It looks to me like at the bottom of the article it seems to say that putting more progenitor cells into the skin might be the answer. Of course that might not be permanent because you need a constant source of these progenitor cells so that is why you need stem cells that continually produce these cells but it does seem like putting in new progenitor cells might get hair growth to start if you add PRP and Acell.
http://missoulian.com/lifestyles/health-med-fit/f4986234-2318-11e0-a240-001cc4c03286.html