Change style of pseudo elements in angular2

Is it possible to change style of pseudo elements using [style] or [ngStyle] in angular2?

in order to get a blur effect on a div acts like an overlay, and I should set up background-image on pseudo element.

I tried something like

<div class="blur" [style.before.backgroundImage]="'url('+ featuredImage[i] + ' )'">

it didn't work. I also tried this

<div class="blur" [ngStyle]="'{:before{ background-image:url('+ featuredImage[i] + ' )}}'">