A portable bilayer microneedle patch for rapid and patient-friendly administration of rabies immunoglobulin and enhanced wound healing

Rising global dog ownership increases the risk of rabies, a viral disease with an almost 100% fatality rate. Current post-exposure prophylaxis (PEP) methods involving injections of human rabies immunoglobulin (HRIG) are invasive and painful, resulting in reduced compliance. Furthermore, delays associated with traditional methods can undermine their effectiveness during emergencies, highlighting the need for more efficient alternatives. This study explored microneedle (MN) patches as a less painful and more patient-friendly method for delivering HRIG. We developed a bilayer MN patch composed of a hyaluronic acid (HA) tip containing HRIG and a polyvinylpyrrolidone (PVP) base incorporating tazarotene (TA). The tip dissolved within two minutes, releasing effective doses of HRIG, while the base released TA to promote wound healing. The patch can be stored in blister packaging, maintaining stability without the need for cold-chain storage. Characterization confirmed the patch's biocompatibility and its ability to enhance cell migration <i>in vitro</i>. <i>In vivo</i> testing using a rabies-infected mouse model demonstrated effective prevention of rabies and improved tissue repair following patch application. The patch's portability, stability, and efficacy make it ideal for emergency scenarios, offering reduced discomfort compared to traditional methods. This approach also broadens the potential applications of microneedles in emergency care and vaccination.