By Meghan Bialt-DeCelie ’19

The explosion of 3-D printing technologies allows custom and precise structures to be made quickly and inexpensively. Researchers led by Thomas Valentin from Brown University utilize stereolithographic 3-D printing to create biocompatible structures that could degrade in response to chemical cues.

The technique of stereolithography involves shooting photons at unpolymerized materials causing them to form crosslinks with themselves to build a structure layer by layer. In this study, researchers performed this type of printing with alginate hydrogels designed to biodegrade on demand. Alginate can ionically bind together via divalent cations in typical physiological environments and can dissociate when those cations are occupied by a compatible chelator. The effectiveness of the alginate to function as a material that can reversibly build structures can vary on the properties of the cations used. Researchers tested various concentrations of barium carbonate, magnesium carbonate, and calcium carbonate cations to create the optimal biomaterial for precise and rapidly degradable 3-D structures.

The adapted alginate hydrogel could form barriers allowing controlled movement of cells without showing signs of toxicity. Structures built with other biomaterials in addition to the reversible alginate opened the door to the possibilities of dynamic and adaptable devices that can be ideal for medical applications such as tissue engineering and drug delivery.  

References

1. Valentin, Thomas, et al., Stereolithographic printing of ionically-crosslinked alginate hydrogels for degradable biomaterials and microfluidics. Lab on a Chip (2017). 18, doi: 10.1039/C7LC00694B
2. Retrieved from: https://commons.wikimedia.org/wiki/File:Stereolithography_apparatus_vector.svg