Angular translate variable replacement

I would like to use a variable in my translation but I don't know how to do it in my template. In my HTML template : ``` <md-input-container class="md-block"> <md-autocomplete md-no-cache="vm.noCache" md-search-text="user.searchUser" md-items="userItem in vm.querySearch(user.searchUser)" md-item-text="userItem.display" md-selected-item-change="vm.selectedItemChange(userItem, user)" md-min-length="0" required> <md-item-template> <span md-highlight-text="user.searchUser" md-highlight-flags="^i">{{userItem.display}}</span> </md-item-template> <md-not-found> {{ 'user.autocomplete.no_user' | translate:'{ username: user.searchUser }' }} </md-not-found> </md-autocomplete> </md-input-container> ``` and my translation file (json) : ``` "user": { "autocomplete": { "no_user" : "No user has been found ({{username}})", } } ``` How can I use user.searchUser to show that message ? Thank very much !