Researchers at Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have developed a technique to 3D print mineralized constructs with just a little serving to hand from micro organism. The method consists of printing a polymer bioink that accommodates micro organism that can produce calcium carbonate when uncovered to a urea answer. The 2-step course of additionally entails printing a assemble after which exposing it to urea for a number of days, over which era the micro organism naturally mineralize the construction. The method permits researchers to accommodate a few of the limitations of 3D printing, resembling stream necessities for bioinks, however nonetheless create a inflexible mineralized construction that might pave the way in which for bone implants.
Bioprinting goes from power to power, with monumental potential in creating customized tissue implants to deal with quite a lot of circumstances. The printing course of permits researchers to print reside cells and biocompatible matrix supplies to create a dwelling assemble. Whereas the method has monumental promise, some tissues are tougher than others to print.
First off, bioinks should adhere to a number of primary traits with a purpose to be printed successfully. “3D printing is gaining growing significance basically, however the variety of supplies that may be 3D printed is restricted for the straightforward cause that inks should fulfill sure stream circumstances,” mentioned Esther Amstad, a researcher concerned within the research. “For instance, they have to behave like a stable when at relaxation, however nonetheless be extrudable via a 3D printing nozzle — type of like ketchup.”
This stream requirement makes it harder for the ultimate printed product to be inflexible, which is a limitation when printing bone. Up to now, researchers have tried to incorporate small mineral particles inside the ink, however the ensuing printed constructs had been usually too tender or suffered different mechanical points, together with shrinking and cracking.
“So, we got here up with a easy trick: as an alternative of printing minerals, we printed a polymeric scaffold utilizing our BactoInk, which is then mineralized in a second, separate step,” mentioned Amstad. “After about 4 days, the mineralization course of triggered by the micro organism within the scaffold results in a ultimate product with a mineral content material of over 90%.”
The micro organism inside the ink are referred to as Sporosarcina pasteurii and can produce and secrete calcium carbonate when the researchers expose the printed assemble to a urea-containing answer. Nevertheless, the strong constructs could be decontaminated after this mineralization course of by soaking them in ethanol, guaranteeing that the micro organism don’t make it into the affected person.
Examine in journal Supplies At the moment: 3D printing of living structural biocomposites
By way of: EPFL