A LEGO-Like Microarray

Although high-throughput screening provides a powerful means to evaluate drug candidates, the expense of sophisticated facilities and robots limits access to its techniques. Now researchers demonstrate a simple and cheap polymer-based benchtop microarray that doesn't need a robot to deliver compounds (Anal. Chem., DOI: 10.1021/ac200267t)

The new technique, developed by Ali Khademhosseini of Harvard University and his colleagues, delivers compounds through a layer of porous hydrogel to an underlying array of microwells. Like a LEGO piece, the hydrogel layer contains bumps that can fit into individual microwells. When the hydrogel interlocks with the microwell array, the bumps slowly release into the wells compounds to be screened.

The researchers tested their method with MCF-7 breast cancer cells. They produced an array with 2,100 polymer microwells on a standard microscope slide. They then used standard techniques to construct the compound-filled bumps on the hydrogel. After allowing the two layers to sit together for 12 hours, the scientists removed the hydrogel and treated the cells with fluorescently-labeled molecules to quantify the ratio of apoptosis, or programmed cell death, versus necrosis in these samples.

At only $1 to $2 per chip, the technique offers high-throughput screening at much lower cost than conventional methods, says Khademhosseini. He and his colleagues want to adapt the technology to personalized medicine and diagnostics. "We'd like for people to be able to take a drop of blood or saliva and do a variety of medical screens," Khademhosseini says. In another step toward portable diagnostics, the researchers have recently used a webcam with a similar screening system to observe "beating" cardiomyocytes. (Lab Chip, DOI: 10.1039/c1lc20098d).