Genetic Engineering Brings Little Shop of Horrors to Life
Bio-Engineering Chimera Parts
The news these days reminds me of a desert landscape as twilight deepens with mirages, undulating shadows, and stark contrasts. I return to cover some of the news from the Exponential Medicine conference in San Diego. One of the speakers was Dr. Andrew Pelling at the University of Ottawa, who was intrigued to see if he could manifest game-changing medicine and bring to life the science fiction movie cult classic The Little Shop of Horrors. Just gist of the movie, if you have not seen it, was the creation of a cannablistic plant called Aubrey 2. Carnivorous plants such as the Venus Fly Trap are a part of the Laws of Nature, but this plant ate people. "What you have here is a plant-like creature with mammalian features," said Pelling at the Exponential Medicine conference. “So we started wondering: can we grow this in the lab?”
Pelling set out to see whether grocery-store-bought plants can supply the necessary structure for engineering replacement human tissues.
Rise of Mechanobiology
Pelling and other innovators are viewing everything in the world as the microenvironment to bio-engineer human tissue and spare parts for the body. Can one, let's say, fabricate a replacement ear? Today, scientists carve and shape bio-compatible materials or 3D print hollow support structures. These would then be seeded with human stem cells and meticulously nurtured and nourished to coax them to grow. After intensive incubation the cells spread as skin-like cells on the scaffold which will eventually become a replacement ear. This is a very laborious and costly procedure. Pelling and researchers began to look at cells as living components that stretch, compress, and sheer producing mechanical forces that can be exploited. Mechanical forces regulate the molecular machinery of your cells. Physical forces can drive cells to divide and migrate through tissues as our genetic code guides the formation of an entire body.
Mechanically stimulating cells changes their behavior. Pelling's team put skin cells in a Petri dish, salted it with cancer cells which instantaneously huddled together into balls with a clearly demarcated barrier between microtumor and skin cells. Things changed when the team simulated breathing by stretching the cells. The result as that the cells became aggressive and bored into the layer of skin.
“There’s no gene modification…or biochemistry going on here. This is a purely mechanical influence,” said Pelling, who discovered that the shape of their microenvironment is enough to direct cell actions into forming three-dimensional complex patterns. The team also discovered that cells learn to separate and spatially pattern over long ranges.
The stage was set to for the team to take their discoveries to the next level, the hybrid apple-ear.
Microscopically, the microenvironment of an apple has the same engineering surfaces for fabricating replacement tissues. That discovery got the team to wonder: is it possible to exploit that surface pattern of plants to grow human organs?
Much as an artist begins their masterpiece with a new canvas, the team washed away all the plant cells, DNA, and biomolecules from an apple. What remained was a fibrous scaffold, a falsework canvas. The team then brushed human and animal cells inside the scaffold and they began to grow. And so they hand-carved an apple into the shape of a human ear, and within a few weeks transformed the apple into a fleshy human ear.
The next step is truly alarming, for when the team implanted this apple scaffolding into a mouse the rodent cells invaded the hybrid matrix and produced new collagen and blood vessels to keep the scaffold alive.
Supposedly, there are three ethical standards for engineered tissues:
They are safe,
They are biocompatible,
They come from a sustainable, ethical source.
“This thing is becoming a living part of the body and it used to be an apple, and we did this by going to the grocery store,” said Pelling.
Moving to the Medical Market
Pelling is especially excited by his finding of the simplicity and elegant exploitation of the physical structure of the plant. We have been on a slippery slope since the advent of genetically modifying of plants with human, animal, insect, and other foreign constructs.
The team will expand this same technology to engineer soft tissue cartilage, bone, and spinal cord and nerve repair. Pelling is excited to see bold ideas translate into a medical revolution. He is convinced that we should not restrict ourselves to the body parts nature gave us. If the shape of a scaffold is the sole determinant of engineering a tissue or organ, why not design our own?
You guessed it, here come the Spock ears! Pelling has commissioned a design company to sketch out the scaffold for three different types of ears: an average human ear, a pointy Spock-shaped one, and a wavy one designed to suppress or enhance different frequencies to augment hearing.
“The point I want to emphasize is…the strength of blue-sky thinking is actually coupling it to the rigor of the scientific method,” Pelling concluded. Ultimately this is how we’ll create more inventions and solve problems.
Blood of the Chimera
Image access: Reservoir of Blood-Forming Stem Cells Discovered in the Human Gut
Inventing scaffolding to augment and alter life is not the only discovery on the table. Scientists at Columbia University’s Vagelos College of Physicians and Surgeons report a surprising new finding: the human intestine may provide up to 10% of blood cells in circulation from its own reservoir of blood-forming stem cells. Previously, blood cells were thought to be created exclusively in the bone marrow from a special population of stem cells. The team’s study (“Human Intestinal Allografts Contain Functional Hematopoietic Stem and Progenitor Cells that are Maintained by a Circulating Pool”) appears in Cell Stem Cell.
https://shepherdsheart.life/blogs/news/genetic-engineering-brings-little-shop-of-horrors-to-life
沒有留言:
發佈留言