How to make your plasma membrane from scratch
A group of researchers has developed a method of making a cell membrane from a few sheets of graphene.
This method could potentially pave the way for the production of more powerful membranes, which could lead to new forms of medical devices.
Graphene is an incredibly light material that is made up of a series of carbon atoms arranged in a lattice.
It has great electrical and chemical properties, which makes it ideal for applications like flexible electronics, computer chips, and solar panels.
But it also has many limitations, including its lack of conductivity.
Researchers at the Massachusetts Institute of Technology (MIT) have been trying to make graphene into a cell-membrane composite by using graphene’s electrical and mechanical properties to form an alloy of carbon nanotubes.
The team discovered that these properties could be used to make the desired cell membrane.
The new process, which they describe in the journal Nature Communications, uses a special technique called the “graphene-to-cell” (G2C) method.
This allows the team to build a thin sheet of graphene onto which they can place a mixture of polyvinyl chloride (PVC) and polypropylene (PP) that have been used to manufacture the cell membrane so far.
The process creates a thin layer of graphene that contains a thin polyester film, while the polyvinylethylene film contains a more robust material that can resist electrical and thermal degradation.
The team was able to get the cell-mesh to form by using a series (100-nm) pattern to build up a thin film of graphene, but they needed to first get the process to work in a liquid state.
They started by heating a polyvinylene film to just under boiling point to create a catalyst, and then the team started to work on the membrane by using an ion-exchange process.
This involved applying the mixture of PVC and PP to the polystyrene and then transferring it to the membrane, where it is sandwiched between a polymer matrix and a polymer membrane.
This process, known as “polystyrene-based membrane assembly,” allows the membrane to be made up out of just the two materials.
“The first step was to heat up the polymer matrix, which we call ‘solidified polymer,’ so that we could remove the polymer, which had some sort of an ionic charge,” says lead author Dr. Yuqing Wang, who is also a professor of materials science and engineering.
“We then used this to separate out the two membranes, so that the polymer can be separated.”
To get the membrane assembly to work, the team had to heat the mixture up and then transfer it to a solution of graphene oxide.
The membrane assembly is made of two layers of graphene on top of a polystyrian polymer matrix.
When the mixture is heated to just below boiling point, the polymers in the polymer layer break down and the graphene oxide is released into the solution.
The researchers then used the reaction to heat and remove the polymeric layer from the membrane and start the reaction again.
“Then we used a second step to heat a second polymer layer to just above boiling point,” Wang says.
This was done by heating the mixture to about 350°C and then moving the mixture from the polymer to the polymer membrane, so the membrane could start to break down.
The first polymer layer is then removed and the second polymer is transferred to the cell.
Once the membrane is assembled, it’s ready to be used.
“This is the first time we’ve actually seen a cell’s membrane assembled using the G2C method,” Wang adds.
“It’s quite a feat, but it’s also a demonstration of how graphene can be used as a material to make membranes.”
The new method could also help in the production and storage of new membranes, because they can be made to withstand different temperatures, chemical conditions, and even the presence of light.
“If we can make membranes that can withstand a wide range of chemical conditions and also light, then we could be able to develop membrane technologies that are more effective at the cells that we want to use them for,” Wang notes.