One barrier to printing or culturing replacement organs has been the difficulty of getting them to grow blood vessels needed to keep them alive once implanted into a body. Now, nanoengineers at the University of California at San Diego have solved the problem.
Until now, the process of nurturing living blood vessels has been slow. It’s usually produced only one tube at a time. In contrast, the San Diego team has produced “vasculature” – the network of vessels needed for tissues to remain alive. The vessel network also shows promise in integrating with a body’s existing circulatory system.
The process, which takes seconds, begins with a computer making a 3D model of the tissue needing vasculature. The computer sends snapshots of the model to millions of microscopic mirrors that beam the images as patterns of UV light onto a solution of live endothelial cells – which line blood vessels – mixed with polymers that harden when the light strikes them. The polymers create a scaffold that supports the cells as they grow into the network of vessels.
The researchers fashioned test structures, let them grow for a day, then implanted them into mice. Two weeks later, the lab-grown vessels had integrated with the body and were fully functioning.
Next, the researchers will refine the technique to add vessels that carry nutrients to, and waste from, tissues.
Meanwhile, bioengineers at Spain’s Universidad Carlos III de Madrid have developed a 3D printer that can lay down human skin ready for transplanting.
Culturing skin for transplanting to burn or injury patients isn’t new. But, until now, much of the process has been slow and laborious, requiring manual labor and weeks to gin up enough tissue to cover a large burn area, for example.
In contrast, the new printer can spin out a 40-inch-by-40-inch patch of skin in 35 minutes.
The printer first layers the epidermis, the skin’s tough outer layer, and then the dermis, the inner layer. It includes the cells that make the collagen that gives skin elasticity and strength.
The researchers envision making two kinds of skin. One is generic, from off-the-shelf ingredients, that can be used to test cosmetics, bug repellant and other skin-touching products. The other will use cells from a specific individual to make skin only for that person.
The technology is being brought to market by the BioDan Group, a Spanish private-sector biotech firm.
TRENDPOST: Combining 3D bioprinting of bone, skin, vessels and soft tissue with stem-cell technologies that grow new organs will enable medical science to replace or rejuvenate most human parts by 2050.