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Tom Ulrich

UV light-activated aptamers Dan Kohane drug delivery

Short snippets of DNA called aptamers (red) readily get into cancer cells (green and blue) on their own (left panel). They can't penetrate cells when stuck to an oligonucleotide (center), but regain the ability when the oligonucleotide's bonds are broken by UV light (right). (Images courtesy Lele Li, PhD.)

You have a drug. You know what you want it to do and where in the body you need it to go. But when you inject it into a patient, how can you make sure your drug does what you want, where you want, when you want it to?

Daniel Kohane, MD, PhD, who runs the Laboratory of Biomaterials and Drug Delivery at Boston Children’s Hospital, has one potential solution. In the Proceedings of the National Academy of Sciences, Kohane; postdoctoral fellows LeLe Li, PhD, and Rong Tong, PhD; and Robert Langer, PhD, of Massachusetts Institute of Technology, describe a drug- targeting system that’s based on a combination of ultraviolet (UV) light and short, single strands of DNA called aptamers. Full story »

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A biospleen is born

by Tom Ulrich on November 17, 2014

biospleen sepsis Wyss Institute Donald Ingber

The Wyss Institute's biospleen. (Photos courtesy of the Wyss Institute)

On a Friday morning a few years ago, a childhood friend of mine walked into his doctor’s office, saying his hip hurt. The pain was pretty severe, and had been getting worse for several days.

By Saturday morning, he was in intensive care, fighting for his life against an overwhelming case of sepsis. He survived, but at a cost: he’s now a quadruple amputee.

It’s people like him—and the other million-plus Americans who develop sepsis every year—that Donald Ingber, MD, PhD, and his team had in mind while developing the biospleen, a device that filters sepsis-causing pathogens from the blood. Announced to the world in September, the biospleen grew out of the organs-on-chips technology that Ingber’s team at the Wyss Institute for Biomedically Inspired Engineering launched commercially this past summer.

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gene editing CRISPR T-cells stem cells HIV

The CRISPR system (red) at work.

CRISPR—a gene editing technology that lets researchers make precise mutations, deletions and even replacements in genomic DNA—is all the rage among genomic researchers right now. First discovered as a kind of genomic immune memory in bacteria, labs around the world are trying to leverage the technology for diseases ranging from malaria to sickle cell disease to Duchenne muscular dystrophy.

In a paper published yesterday in Cell Stem Cell, a team led by Derrick Rossi, PhD, of Boston Children’s Hospital, and Chad Cowan, PhD, of Massachusetts General Hospital, report a first for CRISPR: efficiently and precisely editing clinically relevant genes out of cells collected directly from people. Specifically, they applied CRISPR to human hematopoietic stem and progenitor cells (HSPCs) and T-cells.

“CRISPR has been used a lot for almost two years, and report after report note high efficacy in various cell lines. Nobody had yet reported on the efficacy or utility of CRISPR in primary blood stem cells,” says Rossi, whose lab is in the hospital’s Program in Cellular and Molecular Medicine. “But most researchers would agree that blood will be the first tissue targeted for gene editing-based therapies. You can take blood or stem cells out of a patient, edit them and transplant them back.”

The study also gave the team an opportunity to see just how accurate CRISPR’s cuts are. Their conclusion: It may be closer to being clinic-ready than we thought. Full story »

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Dolly sheep cloning somatic cell nuclear transfer epigenetics

Dolly the sheep, the first mammalian example of successful somatic cell nuclear transfer. (Toni Barros/Wikimedia Commons)

We all remember Dolly the sheep, the first mammal to be born through a cloning technique called somatic cell nuclear transfer (SCNT). As with the thousands of other SCNT-cloned animals ranging from mice to mules, researchers created Dolly by using the nucleus from a grown animal’s cell to replace the nucleus of an egg cell from the same species.

The idea behind SCNT is that the egg’s cellular environment kicks the transferred nucleus’s genome into an embryonic state, giving rise to an animal genetically identical to the nucleus donor. SCNT is also a technique for generating embryonic stem cells for research purposes.

While researchers have accomplished SCNT in many animal species, it could work better than it does now. It took the scientists who cloned Dolly 277 tries before they got it right. To this day, SCNT efficiency—that is, the percent of nuclear transfers it takes generate a living animal—still hovers around 1 to 2 percent for mice, 5 to 20 percent in cows and 1 to 5 percent in other species. By comparison, the success rate in mice of in vitro fertilization (IVF) is around 50 percent.

“The efficiency is very low,” says Yi Zhang, PhD, a stem cell biologist in Boston Children’s Hospital’s Program in Cellular and Molecular Medicine. “This indicates that there are some barriers preventing successful cloning. Thus our first goal was to identify such barriers.” Full story »

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Hematopoietic hierarchy aging blood cell hematopoietic stem cell blood disorder Derrick Rossi

Blood-forming hematopoietic stem cells (top) give rise to all blood and immune cell types. In children with SCID, the steps leading to immune cells are broken.

In the world of fatal congenital immunodeficiency diseases, good news is always welcome, because most patients die before their first birthday if not treated. Babies with severe combined immunodeficiency disease, aka SCID or the “bubble boy disease,” now have more hope for survival thanks to two pieces of good news.

Transplants are looking up

First came a July paper in the New England Journal of Medicine (NEJM) by the Primary Immune Deficiency Treatment Consortium. This North American collaborative analyzed a decade’s worth of outcomes of hematopoietic stem cell transplant (HSCT), currently the only standard treatment option for SCID that has a chance of providing a permanent cure. Full story »

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Dallas map Ebola electronic health records

(Google Maps)

The Ebola situation in Dallas—with one patient death, two nurse exposures, dozens under quarantine, and talk last week of declaring a state of emergency in the city—has thrown into stark relief the gaps between public health and frontline clinical care. But those gaps also present opportunities to make public health data work harder and to change how doctors approach clinical care in times when events and information are changing at Internet speed.

That’s the gist of an editorial by Boston Children’s Hospital’s Kenneth Mandl, MD, MPH, published Monday in the Journal of the American Medical Association.

It comes down to making electronic health records (EHRs) work more flexibly, in ways that help promote situational awareness among clinicians during times of crisis and flag instances when a patient’s condition may require more attention than usual. Full story »

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Global Pediatric Innovation Summit Awards big dataWhere is the next generation of therapeutic innovations going to come from? Population-level genomic studies? The fitness trackers on everyone’s wrist? Mining electronic medical records? People’s tweets, Yelps and Facebook posts?

How about all of the above?

What all of these things have in common is data. Lots of it. Some of it represents kinds of data that didn’t exist 5 or 10 years ago, but all of it is slowly beginning to fuel the pharma sector’s efforts to create the next blockbuster drug or targeted therapeutic.

At least, it should be. Full story »

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Tamiflu influenza neuraminidase inhibitors conflicts of interest

(stanrandom/Flickr)

This winter, if your doctor suggests that you take Tamiflu, you might want to ask for a conflict of interest statement: a new study suggests that doctors who received payments from the makers of flu-fighting neuraminidase inhibitors—drugs like Tamiflu® and Relenza®—were more likely to view the drugs’ prowess in a favorable light.

In the study, published last week in the Annals of Internal Medicine, a team led by Boston Children’s Hospital’s Florence Bourgeois, MD, MPH, tallied up the financial connections of doctors who participated in 37 reviews of neuraminidase inhibitors.

While it’s been unclear for years whether these drugs really are effective against influenza, it was crystal clear that financial relationships are associated with positive reviews. Full story »

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Breast cancer cholesterol ezetimibe Zetia angiogenesisYou are what you eat, the saying goes. For some conditions (think cardiovascular disease or type 2 diabetes), there are clear connections between diet, health and illness.

For breast cancer, the picture is less clear. Many epidemiologic and laboratory studies have examined the Western diet (in particular, cholesterol) and its relation to breast cancer, with conflicting results.

“There’s been a raging debate in the field,” says Christine Coticchia, PhD, who works in the laboratory of Boston Children’s Hospital’s Vascular Biology Program director, Marsha Moses, PhD. “The biology of cancer and of cholesterol are so complex, and there are many subsets of breast cancer. In order to find any connections, you have to ask very specific questions.”

Banding together with Keith Solomon, PhD, in Boston Children’s Urology Department,  Coticchia and Moses asked whether dietary cholesterol might encourage progression of the most aggressive, so-called “triple-negative” breast tumors. As they report in the American Journal of Pathology, they found a big impact, at least in mice. But it’s too early to say just yet that cutting back on cholesterol will help women avoid breast cancer. Full story »

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Organs-on-chips drug testing drug discovery mechanobiology microfluidics Wyss Institute Vascular Biology Program

(Credit: Wyss Institute)

With the launch this summer of Emulate Inc., organs-on-chips—a disease-modeling platform we’ve covered several times on Vector—made the jump from academic to commercial development.

Though developed at the Wyss Institute for Biologically Inspired Engineering, the chips’ story actually began more than 20 years ago in Boston Children’s Hospital’s Vascular Biology Program (VBP). It’s a story that brings together characters from multiple fields and emerges from one fundamental concept: that mechanical forces are critical to the function and fate of cells, tissues and organs. Full story »

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