Abstract
Messenger RNA (mRNA) therapeutics are a promising strategy to combat diverse diseases. Traditional lipid nanoparticle (LNP) formulations for mRNA delivery contain poly(ethylene) glycol (PEG), a polymer widely used in drug delivery carriers but that recently has been associated with efficacy and immunogenicity concerns. Here we report poly(carboxybetaine) (PCB) lipids as surrogates for PEG-lipids used in mRNA formulations. In vitro studies with immortalized and primary cells show that PCB-containing LNPs have higher mRNA transfection efficiency than PEG-containing LNPs across different formulations. Moreover, primary cell engineering and in vivo immunization studies in mice further demonstrate greater therapeutic efficacy of PCB-containing LNPs over their PEG counterparts. Mechanistic assays show that this improvement is attributed to enhanced endosomal escape of PCB-containing LNPs. These formulations exhibit a safe immunotoxicity profile and effectively mitigate the accelerated blood clearance effect that has been observed for PEG-containing LNPs, enabling repeated administrations without efficacy loss. Overall, these findings highlight PCB-containing LNPs as a potent and safe mRNA delivery platform for clinical applications.
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Data availability
All data in this study are available within the Article and its Supplementary Information. The raw and analysed datasets generated during the study are available for research purposes from the corresponding author on request. Source data are provided with this paper.
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Acknowledgements
We acknowledge financial support from the National Institute of Allergy and Infectious Diseases (NIAID R01AI178125-01), the National Cancer Institute (NCI U54 CA272688), Robert Langer ’70 Family and Friends Professorship and Cornell NEXT Nano Initiative. Animal IVIS images were acquired through the Cornell Institute of Biotechnology’s Imaging Facility under support of the National Institutes of Health (NIH S10OD025049). The cryo-EM analysis was performed at the State University of New York College for Environmental Science and Forestry Analytical & Technical Services facility. S.W. performed the cryo-EM analysis and is supported by NIH (R35 GM141908). M.G. and S. Lipkin provided guidance and support in the hPBMC experiments and are supported by NCI U54 CA272688 and NIAID R01AI178125-01. BioSAXS experiments were conducted at the Center for High-Energy X-ray Sciences (CHEXS) at Cornell University, which is supported by the National Science Foundation (BIO, ENG and MPS Directorates) under award no. DMR-1829070, and the Macromolecular Diffraction at Cornell High Energy Synchrotron Source (MacCHESS) facility at Cornell University, which is supported by the National Science Foundation (NSF DMR-1829070), and the Macromolecular Diffraction at CHESS (MacCHESS) facility at Cornell University, which is supported by award NIH (1-P30-GM124166-01A1), and by New York State’s Empire State Development Corporation (NYSTAR). We also acknowledge generous assistance from R. Gillilan on the data collection of BioSAXS experiments. Finally, this work also made use of the Cornell University NMR Facility, which is supported, in part, by the NSF through MRI award CHE-1531632.
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Contributions
S. Luozhong and S.J. conceptualized and designed this study. S. Luozhong, P.L. and Z.Y. performed the chemical synthesis and characterization. S. Luozhong, R. Li, E.D., Y.C. and K.M. performed the in vitro and in vivo experiments. S. Luozhong, R. Li, Y.H., Z.C., M.C., C.M., D.B., P.Z. and Y.M. performed the molecular biology experiments and biological assays. S. Luozhong, R. Li, P.L., Y.C., C.M., A.K. and R. Lai performed the LNP characterizations. S.W. performed the cyro-EM imaging. S. Luozhong, M.G. and S. Lipkin performed the hPBMC experiments. R. Li supervised and performed the experiments during the peer review process. S. Luozhong and S.J. wrote the paper, and all authors discussed and commented on it.
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S. Luozhong, P.L., Z.Y. and S.J. are authors of a patent application related to this work (PCT/US2021/064639) filed by Cornell University in the United States. S. Luozhong, R. Li, P.L. and S.J. are authors of a patent related to this work (PCT/US2024/048135) filed by Cornell University in the United States. The other authors declare no competing interests.
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Luozhong, S., Liu, P., Li, R. et al. Poly(carboxybetaine) lipids enhance mRNA therapeutics efficacy and reduce their immunogenicity. Nat. Mater. (2025). https://doi.org/10.1038/s41563-025-02240-8
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DOI: https://doi.org/10.1038/s41563-025-02240-8
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