Haven't we already had this for a long time? Targeted drug delivery using Nano technology? A lesser complicated version and less of the sci fi but the technolog

Haven't we already had this for a long time? Targeted drug delivery using Nano technology? A lesser complicated version and less of the sci fi but the technology has been here and proven for a long time with some FDA approved drugs already. Most of the drugs are still in trial but targeted drug delivery looks promising.