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Category: biotech/medical – Page 51

Engineering a Mechanoresponsive DNA Origami Capsule for Drug Delivery to Narrowed ArteriesClick to copy article linkArticle link copied!

Omer et al. design a DNA origami box with a lid held closed by an elastic single-stranded DNA spring. The box may selectively open in blood vessels with pathological levels of shear flow, facilitating drug delivery to sites of thrombosis while minimizing off-target toxicity. It should be noted that this paper focused entirely on the box’s design and mechanical validation (via optical tweezers) and did not perform any experiments to show drug delivery. Nonetheless, this is a good start and I’m glad to see people thinking about DNA origami for therapeutic applications. [ https://pubs.acs.org/doi/10.1021/acs.nanolett.5c04066](https://pubs.acs.org/doi/10.1021/acs.nanolett.5c04066)

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Once Thought To Support Neurons, Astrocytes Turn Out To Be in Charge

Misha Ahrens’ team at Janelia Research Campus placed zebra fish in virtual reality where swimming produced no progress. Normally, fish give up after ~20 seconds. The researchers found astrocytes were “counting” swim attempts via accumulating calcium. When calcium reached a threshold, astrocytes released adenosine to suppress swimming circuits. When researchers disabled astrocytes with a laser, the fish never stopped swimming; when they artificially activated astrocytes, the fish stopped immediately. This showed astrocytes actively mediate the transition from hope to hopelessness.

Marc Freeman’s lab showed norepinephrine doesn’t just activate astrocytes—it changes their “hearing.” At low norepinephrine (low arousal), astrocytes ignore synaptic activity. At high norepinephrine (high arousal), astrocytes suddenly “listen” to every synapse and modulate neuronal response accordingly. This creates a dynamic gain control system layered atop neuronal networks.

“We did expect that, in large part, the effect of norepinephrine on synapses would be mediated by astrocytes,” Papouin said. “But we did not expect all of it to be!”

The finding of parallel molecular pathways in such distinct species as fruit flies, zebra fish, and mice points to “an evolutionarily conserved way in which astrocytes can profoundly affect neural circuits,” Freeman said.

The results suggest a gaping hole in previous theories of neuromodulation. “In the past, neuroscientists studied neuromodulators and knew they were important in regulating neural circuit function, but none of their thinking, none of their diagrams, none of their models had anything in them other than neurons,” Fields said. “Now we see that they missed a big part of the story.”

Insect salivary effectors disrupt PIEZO1-centric mechanoimmunity against piercing-sucking vectors

Huang et al. identify the mechanosensitive channel PIEZO1 as a plant immune hub that decodes insect-feeding-derived mechanical forces and Ca2+-activated defense responses. They characterize a self-amplifying immune circuit and identify that Bsp9, an evolutionarily conserved insect salivary effector, subverts this pathway. This work provides a framework for engineering plant disease resistance.

Signature in blood to better predict type 2 diabetes risk

The metabolites associated with type 2 diabetes were also found to be genetically linked to clinical traits and tissue types that are relevant to the disease. Furthermore, the team developed a unique signature of 44 metabolites that improved prediction of future risk of type 2 diabetes. ScienceMission sciencenewshighlights.

Diabetes, a metabolic disease, is on the rise worldwide, and over 90 percent of cases are type 2 diabetes, where the body does not effectively respond to insulin. Researchers identified metabolites (small molecules found in blood generated through metabolism associated with risk of developing type 2 diabetes in the future and revealed genetic and lifestyle factors that may influence these metabolites. They also developed a metabolomic signature that predicts future risk of type 2 diabetes beyond traditional risk factors. Their results are published in Nature Medicine.

In this study, researchers tracked 23,634 individuals with diverse ethnic backgrounds across 10 prospective cohorts with up to 26 years of follow-up. These individuals were initially free of type 2 diabetes. The team analyzed 469 metabolites in blood samples, as well as genetic, diet, and lifestyle data, to see how they relate to risk of developing type 2 diabetes. Of the metabolites examined, 235 were found to be associated with a higher or lower risk of developing type 2 diabetes, 67 of which were new discoveries.

“Interestingly, we found that diet and lifestyle factors may have a stronger influence on metabolites linked to type 2 diabetes than on metabolites not associated with the disease,” said first and co-corresponding author. “This is especially true for obesity, physical activity, and intake of certain foods and beverages such as red meat, vegetables, sugary drinks, and coffee or tea. Increasing evidence suggests that these dietary and lifestyle factors are associated with greater or lower risk of type 2 diabetes. Our study revealed that specific metabolites may act as potential mediators, linking these factors with type 2 diabetes risk.”

Substituting stereotactic body radiation therapy boost for brachytherapy in Mayo protocol for peri-hilar cholangiocarcinoma

Blood vessels are less like straight pipes and more like a crowded city road map, with turns, forks, and sudden choke points that can change how traffic moves. For a long time, many lab built vessel models skipped that complexity and relied on simple, straight channels, even though real vessels rarely behave that neatly.

Researchers in the Department of Biomedical Engineering at Texas A&M University are trying to close that gap with a customizable vessel-chip method. The goal is to recreate the kinds of shapes that matter in disease, so experiments on blood flow and potential treatments reflect what happens in the body more closely and can better support drug discovery.

Vessel-chips are engineered microfluidic devices that mimic human vasculature on a microscopic scale. Instead of studying blood flow in animals or oversimplified lab setups, scientists can use these chips to examine how fluid forces move through vessel-like structures in a controlled environment. Because the design can be tailored, the platform can also support patient-focused studies, which is especially useful when small differences in anatomy may affect how disease develops or how a therapy performs.

How the Incas Performed Skull Surgery More Successfully Than U.S. Civil War Doctors

Granted access to a time machine, few of us would presumably opt first for the experience of skull surgery by the Incas. Yet our chances of survival would be better than if we underwent the same procedure 400 years later, at least if it took place on a Civil War battlefield.

Researchers identify new blood markers that may detect early pancreatic cancer

NIH-funded, four-marker panel could one day help catch one of deadliest cancers at more treatable stages.

National Institutes of Health (NIH)-supported investigators have developed a blood test to find pancreatic ductal adenocarcinoma, one of the deadliest forms of cancer. The new test could improve survival rates from pancreatic cancer, which tends to be diagnosed at late stages when therapy is less likely to be effective. The findings were published in Clinical Cancer Research.

Overall, only about 1 in 10 pancreatic cancer patients survive more than five years from diagnosis. However, experts expect that when the cancer is found and treated at an earlier stage, survival would improve. While finding the cancer early is key, there are no current screening methods to do so.

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