"New heart valve -- stat!" demands the cardiac surgeon. The OR technician turns some dials on the 3-D bio-printer, flips a switch, and the heart valve is created layer by layer. Soon it will be sewn into the patient's heart with no fear of rejection. Why? Because it was created from the patient's own cells.

The above scene is not as farfetched as you may think. Researchers at the Wake Forest Institute for Regenerative Medicine have been working on bio-printing technology for several years. Even though they have not yet printed up a human body part, they do envision human trials in two to five years. These first body parts will be simple tissues such as skin, vertebral disks, and knee cartilage. Complex organs such as livers and kidneys would be further down the road.

More than one way to grow your own ...
Bio-printing is just one avenue of organ regeneration research. Researchers have also built human bladders and urethras by seeding bioabsorbable molds the size and shape of the desired organs with the patients' own cells. This procedure has been successfully performed, with a handful of patients receiving new bladders more than ten years ago.

A growing need ...
With more than 110,000 people in the United States alone waiting for donor organs, and many more worldwide, the huge potential of regenerative medicine has not gone unnoticed by mainstream companies.

 Medical technology giant Medtronic (NYSE: MDT) has already bought into a small biotech company affiliated with the Wake Forest Institute that specializes in the bioabsorbable mold technique of organ regeneration. Medtronic's payoff would be the licensing rights for the smaller company's "Neo-Kidney Augment" program (if it makes it through clinical trials). Johnson & Johnson (NYSE: JNJ) has also bought into that same company.

Brave new world for investors
This is such a new area of medicine that any direct investment in organ regeneration would be highly speculative, but there are ways to invest indirectly.

Medtronic and Johnson & Johnson may be your best route. They are solid, dividend paying companies that are not betting the farm on organ regeneration, but their investments would put them in a fine position to profit from any breakthroughs.

For investing in companies that are already making the 3-D printers that could potentially be used in production bio-printers, look to 3-D Systems (NYSE: DDD) and Stratasys (Nasdaq: SSYS). They are already being used to build dental crowns and custom prosthetic limbs. Once the bio-kinks are worked out of printing up organs, then I think they'd be ready.

Keep your eye on further developments with the above companies by clicking here to put them on your Watchlist.