3D Printed Blood Vessels Contract Like Human Vessels
A blood vessel sample templates which Rice University bioengineers 3D printed using a special blend of powdered sugars. This powder is a special ingredient in the recipe for mimicking the body’s complex branched blood vessels in lab-grown tissues. Bio-engineers have shown that they could keep packed cells alive for at least two weeks in relatively large constructs by creating complex blood vessels network from 3D printed sugar. The researchers joined on this project by colleagues from Washington school of medicine and the college of engineering and some other renowned institutions.
One of the major hurdles in engineering relevant tissues packing a large structure with millions of living cells. Delivering enough oxygen and nutrients to all of the cells across a large volume of tissues becomes a monumental challenge. The researcher explained that nature solved the problem through the evolution of complex vascular networks that weave through tissues and organs in patterns.
These vessels simultaneously become smaller in thickness but greater in number as they got branch away from the main central trunk. This branching allows oxygen and other important nutrients to be efficiently transferred to cells throughout the body. Developing new technologies and materials to mimic naturally happening vascular networks; we are getting closer to that point where we can get oxygen and nutrients to a sufficient number of cells to get long term therapeutic functions.
Sugar templates were printed with an open-source, modified laser cutter in the lab. It is like making a very precise crème Brulee whose original inspiration for the project was a complicated dessert. The complex and detailed structures are designed possible by selective laser sintering a 3D printing process that fuses minute grains of powder into solid 3D objects.
In contrast to some other common extrusion 3D printing, where melted strands of material are deposited using a nozzle, laser sintering works by softly melting and combining small regions in a packed bed of dry powder. Both extrusion and laser sintering build 3D shapes one 2D layer at a time, but the laser technology enables the generation of structures that would be prone to cave in if extruded.
A few years back artificial blood vessels have been created using human cells and 3D printing can contract like natural human vessels; making them potentially practical for clinical usage. Following successful testing in rats, researchers claimed that these new blood vessels are fully functional and they are outperforming with the existing engineered tissues.
These biometric vessels were made using triple-coaxial 3D bio-inks, formulated from smooth muscle cells taken from the human aorta and endothelial cells from the umbilical veins. These fabricated vessels have dual-layer architecture. These artificial blood vessels are important tools that can help save patients suffering from cardiovascular diseases. There are some products in clinical usage designed from polymers but they don’t have living cells and vascular functions.
Some of the earlier attempts to build small-diameter blood vessels are fragile and easily damaged this is what scientists said. They use a stripped-down version of extracellular material such as collagen-based bio-inks. Whereas material from native blood vessels contains collagen plus diverse bimolecular which provides some microenvironment for cell growth by preserving the complexity of blood vessels. Researchers announced that this provides enhanced strength and anti-thrombosis function.
These blood vessels get matured in a laboratory designed to tune the biological and physical characteristics to precise wall thickness, alignment, burst pressure, and ability to contract.
The lab-made vessels are grafted into six rats as abdominal aorta; over several weeks the scientists observed that rats fibroblasts forming layers of connected tissues on the implant surface, which integrate into the living and existing tissues. The researcher aims to improve the vessel’s strength and planning a long-term evaluation of vascular grafts.