3D-printed, lifelike heart models could help train tomorrow's surgeons (video)
IMAGE: RESEARCHERS HAVE DEVELOPED A WAY TO 3D PRINT A FULL-SIZE MODEL OF A PATIENT'S OWN HEART. view more
CREDIT: AMERICAN CHEMICAL SOCIETY
Full-size, realistic models of human organs could help surgeons train and practice before they cut into a patient. However, it's been challenging to make inexpensive models of a size, complexity and material that simulates human organs. Now, researchers reporting in ACS Biomaterials Science & Engineering have developed a way to 3D print a full-size model of a patient's own heart. Watch a video of how they made the 3D organ here.
For complex heart surgeries, having a chance to plan and practice on a realistic model could help surgeons anticipate problems, leading to more successful outcomes. Current 3D printing techniques have been used to make full-size organ models, but the materials generally don't replicate the feel or mechanical properties of natural tissue. And soft, tissue-like materials, such as silicone rubbers, often collapse when 3D printed in air, making it difficult to reproduce large, complex structures. Eman Mirdamadi, Adam Feinberg and colleagues recently developed a technique, called freeform reversible embedding of suspended hydrogels (FRESH), which involves 3D printing soft biomaterials within a gelatin bath to support delicate structures that would otherwise collapse in air. However, the technique was previously limited to small objects, so the researchers wanted to adapt it to full-size organs.
The team's first step was to show that alginate, an inexpensive material made from seaweed, has similar material and mechanical properties as cardiac tissue. Next, the researchers placed sutures in a piece of alginate, which held even when stretched -- suggesting that surgeons could practice stitching up a heart model made from the material. In preparation for making the heart model, the team modified their FRESH 3D printer to make larger objects. They used this device and magnetic resonance imaging (known as MRI) scans from a patient to model and print a full-size adult human heart, as well as a section of coronary artery that they could fill with simulated blood. The heart model was structurally accurate, reproducible and could be handled outside of the gelatin bath. The method could also be applied to printing other realistic organ models, such as kidneys or liver, the researchers say.
The authors acknowledge funding from the Office of Naval Research, the U.S. Food & Drug Administration and the National Institutes of Health.
The abstract that accompanies this paper can be viewed here.
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3D bioprinted heart provides new tool for surgeons
IMAGE: A 3D BIOPRINTED HEART MODEL DEVELOPED BY ADAM FEINBERG AND HIS TEAM. view more
CREDIT: CARNEGIE MELLON UNIVERSITY COLLEGE OF ENGINEERING
Professor of Biomedical Engineering Adam Feinberg and his team have created the first full-size 3D bioprinted human heart model using their Freeform Reversible Embedding of Suspended Hydrogels (FRESH) technique. Showcased in a recent video by American Chemical Society and created from MRI data using a specially built 3D printer, the model mimics the elasticity of cardiac tissue and sutures realistically. This milestone represents the culmination of two years of research, holding both immediate promise for surgeons and clinicians, as well as long term implications for the future of bioengineered organ research.
The FRESH technique of 3D bioprinting was invented in Feinberg's lab to fill an unfilled demand for 3D printed soft polymers, which lack the rigidity to stand unsupported as in a normal print. FRESH 3D printing uses a needle to inject bioink into a bath of soft hydrogel, which supports the object as it prints. Once finished, a simple application of heat causes the hydrogel to melt away, leaving only the 3D bioprinted object.
While Feinberg's lab has proven both the versatility and the fidelity of the FRESH technique, the major obstacle to achieving this milestone was printing a human heart at full scale. This necessitated the building of a new 3D printer custom made to hold a gel support bath large enough to print at the desired size, as well as minor software changes to maintain the speed and fidelity of the print.
Major hospitals often have facilities for 3D printing models of a patient's body to help surgeons educate patients and plan for the actual procedure, however these tissues and organs can only be modeled in hard plastic or rubber. Feinberg's team's heart is made from a soft natural polymer called alginate, giving it properties similar to real cardiac tissue. For surgeons, this enables the creation of models that can cut, suture, and be manipulated in ways similar to a real heart. Feinberg's immediate goal is to begin working with surgeons and clinicians to fine tune their technique and ensure it's ready for the hospital setting.
"We can now build a model that not only allows for visual planning, but allows for physical practice," says Feinberg. "The surgeon can manipulate it and have it actually respond like real tissue, so that when they get into the operating site they've got an additional layer of realistic practice in that setting."
This paper represents another important marker on the long path to bioengineering a functional human organ. Soft, biocompatible scaffolds like that created by Feinberg's group may one day provide the structure onto which cells adhere and form an organ system, placing biomedicine one step closer to the ability to repair or replace full human organs.
"While major hurdles still exist in bioprinting a full-sized functional human heart, we are proud to help establish its foundational groundwork using the FRESH platform while showing immediate applications for realistic surgical simulation," added Eman Mirdamadi, lead author on the publication.
Published in ACS Biomaterials Science and Engineering, the paper was co-authored by Feinberg's students Joshua W. Tashman, Daniel J. Shiwarski, Rachelle N. Palchesko, and former student Eman Mirdamadi.
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Modeling incorporates imaging data into the final 3D printed object.
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A needle prints the alginate into a hydrogel bath, which is later melted away to leave the finished model.
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