Graduate Student university of Illinois Rockford, Illinois, United States
Introduction/Rationale: Lymphatic filariasis is a mosquito-borne neglected tropical disease-causing lymphatic dysfunction and long-term disability. Despite global control efforts, no effective vaccine exists. Our laboratory developed Lf Guard, a cGMP-manufactured recombinant tetravalent rBmHAXT(ΔCys) antigen. Conventional injectable vaccines face challenges, including dependence on a cold chain, logistics, and needle-related barriers. These limitations highlight the need for a non-invasive delivery platform. We present a liposome-loaded dissolvable microneedle (Lipo-dMN) system designed to improve antigen stability, dermal targeting, and minimally invasive administration.
Methods: Cationic liposomes incorporating Lf Guard (1 mg/mL) were synthesized by thin-film hydration. Size, PDI, and zeta potential were measured by DLS; morphology by SEM. Encapsulation efficiency was quantified using BCA assay. Antigen integrity and functionality post encapsulation was assessed via SDS-PAGE and Western blot. Dissolvable microneedles were fabricated using PDMS molds containing 1000 µm-high pyramidal needles (200 µm base, 10×10 array) by centrifugation casting of HA–trehalose matrices with antigen-loaded liposomes, followed by a PVP backing layer. Needle structure was examined by SEM, and FITC-BSA liposomes were used only for tip-loading visualization.
Results: The optimized formulation showed a 264 nm size, 0.419 PDI, and +3.22 mV zeta potential, indicating stable vesicles. Encapsulation efficiency was high (≈98%). SEM confirmed spherical liposomes; SDS-PAGE and Western blot verified preserved antigen integrity. Microneedles showed uniform 1000 µm height and sharp, robust architecture. Fluorescence imaging confirmed accurate localization of liposomal cargo within needle tips.
Conclusion: The Lipo-dMN platform maintains antigen structure, achieves high loading efficiency, and provides precise intradermal deposition through a non-invasive, scalable vaccine delivery system for lymphatic filariasis.
