Researchers at Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have developed a way to 3D print mineralized constructs with a bit serving to hand from micro organism. The approach consists of printing a polymer bioink that comprises micro organism that can produce calcium carbonate when uncovered to a urea answer. The 2-step course of additionally includes 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 strategy permits researchers to accommodate a number of the limitations of 3D printing, resembling movement necessities for bioinks, however nonetheless create a inflexible mineralized construction that might pave the way in which for bone implants.
Bioprinting goes from energy to energy, with huge potential in creating customized tissue implants to deal with a wide range of circumstances. The printing course of permits researchers to print reside cells and biocompatible matrix supplies to create a residing assemble. Whereas the approach has huge promise, some tissues are tougher than others to print.
First off, bioinks should adhere to a number of fundamental traits with a purpose to be printed successfully. “3D printing is gaining rising significance generally, however the variety of supplies that may be 3D printed is proscribed for the straightforward purpose that inks should fulfill sure movement circumstances,” stated Esther Amstad, a researcher concerned within the examine. “For instance, they have to behave like a strong when at relaxation, however nonetheless be extrudable by way of a 3D printing nozzle — form of like ketchup.”
This movement requirement makes it harder for the ultimate printed product to be inflexible, which is a limitation when printing bone. Previously, researchers have tried to incorporate small mineral particles throughout the ink, however the ensuing printed constructs have been usually too gentle 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,” stated Amstad. “After about 4 days, the mineralization course of triggered by the micro organism within the scaffold results in a remaining product with a mineral content material of over 90%.”
The micro organism throughout 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 sturdy constructs will be decontaminated after this mineralization course of by soaking them in ethanol, making certain that the micro organism don’t make it into the affected person.
Examine in journal Supplies Right this moment: 3D printing of living structural biocomposites
By way of: EPFL