5 3D Printing Technologies on Every Bioengineer’s Wish List

This photograph shows high throughput bioprinting of cells into microwells. (Image courtesy of Ozbolat Lab/Penn State.)

We can already 3D print custom prosthetics, but today’s bioengineers have even bigger plans for the capabilities that come with 3D printing technology. Here, we take a look at five ways bioengineers want to use 3D printing.

1) Organs-on-a-Chip

Organs-on-a-chip are 3-D systems microengineered to duplicate human tissue. It is the point of intersection between microfluidic fabrication and bioprinting. The main challenge here is in manufacturing and the ability to expand the use of this technology.

This lung-on-a-chip mimics the mechanical and biochemical properties of the human organ. (Image courtesy of Wyss Institute/Harvard.)

However, 3D printing technology can mitigate or even eliminate this issue by significantly reducing production costs. The technology has already been used to grow lung, gut and pancreatic tissues on chips using human stem cells.

"In future studies, more advanced 3D bioprinters that can print a range of viscous materials may be utilized to print and fabricate both the microfluidic platform and patterned complex tissues inside the device simultaneously,” said Savas Tasoglu, assistant professor of mechanical engineering at the University of Connecticut. “Such closed integrated systems will greatly simplify the fabrication of organ-on-a-chip models and enable faster iterations of organ-on-a-chip designs."

2) Skin Manufacturing

Skin bioprinting requires the use of sophisticated machine controls for tissue engineering. This technology is already able to create pigmented skin models, aging skin models, vasculature networks and hair follicles. The printed skin is made from cells set down on a collagen gel. After just 10 days of cultivation, this printed skin already showed signs of intercellular connections and biologically normal cell markers. Engineering researchers have also been able to grow blood vessels this way.

Cosmetics maker L'Oreal has partnered with bioprinting company Organovo to develop 3D-printed skin for cosmetics testing. (Image courtesy of L'Oreal/Organovo.)

While this bioengineering technology is tangibly within reach, the designs necessary to help patients—such as those with burns or chronic wounds—are only beginning to be explored. Regarding the exciting possibilities for this technology, Wei Long Ng and co-authors at the Nanyang Technological University in Singapore commented:

"Although the ultimate goal of bioprinting a skin equivalent with complete functional performance has yet to be achieved, bioprinting shows promises in several critical aspects of skin tissue engineering, including creating pigmented and/or aging skin models, vasculature networks, and hair follicles."

3) Facial Reconstruction

Craniofacial reconstruction requires a significant amount of development in order to realize its true potential. In the short term, 3-D printed scaffolds have shown promise for treating spot defects.

Shirley Anderson's life-like facial prosthetic was made with a 3D-printed mold. (Image courtesy of Formlabs.)

Bone, cartilage, skin, muscle, blood vessels, and nerves have already been printed. However, complex designs for patient implants are still being developed. This technology would benefit people with cancer or patients who have experienced facial trauma.

To achieve this goal, bioengineers must conduct long-term studies and develop sophisticated polymers and a reliable manufacturing process for bioprinted constructs. In the future, a handheld bioprinting device could be used to deliver cells into tissues for treating external craniofacial tissues.

4) Multi-Organ Drug Screens

Neural stem cells (purple) and neurons (green) comprise this brain organoid developed by Madeline Lancaster. (Image courtesy of Madeline Lancaster/IMBA.)

3D bioprinting is demonstrating that precise models can improve the way we evaluate new drugs. For example, it can be used to generate "organoids" made up of multiple cell types, as well as a tumor model with engineered blood vessels. While such approaches could make it possible to quickly monitor drug interactions in real time in multiple organs, much more iteration (e.g., adding blood vessels, connecting organ models) will be needed to realize this vision.

5) Plug-in Blood Vessels

Finally, we look at 3D-printed blood vessel networks in bioengineered tissues. This technology involves stacking 2D layers of cells, or bioprinted 3D networks, which have allowed for a high level of spatial control. Recent research has determined that patterning vascular cells within engineered tissues provides maximum control over the organization of these structures.

This photograph shows inkjet bioprinting for heterocellular tissue models. (Image courtesy of Ozbolat Lab at Penn State.)

A present challenge faced by this technology is the creation of tissues with blood vessel networks for direct connection to arteries or veins. Vascular structures are crucial in ensuring tissue survival following implantation as well as accurate replication of body parts.

"Vascularization is currently regarded as one of the main hurdles that need to be taken to translate tissue engineering to clinical applications at a large scale," said bioengineers Jeroen Rouwkema and Ali Khademhosseini, both of MIT and Harvard. "It is clear that approaches that focus on the active patterning of vascular cells within engineered tissues provide the highest level of control over the initial organization of vascular structures."

For further reading on 3D bioprinting, check out this article on growing living bones to replicate original anatomical structures.