From the category archives:

Regenerative medicine

(Wikimedia Commons)

How do cells figure out how to build three-dimensional organs with multiple kinds of tissues? A group of engineers, geneticists, biochemists and cell biologists at Children’s Hospital Boston and Harvard’s Wyss Institute for Biologically Inspired Engineering sunk their teeth into this mystery – starting, in fact, with the tooth.

Scientists have known for more than a century that the growth of many organs (including tooth, cartilage, bone, muscle, tendon, kidney and lung) begins with the formation of a compact cell mass called “condensed mesenchyme.” But what makes this mass form to begin with? Until now, no one knew. Full story »

Leave a comment

Untreated carpal tunnel syndrome causing atrophy of the muscles of the thumb (Harry Gouvas/Wikimedia Commons)

It’s common in medicine for physicians to “wait and see” before taking treatment to a more invasive (or expensive) level. But when it comes to motor nerve injuries, combined laboratory and clinical evidence suggests that approach may be fundamentally wrong.

That would go for injuries including carpal tunnel syndrome, cubital tunnel syndrome (a compression injury of the ulnar nerve in the elbow), nerve damage from surgery or chemotherapy, and brachial plexus avulsion injuries (these often happen when people fall off their bikes; the arm is bent backwards and nerves get ripped out of the spinal cord).

In serious cases, patients may recover sensory function, but rarely recover full muscle function and strength. Lab studies by neuroscientists at Children’s Hospital Boston provide a biological explanation, and therein may lie a solution.

It’s not that injured motor nerve fibers don’t regrow – they can. It’s that they don’t grow fast enough. Full story »

Leave a comment

People who have had a heart attack or have coronary artery disease often sustain damage that weakens their heart. Milder forms of heart failure can be treated with medications, but advanced heart dysfunction requires surgery or heart transplant. A team of physicians, engineers and materials scientists at Children’s Hospital Boston and MIT offers two alternative ways to strengthen weakened, scarred heart tissue — both involving nanotechnology.

One approach blends nanotechnology with tissue engineering to create a heart patch laced with gold whose cells all beat in time – as shown in the above video.

The other uses minute nanoparticles that can find their way to dying heart tissue, carrying stem cells, growth factors, drugs and other therapeutic compounds. Full story »


This two-part series, a response to the recent appeals court decision lifting an injunction on federal funding of human embryonic stem cell research, was co-authored by M. William Lensch, George Q. Daley, and Leonard Zon of the Stem Cell Research Program at Children’s Hospital Boston. (Read Part 1.)

While there is reason for optimism, the April 29 appeals court ruling lifting the injunction on federal funding for human embryonic stem cell (hESC) research will not be the last chapter in the story of such research in the United States. And there are moments in this story that hold cause for greater alarm. Full story »

Leave a comment

This two-part series, a response to the recent appeals court decision lifting an injunction on federal funding of human embryonic stem cell research, was co-authored by M. William Lensch, George Q. Daley, and Leonard Zon of the Stem Cell Research Program at Children’s Hospital Boston.

It came as a welcome relief when on April 29 the U.S. Court of Appeals vacated a lower court’s injunction against federal funding of human embryonic stem cell (hESC) research. For those of us working on research projects involving hESCs, whether funded through the National Institutes of Health (NIH) or other federal agencies, it meant that we are once again free to continue our work … for now.

The “for now” part relates to the fact that the recent ruling is but one chapter in the ongoing story of hESC research funding. The desultory nature of federal funding for hESC research has been a constant source of uncertainty for scientists and the general public alike, and to understand the full story, we need to look back to the mid 1990s, before the derivation of the first hESC lines. Full story »

Leave a comment

A tissue engineered cartilage tube ready for implantation.

Tissue-engineered repairs and replacement parts aren’t just concepts out of science fiction – they promise to provide the ideal solution for thousands of children born each year with congenital anomalies or who suffer devastating injuries. A study released yesterday in The Lancet and covered on NPR reports on the latest tissue engineering advance.

Anthony Atala, a former Children’s Hospital Boston urologist and now director of the Institute for Regenerative Medicine at Wake Forest University School of Medicine, reports on five young boys in Mexico City whose damaged urethras he replaced with laboratory-grown urethras over five years ago. The patients had suffered damage to their urinary tracts from auto accidents, leaving them unable to urinate without a catheter.

In an approach he began at Children’s back in the late 1990s, Atala and his colleagues took a biopsy of bladder tissue from each boy, and expanded the cells in the laboratory until there were approximately 100 million cells Full story »

Leave a comment

A patient's own cells may be able to create fat tissue with its own blood supply. (Image: Jagiellonian University Medical College)

The majority of the millions of plastic surgeries performed in the U.S. each year aren’t cosmetic procedures for Hollywood starlets or Beverly Hills housewives trying to hold on to their youthful looks. They’re reconstructive operations for patients with disfiguring injuries, tumor resections and congenital defects such as childhood hemangiomas, which can occur on the face.

A big challenge in reconstruction is compensating for the loss of a large volume of subcutaneous fat. Currently, there are three ways to do this, none of them ideal. Full story »

Leave a comment

Tal Dvir, PhD, is a postdoctoral fellow in the laboratories of Robert Langer, ScD (MIT) and Daniel Kohane, MD, PhD (Children’s Hospital Boston, Harvard Medical School).

As tissue engineers, we seek to develop functioning substitutes for damaged tissues and organs. Generally, this means seeding cells onto 3-dimensional porous scaffolds made of biomaterials, which provide mechanical support and instructive cues for the developing engineered tissue. Now it’s time to go to the next level, and make complex tissues that can really do things — contract, release growth factors, conduct electrical signals and more. Things our own cells and tissues do.

A review by Dvir et al:

Engineering a functional tissue is difficult. Cells must be organized into tissues with structural and physiological features resembling actual structures in the body. The outer connective tissue that supports cells, known as the extracellular matrix, is especially interesting to us. The matrix and its components — fibers, adhesion proteins, proteoglycans and others — provide cells with a wealth of information that regulates cell growth, shape, migration and differentiation.

To mimic these physiologic features, we work at the nanoscale – creating structures at the range of 1 billionth of a meter, Full story »

Leave a comment

In my job as a science writer at Children’s, I comb the organization for interesting science and innovation stories that we can push out to various audiences. At the turn of the year, my colleagues ask me to recommend what I see as our top stories. We present this list to funders, industry and physicians who refer patients to us as a way to build our relationships. Today I’m sharing my 2010 list directly with you.

A couple of caveats: Full story »

Leave a comment

For more than a century, neuroscientists have been trying to figure out how to repair broken nerves in the spinal cord-and the rest of the central nervous system-after injury. They’ve produced a steady stream of promising discoveries-treatments that promote nerve growth in the laboratory dish and animals, even some reports of paralyzed rodents regaining motor function. So why are people with spinal cord injury (SCI) still without therapies that repair their nerve damage? Full story »