Artificial heart
Scientists turn spinach leaf into working heart tissue
Researchers have managed to turn a spinach leaf into working heart tissue and are on the way to solving the problem of recreating the tiny, branching networks of blood vessels in human tissue.
Until now, scientists have unsuccessfully tried to use 3D printing to recreate these intricate networks.
Now, with this breakthrough, it seems turning plants with their delicate veins into human tissue could be the key to delivering blood via a vascular system into the new tissue.
Scientists have managed in the past to create small-scale artificial samples of human tissue, but they have struggled to create it on a large scale, which is what would be needed to treat injury.
Researchers have suggested that eventually this technique could be used to grow layers of healthy heart muscle to treat patients who have suffered a heart attack.
Plants and animals of course have very different ways of transporting chemicals around the body.
However, the networks by which they do so are quite similar.
The authors of the study are publishing their findings in research journal Biomaterials in May
The scientists, from the Worcester Polytechnic Institute wrote: “The development of decellularized plants for scaffolding opens up the potential for a new branch of science that investigates the mimicry between plant and animal.”
In order to create the artificial heart, the scientists stripped the plant cells from the spinach leaves, sending fluids and microbeads similar to human blood cells through the spinach vessels and then “seeded” the human cells which are used to line blood vessels into it.
Glenn Gaudette, professor of biomedical engineering at Worcester Polytechnic Institute, said: “We have a lot more work to do, but so far this is very promising.
“Adapting abundant plants that farmers have been cultivating for thousands of years for use in tissue engineering could solve a host of problems limiting the field.”
Source:http://www.telegraph.co.uk/
Third French artificial heart patient ‘doing well’: Carmat executive
A third patient implanted with an artificial heart made by French firm Carmat is doing well six months after his operation, the company’s CEO said on Wednesday
The 73-year-old patient was operated on April 8 and went home from the hospital in August. The first two patients to receive Carmat artificial hearts have died – the first 74 days after being operated and the second after nine months.
“The third patient is doing well. He lives alone near Strasbourg and goes to the hospital once a week for checks. He has a good quality of life,” Carmat Chief Executive Marcello Conviti told Reuters on the sidelines of a conference in Paris.
He declined to comment on remarks in June by the professor who invented Carmat’s artificial hearts that a fourth patient would be fitted with an implant in the coming months.
Carmat is conducting trials of its heart device that is designed as a permanent implant to extend the life of patients without them having to wait for a human heart donor.
After four patients have received the heart and survived for at least 30 days, the trials are to be enlarged to about 20 patients at the European level.
“Today we’ve had patients exposed to the machine for (a total) of 18 months,” Conviti said. “For now everything is going well.”
Carmat’s first transplant patient, a 76-year-old man, died in March last year, two-and-a-half months after his operation.
The second patient died in May after the artificial heart malfunctioned due to a fault with one of the controls in its motor, but no fundamental problems were found with the device.
First Patient Implanted With Carmat Total Artificial Heart Dies.
A 76-year-old man with end-stage heart failure who was the first person implanted with the world’s first permanent, biosynthetic artificial heart has died 75 days after receiving the device. The patient died March 2, 2014, physicians at European Hospital Georges-Pompidou (EHGP) in Paris announced Monday night.
Assistance Publique — Hôpitaux de Paris (APHP) released a statement saying that the cause of death is being investigated but will not be known until a thorough analysis of medical and technical data is conducted.
“The doctors directly involved in postoperative care wish to emphasize the importance of the first lessons they have learned from this first clinical trial regarding patient selection, postoperative care, treatment, and prevention of complications,” says APHP.
The device manufacturer, Carmat, said it is “of course premature to draw conclusions from a single patient, either before or, in this case, beyond the 30-day postimplantation survival period.”
The patient was the first in a feasibility study aiming to enroll four patients suffering from irreversible end-stage, biventricular heart failure (LVEF <30%) who were not eligible for transplantation. The study is examining patient survival at 30 days, prosthesis function, and patient quality of life.
“We are currently recruiting the other three patients,” explained Prof Christian Latrémouille (EHGP) at a French cardiology society meeting in January. “The total artificial heart bioprosthesis, Carmat, is now [officially] in clinical trials.”
Carmat is not expected to communicate the results of the study until implantation and 30-day follow-up is completed in all four subjects.
The patient, whose name has not been made public, was implanted with the device in mid-December; in February, an update from the hospital indicated that the patient had been taken off anticoagulants on January 10; and as of February 18, it reported he was able to walk without respiratory assistance. French newspaper Le Parisien reported today that no signs of thrombosis were seen on the device after postmortem explantation.
By way of comparison, the first patient to receive a heart transplant in 1967, Louis Washkansky, aged 55, survived the operation and lived for just 18 days before succumbing to massive bilateral pneumonia induced by the immunosuppressive regimen.
Fully Implanted Artificial Heart Mimics Cardiac Physiology
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Carmat total artificial heart.
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The brainchild of renowned cardiologist Prof Alain Cribier, the Carmat pump was designed with a morphology similar to that of the human heart, with two separate ventricles and four bioprosthetic valves. Unlike left ventricular assist devices (LVADs) approved for use in end-stage heart-disease patients, either as destination therapy or as bridges to transplantation, the Carmat, weighing 900 g, is designed to fully reproduce heart function, using biomaterials, including bovine valves.
The device consists of two ventricular cavities with two volume spaces separated by a flexible biomembrane: one for blood and one for the “actioning fluid,” the company website explains. A flexible, external bag contains this actioning fluid and beats at the same rate as a native heart, displacing the biomembrane and mimicking the movement of the native ventricle wall during heart contraction: that motion admits and ejects the blood. A sensor monitors and regulates prosthesis operation according to patient’s needs.
At present, the investigational device is powered either by a hospital-based console or by an external battery with a battery life of four to six hours. An internal backup battery operates the artificial heart for 20 minutes. The company is currently developing a fuel cell that would increase device autonomy to 16 hours.
Space technology company builds a functioning artificial heart.
Space technology company builds a functioning artificial heart
An artificial heart that took 15 years to develop has been approved for human trials. The device, which was fashioned from biological tissue and parts of miniature satellite equipment, combines the latest advances in medicine, biology, electronics, and materials science.
It’s built by the Paris-based company Carmat and it’s the brainchild of French cardiac surgeon Alain Carpentier. The state-of-the-art device is the result of a collaboration with aerospace giant Astrium, the space subsidiary of EADS, along with support from the French government.
In order for it to qualify for human trials, the developers had to create a heart that could withstand the demanding conditions of the body’s circulatory system. It has to pump 35 million times per year for at least five years — and without fail. This is why Carpentier’s team turned to space technology, which is known for its resilience and compact size.
“Space and the inside of your body have a lot in common,” said Astrium’s Matthieu Dollon in an ESA statement. “They both present harsh and inaccessible environments.”
Indeed, Telecom satellites have similar demands placed upon them; they have to last for at least 15 years and function 36,000 km above Earth.
“Failure in space is not an option,” he added. “Nor is onsite maintenance. If a part breaks down, we cannot simply go and fix it. It’s the same inside the body.”
In addition to space-tech, the artificial heart combines synthetic and biological materials as well as sensors and software to detect a patient’s level of exertion and adjust output accordingly. MIT‘s Technology Review explains more:
In Carmat’s design, two chambers are each divided by a membrane that holds hydraulic fluid on one side. A motorized pump moves hydraulic fluid in and out of the chambers, and that fluid causes the membrane to move; blood flows through the other side of each membrane. The blood-facing side of the membrane is made of tissue obtained from a sac that surrounds a cow’s heart, to make the device more biocompatible. “The idea was to develop an artificial heart in which the moving parts that are in contact with blood are made of tissue that is [better suited] for the biological environment,” says Piet Jansen, chief medical officer of Carmat.
That could make patients less reliant on anti-coagulation medications. The Carmat device also uses valves made from cow heart tissue and has sensors to detect increased pressure within the device. That information is sent to an internal control system that can adjust the flow rate in response to increased demand, such as when a patient is exercising.
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