Максим

@function unicode($str) {
    @if (str-slice($str, 1, 1) != str-slice("\\", 1, 1)) {
        $str: unquote(str-insert($str, str-slice("\\", 1, 1), 1));
    }
    @return unquote("\"")+$str+unquote("\"")
} 


.icon-star {
  content: unicode(e800);
}