3-D Printed Blood Vessels: A New Dimension in Transplant Procedures

There is no underestimating the importance of blood vessels to the human circulatory system. They supply organs with vital nutrients and remove hazardous waste.  Up until now, creating a synthetic network of blood vessels has been scientifically out of reach. Using a  3-D bio-printing technique, a team of researchers from Brigham and Women's Hospital in Boston has successfully managed to fabricate blood vessels. This achievement could be a significant boon to the lives of more than 105,000 Americans awaiting organ donations.

 

Network of Blood Vessels: Source:KomandoNetwork of Blood Vessels: Source:Komando

 

 Supply and demand of blood vessels

The high demand for tissues needed for transplants makes the need for artificial blood vessels constant and significant. The shortage of donors has created a challenging problem, and even for those patients who may be lucky enough to receive a transplant there is always the possibility that the their bodies may reject the foreign tissue.

Bio-printing and organ failure

Bio-printing can revolutionize  the way the medical community deals with organ failure. Bio-printed structures (artificial blood vessels) can be used to save countless lives via transplants or to test the effects of new drugs. In the words of Ali Khademhosseini, PhD biomedical engineer, director of the Biomaterials Innovation Research Center and senior author of a study published online in the journal, Lab on a Chip, "We're trying to create the right architecture for tissues...Previous attempts to  3-D print blood vessels take one or two forms. Researchers either print the actual cells, or they print a structure on which to grow cells, which later dissolves. But printing cells often damages or kills them, and the dissolving structures may contain substances that are harmful to cells."

 

Diagram Illustraitng 3-Printing Process: The TimesDiagram Illustraitng 3-Printing Process: The Times

 

A new study offering new hope

In this study, Khademhosseini and his tream broke new ground by taking a different approach. They printed a template for cell growth that could be extracted later without damaging the cells. Comprised of a sugar-based molecule known as agarose, a polymer (large molecule with many repeated subunits) made from seaweed, which is often used for culturing cells, researchers then implanted the tangled network of blood vessels into a gelatin-like substance known as  hydrogel. This structure became the framework for the growth of mouse cells that developed into blood vessels that could effectively transport nutrients (fluids) to the maturing cells.

 

Blood Vessel System: Source: 3-D PrintingBlood Vessel System: Source: 3-D Printing

 

According to  Khademhosseini, their approach is unique because the fiber templates they have printed can endure being removed to make the necessary channels for blood vessels. In his own words, "This prevents having to dissolve these template layers, which may not be so good for the cells that are entrapped in the surrounding gel."

Problems with this new 3-D printing method

This new method of 3-D printing blood vessels  has amazing potential, but as of yet cannot print very small blood vessels, like capillaries. The materials to date are not strong enough to withstand the process. The plan is to print larger vessels so that the cells could rearrange themselves on the template to form smaller ones. Researchers are also working on current bio-printing methods, particularly on improving materials, resolution and testing of the structures within livng cells and animals.

The future of artificial blood vessels

Progress is moving swiftly in bio-printing research and this process will allow researchers to build organs in the lab. This  is exciting and certain to meet the gowing demands for organ transplants in the neat future.

Closing thoughts on 3-D printing:

3-D printing is already shaking up our age-old notions of what can and cannot be made. ~ Hod Lipson

 


 

 

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