Engineering of an automated nano-droplet dispensing system for fabrication of antigen-loaded dissolving microneedle arrays

Dissolving microneedle arrays (dMNAs) are promising devices for intradermal vaccine delivery. The aim of this study was to develop a reproducible fabrication method dMNAs based on an automated nano-droplet dispensing system that minimizes antigen waste. First, polymer formulation selected dispense sufficiently small droplets (<18 nL) can enter the cavities (base diameter 330 µm). Besides, three linear stages were assembled align dispenser with cavities, and vacuum chamber designed fill dispensed without entrapped air. Lastly, incorporated build fully system. To examine function as carrier, ovalbumin loaded in by mixture formulation, followed determining loading release into skin. results demonstrate functional which deliver skin successfully fabricated via automatic system, hardly any waste encountered. Compared centrifuges mould, it resulted 98.5% volume reduction antigen/polymer solution day shorter production time. This has potential scale-up manufacturing industrial scale.