Background: Three-dimensional cellular models provide a more comprehensive representation of in vivo cell properties, encompassing physiological characteristics and drug susceptibility. Methods: Primary hepatocytes were seeded in ultra-low attachment plates to form spheroids, with or without tumoral cells. Spheroid structure, cell proliferation, and apoptosis were analyzed using histological staining techniques. In addition, extracellular vesicles were isolated from conditioned media by differential ultracentrifugation. Spheroids were exposed to cytotoxic drugs, and both spheroid growth and cell death were measured by microscopic imaging and flow cytometry with vital staining, respectively. Results: Concerning spheroid structure, an active outer layer forms a boundary with the media, while the inner core comprises a mass of cell debris.
The relevance of the gut microbiome, the community of microorganisms living in the digestive tract, to human health is a topic of intense interest. However, among the numerous benevolent bacteria living in the gut, there are some species that are harmful to humans.
For example, certain strains of Escherichia coli produce the genotoxin colibactin, which causes DNA damage and is linked with colon cancer. However, the colibactin molecule is complex and unstable, which has made it challenging to elucidate its chemical structure and the mechanism by which it damages DNA. In the culmination of years of research from multiple laboratories, researchers in a new Science study reveal the structure of the active form of colibactin bound to DNA.
The findings go a long way toward explaining the mutation signatures associated with colibactin exposure and provide substantial insight into how colibactin contributes to colorectal carcinogenesis.
Learn more in a new Science Perspective.
The structure of the bacterial genotoxin colibactin bound to DNA shows how it might contribute to cancer risk.
Light undergoes a unique phenomenon called superscattering, an optical illusion where a very small object scatters far more light than expected. This happens when multiple scattering modes overlap and interact, allowing tiny objects to scatter far more light than their size should allow.
Scientists have now found a way to expand the scope of superscattering beyond optics into the thermal world.
A team of researchers from Taiyuan University of Technology, China, has experimentally demonstrated thermal superscattering by surrounding an object with an active shell comprising arrays of controllable heating and cooling elements along its boundary. This shell allowed the tiny object to fake the thermal signatures of an object nine times larger than itself.
Researchers in the Nanoscience Center at the University of Jyväskylä, Finland, have developed a pioneering computational model that could expedite the use of nanomaterials in biomedical applications. The study presented the first generalizable machine-learning framework capable of predicting how proteins interact with ligand-stabilized gold nanoclusters, materials widely employed in bioimaging, biosensing, and targeted drug delivery.
The adsorption of proteins onto nanomaterial surfaces is fundamental to many biological applications, including bioimaging and biosensing to targeted drug delivery. Gold nanoclusters, in particular, have attracted attention thanks to their biocompatibility and tunable optical properties. Yet existing studies that predict how proteins interact with these ligand-protected nanostructures often focus on isolated cases, leaving researchers without a unified model to guide design.
“This gap has created a clear need for general, scalable models capable of capturing the underlying rules of protein–nanocluster binding,” specifies Postdoctoral Researcher Brenda Ferrari from the University of Jyväskylä
Researchers have unveiled a breakthrough technology that could transform the way scientists build and study lab-grown brain tissue models. The innovation, called Cellular RedOx Spreading Shield (CROSS), delivers long-lasting antioxidant protection to stem cells, enabling the reliable production of high-quality extracellular vesicles (EVs) that strengthen neuron-glia networks.
The study, published in the journal Advanced Functional Materials, was led by University of Illinois Urbana-Champaign chemical and biomolecular engineering professor Hyunjoon Kong and chemistry professor Hee Sun Han, and performed by Ryan Miller, currently a post-doctoral fellow at Georgia Tech.
Jonghwi Lee, in the chemical engineering department at Chung-Ang University in South Korea, and Young Jun Kim at the Korean Institute of Science and Technology–Europe, collaborated on the project.
Every living being must cope with a changing world—summer gives way to winter, one year it floods and the next is a drought. It’s obvious that populations of plants and animals must constantly face new challenges, says University of Vermont scientist Csenge Petak. But what’s not obvious is how these changes in the environment affect evolution.
“Do populations benefit from lots of environmental fluctuations, making new generations more prepared to face future changes,” she wondered, “or are they impaired, forced to readapt again and again, never reaching the heights of fitness that the same populations in a stable environment could achieve?”
To explore this question, she and University of Vermont computer scientist Lapo Frati—as well as two other UVM researchers and one at the University of Cambridge—developed a first-of-its-kind study using a powerful computer model that tracks thousands of generations of digital organisms.