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Category: chemistry – Page 3

Abstract: The changing landscape of urothelial carcinoma: on the edge of paradigm shift

In this Review Joshua J. Meeks discusses advancements in biomarkers and novel therapeutics that are likely to dramatically improve survival of patients with Bladder Cancer.

1Departments of Urology and.

2Biochemistry and Molecular Genetics, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.

3Jesse Brown VA Medical Center, Department of Veterans Affairs, Chicago, Illinois, USA.

Address correspondence to: Joshua J. Meeks, Department of Urology, Biochemistry and Molecular Genetics, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA. Phone: 312.695.8146; Email: [email protected].

How Nanotech Made an Old Leukemia Drug 22,000x Stronger

Structural nanomedicine — what helped give us the COVID vaccine — may now be the key to a potent blood cancer treatment that’s had remarkable early results.

The findings, published in ACS Nano, show that just two doses of the experimental therapy achieved 97.5% tumor growth inhibition in a human AML xenograft mouse model — 59-fold more effective than standard 5-fluorouracil (5-FU) treatment, with no observable side effects.

For a disease with a grim 29% 5-year survival rate — and a cure rate of only 15% in patients older than 70 years — the findings offer a glimpse of how rethinking drug structure, not just chemistry, could advance cancer care.

Mirkin frames the findings within what he calls “the era of structural nanomedicine,” the idea that how you arrange medicinal components at the nanoscale matters as much as the molecules themselves.

Precision tumor imaging with a fluorescence probe and engineered enzymes

Successful cancer surgery depends on a surgeon’s ability to remove tumors, while minimizing harm to healthy tissues. Surgeons currently use glowing dyes which mark cancer cells to help differentiate from healthy cells, but these dyes aren’t perfect and will light up some healthy tissues too. For the first time, researchers including those from the University of Tokyo developed what they call a bioorthogonal fluorescence probe and a matching reporter enzyme that can activate the probe selectively at targeted tumor sites. This enables high-contrast tumor visualization with very low background. This study was performed in mice.

Cancer is a universal issue which affects uncountably many people around the world. Many will turn to surgery in the hope a surgeon will be able to completely remove a tumor leaving healthy tissues unaffected. Various tools and techniques have been developed over the years to improve the way these surgeries are performed, and visual imaging methods such as glowing dyes have proven to be very useful. But one drawback is that some probes can also be activated in healthy tissues by endogenous enzymes, creating background fluorescence and making it harder to judge what should be removed. The opposite is also possible, where cancer cells are left unmarked and are missed during surgery, increasing the chance of recurrence.

“Our group acknowledged this current shortcoming and improved upon this way to make cancer cells light up inside the body. In tests on mice, we delivered a special enzyme to tumors and used a fluorescence probe that only turns on when that enzyme is present,” said Associate Professor Ryosuke Kojima from the Laboratory of Chemical Biology and Molecular Imaging at the University of Tokyo. “Older probes often light up healthy tissue by mistake, creating background noise, but our highly selective, or bioorthogonal, dye probe is designed to stay completely off unless it meets its matching engineered enzyme. We essentially trained the enzyme through repeated mutation and selection, a form of directed evolution, so it could activate the probe strongly enough to work inside living animals.”

Smart fluorescent molecules provide cheaper path to sharper microscopy images

Multiphoton microscopy is used in biomedical research to study cells and tissues. Today, so-called two-photon microscopy is used to study processes within cells, but the technique has limitations in terms of image resolution. Four-photon microscopy provides images with higher resolution. However, such instruments are very expensive and, when studying biological material, the powerful laser light required can damage samples.

“In this project, we have developed molecules to visualize molecular-level details and monitor processes using the more common two-photon microscopy technique. These molecules have the capacity to achieve higher resolution than with four-photon microscopy, although two-photon microscopy is used,” says the project coordinator Joakim Andréasson, Professor at the Department of Chemistry and Chemical Engineering at Chalmers University of Technology.

“In the long term, results from studies of this kind may provide new insights into diseases, pharmaceuticals and the very smallest building blocks of life.”

A rewritable DNA hard drive may help solve the growing data storage crisis

Around the world, scientists are exploring an unexpected solution to the growing data crisis: storing digital information in synthetic DNA. The idea is simple but powerful—DNA is one of the most compact, durable information systems on Earth. But one issue has held the field back. Once data is written into DNA, it can’t be changed.

Now, researchers at the University of Missouri are helping to solve that problem by transforming DNA from a one-time medium into a rewritable digital hard drive. Their research is published in the journal PNAS Nexus.

“DNA is incredible—it stores life’s blueprint in a tiny, stable package,” said Li-Qun “Andrew” Gu, a professor of chemical and biomedical engineering at Mizzou’s College of Engineering. “We wanted to see if we could store and rewrite information at the molecular level faster, simpler and more efficiently than ever before.”

Tardigrades Reveal Risks and Rewards of Martian Regolith

“It seems that there’s something very damaging in MGS-1 that can dissolve in water — maybe salts or some other compound,” said Dr. Corien Bakermans. [ https://www.labroots.com/trending/space/30263/tardigrades-re…regolith-2](https://www.labroots.com/trending/space/30263/tardigrades-re…regolith-2)

How can Martian regolith (often mistakenly called “soil”) be used to benefit human exploration? This is what a recent study published in the International Journal of Astrobiology hopes to address as a team of scientists investigated how tardigrades (also called “water bears”) could be used to sterilize the Martian regolith for improved functionality, specifically for growing plants. This study has the potential to help scientists, engineers, mission planners, and future astronauts develop new methods for eventually living on Mars and long-term settlements.

For the study, the researchers examined states of two types of tardigrades responded to long-term exposure to Martian regolith simulant known as MGS-1 and OUCM-1, which the researchers note are like the regolith examined by NASA’s Curiosity rover. The purpose of a simulant is necessary since Mars regolith samples has never been returned to Earth. Tardigrades are known for their extreme resilience and scientists have established they have two types of states: active and dormant, as opposed to alive and dead.

The goal of the study was to ascertain if tardigrades could be used to improve the chemical composition of Martian regolith. However, the researchers discovered that the MGS-1 caused significant declines in tardigrade activity after only a few days. The team mitigated this by washing the simulant and introduced new tardigrades, resulting in improved numbers. For OUCM-1, the researchers found this simulant also caused increased tardigrade dormancy while one type of tardigrade was less damaging.

Chemotherapeutic drugs: Cell death- and resistance-related signaling pathways. Are they really as smart as the tumor cells?

Cancer is characterized by the uncontrolled cell proliferation, invasion, and check-point evasion of abnormal cells that are mostly nonfunctional. Cancer can arise due to diet insufficiencies, inherited mutations, and tobacco consumption, to say the least [1, 2]. Cancer’s incident is increasing due to the sedentary lifestyle, overpopulated, polluted megacities, and individuals’ growing desire for consuming processed foods containing preservatives additives [3], [4], [5]. Since cancers might not manifest symptoms in their early onset, it would be difficult or even improbable to treat them when they are diagnosed in their late stage. By and large, tumors are composed of two main parts, including the proliferating cells and stroma, which contains connective tissue and blood supply [6]. Chemotherapy has been among our best options against malignancies.

Chemotherapy is defined by the administration of numerous drugs and chemicals either alone or in combination to kill the cancer cells. Chemotherapeutic drugs kill cancer cells or control their progression all over the patient’s body, while radiation-and surgery-based treatments are directed to a particular site. Cure, control, and palliation are the three objectives of chemotherapies. Killing cancer cells by implementing chemotherapy drugs means “Cure”, whereas “Control” defines the situation that full remission seems far-fetched; therefore, the objective of the therapy would be to decrease the tumor size or to diminish the growth rate and angiogenesis. Palliation aims to alleviate the pain, symptoms, and medical conditions arisen due to cancer. It is mostly accomplished when cancer is in the advanced stages and cannot be eradicated; therefore, our aim would be to improve the quality of life.

The chemotherapy prescription approaches rely on various elements, including the cancer’s type, the cancer’s stage, the patient’s age, the patient’s general health status, the other concurrent health issues, and the history of receiving chemotherapies. Since chemotherapeutic drugs cannot distinguish normal cells against cancerous cells, the prescribed dosage is the other crucial aspect toward achieving the best possible response. The administration dosage depends on the patient’s weight, body surface area, age, nutrition status, history of radiation therapy, and blood cell count. Besides, a suitable drug administration schedule might help obtain the most efficient anti-cancer activity and minimum side effects [7, 8].

Genomic reorganization at the transition to gametogenesis

Using a technique called Hi-C analysis, which looks at how DNA is arranged in three dimensions inside the nucleus, the team found that at this transitional point the genome’s three-dimensional organisation becomes less structured and chromosomes become more separated inside the nucleus.

Creating sperm and eggs in the laboratory (in vitro) remains one of the greatest challenges in reproductive biology. To study this process, scientists use primordial germ cell–like cells (PGCLCs), which are lab-generated cells derived from embryonic stem cells that mimic the embryo’s earliest reproductive cells. However, these PCGLCs often fail to complete all the steps of meiosis, making it difficult to create functional sperm and eggs in petri dishes.

After studying the process in germ cells from the embryos, the team studied lab-generated mouse PCGLCs to see if the centromeres migrated to the periphery of the nucleus in vitro too, but they did not see the same phenomenon.

“The presence of this chromosome conformation in embryonic germ cells, but not lab-grown cells, suggests that this structural change could be required for meiosis to proceed properly, and could explain why meiosis is so difficult to recreate outside the body,” says the author, “but we need to do more work to fully characterise the process before we can say for sure.”

“Our study has uncovered a previously unknown and frankly very surprising restructuring of genome architecture that occurs in developing germ cells, which we believe is critical for a successful execution of meiosis,” says the senior author. ScienceMission sciencenewshighlights.

In our cells, our DNA carries chemical or ‘epigenetic’ marks that decide how genes will be used in different tissues. Yet in the group of specialised cells, known as ‘germ cells’, which will later form sperm and eggs, these inherited chemical instructions must be erased or reshuffled so development can begin again with a fresh blueprint in future generations.

Continue reading “Genomic reorganization at the transition to gametogenesis” | >

Gut bacteria can sense their environment and it’s key to your health

Your gut bacteria are chemical detectives—sniffing out nutrients and even feeding each other to keep your microbiome thriving. Your gut is home to trillions of bacteria that constantly “sense” their surroundings to survive and thrive. New research shows that beneficial gut microbes, especially common Clostridia bacteria, can detect a surprisingly wide range of chemical signals produced during digestion, including byproducts of fats, proteins, sugars, and even DNA. These microbes use specialized sensors to move toward valuable nutrients, with lactate and formate standing out as especially important fuel sources.

The gut microbiome, also called the gut flora, plays a vital role in human health. This enormous and constantly changing community of microorganisms is shaped by countless chemical exchanges, both among the microbes themselves and between microbes and the human body. For these interactions to work, gut bacteria must be able to detect nutrients and chemical signals around them. Despite their importance, scientists still know relatively little about the full range of signals that bacterial receptors can recognize.

A key question remains. Which chemical signals matter most to beneficial gut bacteria?

Astronomers shocked by how these giant exoplanets formed

JWST just found evidence that some “super-Jupiters” may have formed like planets, not failed stars. A distant star system with four super-sized gas giants has revealed a surprise. Thanks to JWST’s powerful vision, astronomers detected sulfur in their atmospheres — a chemical clue that they formed like Jupiter, by slowly building solid cores. That’s unexpected because these planets are far bigger and orbit much farther from their star than models once allowed.

Gas giants are enormous planets made primarily of hydrogen and helium. They may contain dense central cores, but unlike Earth, they do not have solid surfaces you could stand on. In our solar system, Jupiter and Saturn are classic examples. Beyond our neighborhood, astronomers have identified many gas giant exoplanets, some far larger than Jupiter. The most massive of these worlds begin to resemble brown dwarfs, substellar objects sometimes called “failed stars” because they do not fuse hydrogen.

This overlap raises a major question in astronomy. How exactly do these massive planets form? One possibility is core accretion, the same process believed to have created Jupiter and Saturn. In this scenario, a solid core slowly builds up inside a disk of dust and ice, gathering rocky and icy material until it becomes massive enough to pull in surrounding gas. Another possibility is gravitational instability, where a swirling cloud of gas around a young star collapses quickly under its own gravity, forming a large object more like a brown dwarf.

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