Biotechnology-2020
Wednesday 26 February 2020
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
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 tendons. One 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.
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