Lipid nanoparticles used to ship mRNA in vaccines or therapeutics usually depend on poly(ethylene) glycol (PEG) to reinforce their stability, lengthen their circulation time and evade immune detection. Nevertheless, PEG can intrude with the mobile uptake and subsequent endosomal escape of mRNA, negatively affecting the efficiency of mRNA–lipid nanoparticles. Furthermore, the induction of anti-PEG antibodies can result in immunogenicity towards mRNA therapeutics. Now, reporting in Nature Supplies, Shaoyi Jiang and staff changed PEG with the zwitterionic polymer poly(carboxybetaine) (PCB) to enhance the efficacy and repeated administration security of mRNA–lipid nanoparticles.
To handle the problems associated to PEG, Jiang and staff substituted PEG with the zwitterionic polymer PCB. “PCB comprises glycine betaine in its aspect chain, which is biocompatible and non-toxic”, says Jiang. “As well as, its hydrophilic nature prevents the induction of antibodies, because it serves as a further power barrier for epitope recognition, making the event of polymer-specific antibodies harder.”
