Pesticide

A process for manufacturing chitosan nanoparticles having adhered RNA, the process comprising the following steps:

• A) formation of chitosan microparticles;
• i) providing an aqueous solution of chitosan, wherein the concentration of chitosan is 0.01-5%;
• ii) adjusting pH of the solution to 5-6;
• iii) adding cross-linking agent to a ratio crosslinking agent:chitosan of 1:1 to 1:4, preferably 1:2 in the solution, whereby chitosan microparticles are formed;
• preferably by ionic gelation,
• iv) providing an aqueous suspension of the chitosan microparticles formed by precipitation,
• B) formation of chitosan nanoparticles from microparticles;
• i) forming chitosan nanoparticles, from the chitosan microparticles formed by the ionic gelation;
• C) RNA coating on chitosan nanoparticles
• i) adding RNA to the aqueous solution of the chitosan nanoparticles,
• ii) adding RNA to a ratio of RNA:chitosan of 1:80 in the solution;
• wherein chitosan nanoparticles having adhered RNA are formed;
• and
• iii) adding cationic surfactant to the chitosan nanoparticles.