Journal of Nanomedicine & Biotherapeutic Discovery
Open Access

Programmable DNA Nanostructures for Modular Vaccine Delivery against Emerging Infectious Diseases

Tianrun Jinbo^{* *}Correspondence: Tianrun Jinbo, Department of Nanomedicine, University of Sao Paulo, Sao Paulo, Brazil, Email:

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Description

The emergence of novel pathogens presents a continuous challenge to global public health, requiring rapid development of effective vaccines. Traditional vaccine platforms often necessitate lengthy optimization processes for each pathogen, creating significant delays in pandemic response capabilities. Here, we present a highly adaptable DNA origami nanostructure platform designed to function as a modular vaccine delivery system capable of rapid reconfiguration for emerging infectious diseases. Using computational design and high-throughput experimental validation, we created tetrahedral DNA nanostructures approximately 50 nm in size containing precisely positioned attachment sites for both antigenic proteins and immunostimulatory molecules.

The tetrahedral DNA scaffold was designed with strategically positioned sticky-end sequences serving as docking sites for complementary DNA-conjugated protein antigens, allowing precise control over antigen density and spatial arrangement. Additionally, unmethylated CpG sequences were incorporated into the scaffold, providing intrinsic adjuvant activity through Toll-Like Receptor 9 (TLR9) activation. Using the Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein as a model antigen, we demonstrated highly efficient conjugation (>90% efficiency) with retained protein functionality, as confirmed by Angiotensin-Converting Enzyme 2 ACE2 binding assays. The modular design allows for rapid exchange of the antigenic component through simple modification of the complementary DNA sequence on the target protein, facilitating swift adaptation to emerging pathogens without requiring complete redesign of the delivery platform.

Immunological evaluation in C57BL/6 mice demonstrated superior humoral immune responses compared to conventional protein subunit formulations, with neutralizing antibody titers approximately 8-fold higher than alum-adjuvant protein at equivalent antigen doses. Flow cytometric analysis of draining lymph nodes revealed enhanced dendritic cell activation and antigen presentation, with significantly increased germinal center formation observed by immunohistochemistry. T cell responses were notably balanced between Th1 and Th2 phenotypes, avoiding the potentially problematic Th2 bias often observed with aluminum-based adjuvants. Memory B cell analysis at 6 months post-immunization demonstrated robust persistence, suggesting potential for durable protection.

Challenge studies using the K18-hACE2 transgenic mouse model demonstrated complete protection against lethal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) challenge following a two-dose immunization regimen, with viral loads below detection limits in both upper and lower respiratory tracts. To demonstrate modularity, we rapidly adapted the platform to display the prefusion-stabilized F protein from Respiratory Syncytial Virus (RSV) and the receptor binding domain from Nipah virus, achieving comparable manufacturing consistency and immunogenicity profiles within weeks of target selection. Thermal stability studies revealed exceptional resistance to degradation, with antigen presentation functionality maintained following storage at 25°C for 4 weeks or at 4°C for 6 months, suggesting potential advantages for deployment in resource-limited settings.

Conclusion

The scalability of this approach was validated through successful Good Manufacturing Practice (GMP)-compatible production utilizing automated DNA synthesis and assembly techniques, yielding consistent nanostructures at scales suitable for clinical application. Preliminary toxicology studies in rats showed no significant adverse effects following repeated administration at doses up to 10-fold higher than projected human doses. This programmable DNA nanostructure platform represents a promising approach for rapid vaccine development against emerging infectious diseases, potentially reducing response time from antigen identification to clinical administration while simultaneously enhancing immunogenicity and stability profiles compared to conventional vaccine formulations.