A Non-Invasive Dissolvable Microneedle Platform for Liposome-Encapsulated rBmHAXT(ΔCys) Delivery Against Lymphatic Filariasis 2304452

Abstract Introduction 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. Funding Source n/a Topic Categories Vaccines and Immunotherapy (VAC)