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Comment by Dr. Krishna Kumari Challa on January 10, 2022 at 9:10am

Engineered nanomaterial captures off-target cancer drug to prevent tissue damage

 Standard chemotherapies may efficiently kill cancer cells, but they also pose significant risks to healthy cells, resulting in secondary illness and a diminished quality of life for patients. To prevent the previously unavoidable damage, researchers have developed a new class of nanomaterials engineered to capture chemotherapy drugs before they interact with healthy tissue.

The method, now available online prior to the March issue of Materials Today Chemistry, is based on hairy cellulose nanocrystals—nanoparticles developed from the main component of plant cell walls and engineered to have immense numbers of polymer chain "hairs" extending from each end. These hairs increase the potential drug capture capacity of the nanocrystals significantly beyond that of conventional nanoparticles and ion exchange resins.

For some organs, like the liver, chemotherapy can be locally administered through catheters. If we could place a device based on the nanocrystals to capture the excess drugs exiting the liver's inferior vena cava, a major blood vessel, clinicians could potentially administer higher doses of chemotherapy to kill the cancer more quickly without worry about damaging healthy cells. Once the treatment is finished, the device could be removed.

To produce the hairy cellulose nanocrystals capable of capturing chemotherapy drugs, the researchers chemically treated cellulose fibers found in softwood pulp and imparted a negative charge on the hairs, making them stable against the ionic composition of blood. According to the researchers this corrects a fault of conventional nanoparticles, whose charge can be rendered inert or reduced when exposed to blood, limiting the number of positively charged drug molecules with which it can bind to insignificant numbers.

The nanocrystals' binding efficacy was tested in human serum, the protein-rich portion of blood that does not contain red or white blood cells or platelets. For every gram of hairy cellulose nanocrystals, more than 6,000 milligrams of DOX were effectively removed from the serum.

The researchers also found that the nanocrystals had no harmful effect on red blood cells in whole blood or on cell growth in human umbilical vein endothelial cells.

1. Sarah A.E. Young, Joy Muthami, Mica Pitcher, Petar Antovski, Patricia Wamea, Robert Denis Murphy, Reihaneh Haghniaz, Andrew Schmidt, Samuel Clark, Ali Khademhosseini, Amir Sheikhi. Engineering hairy cellulose nanocrystals for chemotherapy drug capture. Materials Today Chemistry, 2022; 23: 100711 DOI: 10.1016/j.mtchem.2021.100711

https://researchnews.cc/news/10976/Engineered-nanomaterial-captures...

Comment by Dr. Krishna Kumari Challa on January 9, 2022 at 11:42am

This long-lasting hydrogel could be used to replace damaged human tissues

Comment by Dr. Krishna Kumari Challa on January 8, 2022 at 12:29pm

How the Heart Changes with Exercise

Comment by Dr. Krishna Kumari Challa on January 8, 2022 at 12:25pm

 Researchershave discovered details of how proteins produced by oral epithelial cells protect humans against viruses entering the body through the mouth. They also found that oral bacteria can suppress the activity of these cells, increasing vulnerability to infection.

A family of proteins known as interferon lambdas produced by epithelial cells in the mouth serve to protect humans from viral infection, but the oral bacteria Porphyromonas gingivalis reduces the production and effectiveness of those important frontline defenders.

Researchers found that certain pathogenic bacterial species, P. gingivalis, which cause periodontal disease, can completely suppress interferon production and severely enhance susceptibility to viral infection. These resident oral plaque bacteria play a key role in regulating anti-viral responses.

he mouth often is a gateway into the body for viruses that infect the gastrointestinal tract and lungs such as SARS-CoV-2, human immunodeficiency virus (HIV), herpes simplex and cancer-causing viruses such as human papillomavirus (HPV).

P. gingivalis, a common oral bacterium that causes periodontal disease, has been linked to numerous other diseases, including Alzheimer's disease and rheumatoid arthritis. Recent clinical studies have shown that immune suppression in patients with periodontitis can enhance susceptibility to HIV, herpes simplex and HPV.

Improved understanding of how interferons provide broad antiviral protection and activate antiviral genes to protect people from viruses, as well as how P. gingivalis compromises their protection, may lead researchers to clinical approaches to increase that protection. Research  has revealed connections between P. gingivalis and multiple other diseases and conditions, including rheumatoid arthritis, Alzheimer's disease and esophageal cancer.

1. Carlos J. Rodriguez-Hernandez, Kevin J. Sokoloski, Kendall S. Stocke, Himabindu Dukka, Shunying Jin, Melissa A. Metzler, Konstantin Zaitsev, Boris Shpak, Daonan Shen, Daniel P. Miller, Maxim N. Artyomov, Richard J. Lamont, Juhi Bagaitkar. Microbiome-mediated incapacitation of interferon lambda production in the oral mucosa. Proceedings of the National Academy of Sciences, 2021; 118 (51): e2105170118 DOI: 10.1073/pnas.2105170118

https://researchnews.cc/news/10948/Researchers-reveal-how-oral-bact...

Comment by Dr. Krishna Kumari Challa on January 8, 2022 at 11:31am

Researchers used a technique called electron paramagnetic resonance (EPR) spectroscopy to identify previously unreported changes in the shape, or conformation, of the ABC exporter from a bacterium called Bacillus subtilis as it interacts with ATP.

They proposed that ATP power, in a series of complex steps, drives the transition between inward-facing and outward-facing conformations of the exporter. After binding the antibiotic, for example, the exporter "turns around" so it can expel its cargo from the cell.

This motion is driven by the transduction (conversion) of chemical energy into mechanical energy resulting from asymmetrical and sequential binding of two ATP molecules to different parts of the protein complex (the ATP binding cassettes). Asymmetrical binding thus drives conformational change.

To prove their theory, the researchers had to capture an image of the conformational change. So they turned to another resource, cryogenic electron microscopy, which enables measurement of atomic distances at cryogenic temperatures, below minus 320 degrees Fahrenheit.

The cryo-EM studies were conducted at the Pacific Northwest Center for Cryo-EM in Portland, Ore. In combination with an EPR spectroscopy method called DEER and molecular dynamics simulation, the studies revealed for the first time an ATP-loaded, inward-facing structure with two drug molecules bound asymmetrically.

This conformation suggests that drugs could be designed to prevent the bacterial exporter from turning around and expelling the antibiotic by "trapping" it in its inward-facing state.

Tarjani M. Thaker et al, Asymmetric drug binding in an ATP-loaded inward-facing state of an ABC transporter, Nature Chemical Biology (2021). DOI: 10.1038/s41589-021-00936-x

https://phys.org/news/2022-01-explores-bacteria-drug-resistant.html...

Comment by Dr. Krishna Kumari Challa on January 8, 2022 at 11:29am

Study explores how bacteria become drug resistant

Researchers  have revealed recently more of the inner-workings of a two-stage "molecular motor" in the cell membrane that enables bacteria to become resistant to drugs.

Their findings, which were reported recently in the journal Nature Chemical Biology, will aid the search for inhibitors that can "turn off" the protein, called an ABC transporter. They also inform efforts to block the human version of the transporter that enables tumor cells to become resistant to chemotherapy.

Understanding how transporters work is essential to developing drugs to block them.

A primary vehicle for resistance is the multi-drug ABC (ATP-binding cassette) exporter. ABC exporters use ATP hydrolysis—the release of chemical energy stored in ATP molecules—to traffic a wide variety of molecules across cell membranes.

ATP energy provides the power for ABC exporters to bind toxic chemicals, then turn around and expel them from the cell. In the case of antibiotic-resistant bacteria, however, this survival tactic can prove deadly to the human host they have invaded.

Part1

Comment by Dr. Krishna Kumari Challa on January 7, 2022 at 12:57pm

“To the limits of our knowledge as humans, we’ve analysed and teste...

Engineer Michael Kaplan, who kicked off the planning of the James Webb Space Telescope in the 1990s, gives insight into how the wildly ambitious project came to be — and what comes next. (The Times of Israel | 19 min read)

Comment by Dr. Krishna Kumari Challa on January 7, 2022 at 12:55pm

Omicron struggles to infect the lungs

Mounting evidence from animal studies suggests that the Omicron coronavirus variant does not multiply readily in lung tissue. This offers a tantalizing explanation for early hints that it causes less-serious disease than does the Delta variant: Omicron might not infect cells deep in the lung as readily as those in the .... Experiments in lung cells and lung organoids suggest that this could be because of a protein called TMPRSS2, which protrudes from the surfaces of many cells in the lungs. Omicron struggles to infect cells through TMPRSS2. Scientists emphasize that Omicron still threatens to overload health systems because of its hyper-transmissibility.

Comment by Dr. Krishna Kumari Challa on January 7, 2022 at 12:52pm

New research shows gene exchange between viruses and hosts drives evolution

The first comprehensive analysis of viral horizontal gene transfer (HGT) illustrates the extent to which viruses pick up genes from their hosts to hone their infection process, while at the same time hosts also co-opt useful viral genes.

HGT is the movement of genetic material between disparate groups of organisms, rather than by the "vertical" transmission of DNA from parent to offspring. Previous studies have looked at HGT between bacteria and their viruses and have shown that it plays a major role in the movement of genes between bacterial species. However a new study, published in Nature Microbiology, looks at interactions between viruses and eukaryotes, which include animals, plants, fungi, protists and most algae.

We knew from individual examples that viral genes have played a role in the evolution of eukaryotes. Even humans have viral genes, which are important for our development and brain function.

Researchers  examined viral-eukaryotic gene transfer in the genomes of hundreds of eukaryotic species and thousands of viruses. They identified many genes that had been transferred and found that HGT from eukaryotes to viruses was twice as frequent as the reverse direction.

In contrast to viruses, eukaryotic organisms retained fewer viral genes, although the ones that were kept appear to have had a major impact on host biology over evolutionary time.

Many of these viral-derived genes appear to have repeatedly affected the structure and form of different organisms, from the cell walls of algae to the tissues of animals. This suggests that host-virus interactions may have played an important role in driving the diversity of life we see today. These transfers not only have evolutionary consequences for both virus and host, but could have important health implications.

HGT allows genes to jump between species including viruses and their hosts. If the gene does something useful, it can sweep through the population and become a feature of that species. This can lead to a rapid emergence of new abilities, as opposed to the more incremental changes that result from smaller mutations.

Although viruses such as Zika and coronaviruses do not appear to participate in these gene transfers, they often manipulate similar genes in their hosts through complex mechanisms. Future research into these transferred genes may therefore provide a novel approach for understanding the infection processes of these and other viruses which could be important for drug discovery.

Nicholas A. T. Irwin, Alexandros A. Pittis, Thomas A. Richards, Patrick J. Keeling. Systematic evaluation of horizontal gene transfer between eukaryotes and viruses. Nature Microbiology, 2021; DOI: 10.1038/s41564-021-01026-3

https://researchnews.cc/news/10930/New-research-shows-gene-exchange...

Comment by Dr. Krishna Kumari Challa on January 6, 2022 at 12:04pm

Magic Acid: Fluorosulfonic acid + Antimony pentafluoride

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