Thursday, 8 August 2019

Artificial enzymes perform reactions on living cells

Nature has evolved thousands of enzymes to facilitate the many chemical reactions that take place inside organisms to sustain life. Now, researchers have designed artificial enzymes that sit on the surfaces of living cells and drive reactions that could someday target drug therapies to specific organs.

What does that mean??

Metalloenzymes are a class of enzymes that contain a metal ion, such as zinc, iron or copper. The metal ion helps the enzyme speed up, or "catalyze," chemical reactions that would otherwise occur very slowly or not at all. Scientists would ultimately like to develop a method to produce therapeutic drugs only at the sites of specific cells or organs of the human body, which could reduce side effects, and enzymes could help them reach that goal. Researchers set their sights on engineering an artificial enzyme that could catalyze a useful reaction, called the Diels-Alder reaction, right on the surfaces of living cells. Chemists use this reaction to synthesize drugs, agrochemicals, and many other molecules.

How do they work on it:

To make their artificial enzyme, the researchers began with a protein called the A2A adenosine receptor, which is naturally present on the surfaces of some cells in the body. They modified a molecule that binds to this receptor with a copper-containing the chemical group that catalyzes the Diels-Alder reaction. When the researchers placed the resulting compound in a culture dish containing living human cells, it attached to the A2A adenosine receptors on the cells, forming an artificial enzyme. This enzyme catalyzed the Diels-Alder reaction with an up to 50 percent yield. The researchers say that in the future, artificial enzymes might be designed that bind to proteins found only on specific cell types, for example, cancer cells. Then, the enzyme could convert an inactive compound into a drug to selectively kill those cells.

Tuesday, 23 July 2019

Scientists recreate blood-brain barrier defect outside the body

Scientists can't make a living copy of your brain outside your body. That's the stuff of science fiction. But in a new study, they recreated a critical brain component, the blood-brain barrier that functioned as it would in the individual who provided the cells to make it. Their achievement provides a new way to make discoveries about brain disorders and, potentially, predict which drugs will work best for an individual patient.

What’s the function of BBB?

The blood-brain barrier acts as a gatekeeper by blocking toxins and other foreign substances in the bloodstream from entering brain tissue and damaging it. It also can prevent potential therapeutic drugs from reaching the brain. Neurological disorders such as amyotrophic lateral sclerosis (Lou Gehrig's disease), Parkinson's disease and Huntington's disease, which collectively affects millions of people, have been linked to defective blood-brain barriers that keep out biomolecules needed for healthy brain activity.

How it was generated:

For their study, a team of investigators generated stem cells known as induced pluripotent stem cells, which can produce any type of cell, using an individual adult's blood samples. They used these special cells to make neurons, blood-vessel linings, and support cells that together make up the blood-brain barrier. The team then placed the various types of cells inside Organ-Chips, which recreated the body's microenvironment with the natural physiology and mechanical forces that cells experience within the human body.

The living cells soon formed a functioning unit of a blood-brain barrier that functions as it does in the body, including blocking entry of certain drugs. Significantly, when this blood-brain barrier was derived from cells of patients with Huntington's disease or Allan-Herndon-Dudley syndrome, a rare congenital neurological disorder, the barrier malfunctioned in the same way that it does in patients with these diseases.

Well!! This was not the first time:

Scientists have created blood-brain barriers outside the body before, this study further advanced the science by using induced pluripotent stem cells to generate a functioning blood-brain barrier, inside an Organ-Chip, that displayed a characteristic defect of the individual patient's disease.

The study's findings open a promising pathway for precision medicine. The possibility of using a patient-specific, multicellular model of a blood-brain barrier on a chip represents a new standard for developing predictive, personalized medicine.

Thursday, 18 July 2019

Eggshells can enhance the growth of new, strong bones

Eggshells can enhance the growth of new, strong bones needed in medical procedures, a team of researchers has discovered.

Through the innovative process, crushed eggshells are inserted into a hydrogel mixture that forms a miniature frame to grow bone in the laboratory to be used for bone grafts. To do so, bone cells would be taken from the patient's body, introduced into this substance and then cultivated in an incubator before the resulting new bone is implanted into the patient.

How it works:

The research demonstrates that when eggshell particles - which are primarily made of calcium carbonate - are incorporated into the hydrogel mixture, they increase bone cells' ability to grow and harden, which could potentially result in faster healing. And, because the bone would be generated from cells taken from the patient, the possibility the individual's immune system would reject the new material is greatly reduced.
The process could also be used to help grow cartilage, teeth, and tendonsOne day, eggshell particles could also serve as a vehicle to deliver proteins, peptides, growth factors, genes and medications to the body.

Tuesday, 25 June 2019

Edible insects? Lab-grown meat? The real future food is lab-grown insect meat

Livestock farming is destroying our planet. It is a major cause of land and water degradation, biodiversity loss, acid rain, coral reef degeneration, deforestation and of course, climate change. Plant-based diets, insect farming, lab-grown meat, and genetically modified animals have all been proposed as potential solutions. Which is best? All of these combined, say researchers.

Alternatives to conventional meat farming:

Genetically modified livestock, for example, that produce less methane or resist disease can do little to relieve issues like land and water degradation, deforestation and biodiversity loss. But for meat-lovers, soy- or mushroom-based substitutes just don't hit the spot -- and some plant crops are as thirsty as livestock.

Insect farming has a much lower water and space requirement, think vertical farming and twice as much of a cricket is edible than of a big-boned, big-bellied cow. Unsurprisingly though, creepy crawlies are proving even harder for consumers to swallow.

Finally, lab-grown meat could squeeze water and space savings furthest of all, without compromising on taste. Culturing beef, pork or chicken cells might require even more energy and resources than livestock farming

Lab-grown insect meat:

Research for these applications has led already to inexpensive, animal-free growth media for insect cells including soy and yeast-based formulas as well as successful 'suspension culture'.

Technology developed to stimulate the movement of insect tissue for bio-robotics could also be applied to food production, since regular contraction may be required for cultured insect muscle to develop a 'meaty' texture. A particularly efficient method is optogenetic engineering, whereby cells are made to contract in response to light by introducing a new gene -- another advantage of insect cells, which more readily accept genetically modifications then do other animal cells.


How will it tastes?

So, future food production could be a sight to behold: silent discos of insect muscles, flexing to the pulse of lasers in vast pools of soy juice. But how will it taste?

According to researchers, despite this immense potential, cultured insect meat isn't ready for consumption. Research is ongoing to master two key processes: controlling the development of insect cells into muscle and fat and combining these in 3D cultures with a meat-like texture. For the latter, sponges made from chitosan a mushroom-derived fiber that is also present in the invertebrate exoskeleton are a promising option.

Friday, 21 June 2019

Meditation and Yoga can 'reverse' DNA reactions which cause Stress

Mind-body interventions (MBIs) such as meditation, yoga and Tai Chi don't simply relax us; they can 'reverse' the molecular reactions in our DNA which cause ill-health and depression, according to a study.

Reason of Stress:

When a person is exposed to a stressful event, their sympathetic nervous system (SNS) -- the system responsible for the 'fight-or-flight' response -- is triggered, in turn increasing production of a molecule called nuclear factor kappa B (NF-kB) which regulates how our genes are expressed.

NF-kB translates stress by activating genes to produce proteins called cytokines that cause inflammation at the cellular level -- a reaction that is useful as a short-lived fight-or-flight reaction, but if persistent leads to a higher risk of cancer, accelerated aging and psychiatric disorders like depression.

How it works:

According to the study, however, people who practice MBIs exhibit the opposite effect - namely a decrease in the production of NF-kB and cytokines, leading to a reversal of the pro-inflammatory gene expression pattern and a reduction in the risk of inflammation-related diseases and conditions.

More needs to be done to understand these effects in greater depth, for example how they compare with other healthy interventions like exercise or nutrition. But this is an important foundation to build on to help future researchers explore the benefits of increasingly popular mind-body activities.

Tai Chi improving brain metabolism:

A growing body of evidence consisting of morphological magnetic resonance imaging (MRI) and functional MRI data suggests that Tai Chi can induce beneficial neuroplasticity. As a result, recent literature suggests the use of Tai Chi to treat both physical and psychological disorders, including stroke, Parkinson's disease, traumatic brain injury, and depression.

Tuesday, 11 June 2019

The bacteria building your baby

The bacteria building your baby: 

Exposure to influential bacteria begins before we are born, new evidence confirms

Researchers have laid to rest a longstanding controversy: Is the womb sterile? A new study used uniquely rigorous contamination controls to confirm that exposure to bacteria begins in the womb and could help to shape the developing fetal immune system, gut, and brain.

The not-so-sterile womb:

Over the last decade, numerous studies have detected bacterial DNA in amniotic fluid and first-pass meconium [baby's first poop], challenging the long-held assumption that the womb is sterile
It is important to conclusively determine whether the healthy womb harbors bacteria say the researchers, because this 'fetal microbiome' would likely have a significant impact on the developing immune system, gut, and brain.

The fetal microbiome:

Interestingly, the meconium microbiome varied hugely between individual newborns. The amniotic fluid microbiome, for the most part, contained typical skin bacteria, such as Propionibacterium acnes and Staphylococcus species.

A developmental role:

But what might these bacteria be doing in the womb?

None of these women or their babies had any sign of infection. In fact, the fetal microbiome may prove to be a beneficial regulator of early development.

Researchers have found that levels of important immune modulators in meconium and inflammatory mediators in amniotic fluid varied according to the amount and species of bacterial DNA present. This suggests that the fetal microbiome has the potential to influence the developing fetal immune system.

Monday, 3 June 2019

Transgenic fungus rapidly killed malaria mosquitoes in West African study

Transgenic fungus rapidly killed malaria mosquitoes in West African study

A fungus - genetically enhanced to produce spider toxin - can rapidly kill huge numbers of the mosquitoes that spread malaria, a study suggests.
Trials, which took place in Burkina Faso, showed mosquito populations collapsed by 99% within 45 days. The researchers say their aim is not to make the insects extinct but to help stop the spread of malaria. The disease, which is spread when female mosquitoes drink blood, kills more than 400,000 people per year.
Worldwide, there are about 219 million cases of malaria each year.

How it was done??

1.  Conducting the study, researchers at the University of Maryland in the US - and the IRSS research institute in Burkina Faso - first identified a fungus called Metarhizium pingshaense, which naturally infects the Anopheles mosquitoes that spread malaria.

2.  The next stage was to enhance the fungus. "They're very malleable, you can genetically engineer them very easily," Prof Raymond St Leger, from the University of Maryland. They turned to a toxin found in the venom of a species of funnel-web spider in Australia. The genetic instructions for making the toxin were added to the fungus's own genetic code so it would start making the toxin once it was inside a mosquito.
Laboratory tests showed the genetically modified fungus could kill quicker, and that it took fewer fungal spores to do the job. 

3.  The next step was to test the fungus in as close to real-world conditions as possible. 
A 6,500-sq-ft fake village - complete with plants, huts, water sources and food for the mosquitoes - was set up in Burkina Faso. It was surrounded by a double layer of mosquito netting to prevent anything from escaping. 
The fungal spores were mixed with sesame oil and wiped on to black cotton sheets. The mosquitoes had to land on the sheets to be exposed to the deadly fungus. The researchers started the experiments with 1,500 mosquitoes. 
Tests also showed the fungus was specific to these mosquitoes and did not affect other insects such as bees.

Artificial enzymes perform reactions on living cells

Nature has evolved thousands of enzymes to facilitate the many chemical reactions that take place inside organisms to sustain life. Now...