Finland-based UPM Biofore, a company that works in the forest-based industry seeking sustainable solutions, is making inroads into the world of 3D printing with the development of new bioprinting materials through its UPM Biomedicals division. The materials, marketed under the GrowInk range, are non-animal derived hydrogels designed to support cell growth and differentiation by mimicking in vivo environments.
The GrowInk bioinks were introduced for the first time at SLAS2020, where UPM promoted the materials’ versatility in the bioprinting sphere. According to the company, the non-animal derived materials are suitable for a range of applications, including cell encapsulation, scaffold preparation for tissue engineering, drug discovery and regenerative medicine.
The innovative bioinks are made up of two main ingredients: water and nanofibrillar cellulose. Together, the ingredients produce a fully defined matrix that can be mixed with cells and customized with growth factors or adhesion proteins. According to UPM, over 150 different cell types have been cultured in nanofibrillar cellusose.
The versatile bioinks can be diluted for tunable viscosities, enabling users to match the material to the requirements of the cells they are using. Further, the ready-to-use inks are stable at room temperature and can be used with or without a crosslinking agent.
UPM also points out that the GrowInk range of hydrogel materials is compatible with a broad range of 3D printers, especially extrusion-based systems. UPM reports successful use of its bioinks with EnvisionTEC’s 3D-Bioplotter, Inventia Life Sciences’ Rastrum 3D Bioprinter, Poietis’ NGB-R Bioprinter, CELLINK’s Inkredible+ and Bio X systems, regenHU’s 3D Discovery, 3DTech’s Brinter and Rokit’s Rokit Invivo.
Today, the GrowInk product range consists of three bioink varieties: GrowInk-N, an opaque gel composed of nanofibrillar cellulose; GrowInk-T, a transparent gel composed of anionic nanofibrillar cellulose; and GrowInk-ALG, an opaque gel made from nanofibrillar cellulose and alginate. All the bioinks are developed for research use only, not for diagnostic or therapeutic applications.
Putting GrowInk to the test
In a recent study, UPM’s GrowInk-T was tested on the RASTRUM 3D bioprinter by Inventia Life Sciences. The bioprinter, which uses a droplet-based technique to deposit cells and matrix components, printed a combination of GrowInk-T and human breast cells (MCF-7, ATCC HTB-22) to determine the ink’s viability for supporting cell growth. The system was able to print a 96 well plate in under 10 minutes and, ultimately, tests showed that the UPM bioink was biocompatible and was able to support cell viability for MCF-7 cells.
In another test, UPM Biomedicals partnered with Poietis to evaluate GrowInk-N and GrowInk-T materials with the NGB-R platform. Various experiments demonstrated that both bioinks were easy to print using the printer’s laser and pneumatic extrusion processes. GrowInk-N, the more viscous of the two, resulted in marginally better structural stability, though both were printed reproducibility and with high precision.
UPM said of its new bioink materials: “GrowInks have high potential for various applications in bioprinting and tissue models in comparison with conventional cross-linked 3D hydrogels and scaffolds, as GrowInks are ready-to-use and stable, and the absence of animal-derived components opens up new possibilities for the bioinks to better recapitulate the ECM environment in tissue engineering.”