The buffers used in downstream purification play a critical role in drug manufacturing. However, they can be expensive and difficult to manage. Now, a novel approach called “electrified purification”—developed by Nyctea Technologies—offers an alternative.

Electrified purification is based on a conductive polymer that changes in response to electric signals. These changes can help control chromatography more effectively than buffer-based approaches, says Nyctea CEO and founder, Gustav Ferrand-Drake del Castillo.

“Think of it as a polymer coating that instantly goes from being sticky to anti-fouling by electric impulse,” he tells GEN.

“The advantages are that you can run this purification entirely in a neutral pH buffer of your choice and remove problematic elution buffers. For instance, imagine replacing low pH buffers used in the purification of mAbs in protein A, or imidazole used to purify His-tagged proteins.”

Nyctea claims the approach significantly increases yields—the firm’s current record is a 600% bump compared with commercial chromatography systems.

The use of electrical impulses also speeds up the purification process, Ferrand-Drake del Castillo says, explaining that “instant millisecond switches reduce the cycle time and use of raw materials by replacing elution chemicals and reducing water use by up to 60%.”

He adds, “Our coating is compatible with Protein A, meaning we can attach ligands to make the coating ultra-specific. We are also working on a version of the product that is ligand-free, meaning highly efficient ion-exchange with extremely high specificity without requiring an affinity ligand. This is still early in development, but we are convinced we can get there.”

Partnerships

Nyctea, a spinout from Gothenburg’s privately-owned Chalmers University of Technology, was founded in 2020 to commercialize electrified purification. At present, the focus is on finding ways to use it at scale.

Ferrand-Drake del Castillo says: “The material science behind Nyctea purification was invented four years ago and we are still early in a rapid learning curve.

“This means we have not yet developed large-scale off-the-shelf products, and still need to validate many industrial use-cases to build the necessary data for industry-wide adoption of the technology. However, we already have use cases where we exceed existing commercial products in performance, which is exciting considering that our product is still in its infancy,” he adds.

Scientists from Cornell University, University of California, San Francisco (UCSF), and elsewhere have found that a surplus of membrane proteins may help bacteria survive antibiotic exposure. These proteins are part of a shuttling mechanism that bacteria use to pump out a wide spectrum of antibiotics along with other physiological substrates from the cell. The researchers are now focused on using chemical and mechanical manipulations to disrupt the process so that antibiotics can be more effective.

Details of the study were published in Cell Reports Physical Science in a paper titled, “Transporter excess and clustering facilitate adaptor-protein shuttling for bacterial efflux.”

In it, the researchers describe how an imbalance in the three-part protein complex—MacAB-TolC—helps gram-negative bacteria resist antibiotics. The MacAB-TolC complex, known as a multidrug efflux pump, spans the cell’s inner and outer membranes, as well as the periplasm that connects them. Each protein occupies a different location: TolC on the outer membrane, MacB on the inner membrane, and MacA in the periplasm, although it is anchored on the inner membrane. This protein complex forms a conduit that drains out antibiotics as well as virulence factors produced by the bacterial cell.

The three proteins need to assemble in a specific stoichiometry to pump out toxins. Two MacB proteins assemble with six MacA proteins, then three TolC proteins. Scientists understand this ratio well. What’s not been clear is how molecules in the periplasm enter the channel that runs through the complex and through which substrates they get pumped, once the structure is assembled.

“You basically have these extra Bs that don’t have A partners to assemble. And of course, the cell does not do this for no reason,” said Peng Chen, PhD, study lead and a professor of chemistry at Cornell University. “We found out a good reason is that when you have this extra B, because it does not have A associated with it, it naturally has an opening for the substrate to go in. So once the substrate can bind to the extra B, some of the As that are initially associated with B can migrate over to assemble. And once it’s assembled, they can pump the substrate out.”

As part of the study, the researchers tested whether the mechanism could be interrupted. They used a microfluidic device developed at UCSF that applies mechanical stress to change bacteria’s toxin resistance. They found that squeezing E. coli through the device deformed the cell enough to disrupt the assembled complex and prevent it from resisting antibiotics.

The scientists believe that the behavior observed in E. coli likely exists in other systems. “This imbalance of protein stoichiometry must exist for many types of protein complexes. But how does a cell utilize this imbalance?” Chen said. “Now we have one example that shows this particular imbalance might be, functionally, very relevant. So anytime that we study protein complexes in the cell, we always want to measure the relative amount in the entire cell versus their relative amount in a particular complex. Do they actually match?”

Selective serotonin reuptake inhibitor (SSRI) antidepressants are some of the most widely prescribed drugs in the world, and new research suggests they could also protect against serious infections and life-threatening sepsis. Scientists at the Salk Institute studying a mouse model of sepsis uncovered how the SSRI fluoxetine can regulate the immune system and defend against infectious disease, and found that this protection is independent to peripheral serotonin. The findings could encourage additional research into the potential therapeutic uses of SSRIs during infection.

“When treating an infection, the optimal treatment strategy would be one that kills the bacteria or virus while also protecting our tissues and organs,” commented professor Janelle Ayres, PhD, holder of the Salk Institute Legacy Chair and Howard Hughes Medical Institute Investigator. “Most medications we have in our toolbox kill pathogens, but we were thrilled to find that fluoxetine can protect tissues and organs, too. It’s essentially playing offense and defense, which is ideal, and especially exciting to see in a drug that we already know is safe to use in humans.”

Ayres is senior author of the team’s report in Science Advances. In their paper, titled “Fluoxetine promotes IL-10–dependent metabolic defenses to protect from sepsis-induced lethality,” the investigators stated, “Our work reveals a beneficial ‘off-target’ effect of fluoxetine, and reveals a protective immunometabolic defense mechanism with therapeutic potential.”

Selective serotonin reuptake inhibitor antidepressants are prescribed for their ability to increase serotonergic signaling in the brain, but they are also known to have a broad range of effects beyond the brain, including immune and metabolic effects, the authors wrote. “It is now recognized that SSRIs also have a wide range of peripheral effects including regulation of immune and metabolic processes.”

Prior research has also found that users of SSRIs such as fluoxetine had less severe COVID-19 infections and were less likely to develop long COVID. Another study found that fluoxetine was effective in protecting mice against sepsis, a life-threatening condition in which the body’s immune system overreacts to an infection and can cause multi-organ failure or even death.

“… SSRIs have been shown to protect against sepsis in animal models and improve outcomes in patients infected with severe acute respiratory syndrome coronavirus 2,” the investigators stated. However, they pointed out that the mechanisms underlying these protective effects have remained unclear.

While our immune systems do their best to protect us against infections, sometimes they can overreact. In sepsis, the inflammatory response spins so out of control that it starts damaging a person’s own tissues and organs to the point of failure. “Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection,” the authors further commented. “Sepsis is largely driven by an overexuberant inflammatory response to an infection.” This same overreaction is also characteristic of severe COVID-19 illness.

One solution might be to suppress the inflammatory response, but doing so can actually make patients more vulnerable to their initial infection and more susceptible to new infections. Timing is also critical, as immunosuppressive drugs need to be administered before any tissue damage has taken place. And while numerous clinical trials have been performed with neutralizing antibodies that target pro-inflammatory cytokines, the team pointed out, “… these approaches have been met with little success.”

Instead, an ideal treatment would proactively control the intensity and duration of the immune response to prevent any bodily damage and also kill the infection that puts the body at risk to begin with. “Host-directed therapeutics that can control the degree and duration of an immune response to allow pathogen killing but prevent the escalation of the response to a cytokine storm and that also promote metabolic adaptation to the infected state may offer more therapeutic benefit than strategies that focus only on blocking the pro-inflammatory response,” they suggested.

To understand what SSRIs might be doing in this context, Ayres and colleagues studied mice with bacterial infections and separated them into two groups, one pretreated with fluoxetine and the other not given fluoxetine pretreatment. The results demonstrated that mice pretreated with fluoxetine were protected from sepsis, multi-organ damage, and death.

To better understand the findings the team carried out a number of investigations. They first measured the number of bacteria in each mouse population eight hours after infection. They found that mice treated with fluoxetine had fewer bacteria at this stage, signifying a less severe infection, and indicating that fluoxetine had antimicrobial properties that allowed it to limit bacterial growth.

Next, the researchers measured the levels of different inflammatory molecules in each group. They saw more anti-inflammatory IL-10 in their pretreated populations and deduced that IL-10 prevented sepsis-induced hypertriglyceridemia—a condition in which the blood contains too many fatty triglycerides. This enabled the heart to maintain the proper metabolic state, protecting the mice from infection-induced morbidity and mortality.

The team also decoupled this IL-10-dependent protection from multi-organ damage and death from their earlier discovery of fluoxetine’s antimicrobial effects, in turn revealing the drug’s dual-purpose potential to kill pathogens and alleviate infection-induced damage to the body.

To understand how fluoxetine’s influence on serotonin levels might be contributing to these effects, the researchers also looked at two new mouse populations. Both were pretreated with fluoxetine, but one had circulating serotonin, while the other did not. Circulating serotonin is a chemical messenger that travels the brain and body, and is involved in regulating mood, sleep, and pain. Ayres and colleagues found that fluoxetine’s positive health outcomes were entirely unrelated to circulating serotonin. Regardless of whether the mice had serotonin in circulation, they experienced the same infection defense benefits from fluoxetine. “We found that fluoxetine pretreatment promotes both resistance and cooperative defenses in a peripheral serotonin-independent manner,” they wrote.

“That was really unexpected, but also really exciting,” commented study first author Robert Gallant, PhD, a former graduate student researcher in Ayres’ lab. “Knowing fluoxetine can regulate the immune response, protect the body from infection, and have an antimicrobial effect—all entirely independent from circulating serotonin—is a huge step toward developing new solutions for life-threatening infections and illnesses. It also really goes to show how much more there is to learn about SSRIs.”

Ayres and Gallant say their next step is to explore fluoxetine dosing regimens appropriate for septic individuals. They’re also eager to see whether other SSRIs can have the same effects.

“Fluoxetine, one of the most prescribed drugs in the United States, is promoting cooperation between host and pathogen to defend against infection-induced disease and mortality,” said Ayres, who is also the head of Molecular and Systems Physiology Laboratories at Salk. “Finding dual protective and defensive effects in a repurposed drug is really exciting.”
In conclusion, the authors wrote, “Our study mechanistically links the anti-inflammatory and metabolic effects of an SSRI and demonstrates that fluoxetine can be used as a prophylactic to protect from sepsis-induced lethality by orchestrating protective immunometabolic mechanisms, which may be leveraged and further explored by future studies.”

The Cultivated B, a Heidelberg, Germany-based company, reports the discovery of a chemical class of FGFR1 agonists mimicking basic fibroblast growth factor’s (bFGF) effect on cell proliferation, an essential component of cell-culture media. A preprint of the study is published on bioRxiv.

“This class of small molecules offers a stable, highly cost-effective alternative, poised to transform cultivated meat, biopharmaceuticals, regenerative medicine, and large-scale cell manufacturing by addressing key challenges,” said Hamid Noori, PhD, CEO and founder of The Cultivated B and a Forbes Councils member.

The discovery revolutionizes cell production by overcoming key bottlenecks such as rapid degradation, high production costs, batch variability, and complex storage requirements, according to Noori, who added that, unlike traditional bFGF, small molecules remain active for over 13 days, thus providing where stability, consistency, and scalability.

“We are unlocking new possibilities for entire industries,” he continued. “This breakthrough has the potential to revolutionize the scalability, consistency, and cost-effectiveness of cell-based product manufacturing, including applications in cultivated meat and cell therapy.”

The Cultivated B was founded in 2009 and develops technologies involved in cellular agriculture, precision fermentation, and bioreactor engineering. The German Institute for Innovation in Sustainability and Digitalization named The Cultivated B the “2024 Employer of the Future.”