PLGA co-loaded Salvia miltiorrhiza polysaccharide and Mn2+ as an adjuvant to induce potent immunity

Yixuan Zhu; Qi Zhao; Pengfei Gu; Yingsai Fan; Ning Ma; Wuchao Zhang; Yongzhan Bao; Xiao Wang; Wanyu Shi

doi:10.1016/j.ijbiomac.2025.140050

PLGA co-loaded Salvia miltiorrhiza polysaccharide and Mn²⁺ as an adjuvant to induce potent immunity

Int J Biol Macromol. 2025 Jan 22:300:140050. doi: 10.1016/j.ijbiomac.2025.140050. Online ahead of print.

Authors

Yixuan Zhu¹, Qi Zhao¹, Pengfei Gu¹, Yingsai Fan¹, Ning Ma¹, Wuchao Zhang¹, Yongzhan Bao¹, Xiao Wang², Wanyu Shi³

Affiliations

¹ College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, No. 2596 Lekai South Street, Baoding 071000, China.
² College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, No. 2596 Lekai South Street, Baoding 071000, China. Electronic address: wxwangxiao418@163.com.
³ College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, No. 2596 Lekai South Street, Baoding 071000, China. Electronic address: shiwanyu2010@126.com.

PMID: 39855513
DOI: 10.1016/j.ijbiomac.2025.140050

Abstract

Developing a novel and potent adjuvant with excellent biocompatibility for immune response augmentation is crucial for enhancing vaccine efficacy. Here, we prepared a stable PLGA nanoparticle by encapsulating MnCl₂/Salvia miltiorrhiza polysaccharide (MS-PLGA) and employed it as an adjuvant in the model antigen OVA (MS-PLGA-OVA) to elicit potent immunity. The biological experiments indicated that the MS-PLGA-OVA could effectively recruit APCs to the injection site and provoke long-term antibodies. Compared with the conventional Alum adjuvanted group, the MS-PLGA-OVA increased the IgG2a antibody titers and CD8⁺T cells maturation, triggering cytotoxic T lymphocyte response and inducing the activation of memory T cells. Importantly, the MS-PLGA could up-regulate the expression of TLRs and cGAS-STING pathway-related genes, thus increasing the DCs maturation, as well as the secretion of interleukin and IFN-β. Collectively, the MS-PLGA system may provide a novel and efficient adjuvant platform for various prophylactic vaccines and insights for the development of the next-generation nano adjuvant.

Keywords: Adjuvant; Cellular immune; Humoral immune; Mn(2+); PLGA; Salvia miltiorrhiza polysaccharide.