An occasional roundup of news items Vector finds interesting.
Blood-brain barrier on chip
The blood-brain barrier protects the brain against potentially damaging molecules, but its gate-keeping can also prevent helpful drugs from getting into the central nervous system. Reporting in PLoS One, a team at the Wyss Institute for Biologically Inspired Engineering describes a 3-D blood-brain barrier on a chip — a hollow blood vessel lined with living human endothelial cells and surrounded by a collagen matrix bearing human pericytes and astrocytes. The cells orient themselves spatially much like they do in a living animal. The system can be used to investigate neuroinflammation (seen in Alzheimer’s, stroke, brain ischemia, multiple sclerosis, traumatic brain injury and other conditions) and to test methods of getting drugs across the human blood-brain barrier. Donald Ingber, MD, PhD, who also holds an appointment in Boston Children’s Hospital’s Vascular Biology program, led the study.
Several interesting recent studies here. One from Germany, reported last week in Nature Genetics, suggests that children can inherit susceptibility to obesity and diabetes acquired as a result of their parents’ diets — through epigenetic factors acting in utero. As one coauthor told The Scientist, “Our findings give back a certain responsibility to the parents. They really have the possibility to affect what offspring inherit in their epigenome.”
A study in Cell Stem Cell, led by the Harvard Stem Cell lnstitute (with several co-authors at Boston Children’s), showed that tissue from the lower stomach can be engineered to create implantable “mini organs” with insulin-secreting beta cells. In diabetic test mice, these implants were capable of controlling blood sugar.
Finally, a team at the University of North Carolina at Chapel Hill and North Carolina State University describes a synthetic skin patch for diabetes. It’s covered with tiny needles that are stuffed with natural beta cells. The needles poke into the capillaries and blood vessels, delivering doses of insulin. Synthetic nanovesicles filled with glucose-sensing chemicals help ensure that insulin is released only when needed.
23-chromosome stem cells: Less is more?
In Nature last week, researchers at Hebrew University of Jerusalem, Columbia University Medical Center and the New York Stem Cell Foundation Research Institute describe using human eggs to create embryonic stem cells that carry only 23 chromosomes — half the normal 46. These haploid stem cells, which carry DNA from just one parent, could provide a novel research tool. It’s easier to edit their genes, and it’s easer to detect a single-copy genetic defect because the backup copy from the other parent is absent. Haploid embryonic stem cells may also be well suited to cell-based therapies, more readily providing a match for transplantation. For more, this Washington Post article includes video.
Marijuana for seizures?
Many parents of children with severe, medication-resistant epilepsy have become interested in medical marijuana. The developer of an experimental drug derived from marijuana announced clinical trial results last week indicating that its drug, Epidiolex, may reduce seizure frequency. Over 14 weeks of treatment, convulsive seizures were reduced by 39 percent in Epidiolex-treated patients with a rare epilepsy called Dravet syndrome. The reduction was just 13 percent with placebo.
“I’m very proud and happy about this study because it is science — we did things the way they should be done,” the study’s lead investigator, Dr. Orrin Devinsky of the Comprehensive Epilepsy Center at New York University Langone Medical Center, told The New York Times.
Hundreds of other children and young adults have been using Epidiolex outside of clinical trials, the Times reports. The drug’s developer, London-based GW Pharmaceuticals, has another Dravet trial wrapping up and two trials in patients with Lennox-Gastaut, another rare epilepsy.