Zahn, J. D. | bioRxiv Science

bioRxiv2025

Evaluation of Antigen Expression and Early Immune Response following Cutaneous Suction-mediated DNA Delivery

Suction-based in vivo cutaneous DNA transfection is a newly developed, cost-effective method that produces high transfection efficiency. This method has shown robust immunogenic responses following SARS-CoV-2 DNA vaccination in both pre-clinical studies and clinical trials. The current work investigates suction-based transfection and immune activation on a detailed, cellular level. The spatiotemporal patterns of antigen expression in rat skin following suction-induced delivery of a pEGFP-N1 plasmid and a SARS-CoV-2 DNA vaccine are evaluated via immunofluorescence staining, which demonstrates early and prolonged expression. The epidermis is identified as the primary location of transfection, and the transfected cells are primarily epidermal keratinocytes. Early immune response is assessed by detection of antigen presenting cells (APCs) following suction-induced DNA vaccination.

bioengineering↗

bioRxiv2024

Tissue Tension and Strain as Indicators of Suction-mediated Cutaneous DNA Transfection: A Parametric Study

Cutaneous suction-based transfection is a recently developed technique that is painless and simple-to-use for the delivery of DNA for nucleic-acid-based vaccines. The technique promises high efficiency for both antigen expression and immunogenicity as demonstrated in both animal studies and human clinical trials. To realize this promise, a parametric study and systematic evaluation on the efficacy of cutaneous suction as a transfection method was performed. Using Green Fluorescent Protein (GFP) plasmid expression as a transfection reporter in a rat model, the expression level as a function of both suction nozzle size and suction pressure was quantified. A numerical model was employed to compute skin deformation in terms of strain, which was used to correlate with GFP expression. Based on these results, two quantities, total integrated strain and tissue tension, are proposed as indicators of expression level that can be used to guide protocol development and optimization. These indicators are also discussed in relation to possible cellular uptake mechanisms.

bioengineering↗