Abstract

Laponite® 2D Nanosilicates (NS) are disc-shaped platelets (~30 nm diameter, ~1 nm thick) with positively charged edges and negatively charged faces, capable of loading proteins, drugs, and nucleic acids via electrostatic interactions to form a house-of-cards gel that sequesters cargo. Here, we evaluated NS for sustained delivery of antigens and Toll-like receptor (TLR) agonists to extend germinal center duration and enhance antibody quality. The model antigen ovalbumin (OVA) was adsorbed onto NS at acidic pH in a ~1:1 ratio, with partial unfolding that remained stable at physiological pH. NS-OVA complexes were efficiently internalized by dendritic cells, with uptake driven primarily by clathrin-mediated endocytosis, raft engagement, and macropinocytosis. Antigen processing and presentation occurred through both MHC-I and MHC-II pathways, as demonstrated by inhibition studies and antigen presentation assays. Mechanistic analyses revealed dose-dependent cytotoxicity and inflammasome activation, including interleukin-1β (IL-1β) release at higher doses. In vivo imaging showed prolonged depot formation of NS-OVA at the injection site compared with free OVA, correlating with higher OVA-specific IgG titers following vaccination. RNA sequencing indicated modest early transcriptional changes (4 hours) and robust regulation at 24 hours in pathways related to interferon signaling, IL-1β, dendritic cell activation, and antigen processing. Overall, NS are safe and effective at enhancing antigen uptake, processing, and immune responses, supporting their potential as a vaccine delivery platform.

Committee Chair

Dr. Jai Rudra

Committee Members

Dr. Cory Berkland Dr. Silviya Zustiak

Degree

Master of Science (MS)

Author's Department

Biomedical Engineering

Author's School

McKelvey School of Engineering

Document Type

Thesis

Date of Award

Winter 12-15-2025

Language

English (en)

Author's ORCID

https://orcid.org/0009-0001-5523-7780

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