Problems with cyrrilic text encoding in DataGridView

Hello guys. I have got text encoding problem. I have DataGridView with one column (Name), when I want to populate changes in this column to db, I use Convert.ToString() or Value.ToString() methods to convert object to string, but after saving these changes to db, cyrillic symbols in Name column become unreadable. This problem doesn't occure, when I change similar property in textbox (not DataGridView), in this situation all data saves properly. My database encoding configuration is UTF8. Ask me, if you have any additional questions. Thank you.