structures that are carteligenous or bone and do not need vascularization can be done without 3d printing. How do we know? Artificial teeth implants, hip replacements, skin grafts are all being done because they do not require blood supplies nor nerves to remain viable and absolutely have therapeutic value. That is why they are being done first - they are "easier" to do. None of these replacement structures are nearly as good as the original living component but they DO provide basic live giving functionality so that the recipient can remain alive and reasonably functional until the time when a real living bioidentical replacement part becomes available. For context, I have a dental implant. I has no nerve, and thus, when I brush my teeth, my sensing brain "knows" that spot is a hole. It is only my conscious mind that is aware that there's really something there. Our teeth have nerves so that they serve as "fingertips" for the mouth. Having no nerve is liking have a dead finger. It is VERY much missed.
So, we should applaud all progress that restores function as we proceed into a world where full and perhaps even augmented bioidentical function in part made possible by Organovo 3d tissue printing joins the mainstream of clinical practice.
Sentiment: Strong Buy
To illustrate the need for bioidentical innervated and vasularized tissues along with micro-surgical precision, here is a description of the loss and very very gradual restoration of sensation in current skin graft procedures.
"Reinnervation of the (skin) graft occurs from the recipient bed (usually dermis) and from the periphery along the empty neurolemma sheaths of the graft. Sensation returns to the periphery (outside boundary) of the graft and proceeds toward the center. This process usually begins during the first month but is not complete for several years following grafting. Full-thickness grafts reinnervate more completely than do split-thickness grafts. Reinnervation is always incomplete, and some degree of permanent derangement persists. Usually, the patient develops protective sensation but not normal perception. Pain is usually the first perceived sensation, followed later by touch, heat, and cold.