Biomedical Engineering Professor Shuichi Takayama is making headlines with the development of his “Kidney on a chip” device. Takayama and a team of University of Michigan researchers developed the chip to replicate how medications move through the kidneys, and measure how different drugs effect the organs.
"When you administer a drug, its concentration goes up quickly and it's gradually filtered out as it flows through the kidneys. A kidney-on-a-chip enables us to simulate that filtering process, providing a much more accurate way to study how medications behave in the body." - Prof. Shuichi Takayama
An innovative approach to an old problem
The microfluidic chip is essentially comprised of three distinct layers- an upper layer and bottom layer, separated by a membrane containing human kidney cells. Taking into account that the same dosage of a drug can result in different reactions depending on how it is administered, researchers used two methods of testing the device. The first involved injecting the device with a slow but constant stream of medication during the trial period, while the second was a more concentrated one-time dose. Though the dosages were the same, it was found that the singular dose was significantly less traumatic to the kidneys than the continuous option.
When you consider that two-thirds of patients in the ICU suffer from kidney damage, and that 20% of these injuries are exasperated by toxic medications, it is clear to understand why we need more effective dosing methods. Animal testing has been the norm for testing drug toxicity, but the controversial method has shortcomings when examining the reliability and accuracy of the tests. Humans process medications at a slower rate than animals, making it extremely difficult to predict exactly how the results from animal trials will translate in human tissue and organs. The “kidney on a chip” technology will eliminate this issue because it allows doctors to test drugs with actual human kidney cells.
Drug safety in pediatrics
Variations in reactions to drugs exist between humans and animals, as well as adults and children. Ailments such as dehydration and blood loss have a more severe effect on children, and the same rule applies when it comes to the medications that children receive. A surprising fact is that historically, only 20–30% of drugs approved by FDA have been labeled for use in children, as most clinical trials are conducted on adults. Dianne Murphy, MD, FDA Director of Pediatric Therapeutics, explained that an overall lack of clarity exists when determining the appropriate method of testing drug safety in children.
“We had the peculiar situation of demanding a very high level of proof before a product was marketed for adults, but then having it used 'off-label' in children. This means that FDA did not have studies on how the product did or did not work in children, what different kinds of reactions children might have, or what the proper dose would be over the wide range of children's ages, weights, and developmental stages.”
The technology used in Takayama’s device is the answer to Murphy’s call for more precise pediatric dosing, as well as a solution to the problem of medication dosage errors in critical care settings. Devices such as “heart on a chip” and “gut on a chip” are also under development, which leads us to believe that the technology will soon be used to analyze the relationship between cells and drugs in a range of major human organ systems.