Medical Bulletin 24/ February/ 2025

Here are the top medical news for the day:

Decades-Old Hepatitis B Mystery Unveils Promising New Treatment

In their effort to answer a decades-old biological question about how the hepatitis B virus (HBV) is able to establish infection of liver cells, research led by Memorial Sloan Kettering Cancer Center (MSK), Weill Cornell Medicine, and The Rockefeller University identified a vulnerability that opens the door to new treatments.

The team successfully disrupted the virus’s ability to infect human liver cells in the laboratory using a compound already in clinical trials against cancer — laying the groundwork for animal model studies and potential drug development based on their insights, according to findings published in Cell journal.

Chronic hepatitis B virus (HBV) infection is an incurable pathogen responsible for causing liver disease and hepatocellular carcinoma. During the genesis of infection, HBV establishes an independent minichromosome consisting of the viral covalently closed circular DNA (cccDNA) genome and host histones. The viral X gene must be expressed immediately upon infection to induce degradation of the host silencing factor, the Smc5/6 complex.

However, the relationship between cccDNA chromatinization and X gene transcription remains poorly understood. By establishing a reconstituted viral minichromosome platform, the researchers found that nucleosome occupancy in cccDNA regulates X transcription.

They corroborated these findings in situ and further showed that the chromatin-destabilizing molecule CBL137 inhibits full-length X transcription and HBV infection in primary human hepatocytes. The results of the study shed light on a long-standing paradox and represent a potential therapeutic approach for the treatment of chronic HBV infection.

The research was led by chemical biologist Yael David, PhD, at MSK, working together with hepatologist and virologist Robert Schwartz, MD, PhD, at Weill Cornell Medicine and Viviana Risca, PhD, at The Rockefeller University.

Ref: Nicholas A. Prescott,Tracy Biaco,Andrés Mansisido et al. A nucleosome switch primes hepatitis B virus infection, Cell: DOI: 10.1016/j.cell.2025.01.033

Innovative Molecular Approach Offers New Hope for Fragile X Syndrome Treatment, Study shows

Building on more than two decades of research, a study by MIT neuroscientists at The Picower Institute for Learning and Memory reports a new way to treat pathology and symptoms of fragile X syndrome, the most common genetically-caused autism spectrum disorder. The team showed that augmenting a novel type of neurotransmitter signaling reduced hallmarks of fragile X in mouse models of the disorder.

The new approach described in Cell Reports works by targeting a specific molecular subunit of “NMDA” receptors that they discovered plays a key role in how neurons synthesize proteins to regulate their connections, or “synapses,” with other neurons in brain circuits. The scientists showed that in fragile X model mice, increasing the receptor’s activity caused neurons in the hippocampus region of the brain to increase molecular signaling that suppressed excessive bulk protein synthesis, leading to other key improvements

“One of the things I find most satisfying about this study is that the pieces of the puzzle fit so nicely into what had come before,” said study senior author Mark Bear, Picower Professor in MIT’s Department of Brain and Cognitive Sciences. Former postdoc Stephanie Barnes, now a lecturer at the University of Glasgow, is the study’s lead author. Bear’s lab showed that fragile X and another autism disorder, tuberous sclerosis (Tsc), represented two ends of a continuum of a kind of protein synthesis in the same neurons. In fragile X there was too much. In Tsc there was too little. When lab members crossbred fragile X and Tsc mice, in fact, their offspring emerged healthy as the mutations of each disorder essentially canceled each other out.

For Bear and Barnes these studies raised the prospect that if they could pinpoint how NMDA receptors affect protein synthesis they might identify a new mechanism that could be manipulated therapeutically to address fragile X (and perhaps tuberous sclerosis) pathology and symptoms.

The team now hypothesizes, based on another prior study in the lab, that the beneficial effect to fragile X mice of the 2B subunit’s CTD signaling is that it shifts the balance of protein synthesis away from an all-too-efficient translation of short messenger RNAs (which leads to excessive bulk protein synthesis) toward a lower efficiency translation of longer messenger RNAs.

Ref: Stephanie A. Barnes, Aurore Thomazeau, Peter S.B. Finnie. Non-ionotropic signaling through the NMDA receptor GluN2B carboxy-terminal domain drives dendritic spine plasticity and reverses fragile X phenotypes, Cell Reports: DOI: 10.1016/j.celrep.2025.115311

Pioneering Retinal-Surgery Robot from University of Utah Shows Early Promise

When even the most highly trained surgeons perform procedures on the retina—one of the smallest, most delicate parts of the human body—the stakes are high. Surgeons must account for patients’ breathing, snoring, and eye movements, along with their own involuntary hand tremors, while they work on a layer of cells less than a millimeter thick. That’s why researchers at the University of Utah’s John A. Moran Eye Center and the John and Marcia Price College of Engineering have collaborated to create a new robotic surgery device that aims to give surgeons “superhuman” hands.

The robot itself is extremely precise, executing movements as small as one micrometer (smaller than a single human cell). It is mounted directly to the patient’s head using a helmet, such that subtle (and sometimes not so subtle) movements of the patient’s head are compensated for, keeping the eye quite still from the perspective of the robot. The robot also scales down the surgeon’s movements, measured using a handheld robotic device known as a haptic interface, to the much smaller surgical site within the eye, compensating for hand tremors along the way.

The researchers successfully tested the robot using enucleated pig eyes, publishing their results this week in the journal Science Robotics. The study was led by Jake Abbott, a professor in the U’s Department of Mechanical Engineering, and Moran Eye Center retinal specialist Paul S. Bernstein.

Because the device is not yet approved to operate on human subjects, testing required a human volunteer fitted with special goggles that allowed an animal eye to be mounted just in front of their natural eye. This allowed the researchers to test the robot’s ability to compensate for head motion and correct for hand tremors, all while operating on animal tissue, at no risk to the volunteer. These results demonstrate the robot has the potential to improve patient care, according to co-author Eileen Hwang, a Moran Eye Center retinal surgeon.

Ref: Nicholas R. Posselli et al. Head-mounted surgical robots are an enabling technology for subretinal injections.Sci.Robot.10,eadp7700(2025).DOI:10.1126/scirobotics.adp7700

Eco-Friendly Haircare: Biobased Lignin Gels Revolutionize Hair Conditioning

Researchers at Stockholm University have developed a fully biobased hair conditioner using lignin gel emulsions, offering a sustainable and environmentally friendly alternative to conventional haircare products.

Hair conditioners typically contain 20–30 ingredients, many derived from petroleum and oleochemicals, raising concerns about sustainability and environmental impact. A new study published in Science Advances, demonstrates that micellar lignin gels can effectively stabilize emulsions with natural oils, reducing the need for synthetic surfactants and complex stabilizers commonly used in commercial formulations. The research team, led by Mika Sipponen at Stockholm University, sought to explore lignin, a common and renewable component in wood biomass, as a multifunctional component for hair conditioning.

“Our findings highlight lignin’s potential as a stabilizer in oil-in-water emulsions, enabling a more natural and sustainable approach to hair conditioning,” says Mika Sipponen. “By using wood-derived lignin directly without any chemical modification, we not only simplify the ingredient list but also eliminate the need for organic solvents, making the process more eco-friendly.”

The lignin gel-based conditioner was tested against a commercial hair conditioner, showing comparable emulsion stability, viscosity, and conditioning performance. A formulation with 6 percent coconut oil effectively lubricated damaged hair, reducing wet combing force by 13 percent, as confirmed by combing force measurements and multiscale microscopy analysis. Importantly, the product was easily rinsed off from paper and skin with cold water despite its dark color, demonstrating practical usability.

This innovation paves the way for greener haircare solutions that align with growing consumer demand for sustainable personal care products. The researchers anticipate further exploration of lignin-based formulations for broader applications in the personal care industry.

Ref: Fengyang Wang et al.Lignin gel emulsions for environmentally benign hair conditioning.Sci. Adv.11,eadr8372(2025).DOI:10.1126/sciadv.adr8372