Medical Bulletin 17/November/2025

The microrobot consists of a tiny spherical capsule made of a soluble gel shell containing iron oxide nanoparticles that give it magnetic properties. These nanoparticles allow the capsule to be guided inside the body using an electromagnetic navigation system.

The capsule is injected via a special catheter into the bloodstream or cerebrospinal fluid, then precisely steered to the thrombus with three distinct magnetic navigation methods, enabling it to navigate complex brain vessel networks at speeds up to 4 millimeters per second—even swimming against blood flow exceeding 20 centimeters per second.

The gel capsule also contains the therapeutic agent, such as a clot-dissolving drug, which is released upon application of a high-frequency magnetic field that heats the nanoparticles, dissolving the capsule and freeing the medication exactly where it is needed.

Researchers validated this approach through extensive trials using realistic silicone vessel models and animal tests, achieving drug delivery success in over 95% of cases.

This innovative microrobot system represents a major advance in targeted, minimally invasive stroke therapy and holds promise for treating other localized conditions like infections and tumors. Its development merges robotics, materials science, and medicine, heralding a new era in precision healthcare.

The team is now focused on moving rapidly toward human clinical trials to bring this technology into operating rooms globally, with the goal of improving outcomes and offering new hope to stroke patients.

REFERENCE: Fabian C. Landers et al. ,Clinically ready magnetic microrobots for targeted therapies.Science390,710-715(2025).DOI:10.1126/science.adx1708

Study finds high-protein breakfasts boost fullness but but do not change how much you eat later

A new study from Newcastle University explores whether plant-based proteins can rival animal-based proteins in curbing hunger after breakfast. With growing concerns about sustainability and ethics, this research, published in European Journal of Nutrition, addresses whether plant and animal proteins differ in their ability to suppress appetite and influence subsequent calorie intake.

Protein is essential for health, but environmental and ethical concerns have increased interest in plant-based alternatives. Protein impacts digestion, metabolism, and appetite by stimulating satiety hormones like PYY and GLP-1, while suppressing ghrelin. Studies show varied results: some find certain plant proteins more satiating; others favor whey. Liquids generally suppress appetite less than solids, but the influence of protein source on this difference remains unclear.

The research involved 18 healthy adults in a randomized crossover design. Participants consumed three breakfast types on separate occasions: a plant-based high-protein drink (30 g protein, 7.8 g fiber), an animal-based high-protein meal (30 g protein, 4.5 g fiber), and a low-protein, high-carb meal. After fasting overnight and avoiding caffeine and exercise, they consumed the breakfasts under controlled lab conditions. Appetite was assessed using visual analog scales for four hours, and blood samples were collected to measure satiety hormones peptide YY (PYY) and glucagon-like peptide-1 (GLP-1). Finally, participants ate an ad libitum lunch to test how breakfast affected later food intake.

Results showed both high-protein breakfasts significantly boosted PYY and GLP-1 levels compared to the low-protein meal, with no meaningful difference between plant- and animal-based proteins. Subjective appetite decreased more after the plant-based drink, though differences were modest. Importantly, calorie intake at lunch did not differ across breakfast types or age groups. Hormone levels correlated weakly and non-significantly with energy intake.

The study concludes that plant-based protein drinks can match animal-based meals in stimulating satiety hormones and reducing appetite, offering a practical, sustainable breakfast option. However, these hormonal and appetite differences did not translate into decreased food intake later. Limitations include the small older adult sample and lack of testing different meal forms. Future research should examine long-term adherence and real-world effects.

This work supports plant proteins as effective alternatives to animal sources for appetite control, aligning sustainability with nutrition goals without compromising satiety.

REFERENCE: Watson, A.W., Brooks, A., Moore, L. et al. The effect of consuming different dietary protein sources at breakfast upon self rated satiety, peptide YY, glucagon like peptide-1, and subsequent food intake in young and older adults. Eur J Nutr 64, 315 (2025). https://doi.org/10.1007/s00394-025-03839-y

Study finds hidden immune cells in brain may regulate anxiety levels

THUMB: Hidden Brain Immune Cells Could Be Controlling Your Anxiety

New research from the University of Utah reveals that two distinct groups of immune cells in the brain, called microglia, have opposing roles in regulating anxiety. Unlike neurons which transmit signals, microglia act as an anxiety “accelerator” and “brake.” One subset, non-Hoxb8 microglia, increases anxious behaviors like repetitive grooming and avoidance, while Hoxb8 microglia reduce anxiety and counterbalance this effect.

Anxiety disorders affect over 300 million people worldwide and represent one of the fastest-growing mental health challenges globally. Factors such as increased stress, urbanization, and social isolation contribute to its rising prevalence. Despite its commonality, many cases remain undiagnosed or untreated, highlighting an urgent need for improved awareness and interventions.

Anxiety affects the brain by overactivating the amygdala, which processes fear and emotions, and impairing the prefrontal cortex responsible for regulation and decision-making. Chronic anxiety leads to structural and functional changes in these areas, disrupting emotional control and increasing stress sensitivity. This can result in difficulties with focus, memory, and emotional regulation.

To study this, researchers transplanted each microglial type separately into mice that lacked these cells. Mice receiving only non-Hoxb8 microglia showed heightened anxiety behaviors, while those with Hoxb8 microglia acted normally. Importantly, mice with both microglial types displayed balanced anxiety levels, showing these cells work together to regulate anxiety precisely.

This finding challenges the traditional view that anxiety is mainly controlled by neurons, highlighting the immune system’s crucial role in brain function and mental health. It also opens the door to novel treatments, focusing on microglia to either enhance their calming effects or inhibit their anxiety-promoting activity.

Since humans also have these microglial populations, this discovery could lead to more targeted therapies for anxiety disorders in the future, moving beyond current psychiatric drugs that primarily target neurons. Though clinical applications are still forthcoming, this study marks a major shift in understanding and potentially treating anxiety by modulating the brain’s immune cells rather than just neural circuits.

REFERENCE: Donn A. Van Deren, Ben Xu, Naveen Nagarajan, Anne M. Boulet, Shuhua Zhang, Mario R. Capecchi. Defective Hoxb8 microglia are causative for both chronic anxiety and pathological overgrooming in mice. Molecular Psychiatry, 2025; DOI: 10.1038/s41380-025-03190-y