BY: LISA MICHAELS
Recent experiments from research scientists at the Chemical and Biological Engineering department of the University of Sheffield, England have led to an exciting medical innovation. Their work has leveraged the use of new 3D inkjet printing technology to produce tiny silk micro-rockets.
These are swimming devices of microscopic dimensions which can be used as a delivery system in bio-research, medicine, and other biological environments. One hope is that the devices might soon be used for delivering drugs to specific locations in the body. This could represent an important breakthrough in the medical field for treating various diseases.
Similar microscopic swimming devices, such as nanobots, have been tested previously for treatments of the human body as well as other biological applications but have typically raised issues of concern. Prior devices tended to be expensive, hard to build to quality specifications and faced problems associated with biodegradability, power supply, size and material used.
The newly designed 3D silk micro-rockets are made out of safe material and are completely biodegradable. The micro-rockets are only 300 microns in length by 100 microns in diameter – about the width of one of the hairs on your head. They create their own thrust in order to “swim” through biological fluids containing a suitable fuel.
By using innovative reactive inkjet printing (RIJ) methods, researchers were able to form tiny “rockets” by the combination of two different solutions. Silk is dissolved in solution and mixed with a reactive enzyme, which is applied by a 3D inkjet printer into a column shape that represents the “rocket”. Printing methanol on top of the silk-enzyme layer triggers a reaction that leads to a rigid outer layer trapping the enzyme within the silk’s lattice structure.
The result forms a unique tool – independent, silk-based micro-rockets with a catalyst which can control distribution and direction of thrust. The secret behind this mode of propulsion is a ground-breaking 3D printing device that can combine the liquid silk with a biological enzyme. The enzyme serves as the catalyst for the thrust, while the silk forms the rocket, resulting in a device that is much safer, simpler, and cheaper to make than similar attempts of the past to create independent delivery mechanisms. This removes some of the major barriers to successful use of micro-rockets outside a laboratory.
The fuel being used is hydrogen peroxide, the same fuel often used in the giant rockets which have taken men to the moon. For our tiny delivery system, when the enzyme-laden silk rocket is placed in a fluid containing this fuel, the enzymes react by releasing oxygen that propels the microscopic rocket. Researchers are able to control the direction and movement of the micro-rocket by adjusting the location of the enzymes within the silk structure.
The Future of Medicine?
The 3D printing technology has many great advantages including limitless applications across different industries. Thanks to 3D printers, the medical industry has seen many great advancements. This research is likely to have a significant impact on cancer treatment and other medical problems, as these 3D-printed devices could feasibly be designed to seek out cancerous growths and destroy harmful cells without causing the damage to the human body usually found in radiation, chemical, or other invasive procedures.
While the idea may have provided some excitement in the possibility of fighting cancer, the little rockets aren’t ready yet for release to the medical community. The hydrogen peroxide fuel being used for thrust is toxic to the human system. In addition, though the tiny rockets are only about the size of a human hair, that’s still too big to be safely injected into your body, as they could easily become lodged in a vein or organ and create additional health risks.
As 3D printing technology progresses, it’s hoped that in the future even finer and more accurate printers could create smaller rockets that could safely pass through the human system without obstructing bodily processes or causing inflammation or injury. In the meantime, however, they may become suitable for medical uses outside the body, such as testing for cancer cells in tissue and blood sample.
3D printing has already enabled great advancements in the field of medicine such as printing body parts and prosthetics. With 3D-printed micro-rockets, scientists have created optimism in the medical community for the potential to deliver drugs directly and precisely within the human body. The technology still needs to be perfected and once it is, it will provide numerous benefits to the medical industry.