CHEARS

For centuries, humans have dreamt of the day when we could grow new body parts to replace the ones we lost as Regeneration is the natural process of replacing or restoring damaged or missing cells, tissues, organs, and even entire body parts to full function in plants and animals.

Now researchers are actually finding ways to turn those dreams into reality.

Stem cells play an important role in regeneration because they can develop into many different cell types in the body and renew themselves millions of times, something specialized cells in the body such as nerve cells cannot. Scientists are exploring whether a person’s own stem cells could “grow” replacement tissue that wouldn’t be rejected by the body’s immune system.

Sometime in the next few decades, humans may be able to regrow a finger here, a toe there – and maybe even fresh patches of beating heart tissue.

That trick could work for humans as well as fish. Researchers from the Gladstone Institutes showed that they could turn human scar tissue into electrically conductive tissue in a lab dish by fiddling with just a few key genes.

We humans already have demonstrated some ability to regenerate body parts: For example, very young children can fill out the tips of chopped off fingers and toes. Young mice are able to regenerate toes, too. More complex animals such as mammals have limited regenerative capacities. These include:

• Forming thick scars in tissues and skin to promote the healing of injured or amputated body parts.

• Regrowing hair and skin.

• Healing a bone fracture by using new tissue to knit the bone pieces together.

Regeneration in humans is the regrowth of lost tissues or organs in response to injury. This is in contrast to wound healing, or partial regeneration, which involves closing up the injury site with some gradation of scar tissue.

Despite the recent progress, some researchers are cautious about predicting how studies of animal regeneration will be applied to humans.

At the same time, the field is reaching a pivotal point. Within the next two or three years, studies of salamander genetics should break open a lot of possibilities so changes coming knocking on our door.