Nanocellulose obtained from wood has amazing material properties. Researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
Empa researcher Michael Hausmann is using nanocellulose as the basis for a new kind of implant made in the 3D printer.
Empa
Researcher Michael Hausmann has printed a human ear made of nanocellulose in a 3D printer. "In viscous state, cellulose nanocrystals can easily be shaped together with other polymers into complex 3-dimensional structures using a 3D printer, such as the Bioplotter," he explains. Once it has hardened, the resulting structure remains stable, regardless of its softness. Hausmann is currently investigating the characteristics of the nanocellulose hydrogel in order to further optimise stability and the printing process. The researcher already used X-ray analysis to determine how the cellulose is distributed and organised in the biopolymer composite.
For the time being, the printed ear consists of only nanocellulose and an additional biopolymer component. The goal, however, is to equip this basic framework with cells and active substances from the human body in order to produce biomedical implants. In this regard, a new project is currently investigating how cartilage cells can be integrated into the framework. As soon as the colonization of the hydrogel with cells is established, nanocellulose based composites in the shape of an ear could serve as an implant for children with an inherited auricular malformation. As the project advances, the hydrogels contained in nanocellulose will also be used for knee implants in cases of joint wear due to, for example, chronic arthritis.
Implant dissolves in the body
Once the implant has been implanted in the body, part of the material can biodegrade and dissolve in the body over time. Although nanocellulose itself is not degraded, it is nevertheless suitable as a biocompatible material for implant frameworks. "It is also the mechanical performance of cellulose nanocrystals that make them such promising candidates because the tiny but highly stable fibres can extremely well reinforce the produced implant," said Hausmann. Moreover, nanocellulose allows the incorporation of various functions by chemical modifications into the viscous hydrogel. This way, the structure, the mechanical properties and the interactions of the nanocellulose with its environment can be specifically tailored to the desired end product. And last but not least, the raw material cellulose is the most abundant natural polymer on earth.