Lipid membranes regulate the flow of nutrients and communication signaling between cells and protect the sub-cellular structures. Recent attempts to fabricate artificial systems using nanostructures that mimic the physiological properties of natural lipid bilayer membranes (LBM) fused with transmembrane proteins have helped demonstrate the importance of temperature, pH, ionic strength, adsorption behavior, conformational reorientation and surface density in cellular membranes which all affect the incorporation of proteins on solid surfaces. Much of this work is performed on artificial templates made of polymer sponges or porous materials based on alumina, mica, and porous silicon (PSi) surfaces. For example, porous silicon materials have high biocompatibility, biodegradability, and photoluminescence, which allow them to be used both as a support structure for lipid bilayers or a template to measure the electrochemical functionality of living cells grown over the surface as in vivo. The variety of these media, coupled with the complex physiological conditions present in living systems, warrant a summary and prospectus detailing which artificial systems provide the most promise for different biological conditions. This study summarizes the use of electrochemical impedance spectroscopy (EIS) data on artificial biological membranes that are closely matched with previously published biological systems using both black lipid membrane and patch clamp techniques.

The effects of two methods of colonic vascular ligation were studied in 143 consecutive patients who underwent low anterior resection with total mesorectal excision and full mobilization of the splenic flexure. Either the ascending left colic artery (ALCA) was selectively preserved (n = 52) or a flush aortic ligation was performed (n = 91). In those with a protective colostomy, the radiological leak rate was 12 per cent when the ALCA was preserved (n = 41) and 10 per cent when a flush aortic tie was performed (n = 60) (P greater than 0.95; 95 per cent confidence interval (c.i.) for difference -10 to +15 per cent). In those without a colostomy, the clinical leak rates of 9 per cent when the ALCA was preserved (n = 11) and 19 per cent when a flush aortic tie was performed (n = 31) were not significantly different (P greater than 0.10; 95 per cent c.i. for difference -12 to +32 per cent). Proportional hazards analysis showed no association between the method of vascular ligation and the risk of tumour recurrence and death. Anastomotic leak rates, tumour recurrence and survival were not related to the method of vascular ligation.

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Black lipid membranes (BLMs) have been used for detecting single-channel activities of pore-forming peptides and ion channels. However, the short lifetimes and poor mechanical stability of suspended bilayers limit their applications in high throughput electrophysiological experiments. In this work, we present a synthetic solid-state nanopore functionalized with BLM fused with channel protein. A nanopore with diameter of ~180 nm was electrochemically fabricated in a thin silicon membrane. Folding and painting techniques were demonstrated for production of stable suspended BLMs followed by incorporation of transmembrane protein, ENaC. Membrane formation was confirmed by employing electrochemical impedance spectroscopy (EIS) in the frequency regime of 10-10 Hz. Results show that electrochemically fabricated solid state nanopore support resulted in excellent membrane stability, with >1 GΩ of up to 72 and 41 h for painting and folding techniques, respectively. After fusion of ENaC channel protein, the BLM exhibits the stability of ~5 h. We anticipate that such a solid-state nanopore with diameter in the range of 150-200 nm and thickness <1 µm could be a potential platform to enhance the throughput of ion-channel characterization using BLMs.