A chip capable of simulating the “microenvironment” of a tumor has been developed by researchers at Purdue University in West Lafayette, IN.
Image credit: Purdue University photo/Altug Ozcelikkale, Bumsoo Han
This is not the first time that scientists have attempted to use microchip technology to study tumors. In 2011, for instance, Medical News Today reported on the development of a microchip sensor that can be implanted in a patient, next to their tumor, to measure the aggressiveness of its growth.
And in 2012, the Institute of Bioengineering and Nanotechnology in Singapore developed a biochip for studying the effect of drugs on cancer stem cells.
The engineers who created the new chip – known as the tumor-microenvironment-on-chip (T-MOC) device – hope that it will open doors for researchers to study the barriers that prevent the targeted deliveries of cancer therapies.
Research teams are investigating different “targeted delivery” mechanisms that are able to selectively attack tumor tissue. One method of delivery currently under investigation is to use nanoparticles tiny enough to pass through the pores of blood vessels.
Because the endothelial cells in healthy blood vessels are neatly organized, with small pores in their junctions – while the endothelial cells in blood vessels around tumors are irregular and misshapen, with larger pores – these designer nanoparticles may be able to differentiate between the two.
Bumsoo Han, a Purdue University associate professor of mechanical engineering, says that “if nanoparticles were designed to be the right size they could selectively move toward only the tumor.”
Han believes that the T-MOC device may be useful in solving some of the problems researchers investigating the nanoparticle approach have come up against.
For instance, one particular problem associated with the nanoparticle approach is that the interstitial fluid within tumors is of a greater pressure than the interstitial fluid surrounding healthy tissue. This increase in pressure is enough to push out most drug-delivery and imaging agents – only a small percentage of them succeed in reaching the tumor.
The T-MOC team report that their device is capable of simulating the tumor environment to such accuracy that it can provide detailed data on how nanoparticles may negotiate the environment.
About 4.5 cm2, the chip contains cultures of tumor and endothelial cells within “microfluidic” channels, as well as an “extracellular matrix” of collagen – the substance found between cells in living tissue.
As the chip is designed to mimic cancer in humans, its designers believe that it offers an alternative to both petri plates – which are unable to reproduce the complex tumor microenvironment – and research in animals, which does not always show how potential treatments might affect humans.
The Purdue team tested the movement of nanoparticles within the chip using human breast cancer and endothelial cells. Next, the team will study anticancer drugs using the chip. In the future, they may use T-MOC chips to grow tumor cells from patients that can be used to assess how effective specific drugs may be in those patients.
The team’s results so far are published in the Journal of Controlled Release.