Synthesis of Amphiphilic Cationic Poly(β-amino acid) Derivatives and Their PEG Length Optimization for mRNA Transfection

Sung Been Lim; Jun Su An; DongHyun Kang; Ha Yeon Park; Mohit J Mehta; Eunyoung Choi; Beob Soo Kim; Hyun Jin Kim

doi:10.1021/acs.biomac.4c01265

Synthesis of Amphiphilic Cationic Poly(β-amino acid) Derivatives and Their PEG Length Optimization for mRNA Transfection

Biomacromolecules. 2024 Nov 27. doi: 10.1021/acs.biomac.4c01265. Online ahead of print.

Authors

Sung Been Lim¹, Jun Su An¹, DongHyun Kang¹, Ha Yeon Park¹, Mohit J Mehta¹, Eunyoung Choi², Beob Soo Kim², Hyun Jin Kim^{1

3

4}

Affiliations

¹ Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea.
² GenEdit, 3000 Marina Blvd., Brisbane, California 94005, United States.
³ Department of Biological Engineering, College of Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea.
⁴ Biohybrid Systems Research Center, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea.

PMID: 39604039
DOI: 10.1021/acs.biomac.4c01265

Abstract

We synthesized a series of amphiphilic cationic poly(ethylene glycol)-b-poly(β-amino acid) derivatives with various lengths of PEG to investigate the effects of PEG lengths on mRNA transfection. The surface charges of the polyplexes with a DP_OEG ≥ 4 gradually decreased as DP_OEG increased. This indicated that hydrophilic PEG with a DP_OEG ≥ 4 was exposed on the surface of the polyplexes, which was further confirmed using ¹H NMR. Polyplexes with a DP_OEG ≤ 4 exhibited mRNA transfection efficacy similar to that of homopolymers. However, the transfection efficacy of the polyplex with a DP_OEG ≥ 12 markedly decreased, mainly because of the decreased cellular uptake and stability of the polyplexes against serum albumin. This indicated that the PEG length considerably affected the delivery efficacy of IVT mRNA. Our results provide useful information for the fundamental polymer design to optimize the PEG length of amphiphilic cationic polymers for systemic IVT mRNA delivery.