Cell Types

Geron Corp., the first company to work with stem cells derived from human embryos, said Thursday that it's holding settlement talks with a university foundation that sued Geron over licenses to stem cell types. Menlo Park, Calif.-based Geron hopes to resolve the dispute with the Wisconsin Alumni Research Foundation in the near future, the company said.

Breathe in, breathe out — it may seem simple, but lungs are devilishly complicated structures, boasting more than 40 different cell types and an intricate network of tiny blood vessels and air sacs. It's no wonder, then, that engineering lungs in the lab, either for transplantation or study, has been extremely challenging. Now two research groups have made major strides in attacking the problem. One has successfully engineered a lung that can sustain a living rat and the other has created a lung-mimicking device for toxicology studies that acts more like a real lung than any earlier efforts, the groups reported Thursday in the journal Science.

Mice with deep skin wounds can grow new hair, scientists said Wednesday in a finding that offers hope for a baldness remedy for humans. The mice regenerated hair at the site of the wound via molecular processes similar to those used in embryonic development, according to the research published in the journal Nature. The findings show that mammals possess greater regenerative abilities than commonly believed.

The windpipe transplanted into a terminal cancer patient in Sweden is garnering much buzz – and small wonder. The surgery marks the first time a trachea grown from a patient’s stem cells and seeded onto a synthetic, rather than a donor, structure has been transplanted in a human. And it saved a 36-year-old man’s life. The trachea isn’t the first organ born in a lab—and experts say there are many more to come. We talked to Dr. Anthony Atala, a pioneer in the field who in 1999 transplanted the first of several synthetic bladders into young people with bladder disease.

Shares in Geron Corp. rose nearly 15% on Tuesday after the small biotech company said it received a patent that could give it an advantage in the race to produce medicines from human embryonic stem cells. The Menlo Park-based firm's shares closed at $7.98, up $1.02, on Nasdaq, after hitting a 52-week high of $9.75 earlier in the day. Embryonic stem cells are formed in the earliest weeks of pregnancy and are capable of turning into any of the 300 cell types in the body.

Foreign genes can be blasted into plant cells with a miniature shotgun, a process that someday could prove handy for genetic engineering, researchers say. Two kinds of genes injected into onion skin cells have continued to function, according to Cornell University scientists, who reported on their work in the current issue of the British journal Nature.

A specific type of stem cells transplanted into the leg muscles of injured young mice not only repaired the muscle damage but triggered changes in the muscle tissue that made it resistant to normal aging. The surprising finding, which was published Wednesday in Science Translational Medicine suggests that, under the proper conditions, stem cells might regenerate muscle tissue. Researchers led by Bradley Olwin of the University of Colorado, Boulder, took stem cells from the muscles of young donor mice and transplanted them into mice with muscle injuries.

A team of researchers at Massachusetts General Hospital in Boston has engineered functional rat kidneys by stripping donor kidneys of their cells and then repopulating the remaining collagen substructures with new cells. The bioengineered kidneys produced urine in laboratory dishes and when implanted in living animals. The advance could be good news for the 100,000 Americans waiting for donor kidneys for transplant, because it suggests that someday scientists might be able to grow custom-made kidneys for people, using a patient's own cells to seed tissues, said Dr. Harald Ott, a researcher at the Massachusetts General Hospital Center for Regenerative Medicine and senior author of a paper describing the discovery published online Sunday in the journal Nature Medicine . “My goal was to show it's possible,” said Ott, who previously created bioengineered rat lungs and rat hearts using the same technique.

Research in mice suggests that stem cells from the adult brain can be nurtured into heart, liver, muscle and other tissues. If the same results can be achieved with human stem cells, the finding may eliminate the ethical dilemma now blocking stem cell studies that use human fetal tissues, experts say.

Researchers have isolated from adult bone marrow a master cell that can be directed to grow bone or cartilage, a laboratory feat that experts call a major step toward learning to make replacement parts for ailing or aged bodies. The researchers at Osiris Therapeutics in Baltimore report in the journal Science that they isolated a single cell, called a mesenchymal stem cell, and then grew it into a colony of more than a million cells that could be induced to produce bone, cartilage or fat.