Preparation of Modified Konjac Glucomannan Nanoparticles and their Application as Vaccine Adjuvants to Promote Ovalbumin-Induced Immune Response in Mice
Herein, we reported a facile strategy for synthesis of two types of modified konjac glucomannan nanoparticles (NPs). The goal of this project was to explore the potential of the NPs as vaccine adjuvants.
Firstly, anionic carboxymethylated konjac glucomannan (CKGM) and cationic quaternized konjac glucomannan (QKGM) were synthesized by chemical modification of konjac glucomannan (KGM). Subsequently, two types of NPs, CKGM/QKGM and sodium tripolyphosphate (TPP)/QKGM, were prepared through polyelectrolyte complex method and ionic cross-linking method, respectively. The thus-synthesized NPs were then loaded with ovalbumin (OVA) to further evaluate the effect of NPs on immune response in mice.
The encapsulation efficiency of OVA for CKGM/QKGM/OVA and TPP/QKGM/OVA NPs could be 49.2% and 67.7%, respectively, while the drug loading capacity could reach 10.9% and 60%. The NPs showed irregular spherical shape and exhibited good sustained-release properties. In vitro cytotoxicity assay revealed that both the blank and OVA-loaded NPs were not toxic to cells. The OVA-specific IgG, splenocytes proliferation and cytokine levels indicated that the OVA-induced humoral and cellular immune responses were up-regulated by OVA-loaded NPs. What’s more, CKGM/QKGM/OVA NPs elicited both higher IL-2 and IFN-γ production, while TPP/QKGM/OVA NPs elicited both higher IL-4 and IL-10 production.
These results suggest that TPP/QKGM and CKGM/QKGM NPs are promising to be used as vaccine adjuvants. The TPP/QKGM/OVA NPs could induce stronger humoral immune response, while CKGM/QKGM/OVA NPs could enhance the cellular immune response more effectively.
Key wordschemical modification immune response konjac glucomannan nanoparticles vaccine adjuvants
Acid-hydrolysed konjac glucomannan
Cell counting kit-8
Carboxymethylated konjac glucomannan
Dulbecco’s modified Eagle’s medium
Enzyme linked immunosorbent assay
Fetal bovine serum
Fourier transform infrared
3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide
Nuclear magnetic resonance
Phosphate buffer saline
Quaternized konjac glucomannan
Roswell Park Memorial Institute
Standard error mean
Transmission electron microscope
3, 3′, 5, 5’-Tetramethylbenzidine
Acknowledgments and Disclosures
This work was financially supported by the Da BeiNong Group Promoted Project for Young Scholar of HZAU (Grant No. 2017DBN010), the open funds of the State Key Laboratory of Agricultural Microbiology (Grant No. AMLKF201507), the National Natural Science Foundation of China (Grant No. 21503085), and the Natural Science Foundation of Hubei Province (Grant No. 2015CFB233).
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