Researchers at Northeastern University and the University of Texas Arlington have developed a new elastic hydrogel material that could significantly advance the 3D printing of soft living tissues, potentially enabling the creation of artificial blood vessels and human organs.
Guohao Dai, a bioengineering professor at Northeastern University, has been instrumental in refining the hydrogel for 3D printing applications.
According to a report from Northeastern University, the new material overcomes critical limitations that have hindered the fabrication of soft tissues.
While 3D printing is already widely used to create hard implants such as cranial plates, hip joints, and prosthetic limbs, the fabrication of soft tissues remains a major challenge.
Dai, whose expertise lies in 3D bioprinting, stem cells, and vascular bioengineering, emphasized the importance of elasticity in maintaining normal tissue function.
Current 3D printing techniques rely on polymers, plastic filaments, powders, or resin to produce rigid objects that harden upon cooling. However, soft tissues require elastic materials capable of stretching and recoiling—properties that existing materials have struggled to achieve.
“Elasticity is very important for maintaining the normal function of the tissue,” Dai said, as quoted by Northeastern University.
To address this issue, Dai collaborated with Yi Hong from the University of Texas Arlington. Hong’s work focused on making hydrogels elastic, while Dai refined their properties to ensure compatibility with 3D printing.
The resulting material, a liquid hydrogel solution, retains its shape after printing and is capable of encapsulating large amounts of water—an essential feature for growing cells in an environment similar to the human body.
Cells are infused into the hydrogel solution prior to printing. Once the structure is formed, it is exposed to blue light, triggering a photochemical reaction that enhances elasticity without harming the living cells.
“You can print any geometry,” Dai explained. “You can print a tube or a blood vessel.”
After printing, the embedded cells multiply and grow inside the structure. To simulate human conditions, the printed vessels are subjected to pulsatile pressure, mimicking the natural blood flow.
Another critical advantage of the newly developed hydrogel is its biodegradability. Since it is a foreign polymer, Dai’s team designed it to degrade completely, allowing the patient’s own cells to replace it with natural collagen and elastin, ultimately forming a strong, functional blood vessel.
“It’s not native to your body, that is why we wanted it to eventually be gone completely,” Dai said.
Despite this promising progress, Dai noted that printed blood vessels cultured for two weeks remain relatively weak and cannot yet withstand human blood pressure.
He suggested that extending the culturing period to two months could help the cells develop a robust structure, although such experiments remain costly.
Researchers are also working to accelerate the hydrogel’s degradation rate, aiming for it to dissolve within two to three months as the cells mature into functional blood vessels.
