The future of advanced medicine may very well depend on our collective understanding of nano-scale biological systems. Certain embedded nanotechnology and medicine delivery mechanisms could rely heavily on our knowledge of cell membranes. Unfortunately, it is challenging to conduct thorough research on the membranes of live cells due to the fact that not all variables of living systems can be controlled. For this reason, biomimetic membrane research is an important field of study for scientists to explore. Biomimetic (as in, mimicking biology) membranes are a synthetic recreation of biologically occurring membranes, with very similar properties.
Researchers at KIT Institute of Nanotechnology (INT) have developed a new method of producing such membranes: a nanoscaled tip writes tailored pieces of phospholipid membrane onto a graphene-based substrate using multiplexed dip-pen nanolithography. According to the research, phospholipids exhibit better uniformity and mobility over a graphene substrate than over commonly used silicon dioxide-based substrates. Furthermore, graphene is believed by many scientists to be an important material for the design of future generations of nanosensors. However, in order for it to be a viable platform for use in biological systems, it must be appropriately functionalized and kept pristine within such an environment. Since they are based on naturally occurring cell membranes, working biomimetic membranes could be an effective way of isolating and functionalizing a piece of delicate technology within the body. The research also indicates that the charged phospholipid membranes enable electronic doping of the substrate, meaning that this technology could be successfully adapted for a wide variety of nanotechnological platforms aimed for use within the body.
From Nature Communications:
“Graphene in its pristine state and various functionalized derivatives has yielded excellent results in sensing experiments, such as single-atom gas sensitivity, DNA sequencing, and electronic nose. Graphene sensors can operate in a number of different modalities, such as electronic, electrochemical, optoelectronic and nano-electromechanical sensing. There have been a number of demonstration of graphene-based sensors; however, the high sensitivity and selectivity needs to be engineered by attaching various functional groups to graphene, either covalently or non-covalently. In applications in biosensing, a number of receptor molecules that could impart selectivity to graphene would work best as intended if they existed in their native environment, for instance, in a phospholipid cell membrane. In many cases, direct covalent or non-covalent binding of functional groups on graphene can often suppress their behaviour or even denature them. When interfacing graphene with biological systems such as cells or in using it as transducer for biological sensing, an overlay on graphene mimicking cellular membranes could provide a more native environment. One option to achieve this is the assembly of biomimetic lipid membranes on graphene, which was recently demonstrated by vesicle fusion. Other self-assembled monolayers have been deposited on graphene using a variety of techniques. However, these methods lack the ability for a direct spatial control on membrane formation and cannot deposit membranes of different compositions on one device. A functional multiplexed graphene-based sensor, such as an electronic nose or tongue, could be achieved with lipid membranes localized over a specific graphene region as well as membranes of different composition adjacent to each other, with microscale precision.”
Nature Communications: Multiplexed biomimetic lipid membranes on graphene by dip-pen nanolithography