Researchers at the Worcester Polytechnic Institute are developing a method to use the vascular network in spinach leaves to deliver blood, oxygen and nutrients to grow human tissue. (Myocardial Regeneration Lab, Worcester Polytechnic Institute) 
 
 If an overhyped vegetable existed before marketers coined the term superfood — and long before Oprah Winfrey chatted up acai berries with Dr. Oz — look no further than spinach. (Here’s to Popeye, eating the stuff by the can to inflate his biceps.) Spinach alone, of course, won’t pump anyone up. But it does have a few physical properties of the type that excite biomedical engineers. Spinach grows a network of veins, for instance, that thread through its leaves in a way similar to blood vessels through a human heart. 
 
 These leafy veins allowed researchers at Massachusetts’s Worcester Polytechnic Institute to give a new meaning to heart-healthy spinach. The tissue engineers, as they reported recently in the journal Biomaterials, stripped green spinach leaves of their cells. The spinach turned translucent. The scientists seeded the gaps that the plant cells left behind with human heart tissue. Heart cells, in clusters, beat for up to three weeks in this unusual environment. 
 
 The inspiration for the human-plant fusion came over lunch — and, yes, the leafy greens were involved — when WPI bioengineers Glenn Gaudette and Joshua Gershlak began to brainstorm new ways to tackle a deadly medical problem: the lack of donor organs. Of the more than 100,000 people on the donor list, nearly two dozen people die each day while waiting for an organ transplant. 
 
 To meet the demand, scientists have tried to create artificial organs through innovations such as 3-D-printing tissue. So far, however, no one has been able to print a perfect heart. 
 
 “One of the big problems in engineering heart muscle is getting blood flow to all of the cells,” Gaudette, a professor of biomedical engineering at WPI, told The Washington Post. “Heart muscle is pretty thick.” Current technology cannot construct tissue dense enough to replace a damaged heart while also allowing for the tiny blood vessels needed to deliver life-giving oxygen. 
 
 Rather than creating minuscule blood vessels, the scientists decided to borrow from what nature already evolved. First, they removed the cells from spinach leaves purchased at a local market. “We use detergent — soaps — which strips away the cellular material of tissues,” said Gershlak, a WPI graduate student in Gaudette’s lab. “This leaves behind the protein matrix and structure.” The soap punctured plant cell membranes and washed the deflated cells away; the overall effect was not unlike turning over a garden before planting new crops. 
 
 Left behind was cellulose, a plant material known to be compatible with mammal tissue, as well as the intact leaf veins. The scientists seeded the now-vacated cellulose matrix with cardiac muscle cells. After five days, the muscle cells began to beat. 
 
 It was not quite as if researchers grew an entire slab of quivering muscle from spinach. And, though the scientists watched red liquid course through the spinach veins, this was dye, not blood. But to witness individual human cells contracting on a spinach leaf, via microscope, was exciting enough for Gaudette to whip out his cellphone and began recording in grainy video. 
 
 “It was definitely a double take,” Gershlak said, of discovering the beating muscle cells. “All of a sudden you see cells moving.” 
 
 This was not the only instance in which researchers cultivated human tissue on a plant scaffold. Recently, a team of Ottawa scientists stripped an apple of its plant cells, carved a fruit slice to look like a human ear and filled its extracellular matrix with cervical tissue. 
 
 But Gershlak, Gaudette and their colleagues were the first, they said, to use the technique in an attempt to repurpose plant veins. They poured tiny spheres through the spinach leaves. Beads 10 microns in diameter, a size on par with red blood cells, successfully flowed through the vein network. 
 
 Though these early experiments served as proof-of-concept work, Gaudette said the study could be the foundation for stitching the veins of spinach leaves to human blood vessels. “Long term, we’re definitely envisioning implanting a graft in damaged heart tissue,” he said. 
 
 But the researchers first need to make sure that plant scaffolds like these would not be rejected, once inside a host. They also plan to make their heart-spinach hybrids stronger. “If we stack decellularized leaves, can we create a large thickness,” Gaudette wondered, “more along the thickness of a human heart wall?” 
 
 One advantage of working with plants was the cornucopia of options at the scientists’ disposal. In the new report, the biomedical engineers successfully stripped plant cells from parsley, peanut hairy roots and a species of wormwood in addition to spinach. The biomedical engineers imagined that a piece of broccoli or cauliflower, once stripped of its cells, could be a foundation for growing lung tissue. And researchers in Wisconsin, collaborating with the WPI lab, recently strolled through their campus arboretum, plucking exotic leaves to test. 
 
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 Meet the mesentery: Irish scientists say this gut membrane should be upgraded to an organ ||||| One in 10 American adults will have some level of chronic kidney disease, according to the Centers for Disease Control and Prevention. Currently around 600,000 patients in the U.S. have chronic kidney failure. Most rely on dialysis while a fraction of them actually get transplants. Scientists from the University of California, San Francisco are on a mission to create a sophisticated artificial kidney device made with human kidney cells, silicon nanofilters and powered by blood pressure. The project, led by UCSF nephrologist William Fissell and bioengineering professor Shuvo Roy, aims to begin testing the kidney device in 2017. 
 
 Little by little, bioengineered intestines are being grown in the lab to diagnose digestive disorders and to help patients born without a piece of intestine. In 2011, Cornell biological and environmental engineering assistant professor John March began collaborating with Pittsburgh-based pediatric surgeon David Hackam on a small artificial intestine using collagen and stem cells. Then last year in Switzerland, EPFL professor Martin Gijs led a project in the Laboratory of Microsystems to create a miniature intestinal wall from cultured epithelial cells and electronics called NutriChip to identify foods that cause inflammation. Scientists at Harvard’s Wyss Institute also made a “gut-on-a chip” to mimic the real thing using intestinal cells in a tiny silicon polymer device. 
 
 When a ruptured or degenerating disc causes chronic back pain, treatment is limited. At worst, patients undergo surgery to fuse vertebrae together and then have limited flexibility. Over the past several years artificial discs have emerged as an alternative, but they can wear out as they work. In 2011, a research team from Cornell University bioengineered implants using gel and collagen seeded with rat cells that were then successfully placed into rat spines. This summer Duke bioengineers took things further, coming up with a gel mixture they think can help regenerate tissue when injected into the space between discs. 
 
 In April, after an international team of surgeons spent nine hours operating on her at Children's Hospital of Illinois in Peoria, 32-month old Hannah Warren became the youngest patient to ever receive a bioengineered organ. Scientists had made a windpipe for her using her own bone marrow cells. Born without a trachea, she needed help breathing, eating, drinking and talking. Harvard Bioscience created the custom scaffold and bioreactor for the experimental procedure. Sadly Hannah died on July 7 due to complications from a more recent surgery on her esophagus. Despite the high risks, bioengineers say they will continue to move ahead. 
 
 Bioengineers are working on it, but the liver is one of the largest, most challenging organs to recreate. In 2010 bioengineers at Wake Forest University Baptist Medical Center grew miniature livers in the lab using decellularized animal livers for the structure and human cells. This month, a team from the Yokohama City University Graduate School of Medicine published results of a study where they reprogrammed human adult skin cells, added other cell types, and got them to grow into early-stage liver “buds.” Currently the scientists can produce about 100 of them, but the study’s lead author Takanori Takebe told the Wall Street Journal that even a partial liver would require tens of thousands. 
 
 Artificial heart devices have been surgically implanted since the 1980s, but no device has been able to replace the human heart as effectively as a healthy biological one. After all, a human heart pumps 35 million times in a single year. Recently scientists have made advances in adding more biological material to artificial heart devices. In May the French company Carmat prepared to test an artificial device containing cow heart tissue. At Massachusetts General Hospital, surgeon Harald C. Ott and his team are working on a bioartificial heart scaffold while MIT researchers recently printed functional heart tissue from rodent cells. 
 
 Being able to make blood vessels in the lab from a patient’s own cells could mean better treatments for cardiovascular disease, kidney disease and diabetes. In 2011, the head of California-based Cytograft Tissue Engineering reported progress in a study where three end-stage kidney disease patients were implanted with blood vessels bioengineered in the lab. After eight months the grafts continued to work well, easing access to dialysis. Then this month a team at Massachusetts General Hospital found a way to encourage stem-like cells to develop into vascular precursor cells, a key step on the way to becoming blood vessel cells. They generated long-lasting blood vessels in living mice. 
 
 Surgeon Anthony Atala directs the Wake Forest Institute for Regenerative Medicine and is known for growing new human cells, tissues and organs -- particularly ones that advance urology. Atala and his team’s bioengineered bladders succeeded in clinical trials. The bladders were constructed from patients’ cells that were grown over two months on a biodegradable scaffold and then implanted. Patients included children with spina bifida who risked kidney failure. It’s been several years since then and the results are positive. “These constructs appear to be doing well as patients get older and grow,” Atala told the NIH Record. 
 
 Reproducing 3-D biological structures, particularly the complex human ear, presents significant challenges for bioengineers. A team at Princeton University led by mechanical and aerospace engineering associate professor Michael McAlpine used 3-D printing technology to make a functional ear from calf cells and electronic materials. The ear that debuted in May 2013 is no mere replacement -- it can pick up radio frequencies well beyond the range that human ears normally detect. 
 
 Producing small amounts of artificial skin to graft on patients and use for toxicity testing has been possible for years. Human skin cells are cultivated in the lab and then embedded in a collagen scaffold. In 2011, the Fraunhofer Institute for Interfacial Engineering and Biotechnology introduced a system that can rapidly manufacture two-layer artificial skin models. Their Tissue Factory has the capacity to make 5,000 skin sheets in a month. 
 
 When physicians run out of treatment options they look to a nascent field known as bioengineering. Specialized scientists apply engineering principles to biological systems, opening up the possibility of creating new human tissue, organs, blood and even corneas such as the one shown here. Waiting lists for organ transplants continue to be lengthy so the race to save lives with bioengineered body parts is on. Here’s a look at some of the most notable achievements in recent years. 
 
 For the first time, scientists have used stem cells to grow an adult-size human ear on the back of a rat. 
 
 The scientists, who come from the University of Tokyo and Kyoto University, say the ear could be grown to repair faces disfigured in battle or accidents and also help people born without ears or with ear deformities. 
 
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 In the United States alone, a range of about 1 to 5 children out of 10,000 are born with misshapen or missing ears. 
 
 To grow the ear, the team induced pluripotent stem cells to grow into ear cartilage. Those cells were then placed into a kind of biological tubing shaped roughly as an ear. 
 
 The ear form was then implanted under the skin of a live rat and the cells were left to grow for about two months. Around that time, the tubes dissolved, leaving behind the human ear about 2 inches long. 
 
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 It’s not the first time researchers have grown an ear on the back of a rat. 
 
 Back in 2013, a team from Massachusetts General Hospital in Boston used bovine collagen and cells from sheep to grow an ear on a titanium wire frame shaped like the body part. 
 
 So-called tissue engineering is being explored to grow other kinds of body parts, too, including noses and windpipes. 
 
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 The Japanese researchers say because their ear is a living part, it would develop as a child grew. 
 
 They hope to start clinical trials in about five years. 
 
 via The Daily Mail ||||| Photo 
 
 The pigs, all 14 of them, are doing fine. Considering they’d been retrofitted with bone grown in a laboratory, that came as a pleasant surprise. 
 
 “The pigs woke up, and a half-hour later they were eating,” said Gordana Vunjak-Novakovic, a professor of biomedical engineering at Columbia University. “We thought they would be in pain. But no, they’re doing great.” 
 
 Dr. Vunjak-Novakovic and her colleagues have managed to create living bone from stem cells. First, they made a CT scan to create a 3-D image of each pig’s jaw. From cow bone, they sculpted a “scaffold” — a three-dimensional copy of the pig bone. 
 
 They put the scaffold in a nutrient solution along with stem cells extracted from the pigs. The cells attached to the scaffold, forming a new bone identical to the original. Then the researchers implanted the new bone in each pig. They reported their results in Science Translational Medicine. 
 
 There was no problem with rejection, and the new bone integrated with the pig’s own tissue. Clinical trials in humans, however, are at least three years away.
– Popeye knew a thing or two about building muscle, maybe even more than we realized. Per National Geographic, scientists have appropriated the cartoon character's favorite snack—a spinach leaf—to help create new human heart muscle. In doing so, they circumvented a tissue issue that's plagued this type of regenerative medicine and carved a path toward facilitating organ repair down the road. The study published in the Biomaterials journal details that challenge: even though researchers have been able to formulate human heart tissue in a lab, working up the vessels to deliver nutrients to that tissue has been problematic. "The main limiting factor … is the lack of a vascular network," study co-author Joshua Gershlak says in a video on the study. Which is where Popeye's plant food comes in. Scientists at Worcester Polytechnic Institute took a spinach leaf—with its own system of tiny veins to keep it fed and hydrated—removed its plant cells, and then immersed the leaf in a bath of human cells, using the leaf as a "scaffolding" of sorts. They pumped fluids and microparticles through the leaf's veins to demonstrate how oxygen could one day similarly flow through such a vascular system to keep human heart tissue healthy. The researchers were even able to see clusters of the cells "beating" within the leaf. "It was definitely a double take," Gershlak says, per the Washington Post. He and co-author Glenn Gaudette, both bioengineers, came up with the idea while eating lunch one day (which included spinach) and talking about the dearth of donated organs. (In the meantime, please wash that dirty spinach before you chow down.)