Development and evaluation of cell membrane-based biomimetic nanoparticles loaded by Clostridium perfringens epsilon toxin: a novel vaccine delivery platform for Clostridial-associated diseases

Abstract

As Clostridium perfringens (C. perfringens) epsilon toxin (ETX) ranks as the third most potent clostridial toxin after botulinum and tetanus toxins, vaccination is necessary for creatures that can be affected by it to be safe from the effects of this toxin. Nowadays, nanostructures are good choices for carriers for biological environments. We aimed to synthesize biomimetic biodegradable nanodevices to enhance the efficiency of the ETX vaccine. For this purpose, poly(lactic-co-glycolic acid) (PLGA) copolymer loaded with purified epsilon protoxin (proETX) to create nanoparticles called nanotoxins (NTs) and then coated by RBC membrane-derived vesicles (RVs) to form epsilon nanotoxoids (RV-NTs). The resulting RV-NTs shaped smooth spherical surfaces with double-layer core/shell structure with an average particle size of 105.9 ± 35.1 nm and encapsulation efficiency of 97.5% ± 0.13%. Compared with NTs, the RV-NTs were more stable for 15 consecutive days. In addition, although both structures showed a long-term cumulative release, the release rates from RV-NTs were slower than NTs during 144 hours. According to the results of cell viability, ETX loading in PLGA and entrapment in the RBC membrane decreased the toxicity of the toxin. The presence of PLGA enhances the uptake of proETX, and the synthesized structures showed no significant lesion after injection. These results demonstrate that NTs and RV-NTs could serve as an effective vaccine platform to deliver ETX for future in vivo assays.

Keywords:

• Epsilon toxin (ETX)
• Clostridium perfringens
• PLGA
• RBC membrane-derived vesicles (RVs)
• nanotoxoid

Acknowledgements

We would like to thank the workers of Proteomics and Biochemistry, and Anaerobic Bacterial Vaccine Research and Production Departments of Razi Vaccine and Serum Research Institute for their help and support. We thank Ms. Shirin Soltani for her help with the English editing of the manuscript.

Disclosure statement

The authors report no conflict of interest.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

This work was supported by the Razi Vaccine and Serum Research Institute of Iran under Grant Number (12-18-18-066-96029-960766) received by Mojtaba Alimolaei.