Scottish Scientists 3D-Print Embryonic Stem Cells: Next Stop, Lab-Grown Organs
A team at Heriot-Watt University in Edinburgh, Scotland has developed a method for 3D-printing clusters of human embryonic stem cells in a variety of sizes. Researchers have successfully printed 3D cells before, but this is the first time that embryonic cell cultures, which are especially delicate, have been built in three dimensions. Human embryonic stem cells can replicate almost any type of tissue in the human body — and the scientists at Heriot-Watt believe that lab-made versions could one day be used to make organ transplants, thereby rendering donors unnecessary. In the nearer future, 3D-printed stem cells could be used to make human tissue models for drug testing; effectively eliminating the need for animal testing.
(via Scientists 3D-print embryonic stem cells, pave the way for lab-made organ transplants)
New 3D Printing Technique Uses Lasers to Construct Molecule-scale Scaffolds to Grow Tissue
The scientists start with a so-called hydrogel — a material made of macromolecules, arranged in a loose meshwork. Between those molecules, large pores remain, through which other molecules or even cells can migrate.
Specially selected molecules are introduced into the hydrogel meshwork, then certain points are irradiated with a laser beam. At the positions where the focused laser beam is most intense, a photochemically labile bond is broken. That way, highly reactive intermediates are created which locally attach to the hydrogel very quickly.
The precision depends on the laser’s lens system, at the Vienna University of Technology a resolution of 4 µm could be obtained.
“Much like an artist, placing colors at certain points of the canvas, we can place molecules in the hydrogel — but in three dimensions and with high precision,” says Aleksandr Ovsianikov.
This method can be used to artificially grow biological tissue. Like a climbing plant clinging to a rack, cells need some scaffold at which they attach. In a natural tissue, the extracellular matrix does the trick by using specific amino acid sequences to signal the cells, where they are supposed to grow.
In the lab, scientists are trying to use similar chemical signals. In various experiments, cell attachment could be guided on two dimensional surfaces, but in order to grow larger tissues with a specific inner structure (such as capillaries), a truly three dimensional technique is required.
(via Laser beam as a ‘3-D painter’ to grow biological tissue or to create micro sensors)
Harvesting Stem-Cells From Liposuction To Grow Blood Vessels For Transplant
Fat tissue is a plentiful source of stem cells.
Matthias Nollert at the University of Oklahoma in Norman and his colleagues coaxed liposuction-derived stem cells into forming smooth muscle cells found in arteries and veins. They then grew these cells along a thin collagen membrane, which was rolled into a tube the size of a small blood vessel.
As the smooth muscle cells grew, the team subjected them to a battery of mechanical stresses that mimic the expansion and collapse that such a vessel would ultimately experience in the heart. The team hope that this will increase the vessel’s robustness in the body.
Unlike artificial stents, which restore blood flow through narrow or once-blocked arteries, vessels made from your own stem cells wouldn’t run the risk of being rejected by the immune system. Side effects that can occur when damaged vessels are replaced with those taken from other parts of the body would also be avoided.
![The History of Bioprinting in an Infographic
(via The Amazing History And Future Of Bioprinting [Infographic] | WebProNews)](http://24.media.tumblr.com/tumblr_m6w8ywO8jl1qgpcs1o1_500.jpg)
The History of Bioprinting in an Infographic
(via The Amazing History And Future Of Bioprinting [Infographic] | WebProNews)
Functioning Sphincters Grown in the Lab
These new sphincters were started by placing human muscles cells and mouse nerve cells in a circular mold. With the right care and feeding, the cells grew and expanded to make actual sphincters. The sphincters were then implanted in mice, and because of their nerve cells, could connect to the animals’ nervous systems and function much the way mice’s original sphincters did.
