US scientists have made biocompatible membranes in microfluidic chips.

Lab-on-a-chip platforms are becoming extremely useful in biomedical technology such as biosensors. But many devices include membranes that are made of non-biological materials or are made via non-biological routes which can cause toxicity problems in biological applications. Gary Rubloff and his team at the University of Maryland, College Park, have now developed biologically compatible membranes that are made without using costly or hazardous reagents. 

Rubloff used chitosan - a naturally occurring polysaccharide - to create his membranes. In strongly acidic conditions, chitosan is soluble and in basic solutions it forms a hydrogel. So by creating pH gradients in microfluidic channels, Rubloff was able to create semi-permeable membranes inside the chips in a controlled way. 

Chitosan has a rich supply of amine groups to which a wide variety of biomolecules can be attached, explains Rubloff. This allows the membrane to provide a scaffold for biomoleules throughout the chip, potentially opening the door to numerous applications. 

'We expect the membranes to play an important role in a variety of biochip applications, such as discovery of new antibiotic drugs, purification of proteins, analyzing interactions between cells and assessment of chemical or nanoparticle toxicity,' says Rubloff. 

According to Rubloff, the next steps are to ensure reproducibility, make tear-free membranes and to determine their exact properties of the membranes. However he sees a bigger problem, 'In some sense the greatest challenge is in picking which applications to pursue first, since there are so many exciting possibilities with this technology!' 

Edward Morgan

Enjoy this story? Spread the word using the 'tools' menu on the left or add a comment to the Chemistry World blog.