When comparing mRNA stored under the same thermal conditions and delivered with Lipo MM with mRPZ, we observed that mRNA was stable and able to transfect regardless of the time or temperatures tested. Therefore, we confirm the ZIF-8 coating on mRPZ does improve the stability of the mRNA-PEI complex but does not aid the stability of the mRNA for cell transfection. Interestingly, mRNA from mRNA@ZIF-8 stored at room temperature, exfoliated, and transfected using Lipo MM does illicit eGFP expression but is much lower than mRPZ or other Lipofectamine controls with fresh mRNA. Interestingly, these findings do not support the idea that ZIF-8 can thermally stabilize all biomolecules (specifically mRNA); however, the coprecipitation methods used here differ from the biomimetic mineralization methods used in previous works. The application of mRPZ in vitro demonstrates clear improvements over mRNA-PEI and shows varying performance compared to lipid-based commercial reagents, depending on the cell line. In all cell lines used mRPZ either well outperforms mRNA-PEI or performs equally. The best mRNA expression occurred in HEK, HeLa, and CHO cells. mRPZ uptake was greater than 80% in all cell lines, except RAW264.7. Interestingly, cell lines that had lower eGFP expression with mRNA-PEI also had lower eGFP expression with mRPZ, compared to lipid-based reagents. The viability and metabolic activity of tested cells show minimal toxicity from mRPZ, while the viability decreased with Lipo MM. mRPZ shows a distinct delay in the expression of mRNA compared to mRNA-PEI and lipid-based reagents in vitro, a phenomenon repeatedly described in the literature. We hypothesize the ZIF-8 coating dissolution causes the delayed release and hence delayed expression of the mRNA. Given the improved performance over mRNA-PEI alone, we posit the ZIF-8 shell dissolution into its precursors disrupts the strong electrostatic binding of mRNA with PEI. Additionally, this novel encapsulation is translatable to larger nucleic acids and improves the thermal stability of the mRNA-PEI complex at room temperature. Taking the success in vitro further, we tested mRPZ in vivo.