The world of chitosan in 2016 & chitosan as adjuvant in vaccines
At the end of the year we want to give you an overview about chitosan-related publications in 2016 and in the second part we focus on a quite different application of chitosan – how human and veterinary vaccines could benefit from chitosan as adjuvant.
In 2016, 2709 new articles about chitosan and chitosan derivates were published according to gopubmed. Throughout the whole year, China, United States and India were leaders in chitosan research. Researcher from Iran, Brazil, South Korea, and European Countries (Italy, Germany and France) were also industrious in publishing about chitosan. The journal Carbohydrate Polymers published by far the most articles (222) about chitosan. Overall, 96 reviews and 8 clinical trials reported about chitosan and chitosan derivates in 2016.
Table: Journals and Countries, which published most chitosan-related articles in 2016. Source: GoPubMed
Most publications were about chitosan in connection to nanoparticles, pharmaceutical preparations and evaluation studies. The topic tissue was overtaken by polymers in 2016. The authors Jayakumar R. (4 articles), Khan S. (4), Stephen A. (3), Pintado M. (3) and Gübitz G. (3) published the most chitosan-related articles.
|Evaluation Studies as Topic||457|
Table: Top terms regarding chitosan in 2016. Source: GoPubMed
The Vaccine Adjuvant Chitosan Promotes Cellular Immunity via DNA Sensor cGAS-STING-Dependent Induction of Type I Interferons
Carroll E. C., Jin L., Mori A., et al. Immunity 44, 597–608, March 15, 2016. doi: 10.1016/j.immuni.2016.02.004.
Development of new vaccines demands for better adjuvants, to trigger innate and adaptive immune response. Biocompatible chitosan is a promising alternative to widely used aluminum salts for injectable and mucosal vaccines. Researcher from Europe and USA investigated how the adjuvant chitosan (DDA 75-90%, Endotoxin ≤100 EU/g) induces cell-mediated immunity in mice.
- Promotion of dendritic cell maturation by induction of type I interferons (IFNs) in vitro
- DC activation depends on cGAS and STING
- ROS and cytoplasmic DNA are necessary for induction of type 1 IFNs by chitosan
- Antigen-specific T helper 1 (Th1) response is enhanced
Conclusion: The study showed that induction of type I IFNs in dendritic cells are important for efficacy of chitosan as adjuvant. Type I IFNs are produced by activation of the cGAS-STING pathway.
Protective effect of a recombinant VHSV-G vaccine using poly(I:C) loaded nanoparticles as an adjuvant in zebrafish (Danio rerio) infection model
Kavaliauskis A., Arnemo M., Speth M. Developmental and comparative Immunology, 61:248-57, August 2016. doi: 10.1016/j.dci.2016.04.010.
The globally rising demand for fish requires an increase in industrial production by aquaculture. However, aquacultures are vulnerable for infectious diseases. A common infection is the viral hemorrhagic septicaemia virus (VHSV) like for freshwater salmoids. To improve efficacy of vaccines, application of adjuvants is often necessary. In this study, chitosan-poly (I:C) nanoparticels (NPs) were developed as non-specific adjuvant in antiviral vaccines. Physical parameters, biodistribution in vivo and in vitro as well as NP uptake by zebrafish leucocytes were characterized. Additionally, the authors from Oslo compared different vaccine formulations against VHSV (viral hemorrhagic septicaemia virus) with Chitosan-poly (I:C) nanoparticles as adjuvant:
- recombinant glycoprotein G (rgpG) of VHSV + NPs
- inactivated whole virus (iV) + NPs
- rgpG + free poly (I:C)
- rgpG + free chitosan
- Highest survival rate: iV plus NP adjuvant
- Significant protection against VHSV by formulations with poly (I:C)
Conclusion: Chitosan-poly (I:C) NPs show a beneficial effect and might be an useful adjuvant for vaccines in industrial aquaculture.