Microfluidic Etching and Oxime-Based Tailoring of Biodegradable Polyketoesters

A straightforward, flexible, and inexpensive method to etch biodegradable poly(1,2,6-hexanetriol α-ketoglutarate) films is reported. Microfluidic delivery of the etchant, a solution of NaOH, can create micron-scale channels through local hydrolysis of the polyester film. In addition, the presence of a ketone in the repeat unit allows for prior or post chemoselective modifications, enabling the design of functionalized microchannels. Delivery of oxyamine tethered ligands react with ketone groups on the polyketoester to generate covalent oxime linkages. By thermally sealing an etched film to a second flat surface, poly(1,2,6-hexanetriol α-ketoglutarate) can be used to create biodegradable microfluidic devices. In order to determine the versatility of the microfluidic etch technique, poly(ε-caprolactone) was etched with acetone. This strategy provides a facile method for the direct patterning of biodegradable materials, both through etching and chemoselective ligand immobilization.