Supported Lipid Bilayer Arrays Formed from Inkjet-Printed Lipid Spots

Supported lipid bilayer (SLB) arrays are a potentially useful model membrane platform for fundamental biophysical studies and biomedical applications such as high-throughput screening and biosensors. However, SLBs face the challenge of long-term storage for a wide range of applications because they collapse when exposed to the air. In this study, we developed a method to prepare arrays of dried lipids in a form that allows long-term storage and on-site generation of SLBs just before use rather than storing SLBs for a long time. An SLB array was prepared by hydrating inkjet-printed lipid spots on a glass surface surrounded by a patterned polymeric bilayer framework. The lipid spots could be stored under dry conditions for a prolonged period. Upon the addition of aqueous solution, SLBs spontaneously formed from the lipid spots and covered the glass surface by self-spreading. Thus, formed SLBs were confined by the patterned polymeric bilayer. SLBs covered the corrals irrespective of the original lipid spot sizes, if enough lipid material was deposited. We succeeded in forming multiple SLBs with different compositions on a single substrate. Furthermore, we reconstituted an integral membrane protein (rhodopsin) into SLBs having different lipid compositions and evaluated the diffusion coefficients. SLBs could be formed by printing lipid spots that had been stored in air for 42 days. The possibility of storing lipids for a long time in a dried state and forming SLBs onsite should significantly widen their applicability in biophysical and biomedical settings.