David H. Gracias, Ph.D.

A research team led by scientists from Johns Hopkins University have developed a tiny EEG electrode cap to measure activity in a brain model the size of a pen dot. Its designers expect the device to lead to better understanding of neural disorders and how potentially dangerous chemicals affect the brain.

The researchers published their study, “Shell microelectrode arrays (MEAs) for brain organoids,” in Science Advances and say their work expands what can be accomplish with organoids, including mini brains—the lab-grown balls of human cells that mimic some of a brain’s structure and functionality.

“This provides an important tool to understand the development and workings of the human brain,” notes David Gracias, PhD, a Johns Hopkins chemical and biomolecular engineer and one of the creators. “Creating micro-instrumentation for mini-organs is a challenge, but this invention is fundamental to new research… Continue reading.

The tiny, star-shaped ‘theragrippers’ latch onto the intestinal tract, to slowly release their drug payload.

Prof David Gracias is the director of graduate studies in the Department of Chemical and Biomolecular Engineering at Johns Hopkins University. He spoke to BBC Science Focus commissioning editor Jason Goodyer about his latest work on bioinspired microdevices that can release drugs directly into patients’ gastrointestinal systems.

You based the technology on parasitic hookworms. Where did that idea come from?

We’ve been trying to deliver drugs through the gastrointestinal tract, and that is a formidable challenge because the gastrointestinal tract has a mucosa – a mucus layer. It’s kind of like a conveyor belt, it’s constantly moving. It moves and it sheds [cells] in different parts at different rates… Continue reading.

Inspired by a parasitic worm that digs its sharp teeth into its host’s intestines, Johns Hopkins University researchers have designed tiny, star-shaped microdevices that latch onto intestinal mucosa and release drugs into the body.

Made of metal and thin, shape-changing film and coated in a heat-sensitive paraffin wax, “theragrippers,” each roughly the size of a dust speck, can carry a drug and release it gradually into the body.

The team published its results as the cover article in the journal Science Advances. The research was funded by the Scalable Nanomanufacturing Program of the U.S. National Science Foundation… Continue reading.

WASHINGTON, D.C.— The American Institute for Medical and Biological Engineering (AIMBE) has announced the pending induction of David H. Gracias, Ph.D., Professor, Chemical and Biomolecular Engineering, Johns Hopkins University, to its College of Fellows. Dr. Gracias was nominated, reviewed, and elected by peers and members of the College of Fellows For contributions in the development of three dimensional micro and nanopatterned materials and devices for biomedical engineering.