Open AccessQuantitating Endosomal Escape of a Library of Polymers for mRNA Delivery
Author(s) -
Yuhang Jiang,
Qiao Lu,
Yongheng Wang,
Emily Xu,
A. S. L. Ho,
Prati Pal Singh,
Yifei Wang,
Zhaozhong Jiang,
Fan Yang,
Gregory T. Tietjen,
Peter Cresswell,
W. Mark Saltzman
Publication year - 2020
Publication title -
nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.853
H-Index - 488
eISSN - 1530-6992
pISSN - 1530-6984
DOI - 10.1021/acs.nanolett.9b04426
Subject(s) - endosome , transfection , luciferase , intracellular , messenger rna , cytosol , chemistry , drug delivery , in vivo , nucleic acid , biophysics , microbiology and biotechnology , biology , biochemistry , enzyme , gene , organic chemistry
Endosomal escape is a key step for intracellular drug delivery of nucleic acids, but reliable and sensitive methods for its quantitation remain an unmet need. In order to rationally optimize the mRNA transfection efficiency of a library of polymeric materials, we designed a deactivated Renilla luciferase-derived molecular probe whose activity can be restored only in the cytosol. This probe can be coencapsulated with mRNA in the same delivery vehicle, thereby accurately measuring its endosomal escape efficiency. We examined a library of poly(amine- co -ester) (PACE) polymers with different end groups using this probe and observed a strong correlation between endosomal escape and transfection efficiency ( R 2 = 0.9334). In addition, we found that mRNA encapsulation efficiency and endosomal escape, but not uptake, were determinant factors for transfection efficiency. The polymers with high endosomal escape/transfection efficiency in vitro also showed good transfection efficiency in vivo , and mRNA expression was primarily observed in spleens after intravenous delivery. Together, our study suggests that the luciferase probe can be used as an effective tool to quantitate endosomal escape, which is essential for rational optimization of intracellular drug delivery systems.