015","journal-title":"Nat. Biotechnol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"e2002153","DOI":"10.1002\/adhm.202002153","article-title":"Biocompatibility evolves: Phenomenology to toxicology to regeneration","volume":"10","author":"Crawford","year":"2021","journal-title":"Adv. Healthc. Mater."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Aachoui, Y., and Ghosh, S.K. (2011). Extracellular matrix from porcine small intestinal submucosa (SIS) as immune adjuvants. PLoS ONE, 6.","DOI":"10.1371\/journal.pone.0027083"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"e2309843","DOI":"10.1002\/adma.202309843","article-title":"Extracellular matrix scaffold-assisted tumor vaccines induce tumor regression and long-term immune memory","volume":"36","author":"Pal","year":"2024","journal-title":"Adv. Mater."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"4318","DOI":"10.1016\/S0264-410X(01)00153-0","article-title":"The application of biodegradable collagen minipellets as vaccine delivery vehicles in mice and sheep","volume":"19","author":"Lofthouse","year":"2001","journal-title":"Vaccine"}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/13\/11\/1146\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,10]],"date-time":"2025-11-10T09:27:42Z","timestamp":1762766862000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/13\/11\/1146"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,8]]},"references-count":48,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["vaccines13111146"],"URL":"https:\/\/doi.org\/10.3390\/vaccines13111146","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,8]]}}}