This research utilizes the zeolitic imidazole framework-8 (ZIF-8) for the encapsulation and intracellular delivery of nucleic acids, specifically mRNA, for applications in gene delivery. Integrating polyethyleneimine (PEI) addresses the issue of mRNA leakage from ZIF-8, resulting in the delivery and expression of green fluorescent protein (GFP) in vitro and firefly luciferase in vivo.