Insights into the Structure of Comirnaty Covid-19 Vaccine: A Theory on Soft, Partially Bilayer-Covered Nanoparticles with Hydrogen Bond-Stabilized mRNA-Lipid Complexes

被引：28

作者：

Szebeni, Janos ^{[1
,2
,3
,4
]}

Kiss, Balint ^{[5
,6
,7
]}

Bozo, Tamas ^{[5
,6
]}

Turjeman, Keren ^{[8
]}

Levi-Kalisman, Yael ^{[9
,10
]}

Barenholz, Yechezkel ^{[8
]}

Kellermayer, Miklos ^{[5
,6
,7
]}

机构：

[1] Semmelweis Univ, Dept Translat Med, Nanomed Res & Educ Ctr, H-1089 Budapest, Hungary

[2] Univ Miskolc, Dept Nanobiotechnol & Regenerat Med, Fac Hlth Sci, H-2880 Miskolc, Hungary

[3] Sungkyunkwan Univ, Sch Chem Engn, Suwon 16419, South Korea

[4] Sungkyunkwan Univ, Translat Nanobiosci Res Ctr, Suwon 16419, South Korea

[5] Semmelweis Univ, Dept Biophys & Radiat Biol, H-1094 Budapest, Hungary

[6] Hungarian Ctr Excellence Mol Med HCEMM, Vivo Imaging Adv Core Facil, H-1094 Budapest, Hungary

[7] ELKH SE Biophys Virol Res Grp, H-1094 Budapest, Hungary

[8] Hebrew Univ Jerusalem, Hadassah Med Sch, Lab Membrane & Liposome Res, IMRIC, IL-9112102 Jerusalem, Israel

[9] Hebrew Univ Jerusalem, Inst Life Sci, IL-9190401 Jerusalem, Israel

[10] Hebrew Univ Jerusalem, Ctr Nanosci & Nanotechnol, IL-9190401 Jerusalem, Israel

来源：

ACS NANO | 2023年 / 17卷 / 14期

基金：

欧盟地平线“2020”;

关键词：

lipid nanoparticles; phospholipid membranes; Doxil liposomes; SARS-CoV-2; atomic force microscopy; cryo-electron microscopy; dynamic light scattering; MECHANICAL-PROPERTIES; CATIONIC LIPIDS; DELIVERY; SIRNA;

D O I：

10.1021/acsnano.2c11904

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Despite the worldwidesuccess of mRNA-LNP Covid-19 vaccines, thenanoscale structures of these formulations are still poorly understood.To fill this gap, we used a combination of atomic force microscopy(AFM), dynamic light scattering (DLS), transmission electron microscopy(TEM), cryogenic transmission electron microscopy (cryo-TEM), andthe determination of the intra-LNP pH gradient to analyze the nanoparticles(NPs) in BNT162b2 (Comirnaty), comparing it with the well-characterizedPEGylated liposomal doxorubicin (Doxil). Comirnaty NPs had similarsize and envelope lipid composition to Doxil; however, unlike Doxilliposomes, wherein the stable ammonium and pH gradient enables accumulationof C-14-methylamine in the intraliposomal aqueous phase,Comirnaty LNPs lack such pH gradient in spite of the fact that thepH 4, at which LNPs are prepared, is raised to pH 7.2 after loadingof the mRNA. Mechanical manipulation of Comirnaty NPs with AFM revealedsoft, compliant structures. The sawtooth-like force transitions seenduring cantilever retraction imply that molecular strands, correspondingto mRNA, can be pulled out of NPs, and the process is accompaniedby stepwise rupture of mRNA-lipid bonds. Unlike Doxil, cryo-TEMof Comirnaty NPs revealed a granular, solid core enclosed by mono-and bilipid layers. Negative staining TEM shows 2-5 nm electron-densespots in the LNP's interior that are aligned into strings,semicircles, or labyrinth-like networks, which may imply cross-link-stabilizedRNA fragments. The neutral intra-LNP core questions the dominanceof ionic interactions holding together this scaffold, raising the possibility of hydrogen bonding between mRNA and the lipids. Suchinteraction, described previously for another mRNA/lipid complex,is consistent with the steric structure of the ionizable lipid inComirnaty, ALC-0315, displaying free O and -OH groups.It is hypothesized that the latter groups can get into steric positionsthat enable hydrogen bonding with the nitrogenous bases in the mRNA.These structural features of mRNA-LNP may be important for the vaccine'sactivities in vivo.

引用

页码：13147 / 13157

页数：11