3D structures made of collagen using mold design and fabrication
Matrix proteins are an important aspect of maintaining signaling cascades necessary for growth and homeostasis within 3D cellular environments. However, native matrix materials such as collagen contain properties that make it difficult to extrude and subsequently maintain shape fidelity during the 3D bioprinting process. The ability to place materials that are difficult to print within a mold that is fabricated makes it possible to generate complex 3D structures consisting of native matrix materials such as collagen. TSIM® contains a tool which creates a mold around a structure of interest, and properties regarding the mold are sent to the BioAssemblyBot® for 3D fabrication.
Creating a mold around a structure of interest
In this example, a structure is created de novo using the different shape tools within TSIM®. The shapes are then brought together through Boolean operations (Combine two objects tool) creating the final structure of interest. Once this structure is selected, the Create a mold tool is used to generate a mold around the newly created objected. It will create a square mold around the object, after the mold is generated, it will behave as an independent object, and can be manipulated as desired. After the desired location and structure is finalized, a material is then assigned to the structure including necessary print parameters for the successful fabrication of the design.
3D fabrication of a structure using native matrix material
The design and print parameters created within TSIM® are sent to the BioAssemblyBot® for 3D fabrication. In this example, the mold structure is created using a pluronic hydrogel printed with a petri dish. Type I collagen was then poured into the structure quickly to ensure the collagen remained cold and therefore not yet gelled while placing it within the mold. The petri dish was then placed in an incubator for 2 hours to gel the collagen within the pluronic mold. Hank’s balanced salt solution was then poured into the petri dish which was then placed in the incubator overnight to dissolve away the mold. What was then left behind was only the final structure made of collagen.
The utilization of the mold functionality within TSIM® enables 3D structure creation using native matrix materials that are difficult to utilize in the 3D bioprinting process of fabrication. Cell populations can then be placed and grown within these structures, thereby providing the ability to create defined 3D regions of cell populations to localize different cell types for studies in cell-cell interactions, cell migration, growth, or to precisely place different cell populations for whole tissue generation.
To learn about the BioAssemblyBot 400, click here.