Department of Infectious Disease, Imperial College London, London, UK.
Department of Infectious Disease, Imperial College London, London, UK; Department of Materials, Imperial College London, London, UK.
J Control Release. 2024 Oct;374:280-292. doi: 10.1016/j.jconrel.2024.08.016. Epub 2024 Aug 21.
Lipid nanoparticle (LNP) formulation plays a vital role in RNA vaccine delivery. However, further optimisation of self-amplifying RNA (saRNA) vaccine formulation could help enhance seroconversion rates in humans and improve storage stability. Altering either the ionisable or helper lipid can alter the characteristics and performance of formulated saRNA through the interplay of the phospholipid's packing parameter and the geometrical shape within the LNP membrane. In this study, we compared the impact of three helper lipids (DSPC, DOPC, or DOPE) used with two different ionisable lipids (MC3 and C12-200) on stability, transfection efficiency and the inflammation and immunogenicity of saRNA. While helper lipid identity altered saRNA expression across four cell lines in vitro, this was not predictive of an ex vivo or in vivo response. The helper lipid used influenced LNP storage where DSPC provided the best stability profile over four weeks at 2-8 °C. Importantly, helper lipid impact on LNP storage stability was the best predictor of expression in human skin explants, where C12-200 in combination with DSPC provided the most durable expression. C12-200 LNPs also improved protein expression (firefly luciferase) and humoral responses to a SARS-CoV-2 spike saRNA vaccine compared to MC3 LNPs, where the effect of helper lipids was less apparent. Nevertheless, the performance of C12-200 in combination with DSPC appears optimal for saRNA when balancing preferred storage stability requirements against in vivo and ex vivo potency. These data suggest that helper lipid influences the stability and functionality of ionisable lipid nanoparticle-formulated saRNA.
脂质纳米颗粒（LNP）制剂在 RNA 疫苗递送中起着至关重要的作用。然而，进一步优化自我扩增 RNA（saRNA）疫苗制剂可以帮助提高人类的血清转化率并提高储存稳定性。改变可离子化或辅助脂质可以通过磷脂的堆积参数和 LNP 膜内的几何形状相互作用来改变配方 saRNA 的特性和性能。在这项研究中，我们比较了三种辅助脂质（DSPC、DOPC 或 DOPE）与两种不同的可离子化脂质（MC3 和 C12-200）一起使用对稳定性、转染效率以及 saRNA 的炎症和免疫原性的影响。虽然辅助脂质改变了 saRNA 在四种体外细胞系中的表达，但这并不能预测外或体内的反应。辅助脂质的使用影响了 LNP 的储存稳定性，DSPC 在 2-8°C 下四周内提供了最佳的稳定性。重要的是，辅助脂质对 LNP 储存稳定性的影响是其在人皮肤外植体中表达的最佳预测指标，其中 C12-200 与 DSPC 联合使用提供了最持久的表达。与 MC3 LNP 相比，C12-200 LNP 还提高了 SARS-CoV-2 刺突 saRNA 疫苗的蛋白表达（萤火虫荧光素酶）和体液反应，而辅助脂质的作用则不太明显。然而，当平衡储存稳定性要求与体内和体外效力时，C12-200 与 DSPC 联合使用的性能似乎是 saRNA 的最佳选择。这些数据表明，辅助脂质影响可离子化脂质纳米颗粒配方 saRNA 的稳定性和功能。
