You should use use or usage instead of using, because using is a verb form, not a noun.

The use/usage of the opportunities offered by ... became an important element.

 

A significant element became the use/usage of the opportunities offered by ...

Otherwise I think the meanings are similar (without further context).

You should use use or usage instead of using, because using is a verb form, not a noun.

The use/usage of the opportunities offered by ... became an important element.

A significant element became the use/usage of the opportunities offered by ...

Otherwise I think the meanings are similar (without further context).