Human
organs on a stick.
That is how Dr. Danilo A. Tagle,
a Filipino-American scientist, describes “bioengineered
Organs-on-Chips” whose development he is
steering at the U.S. National Institutes of Health (NIH), one of the world's
leading health research institutions.
Dr. Tagle,
Associate Director for Special Initiatives at the NIH National Center for
Advancing Translational Sciences, left the Philippines at the age of 18. This
summer, he was back for a visit as Chair of the Scientific Advisory Committee
on Health at the Philippine Genome Center (PGC).
The bioengineered organs are
placed in a device “similar in size to a USB
memory stick,” he told a scientific
symposium on genomics at the PGC, the country's most advanced gene-related
research complex located at the University of the Philippines Diliman.
The PGC leads local genomics
research, a discipline in genetics studies that sequences, assembles and
analyzes the function and structure of genomes or the complete set of DNA
within a single cell of an organism.
Genomics research can lead to
the development of new drugs, new diagnostic tools, new insights into the
molecular mechanisms of diseases and tailor pharmaceuticals to individual
needs.
Dr. Tagle
leads and manages the NIH Microphysiological Systems and the Extracellular RNA
Communication programs. Before joining the NIH, he was a Program Director for
Neurogenetics at the U.S. National Institute of Neurological Disorders and
Stroke where he was involved in developing programs in genomics-based
approaches for basic and translational research in inherited brain disorders.
Since 1993, he was an
Investigator and Section Head of Molecular Neurogenetics at the U.S. National
Human Genome Research Institute where he was involved in the positional cloning
of genes for Huntington's disease, ataxia-telangiectasia and Niemann-Pick type
C disease.
(Huntington's is an inherited
disease that causes the progressive degeneration of nerve cells in the brain;
Ataxia-telangiectasia is a rare and inherited childhood disorder that affects
the nervous, immune and other body systems; Niemann-Pick type C is an inherited
disease that causes progressive deterioration of the nervous system.)
“Advances in basic and
preclinical science continues to fuel the drug discovery pipeline,” Dr. Tagle
said. “However, only a small fraction of compounds meet the criteria for
approval by the U.S. Food and Drug Administration (U.S. FDA).”
He said more than 30 percent
of promising medications have failed in human clinical trials because they are
found to be toxic; this, despite promising pre-clinical studies in animals.
Another 60 percent fail because they are not effective, he said.
“The challenge of accurately
predicting drug toxicities and efficacies is in part due to inherent species
differences in drug metabolizing enzyme activities and cell-type specific
sensitivities to toxicants,” Dr. Tagle said.
To address this challenge in
drug development and regulatory science, the U.S. NIH invested $70 million on
the five-year Microphysiological Systems that Tagle heads. The so-called Organs-on-Chips Program
aims to develop alternative approaches that would enable early indications and
potentially more reliable readouts of toxicity and efficacy.
The Organ-on-Chips Program is
a partnership between the NIH, the U.S. FDA and the Defense Advanced Research
Projects Agency, a U.S. military think-tank that was instrumental in the early
development of the Internet.
The program hopes to develop
bio-engineered microdevices that represent functional units of the 10 major
human organs: circulatory, respiratory, integumentary, reproductive, endocrine,
gastrointestinal, nervous, urinary, musculoskeletal and immune systems.
“The opportunities for
significant advancements in the prediction of human drug toxicities requires a
multi-disciplinary approach that relies on an understanding of human
physiology, stem cell biology, material sciences and bioengineering,” Tagle
said.
The Organ-on-Chips Program,
he said, is a unique and new platform which “could help
ensure that safe and effective therapeutics are identified sooner and
ineffective or toxic ones are rejected early in the drug development process.”
The microfabricated devices
are useful for modeling human diseases and may prove to be sufficient
alternatives to the use of animal models, Tagle said. (SciencePhilippines)
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