Hydrogel for in Situ Encapsulation of Multiple Black Lipid Membranes

Hydrogels are hydrophilic, porous polymer networks that can absorb water up to thousands of times their own weight. They have many applications, one of which is the encapsulation of free-standing black lipid membranes (BLMs) for novel separation technologies or biosensor applications. We investigated gels for in situ encapsulation of multiple black lipid membranes across apertures in a hydrophobic ethylene tetrafluoroethylene (ETFE) support. These gels consisted of networks of poly(ethylene glycol)-dimethacrylate or poly(ethylene glycol)-diacrylate polymerized using either a chemical initiator or a photoinitiator. The hydrogels were studied with regard to their material properties such as chemical resistance, swelling behaviour, water permeability and porosity. We found that lifetimes of membranes in gel precursor solutions were short compared to lifetimes in buffer. However, crosslinking the gel stabilized the membranes and increased BLM longevity substantially over lifetimes in buffer. Optical images of the membranes and incorporation of the transmembrane peptide gramicidin A showed that the lipid membranes retained their integrity after encapsulation with hydrogel.