(497c) Thermostable RNA Delivery Using 3D Printed Microarray Patches (MAPs)

Reliable and robust microarray patch (MAP) production for vaccine delivery is made possible by emergent manufacturing technologies such as single-digit micron Continuous Liquid Interface Production (CLIP) recently developed by the DeSimone Lab at Stanford University. The use of CLIP enables the production of MAPs which also allows for the utilization of lyophilization to stabilize and trap cargo within hollow structures of the MAP. The MAPs provide a cage for the fragile lyophilized cake, thereby protecting it during skin insertion. Lyophilized vaccines generally are reconstituted and then delivered via injection. In contrast, lyophilizing an RNA vaccine inside of a MAP allows for the delivery of a thermostable vaccine directly into the skin without the need for an external reconstitution step. Lyophilized RNA vaccine formulations in MAPs have shown retained in vitro transfection efficiency when compared to freshly prepared liquid RNA vaccine formulations. Additionally, when lyophilized RNA vaccines in MAPs have been applied to ex vivo porcine skin, transfection efficiency comparable to the liquid formulation has been observed. The lyophilized MAPs have also demonstrated in vivo transfection efficiency in mice comparable to liquid-loaded MAPs. By combining lyophilization of RNA vaccines with MAPs, we hope to develop a platform for reliable, repeatable, and accessible thermostable vaccine delivery.