You all can see the
incredible diversity of life around us.
And we all know that there's so many different forms
of living organisms.
Looking at it, it's hard to believe that
from the scientific point of view,
there is really only one life form on earth.
One life form, which means one type of biology.
So the biochemistry of living processes
is the same in all known life.
The blueprint for all cells is the same.
And looking at the molecular level,
all cells of every organism we ever know living on earth,
will have the same strategy
for storing genetic information,
and for growing and for making proteins and metabolism.
We don't fully understand how
even that one type of cells really works,
because cells are so complex.
They're crowded with proteins, with nucleic acids
and with small molecules.
And millions of people years have been spent
studying biochemistry.
Yet we still don't have a complete map
of even a single type of live cell.
So if you had something so complex,
how would you go about understanding it?
Well one way of doing it is to make it simpler.
And that's the whole point of the field
of synthetic cell engineering.
We want to build a simplest living cell from scratch.
The guiding principle of our field,
is a quote from a brilliant physicist.
A guy who understood the importance of a hands-on approach
to solving problems and paraphrasing him,
"Make it yourself so you know how it's made."
Synthetic cells are
bringing the principles of engineering into biology.
We can make cells with full control of
all of its parts,
just like engineering mechanical devices.
And so in many ways we can think of a synthetic cell
as a biological breadboard or prototyping board,
which is a platform to test different designs,
and to engineer biological systems
as if they're mechanical or electrical.
How do we build a synthetic cell?
The anatomy of most synthetic cells is fundamentally
not that different from all non-living cells.
They're lipid containers, expressing genes into proteins.
The cell is surrounded by a lipid membrane,
and most of the time that membrane is made
of some kind of a lipid known from natural cells.
The phospholipids and cholesterol.
Lipids have a polar hydrophilic head group,
and non-polar hydrophobic tails.
And despite its bad reputation, cholesterol is actually
good for membranes because it makes them flexible.
The membrane often has channels,
which are proteins that allow
transport of nutrients and signals from the outside,
and the removal of waste products
from the inside of the cell.
In synthetic cells we usually use simple channels
that create rather non-specific holes in the membrane.
One of the most common channels is called alpha-hemolysin,
which is originally a bacterial toxin.
Since the main point of having a membrane
is to separate self from the environment,
the inside of the synthetic cell from the outside,
a synthetic cell can also be made in a droplet.
A drop of water, surrounded by oil phase.
And millions of droplets can be made at the same time
in a so-called droplet microfluidic system.
In a droplet, you can't use membrane channels,
since there's no membrane.
But for other applications the microfluidic systems are
widely used to make a lot of,
lots of different types of synthetic cells.
And regardless of how it's done,
the compartment is a relatively simple problem.
The really interesting stuff is what's going on
inside the synthetic cell.
The genes, the protein expression and the metabolism.
Just like natural life,
synthetic cells express proteins from DNA genomes.
Those genomes are usually relatively simple,
up to a dozen genes at a time.
To look at the scale of engineering we're talking about,
we can compare genome sizes of natural and artificial cells.
So humans have about 20,000 genes.
Bacteria about an order of magnitude less.
First live organism
with a completely synthetic genome has 474 genes.
And our non-living synthetic minimal cell,
it usually has about a dozen genes.
So as you can see, there's a lot of room for engineering,
larger synthetic cell genomes,
and also a lot of technical progress
we need to make to get there.
To make a complete cell, complete live cell,
the genes need to be expressed into proteins.
In synthetic cells, protein expression is done by
in vitro translation system.
Actually most of proteins and small molecules
in a synthetic cell are employed in translation processes,
not unlike what happens in live cells.
The in vitro translation system contains
ribosomes, tRNA, RNA polymerases to make mRNA,
enzymes to load amino acids into tRNA,
and small molecules needed for translation.
All of those components are purified,
and then recombined to encapsulate inside a synthetic cell,
creating a synthetic cytoplasm.
The most commonly used in vitro translation system,
is made from component purified from bacteria.
It's possible to use many different source organisms though,
all the way up to a human cell,
derived protein expression systems.
The bacterial system is used because
it's the fastest and cheapest one to work with.
Other organisms are used when we need
to express more complex genes,
or do some post-translational modifications to proteins.
And this is one of the main reasons
why synthetic cells can be thought of as jigsaw puzzles,
because the protein expression and metabolism
can come from any number of different organisms.
It builds a hybrid cell that combines properties
of different kinds of metabolism.
The complete synthetic cell,
a membrane surrounding protein expression system
is not alive.
It performs some but not all functions of live cells.
It's currently a very fast growing area of research.
Although we don't yet have a hard definition
of what makes a cell alive,
by working with synthetic cells we can begin to learn
what confers the properties of live cells,
such as the ability to replicate or grow.
How can we use synthetic cells?
Synthetic cells can have many applications in research,
and many practical applications relevant to everyday life.
For one, understanding natural cells is necessary
for building synthetic cells,
and it works the other way around too.
If we build an understandable synthetic live cell,
we'll learn a ton about natural life.
Similarly making cells from scratch requires
a lot of progress in research technologies.
Building new bio engineering tools,
while having synthetic living systems,
will be a tool in and of itself for biology.
Some other specific applications of synthetic cells
are making new bio-materials not found in nature,
building bio computers that run on
artificial genetic circuits.
Using synthetic cells to reconstitute primordial cells
and studying the origin of life.
Synthetic cells are basics for astropharmacy applications,
and help with search for life elsewhere in the solar system.
And synthetic cells are excellent bio factories,
for making small molecules and protein products,
and for developing new metabolic engineering circuits.
Also the ability to engineer cells and cell-like systems,
is very valuable for studying diseases,
and for making small amounts of drugs,
which will be foundation of future personalized medicine.
In the second part of this talk,
I'll cover different ways to make synthetic cells,
applications of this technology,
and the international community
working on synthetic cell engineering.
(upbeat music)