WHEN BRAIN SURGEONS sit down with patients, the treatment would be much easier if they could simply offer replacement parts.
That鈥檚 impossible to do today, but it鈥檚 not entirely wishful thinking. 新澳门六合彩内幕信息 Davis neurosurgeon Ben Waldau actually has had some groundbreaking success growing parts of human brains.
鈥淚t鈥檚 possible that someone is going to have a stroke and lose function in a portion of their brain,鈥 he said, adding that a specialized bit of brain tissue, or organoid, 鈥渃ould someday be grown to replace it.鈥
The latest development by Waldau and a team from the doesn鈥檛 look like much to the untrained eye: tiny gray blobs no wider than a pencil lead, grown from a volunteer鈥檚 stem cells. What makes these organoids different is what鈥檚 inside: human blood vessels.
Researchers have been able to grow brain organoids before, but without blood vessels the tissue would always die when it reached a certain size. Waldau鈥檚 team was able to show that the lab-grown organoids could grow their own human blood vessels 鈥 a process called vascularization 鈥 when they were coated in the kind of cells that form the lining of blood vessels, with the growth continuing for two weeks after an organoid was implanted in a mouse.
鈥淚t鈥檚 pretty cool that we can show that it鈥檚 connecting with that tissue and surviving,鈥 said Whitney Cary, laboratory manager and director of a team of stem cell specialists at the institute.
The results, , show a possible path to even larger organoids.鈥淰ascularizing organoids opens the door to growing larger organoids and maybe making organoids that are more similar to what we find in the human body,鈥 said Missy Pham, a researcher at the institute and another of Waldau鈥檚 collaborators on the study.
The 新澳门六合彩内幕信息 Davis team couldn鈥檛 tell if the blood vessels actually contained blood because the organoids had to be cut and stained before they could be examined through a microscope, and any blood would have been washed away. But it鈥檚 still a crucial development that shows promise.
鈥淚f a graft is already vascularized it may connect to the host tissue better and it may survive better,鈥 Waldau said.
This doesn鈥檛 mean that scientists will someday grow entire human brains. There would be no point even if they could because brain tissue made in a lab wouldn鈥檛 know what signals to send to the body.
Waldau, though, wants to create new sections of the brain to replace damaged parts, like a motor cortex, for instance.
He knows it鈥檚 a long shot, and if it works, it鈥檒l be decades before it鈥檚 available to patients.
There are many hurdles to overcome: ethical issues, safety concerns, clinical trials and more 鈥 but those tiny gray blobs could change lives.
Current treatments are limited
wishes those replacement parts were available today. He is a 新澳门六合彩内幕信息 Davis Health neurocritical care specialist who treat patients in intensive care after a stroke or traumatic brain injury. When he sees a patient, it鈥檚 often during one of the most challenging experiences of their life.
鈥淚t鈥檚 life-altering, and usually not in a good way,鈥 Martin said. 鈥淵ou鈥檙e normal and then five minutes later you have a severe neurologic problem. It鈥檚 not something you can prepare for.鈥
When brain cells are damaged, they don鈥檛 have a way to recover. 鈥淲hen the brain dies, it dies,鈥 he said.
Sometimes other parts of the brain can be trained to take over some of the function that was lost, but it鈥檚 not a perfect system and often leads to an incomplete recovery. Having replacement parts could lead to full recovery, so Martin couldn鈥檛 be more interested in Waldau鈥檚 success.
鈥淚f we can harness the power he has in the lab and apply that to someone鈥檚 brain, the results could be very powerful,鈥 Martin said. 鈥淚 still think we鈥檙e decades away from that happening, but it鈥檚 not fiction.鈥
Brain organoids could have other uses
Even if brain organoids don鈥檛 end up in a patient鈥檚 skull, they could provide a testing model for a critical brain function that science doesn鈥檛 fully understand.
For example, Lillian Cruz-Orengo wants to know why the brain sometimes fails to block out immune cells that can mistakenly attack perfectly healthy parts of the brain, leading to neurological diseases like multiple sclerosis.
An assistant professor of anatomy, physiology and cell biology in the 新澳门六合彩内幕信息 Davis School of Veterinary Medicine, Cruz-Orengo is working to create better models of the blood-brain barrier so she can better understand it limitations.
鈥淢y focus is, 鈥榃hy does the blood-brain barrier allow the immune cells to get in?鈥 Because a competent blood-brain barrier doesn鈥檛 let immune cells get in.鈥
Blood vessels in the brain are lined with special cells 鈥 the same kind Waldau鈥檚 team used to coat the organoids 鈥 that allow certain materials to pass through, but keep out pathogens and harmful drugs. Damage to the barrier, or leaks, can lead to multiple problems, like neurologic dysfunction, infection, inflammation and death.
Waldau hopes the vessels in his brain organoids will develop these barriers so they function properly and can be used for the kind of life-saving medical research Cruz-Orengo conducts.
For now, Cruz-Orengo is able 鈥 with some difficulty 鈥 to trick cells derived from a human blood-brain barrier to retain their specific properties in a petri dish.
But, as with the recovery of brain-injured patients, there鈥檚 no substitute for the real thing.
Media contact: Cody Kitaura, 新澳门六合彩内幕信息 Davis News and Media Relations, 530-752-1932, kitaura@ucdavis.edu
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