Researchers Use 3D Printing for Precise Control in Programmable Release Drug Delivery Capsules

Science, research, and the technologies of the future go hand in hand–and lately we’ve seen their reach expanding and extending in ways none of us ever would have dreamed of. Nanotechnology is responsible for an expansion many of us weren’t expecting so soon either, as it delves into the realm of smart materials (and what is often also termed 4D printing), to include an innovative area where researchers are busy creating products that will adapt to their changing environments.

While smart 3D printed materials can be as simple as something as apparel and how it morphs to fit the form depending on activity and environment, nanotechnology can also extend to a wide variety of printed objects that morph depending on other materials, signals, and various scenarios–including medication–and this all has the potential to happen inside the human body.

Currently, two universities are working together in creating a new 3D printed therapeutic drug that is loaded with biomolecules and encased in “highly monodisperse core/shell capsules.” Michael McAlpine is an associate professor in mechanical engineering at the University of Minnesota and at Princeton University who is currently collaborating with researchers from Washington University in St. Louis. Together, they have just published a paper in Nano Letters on the subject: “3D Printed Programmable Release Capsules.”

Demonstrating exactly what qualifies the 3D printed capsules as smart materials is that they are able to release the drugs one ‘payload’ at a time, due to gold nanorods which are built into the shell structure. The researchers point out in their paper that they are not the first to attempt to integrate biomolecular objects for use in the human body. Their goal is to overcome the challenges in “manipulating and implementing biomolecular gradients into multiplexed, 3D matrices.”

The structural qualities of the capsules, combined with precise control provided by the innovative 3D printing method, is what makes the system work–and according to the researchers, should work better than previous methods.

“This work provides a promising solution to generating multiplexed spatiotemporal molecular gradients in 3D architectures, which is significant to mimic the dynamic microenvironment surrounding cells in natural tissues, as living organisms guide tissue development through highly orchestrated gradients of biomolecules that direct cell growth, migration, and differentiation in 3D matrices,” says Fanben Meng, a postdoctoral researcher in McAlpines Lab.

Their breakthrough offers a ‘powerful new tool’ because of the following specific features:

• Highly monodisperse capsules
• Efficient casing for payloads
• Precise patterning of capsule arrays
• Flexible and programmable reconfiguration of gradients
• Versatility in hierarchical architectures

“Our work was motivated by the fact that living systems utilize exquisite control of biomolecular gradients to control cell fate and ultimately enable complex functional tissues,” says McAlpine. “We believe that replicating such control is a key to many future advances in bioengineering.”

“There has been tremendous prior work on utilizing microfluidics, particle encapsulation, and stimuli-responsive materials to address some of these challenges,” he adds. “Our findings offer a novel perspective by offering a 3D printing based approach to solve these challenges, which has advantages in precision control over volumes, spatial distributions, and diversity of materials including nanomaterials and biomolecules.”

This new 3D printing technique and resulting breakthrough in biomolecular drug delivery is still a work in progress as researchers continue to explore how they can control different aspects of not only the cell, but tissue engineering altogether. They are also working to refine the design of the shells even further.

Obviously, once researchers refine and pay the way with these capsules, they could fill them with numerous materials such as:

• Drugs
• Nucleic acids
• Enzymes
• Growth factors
• Cell markers
• Other functional proteins

Neither the nano- or 3D and 4D printing chatter are apt to end any time soon, and you can expect they will grow further linked as scientists find more uses in a wide range of sectors from medical to defense to materials sciences. Discuss your thoughts in the 3D Printed Programmable Release Drug Delivery Capsules forum thread over at 3DPB.com.