tissue engineering


If A Tweaked Flatworm Can Suddenly Regrow Its Head, Why Can’t You?

A "Dugesia liguriensis" flatworm (Wikimedia Commons)

A “Dugesia liguriensis” flatworm (Wikimedia Commons)

Here’s an amazing factoid: Human children up to age two or three can regenerate an entire finger-tip — nerves, bone, blood vessels and all.

Then as the years pass, we lose that ability. But early on, we’ve got a bit of the amazing growability that Narnia showed in its Chronicles. (Remember how, when the world was new in The Magician’s Nephew, an iron bar dropped upon the ground sprouted into a lamp-post, and candies into fruit trees?)

I learned that fascinating finger-tip fact from University of San Francisco assistant biology professor James Sikes (except the associations with Narnia were all mine) in connection with an even more fascinating set of papers just out in the journal Nature.

It was a very surprising finding that one gene can rescue a regeneration process that was lost millions of years ago.

Allow me to sum up: Some of the worms known as flatworms or planarians are superstars at regeneration — “We can cut one worm into 250 pieces and have 250 worms a week later,” Sikes said.

In particular, some flatworms can even regenerate their heads. Other planarians are not so good at the grow-back game. In the new research just out in Nature, scientists find that by tweaking just one gene’s signaling pathway, they can restore the power of regeneration to those otherwise headless losers.

Is this surprising? You bet.

“I was shocked,” Sikes said. “It was a very surprising finding that one gene can rescue a regeneration process that was lost millions of years ago.”

I love this stuff. Here, lightly edited, is my chat with Prof. Sikes:

So tell me, please, why can I not regenerate my head?

[Tolerant laughter.] You want to try?

I might want to try if you’d let me know how to do it…!

It comes down to the issue that the regeneration ability is more limited, the more complex an animal is. Continue reading

Children’s Picks For Top 10 Innovation Trends Of 2012

It’s naturally Children’s-centric, but it’s my favorite Top 10 of the new year: Vector, the Children’s Hospital Boston “science and clinical innovation blog,” offers its take on where the cutting edge will be this year, and much of it rings true far beyond the hospital’s walls. (It’s also written by Nancy Fliesler, who may draw a marketing salary but could often be busted for committing journalism.)

The list is a heartening litany of the many ways that research could make medicine better. The headlines are below, and I thought the work described in this paragraph sounded particularly promising:

Getting a completely untested drug through FDA approval is a long, hard road. So researchers and pharmaceutical companies are increasingly repurposing medicines that have already been approved. Rapamycin is a great example of drug that is seemingly useful for just about everything, from immunosuppression to neurocognitive disorders to congenital heart defects. Using high-throughput assays, researchers are taking whole libraries of FDA-approved compounds, throwing them at new medical problems and finding new therapeutic “hits.” The FDA and private companies are lending a hand, and researchers at Stanford created a program that matches the gene activity caused by a disease with drugs inducing the opposite gene activity.

The headlines:
1. Whole-genome sequencing enters the clinic
2. Innovation meets healthcare reform
3. Global health: Medical missions give way to telemedicine
4. Timely diagnosis for behavioral disorders
5. Digital health apps 2.0
6. Repurposing medicines – finding new uses through mass screens
7. Rethinking clinical practice pays off
8. Making the flu less devastating
9. Taking tissue engineering to the next level
10. New pharma R&D models empower academic medical centers

The full post is here.