drugs – Page 2 – Lightsources.org

Encapsulation of drugs for new cancer treatments

2019/02/192019/02/27

Research develops hydrogel from silk protein with potential application in photodynamic therapy

Cancer is a set of diseases characterized by uncontrolled multiplication of cells. One of the main methods for treating this disease is chemotherapy, which uses drugs to block the growth of those cells or to destroy them. In this way, most drugs used interfere with mitosis, the cellular mechanism by which new cells are produced. Therefore, both cancerous and healthy cells are affected, leading to several side effects.
Worldwide, considerable effort has been directed at developing new methods that act directly on the target of treatment. This is the case of so-called photodynamic therapy (PDT), a minimally invasive therapeutic procedure that selectively acts on malignant cells.
The procedure involves the administration of a light-sensitive substance, called a photosensitizing agent. When irradiated at specific wavelengths, the photosensitizer releases oxygen in reactive chemical forms that promote the death of malignant cells, infectious agents and the removal of burns.

Revealing the path of a metallodrug in a breast cancer cell

2019/02/042019/02/15

Some types of cancer cannot be treated with classical chemotherapy. Scientists from Inserm, CNRS, Sorbonne University, PSL university, University Grenoble Alpes and ESRF, the European Synchrotron, are working on a metallorganic molecule as an antitumor drug. Their research has given thorough insights into its mechanism in attacking cancer cells. This study is published in Angewandte Chemie.

Triple-negative breast cancer, which represents 10-20% of breast cancers, is not fuelled by hormones. In fact, it tests negative for estrogen and progesterone receptors and excess HER2 protein. This means that it does not respond to hormonal therapy and antibody medicines. Given that it is more aggressive and often has a higher grade than other types of breast cancer, the scientific community is relentlessly trying to find a treatment.

>Read more on the ESRF website

Image: X-ray fluorescence maps of potassium, an essential physiological element of the cell (K, in pink), and, osmium a constitutive element of the metallocifen (Os, in green), in hormone-independent breast cancer cells exposed to the osmocenyl-tamoxifen derivatives.
Credit: Sylvain Bohic.

Toward a blueprint for anti-influenza drugs

2018/12/072019/01/08

The structures provide an atomic-level blueprint from which to design more effective anti-influenza drugs that can overcome growing drug resistance.

Influenza virus infection is a perennial problem. According to the Centers for Disease Control and Prevention, the 2017-18 flu season saw high levels of emergency-department visits for influenza-like illness, high influenza-related hospitalization rates, and elevated and geographically widespread influenza activity for an extended period.

Although yearly vaccinations can reduce the number of flu infections, these vaccines are able to target only a subset of viral strains—there is, as yet, no “universal vaccine.” As a result, there is still a need for antiviral drugs to treat the illness after infection has occurred. This is especially important for groups of people who can experience serious complications from the flu, such as those with respiratory diseases or immune disorders. In recent years, however, resistance to certain classes of antiviral drugs has become a problem.

Image: Molecular dynamics simulation of a drug molecule, amantadine (cyan sticks), in the M2 proton channel. The drug’s ammonium group (blue tip) mimics hydronium, stabilizing the drug molecule in a position to block the channel.

New cryo-EM Collaboration

2018/09/122018/09/13

UK set to be global leader in providing large-scale industrial access to Cryo-EM for drug discovery thanks to new collaboration.

Thermo Fisher Scientific and Diamond Light Source are creating a step change for life sciences sector, a one-stop shop for structural biology and one of largest cryo-EM sites in the world.
An agreement to launch a new cryo-EM capability for use in the life sciences industry sector by Thermo Fisher Scientific, one of the world leaders in high-end scientific instrumentation, and Diamond Light Source, the UK’s national synchrotron and one of the most advanced scientific facilities in the world, was announced today ahead of the official opening of the new national electron bio-imaging centre (eBIC) which will be held at Diamond on September 12^th 2018.

This announcement confirms Diamond as one of the major global cryo-EM sites embedded with an abundance of complementary synchrotron-based techniques, and thereby, provides the life sciences sector with an offer not available anywhere else in the world.

Professor Dave Stuart, Life Sciences Director at Diamond and MRC Professor of Structural Biology at the University of Oxford, Department of Clinical Medicine, says, “Access to 21^st century scientific tools to push the boundaries of scientific research is essential for both academia and industry, and what we have created here at Diamond is truly unique in the world in terms of size and scale. The new centre offers the opportunity for almost real-time physiology, capturing proteins in action at cryo-temperatures by flash-freezing them at various stages. What Diamond has created with eBIC is an integrated facility for structural biology, which will accelerate R&D for both industry and academic users. The additional advanced instruments made available by Thermo Fisher will position the UK as a global leader in providing large-scale industrial access to cryo-EM for drug discovery research. Our new collaboration provides a step change in our offer for industry users and helps ensure that R&D remains in the UK.”

Image: Close up sample loading Krios I.

A new approach for finding Alzheimer’s treatments

2018/09/102018/09/20

Considering what little progress has been made finding drugs to treat Alzheimer’s disease, Maikel Rheinstädter decided to come at the problem from a totally different angle—perhaps the solution lay not with the peptide clusters known as senile plaques typically found in the brains of Alzheimer’s patients, but with the surrounding brain tissue that allowed those plaques to form in the first place.
It was a novel approach that paid off for Rheinstädter and his team of researchers from McMaster University who used the Canadian Light Source in Saskatoon as part of a study of the effect various compounds have on membranes in brain tissue and the possible impact on plaque formation.

“Alzheimer’s disease has interested me for a long time,” said Rheinstädter, a professor in the Department of Physics and Astronomy and the Origins Institute at McMaster. “It is something almost every Canadian will be affected by in their lives.”

Image: Adam Hitchcock, Adree Khondker and Maikel Rheinstädter.

Just like lego – studying flexible protein for drug delivery

2018/08/302018/09/06

Researchers from the Sapienza University of Rome and its spin-off company MoLiRom (Italy) are spending the weekend at the ESRF to study a protein that could potentially transport anticancer drugs.

Ferritin is a large spherical protein (20 times bigger than haemoglobin) that stores iron within its cavity in every organism. Just like a lego playset, Ferritin assembles and disassembles. It is also naturally targeted to cancer cells. These are the reasons why Ferritin is a great candidate as a drug-transport protein to fight cancer. An international team of scientists from “Sapienza” University of Rome and the SME MoLiRom (Italy) came to the ESRF to explore a special kind of ferritin that shows promising properties. “This is an archaebacterial ferritin that have transformed into a humanised ferritin to try to tackle cancer cells”, explains Matilde Trabuco, a scientist at the Italian SME MoLiRom.

The mechanism looks simple enough: “Ferritin has a natural attraction to cancer cells. If we encapsulate anti-cancer drugs inside it, it will act as a Trojan horse to go inside cells, then it will open up and deliver the drug”.

Ferritins have been widely used as scaffolds for drug-delivery and diagnostics due to their characteristic cage-like structure. Most ferritins are stable and disassemble only by a harsh pH jump that greatly limits the type of possible cargo. The humanised ferritin was engineered to combine assembly at milder conditions with specific targeting of human cancer cells.

First European XFEL research results published

2018/08/28

High number of X-ray pulses per second reduces time needed for the study of biological structures.

Just days before the first anniversary of the start of European XFEL user operation, the first results based on research performed at the facility have been published. In the journal Nature Communications, the scientists, headed by Prof. Ilme Schlichting from Max-Planck-Institute for Medical Research in Heidelberg, Germany, together with colleagues from Rutgers State University of New Jersey, USA, France, DESY and European XFEL, describe their work using the intense X-ray laser beam to determine the 3D structure of several proteins. They demonstrate, for the first time that, under the conditions used at the time of the experiment an increased number of X-ray pulses per second as produced by the European XFEL can be successfully used to determine the structure of biomolecules. As much faster data collection is therefore possible, the time needed for an experiment could be significantly shortened. The detailed determination of the 3D structure of biomolecules is crucial for providing insights into informing the development of novel drugs to treat diseases.

Prof. Ilme Schlichting said: “Our work shows that under the conditions used data can be collected at European XFEL at a rate much faster than has ever been previously possible. As the time and cost of experiments decrease, very soon many more researchers will be able to perform experiments at high repetition rate X-ray lasers. Our results are therefore of interest not only tor the fields of biology and medicine, but also physics, chemistry and other disciplines.”

>Read more on the European XFEL website

Image: Guest scientist Tokushi Sato working at the sample chamber of the SPB/SFX instrument.
Credit: European XFEL

Structure reveals mechanism behind periodic paralysis

2018/08/272018/08/30

The results suggest possible drug designs that could provide relief to patients with a genetic disorder that causes them to be overcome suddenly with profound muscle weakness.

A rare genetic disorder called hypokalemic periodic paralysis (hypoPP) causes sudden, profound muscle weakness in people who occasionally exhibit low levels of potassium in their blood, or hypokalemia. When a patient is hypokalemic, hypoPP affects the function of the muscles responsible for skeletal movement. The disease has been known to stem from mutations in certain membrane proteins that channel and regulate the flow of sodium into cells. Exactly how the mutation affects the proteins’ function, however, was not known.

In earlier work, researchers from the Catterall Lab at the University of Washington had solved the structure of a sodium channel called Na_vAb from a prokaryote (single-celled organism). As a next step, the group decided to see if Na_vAb could serve as a model for studying the mutations that cause hypoPP in humans (eukaryotes), with the goal of finding a way to prevent or treat this disorder.

A leak in the pipe?

In a resting state, muscle-cell membranes keep potassium ions and sodium ions separated, inside and outside the cell, respectively, creating a voltage across the membrane. A chemical signal from a nerve cell sets off a cascade of events that results in sodium ions flowing into the cell, changing the membrane potential and and ultimately triggering muscle contraction.

Image: Three states of the voltage-sensing domain (VSD) of a membrane-channel protein. In the normal state, the water-accessible space (magenta) does not extend through the channel, preventing sodium (gray spheres) from passing through. In the disease state, a clear passage allows sodium to leak through, resulting in muscle paralysis. In the “rescued” state, the binding of guanidinium (blue and yellow spheres) effectively closes the channel and blocks sodium leakage. The red sphere represents the location of the disease-causing mutation. The side-chain sticks represent the voltage sensors of the sodium channel.

Probing tumour interiors

2018/06/192018/06/21

X-ray fluorescence mapping to measure tumour penetration by a novel anticancer agent.

A new anticancer agent developed by the University of Warwick has been studied using microfocus synchrotron X-ray fluorescence (SXRF) at I18 at Diamond Light Source. As described in The Journal of Inorganic Biochemistry, researchers saw that the drug penetrated ovarian cancer cell spheroids and the distribution of zinc and calcium was perturbed.

Platinum-based chemotherapy agents are used to treat many cancer patients, but some can develop resistance to them. To address this issue, scientists from the University of Warwick sought to employ alternative precious metals. They developed an osmium-based agent, known as FY26, which exhibits high potency against a range of cancer cell lines. To unlock the potential of this novel agent and to test its efficacy and safety in clinical trials, the team need to fully understand its mechanism of action.

To explore how FY26 behaves in tumours, the team grew ovarian cancer spheroids and used SXRF at I18 to probe the depth of penetration of the drug. They noted that FY26 could enter the cores of the spheroids, which is critical for its activity and very encouraging for the future of the drug. SXRF also enabled them to probe other metals within the cells, which showed that the distribution of zinc and calcium was altered, providing new insights into the mechanism of FY26-induced cell death.

Figure: (extract) A) Structure of FY26and related complexes, [(ŋ⁶-p-cym)Os(Azpy-NMe₂)X]⁺. B) Bright field images and SXRF elemental maps of Os, Ca and Zn in A2780 human ovarian carcinoma spheroid sections (500 nm thick) treated with 0.7 µM FY26(½ IC₅₀) for 0 or 48 h. Raster scan: 2×2 µm² step size, 1 s dwell time. Scale bar 100 µm. Calibration bar in ng mm^-2. Yellow squares in bright field images indicate areas of the spheroid studied using SXRF. Red areas in SXRF elemental maps indicate the limits of the spheroids. C) Average Os content (in ng mm^-2) as a function of distance from A2780 3D spheroid surface, after treatment for 16 h (green), 24 h (blue) or 48 h (red) with 0.7 µM FY26.

Insights into the development of more effective anti-tumour drug

2018/04/182018/04/23

Natural killer cells are powerful weapons our body’s immune systems count on to fight infection and combat diseases like cancer, multiple sclerosis, and lupus. Finding ways to spark these potent cells into action could lead to more effective cancer treatments and vaccines.

While several chemical compounds have shown promise stimulating a type of natural killer cells, invariant natural killer T cells (iNKT) cells in animal models, their ability to activate human iNKT cells has been limited.

Now, an international team of top immunologists, structural biologists, and chemists published in Cell Chemical Biology the creation of a new compound that appears to have the properties researchers have been looking for. The research was co-led by Monash Biomedicine Discovery Institute’s (BDI) Dr Jérôme Le Nours, University of Connecticut’s Professor Amy Howell and Albert Einstein College of Medicine’s Dr Steve Porcelli. Dr Le Nours used the Micro Crystallography beamline (MX2) at the Australian Synchrotron as part of the study.

The compound – a modified version of an earlier synthesized ligand – is highly effective in activating human iNKT cells. It is also selective – encouraging iNKT cells to release a specific set of proteins known as Th1 cytokines, which stimulate anti-tumour immunity.

Image: 3D structure of proteins behind interaction of new drug that stimulates immune response to cancer cells. (Entire image here)

Success in clinical trials driving a shift in the treatment of blood cancers

2018/04/132018/04/23

The Australian Synchrotron is proud to be growing Australia’s capacity for innovative drug development, facilitating the advance of world-class disease and drug research through to local drug trials. Recent success in clinical trials of Venetoclax, the chronic lymphocytic leukaemia (CLL) drug developed by researchers from the Walter and Eliza Hall Institute and two international pharmaceutical companies is driving a major shift in the treatment of a range of blood cancers, according to a media information from the Peter MacCallum Cancer Centre.

ID23-EH2: Gearing up for serial crystallography

2018/01/292018/02/01

ID23-EH2 is up and running, catering to small samples and serial crystallography experiments. Its small beam and unique diffractometer are the trademarks of this new MX beamline.

“This is amazing”, says David Drew, a user from Stockholm University, on the new ID23-EH2. “There is a perfect beam line to be screening LCP crystals. After 5 years working on this… it is amazing to be able to speed up finding the best spot to collect”, he adds. Drew and his team are on ID23-EH2. They are the first users since ID23-EH2 opened for business this month and have just started the experiment. He works with his team in transport proteins, which carry nutrients across membrane proteins and are important drug targets.

>Read more on the ESRF website

Picture: Max Nanao with the users from the University of Stockholm (Sweden).

The search for an Ebola vaccine

2018/01/222018/01/24

Researchers expertly solved the crystal structures of drugs bound to the outer coating of the Ebola virus to pinpoint the regions that are essential for inhibitory activity.

Ebola is a viral disease that is highly infectious and associated with a high risk of death. It first arose in 1976, from which point it was associated with dozens of small-scale outbreaks; however, in 2013 Ebola was responsible for a huge epidemic in West Africa. Emergency was declared and over 11,000 people lost their lives to the virus. Despite this horrific state of affairs, Ebola still remains an untreatable disease and there is no vaccine to prevent infection.

A mixtape for drug discovery

2017/11/232017/11/29

New method enables automated fast investigation of enzymatic processes

Scientists at DESY have developed a new method that enables automated and fast screening of promising drug candidates. This novel technique, called mix-and-diffuse serial synchrotron crystallography, can image the interaction of potential drug targets with drug candidates or other molecules. The concept has the potential to take structure and fragment based drug design to a new level, as the researchers write in the Journal of the International Union of Crystallography (IUCrJ).

>Read More on the PETRA III website

Image: Principle of the mix-and-diffuse serial synchrotron crystallography: protein crystals are mixed with a solution of a drug candidate and X-rayed on a tape running through the X-ray beam.
Credit: Beyerlein et al., IUCrJ