With drug-resistant infections on the rise and the development of new antibiotics on the decline, the world could use a new strategy in the fight against increasingly wily bacteria. Now, Stanford chemists report November 2 in the Journal of the American Chemical Society a possible solution: a small molecular attachment that helps conventional antibiotics penetrate and destroy their targets.
The attachment, known as r8, helps guide antibiotics through a bacterium’s outer defenses and encourages them to linger, said Alexandra Antonoplis, a graduate student in chemistry and co-lead author with fellow chemistry graduate student Xiaoyu Zang. That penetration and tenacity help kill bacteria, such as methicillin-resistant Staphylococcus aureus, or MRSA, that doctors would otherwise struggle to stop.
Indeed, adding r8 to vancomycin, a first-line defense against MRSA, made the new drug hundreds of times more effective, according to experiments conducted by Antonoplis, Zang, and their advisers, Lynette Cegelski, an associate professor of chemistry, and Paul Wender, the Francis W. Bergstrom Professor of Chemistry. The same strategy, the researchers believe, could apply beyond MRSA to other drugs and infections.
i’ve gotten a few responses here asking for some clarification on this paper and why making essentially squishy plants was important enough to make it into the plant science section of nature, one of the most influential journals in the world, and i’d be happy to oblige and break this down a little!!
so to start off, plants have two kinds of membranes around their cells, while animals only have one. one of these is called the ‘plasma membrane’, which is a soft, squishy kind of membrane that we have as animals that just kind of holds everything in. the other kind that only plants have is called a ‘cell wall’, which in plant cells surrounds the plasma membrane to basically hold everything in even more, and is really rigid and hard instead of squishy. the cell wall is made of a strong substance called ‘cellulose’, which you prob have heard of before, which acts as a really strong support structure to hold up the plant and protect the cells. the cell wall has a lot of different functions, but one of the main ones is structural; the pressure between the cell wall and the water inside the plant’s plasma membrane forming ‘turgor pressure’, which keeps the plant upright (when a plant needs water, it’s turgor pressure goes down, and there isn’t enough water in the cells to push against the cell wall to hold it upright. this is what causes wilting!)
now here’s the problem with cellulose: it’s a BITCH to break down. in settings where people are trying to make biofuels and renewable oils from algae and plant materials (and being successful in limited amounts!!), cellulose is the biggest thing keeping the process from higher efficiency, making it harder for those techniques to keep up with fossil fuels. but removing the cell wall altogether wacks out the plant’s turgor pressure, upon which a TON of natural processes and biological functions in plants are based (turns out that maintaining water pressure is really important when you dont have like, blood to keep stuff going!! or a heart to move shit around!!). so we need some kind of hard thing for the plant cells to push against to keep up hydraulic pressure, but it cellulose is too hard for efficient use in sustainable fuels.
which brings us to this study. im sure u can tell where this is going now. basically, these researchers were like, ‘what if we just added a second plasma membrane?? so its like, thicker, but there’s no cellulose???’.
this worked well. like, really well. i have made an annotated version of some of their results:
so in conclusion: this is a really cool paper, and not only did it show that it could be done, but they actually identified a ton of genes and transcription factors that could be modified to make replacement of a plant cell wall possible by other people.
this is a huge generalization, of course- they have way more data in the paper here if y’all wanna see it for themselves- but overall??? this technology could be really big in increasing the viability and efficiency in biofuels and sustainable biochemicals to be used in stuff like cosmetics, fabrics, plastics, etc.
Imagine your liver being just a big puddle. Some organelles in your cells are exactly that including prominent ones like the nucleolus. Now a synthetic organelle engineered in a lab shows how such puddle organs can carry out complex life-sustaining reaction chains.
An illustration of part of a synthetic organelle without a membrane. Here we see two layers that phase separate like oil and water, but both layers are water. There is no oil. Each layer contains a different solute that gives it its own chemical thermodynamics, keeping it separate from the other one. Chemical reactions cascade from one layer to the next in a chain reaction. The molecules illustrated on the outside are sugars called dextran, a solute. The gray middle layer contains an enzyme, depicted as small yellow spheres that would carry out a step in the reaction cascade.Credit: Georgia Tech
It
sounds simple enough — all of your cells require a constant supply of
oxygen. Your lungs extract it from the air and your blood carries it all
around your body through a vascular network comprising thousands of
miles of veins and arteries. If your heart doesn’t beat at least once
every couple seconds, your brain doesn’t receive enough oxygen-rich
blood to maintain consciousness.
We
don’t understand super high-level biological phenomena like
consciousness. We can’t engineer a conscious array of cells, or even of
transistors. But we understand pretty well the vasculature that supports
consciousness. It’s a series of tubes. Literally. And it may be that if
we can make the tubes and deliver oxygen to a sufficiently large
population of cells, we can make some cool things happen. A conscious
brain is a long shot, a functional piece of liver or kidney decidedly
less so.
The problem is, making vasculature is hard. Cells in a dish
do self-organize to an extent, but we don’t understand such systems
well enough to tell a bunch of cells to grow into a vascularized organ.
An
alternative means of generating physiological structure’s blood vessels
is a bit cruder — design the structure you want, then make a robot that
can physically place the cells and the vessels where you want them. We
call this bioprinting. A major hurdle with bioprinting is the fact that,
while the printer is working, the cells that have been printed are
slowly dying from lack of oxygen. For really big, complex tissues, you
either need a way to supply oxygen while you’re still printing, or you
need a way to make all those blood vessels really fast.
One really fast approach was demonstrated in 2009.
Researchers at Cornell used a cotton candy machine to melt-spin a pile
of sugar fibers. They cast the sugar fibers in a polymer, dissolved them
out with water and made a random vascular network in minutes. In 2012,
researchers at Penn used a hacked desktop 3D printer
to draw molten sugar fibers into a simple lattice and showed that the
same sacrificial casting approach could be used deliver blood to rat
liver cells in a dish, keeping them alive for weeks. Now, researchers at the University of Illinois at Urbana-Champaign have developed the ability to make these sugar fiber networks of any shape and size.
The sprawling bright green lawn has long been a fixture in the dream of American suburban utopia, but when it comes to supporting bees and their pollinating brethren, plain old grass is effectively a waste of space. “A lot of the time, lawns are food deserts for insects,” says Holly Walker. “If you can carve out more niches for flowering plants—particularly pollen-producing plants—that’s such a big deal.”
2. Plant native flowers
Planting locally indigenous plant species in your garden is win-win: you get to show off your hometown pride while simultaneously looking out for all the authentically American bees and other insects that are too often overshadowed by the ubiquitous nonnative honeybee. Oftentimes, flowering plants and pollinators evolve in tandem to optimize their mutualistic relationships. This means that introducing native plants to your garden will lead to a boost in pollinator efficiency, and will help perpetuate species diversity across the board.
3. Diversify your gardens in size, shape and color
When working to improve the well-beeing of your garden’s insects, the old adage “variety is the spice of life” is one you should take to heart. Just as bees themselves come in all shapes and sizes, so too do the plants that attract them. “We want to appeal to all our native bees, big and small,” Walker says, and that means growing plants of different shapes and heights, with flowers of different hues.
4. Take full advantage of the blooming season
We all know that April showers bring May flowers, but let’s not forget about the June to October flowers. By planting a mix of pollinator-friendly species with staggered bloom times, you can keep bees coming to your garden from spring through fall.
5. Create habitats for nesting bees
The idea of redefining garden beauty standards extends beyond winter. All throughout the year, pollinators are looking for habitats to call home, and you can help provide those if you make a little extra effort and embrace the wilder look Gagliardi advocates.
6. Provide sources of water
Anyone who grew up with a pool or birdbath out back can tell you that bees appreciate water. Water helps bees digest their food, and when conveyed home to a hive it serves several additional functions. Water can be used to regulate humidity among a colony of bees, and water brought back by multiple bees can be evaporated to generate an improvised air conditioning effect in the sweltering heat of summer.
7. Don’t mow so often
Fed up with mowing your lawn constantly? By all means, give it a rest. Not only will spending less time making your tedious rounds be a boon for you, it will also give insect life the opportunity to establish a toehold in what would otherwise be an environment impossible to thrive in. As you’ll recall from the first item on this list, lawns aren’t very helpful to bees as a rule, but if you must have a lawn, being a little less militant with your mowing works wonders. Smithsonian gardening buffs suggest that mowing every two to three weeks will keep your grass tidy while still allowing pollinators enough time to capitalize on what flowering plants do crop up before they disappear.
8. Avoid pesticides
Spraying pesticides liberally may seem like a quick and easy solution to keeping garden maintenance hassle-free, but doing so can come at a severe cost. “When researchers go in and do surveys of beehives and honey,” Holly Walker says, “they’re finding traces of fungicides, herbicides and pesticides in there.” In other words, bees are picking up harmful substances in gardens and bringing those substances back to their homes—sometimes with disastrous results.
9. Learn to love imperfection
Welcoming bees into your garden, while certain to enliven and strengthen it, will also force you to abandon the ideal of visually pristine leaves and soil. For James Gagliardi, the trick is to recognize that “imperfections” in your plants are in actuality something to take pride in, for they indicate that the resources you’ve cultivated are not going to waste.
10. Bees are awesome, but so are other pollinators
Smithsonian garden gurus are excited bees will be getting their moment in the spotlight this weekend, but they are also quick to point out that bees aren’t the only pollinators we should be looking out for. “Most people think of bees,” says Gagliardi, “but we want to promote moths and flies and beetles and all those good things too.” Insects tend to be stigmatized as icky and invasive, but all over the world, they are doing the quiet small-scale work needed to keep the biosphere on track.
Thrips are tiny
insects, typically just a millimetre in length. Some are barely half
that size. If that’s how big the adults are, imagine how small a thrips’
egg must be. Now, consider that there are insects that lay their eggs inside the egg of a thrips.
That’s one of them in the image above – the wasp, Megaphragma mymaripenne. It’s pictured next to a Paramecium and an amoeba at the same scale.
Even though both these creatures are made up of a single cell, the wasp
– complete with eyes, brain, wings, muscles, guts and genitals – is
actually smaller. At just 200 micrometres (a fifth of a
millimetre), this wasp is the third smallest insect alive* and a miracle
of miniaturisation.
The wasp has several adaptations for life
at such a small scale. But the most impressive one of all has just been
discovered by Alexey Polilov from Lomonosov Moscow State University,
who has spent many years studying the world’s tiniest insects.
Polilov found that M.mymaripenne has one of the smallest
nervous systems of any insect, consisting of just 7,400 neurons. For
comparison, the common housefly has 340,000 and the honeybee has
850,000. And yet, with a hundred times fewer neurons, the wasp can fly,
search for food, and find the right places to lay its eggs.
On top of that Polilov found that over 95 per cent of the wasps’s
neurons don’t have a nucleus. The nucleus is the command centre of a
cell, the structure that sits in the middle and hoards a precious cache
of DNA. Without it, the neurons shouldn’t be able to replenish their
vital supply of proteins. They shouldn’t work. Until now, intact neurons
without a nucleus have never been described in the wild.
And yet, M.mymaripenne has thousands of them. As it changes
from a larva into an adult, it destroys the majority or its neural
nuclei until just a few hundred are left. The rest burst apart, saving
space inside the adult’s crowded head. But the wasp doesn’t seem to
suffer for this loss. As an adult, it lives for around five days, which
is actually longer than many other bigger wasps. As Zen Faulkes writes,
“It’s possible that the adult life span is short enough that the
nucleus can make all the proteins the neuron needs to function for five
days during the pupal stage.”
…The Tangible Media Group demonstrated a way to precisely transport droplets of liquid across a surface back in January, which it called “programmable droplets.” The system is essentially just a printed circuit board, coated with a low-friction material, with a grid of copper wiring on top. By programmatically controlling the electric field of the grid, the team is able to change the shape of polarizable liquid droplets and move them around the surface. The precise control is such that droplets can be both merged and split.
Moving on from the underlying technology, the team is now focused on showing how we might leverage the system to create, play and communicate through natural materials…
