Maskless Photochemical Printing of Multiplexed Glycan Microarrays for High-Throughput Binding Studies

Spatially encoded glycan microarrays promise to rapidly accelerate our understanding of glycan binding in myriad biological processes, which could lead to new therapeutics and previously unknown drug targets. Here, we bring together a digital micromirror device, microfluidic introduction of inks, and advanced surface photochemistry to produce multiplexed glycan microarrays with reduced feature diameters, an increased number of features per array, and precise control of glycan density at each feature. The versatility of this platform was validated by printing two distinct glycan microarrays where, in the first, different glycans were immobilized to create a multiplexed array and, in another, the density of a single glycan was varied systematically to explore the effect of surface presentation on lectin-glycan binding. For lectin binding studies on these miniaturized microarrays, a microfluidic incubation chip was developed that channels multiple different protein solutions over the array. Using the multiplexed array, binding between eight lectin solutions and five different glycosides was determined, such that a single array can interrogate the binding between 40 lectin-glycan combinations. The incubation chip was then used on the array with varied glycan density to study the effects of glycan density on lectin binding. These results show that this novel printer could rapidly advance our understanding of critical unresolved questions in glycobiology, while simultaneously increasing the throughput and reducing the cost of these experiments.