posted on 2024-02-07, 13:34authored byJiabin Zhang, Kai Wang, Shiyao Xu, Linlin Chen, Haiquan Gu, Yujie Yang, Qi Zhao, Yurou Huo, Bo Li, Yufei Wang, Yubiao Xie, Nan Li, Jiali Zhang, Jianxu Zhang, Qianxue Li
Vaccines
are widely regarded as one of the most effective weapons
in the fight against infectious diseases. Currently, vaccines must
be stored and transported at low temperatures as high temperatures
can lead to a loss of vaccine conformation and reduced therapeutic
efficacy. Metal–organic frameworks (MOFs), such as zeolitic
imidazole framework-8 (ZIF-8), are a new class of hybrid materials
with large specific surface areas, high loading rates, and good biocompatibility
and are successful systems for vaccine delivery and protection. Silk
fibroin (SF) has a good biocompatibility and thermal stability. In
this study, the hepatitis B surface antigen (HBsAg) was successfully
encapsulated in ZIF-8 to form HBsAg@ZIF-8 (HZ) using a one-step shake
and one-pot shake method. Subsequently, the SF coating modifies HZ
through hydrophobic interactions to form HBsAg/SF@ZIF-8 (HSZ), which
enhanced the thermal stability and immunogenicity of HBsAg. Compared
to free HBsAg, HZ and HSZ improved the thermostability of HBsAg, promoted
the antigen uptake and lysosomal escape, stimulated dendritic cell
maturation and cytokine secretion, formed an antigen reservoir to
promote antibody production, and activated CD4+ T and CD8+ T cells to enhance memory T-cell production. Importantly,
HSZ induced a strong immune response even after 14 days of storage
at 25 °C. Furthermore, the nanoparticles prepared by the one-step
shake method exhibited superior properties compared to those prepared
by the one-pot shake method. This study highlights the importance
of SF-coated ZIF-8, which holds promise for investigating thermostable
vaccines and breaking the vaccine cold chain.