Nanotechnology is increasingly allowing the creation of new materials and products whose application is capable of revolutionizing various areas of science. One of the technologies under development today by Embrapa's Nano Network is the controlled release of agricultural inputs. So far there are three controlled release vehicles already developed: (1) a hydrogel made of polyacrylamide (PAAm) reticulated with methylcelullose (MC); (2) chitosan and methacrylic acid nanoparticlesand (3) chitosan and tripolyphosphate nanoparticles. The vehicles are easily produced in industrial scale, a fact which highly favors their economic viability. However, once they are new products, toxicology information is still insufficient. Initially, this project aims to answer important questions about vehicles' toxicology and subsequently, run pre-formulation tests between vehicles and inputs which might benefit from the controlled release technology. Then, the project will be split into two stages. During stage 1, it will concentrate on: how toxic are these vehicles? Hydrogel's toxicology will be more detailed than chitosan's, once the latter is known to be composed of atoxic substances. The toxicity will be investigated by means of: (1) Cytotoxicity tests of the three vehicles in human fibroblast cells (3T3); (2) Acute toxicity of the three vehicles with the use of mice and rats; (3) Hydrogel's subchronic or chronic toxicity in animals, in case the previous tests require that necessity. Pathology tests on animal organs, tissue and cells will inform details regarding the carcinogenicity, neurological and other types of alterations. The results obtained in phase 1 will guide the next stage. In stage 2, the attention will be focused on: Which of the inputs might benefit from controlled release, which are chemically and physiologically compatible with one of the three already available vehicles? The expected result is to obtain at least one vehicle which is compatible with a benefitable input. The hopes are that this research will have important impacts in the development and production of controlled release vehicles, and that it will be possible in the medium term to offer more competitive technologies to the agriculture and stockbreeding sector by means of input controlled release nanotechnology. In the long term, the hopes are that the results will beneficially contribute to the health and conservation of the environment.

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