Abstract:
O desenvolvimento da nanotecnologia vem se intensificando nos últimos anos. Sendo
que os NM já estão sendo utilizados em vários produtos disponíveis no mercado. Dentre
os NM mais utilizados estão os compostos de carbono que embora sejam compostos
somente por este elemento podem ter estruturas diferentes que refletem em suas
aplicações e possivelmente em seus efeitos. Dentre os NM de carbono, o grafeno e o
óxido de grafeno apresentam promissoras características que ampliam sua utilização em
diversos segmentos desde eletrônicos até a distribuição de medicamentos. A
intensificação da produção e utilização destes NM é acompanhada pela liberação destes
nanomateriais no ambiente que pode afetar os organismos vivos, principalmente os
animais aquáticos. Entretanto, pouco se sabe sobre os efeitos do óxido de grafeno em
crustáceos de importância comercial como é o caso do camarão branco Litopenaeus
vannamei. Portanto, a presente dissertação teve como objetivo avaliar os efeitos
biológicos da exposição ao óxido de grafeno em diferentes tecidos do camarão.
The development of nanotechnology has intensified in recent years. Since the NM are
already being used in several products on the market. NM Among the most used are
carbon compounds that although only compounds with this element can have different
structures that reflect in their applications and possibly its effects. Among the NM
carbon, graphene and graphene oxide show promising features that expand its use in
various segments from electronics to drug delivery. Increased production and use of
these NM is accompanied by the release of nanomaterials into the environment that can
affect living organisms, especially aquatic animals.
However, little is known about the effects of graphene oxide in crustaceans of
commercial importance such as the white shrimp Litopenaeus vannamei. Therefore, this
thesis aimed to evaluate the biological effects of exposure to graphene oxide in different
tissues of shrimp.
The nanomaterials (NM) of carbon as graphene oxide has being employed in several
areas such as electronic and biomedicine. Consequently, with increase of use this NM
there is also the bigger release into environment aquatic. However few data are
available about effect in aquatic organisms. So, the objective of present study was to
evaluate the effects of exposure to graphene oxide trough of diet in the shrimp
Litopenaeus vannamei exposed during 4 or 6 weeks. The results showed: 1) An
decrease in reactive oxygen species (ROS); 2) increase in glutamate cysteine ligase
activity (GCL); 3) increase in reduced glutathione (GSH) levels and 4) increase in
glutathione-S-transferase (GST) activity in gills and muscle; 5) increase in total
antioxidant capacity in hepatopancreas and 6) increase in lipidic peroxidation in muscle
and decrease in gills, after 4 weeks of exposure. After 6 weeks were observed: 7)
increase in ROS in muscle and gills; 8) increase in GCL activity in all tissues; 9)
increase in GST activity in muscle and hepatopancreas and 10) increase in total
antioxidant capacity in muscle. The results suggested that graphene oxide can interfere
in antioxidant response in different tissues of Litopenaeus vannamei.
