3D bioprinting nano-enabled bioink to generate cartilage for articular cartilage repair

RESTORE strives towards delaying the onset of osteoartrithis (OA) and design an effective approach to manage the specific unmet clinical needs to treat chondral lesions by developing smart nano-biomaterial-based solutions. One part of this project is developed within RESTORE and is by using 3D bioprinting for cartilage repair. 3D bioprinting technology combined with stem cells enables fabrication of living tissues and organs. Results from the RESTORE project using 3D bioprinting was recently published in the scientific innovation net work (see more here).

This was based on the original article 3D bioprintingin a true OA defect with the title “Collagen 2A Type B Induction after 3D Bioprinting Chondrocytes In Situ into Osteoarthritic Chondral Tibial Lesion” published in the journal Cartilage. The3D bioprinted chondrocytes produces extracellular matrix such as collagen 2A splice variant type B to the same extent as native cartilage. Type 2 collagen can be synthesized in two forms, type A or type B, generated by alternative splicing of the precursor mRNA. Type 2A procollagen contains a cysteine-rich domain in the NH2 terminus of the pro-peptide, and type 2B lack this domain. Type 2A is found in pre-cartilage, and non-cartilage epithelial and mesenchymal cells and the type 2B collagen variant are characteristic for chondrocytes found in cartilage. Remarkable, after 3D bioprinting, collagen type 2 B were shown to be produced at a high quantity, indicating that 3D bioprinting of chondrocytes supports differentiation towards native cartilage. Figure 1C shows antibody staining of collagen 2 in native cartilage of a rat knee. Cartilage is stained for collagen 2 clearly towards the growth plate and some areas lack collagen 2 (Figure 2).

To develop bioink for clinical use, sterilization method is key. The developed nano-enabled bioink (video of 3D bioprinting the sterile ink) is assessed by team at VGR-SUH (figure 3). Cell survival, sterility, bio-printability are important parameters to make the ink for clinical use that are under evaluation.

Figure 1 INCELL 6000 (GE Healthcare) high throughput confocal analysis of section of rat knee stained with A) negative control secondary antibody, B) Nuclei DAPI stain (blue) of the same section as in A. C) Collagen type 2 antibody (yellow) stain of same section as in D) DAPI.

Figure 2 Enlargements of the red square area in Figure 1 C & D of INCELL 6000 (GE Healthcare) confocal high throughput analysis of section of rat knee of Collagen type 2 antibody stain (yellow) and nuclei (DAPI stain, blue).

Figure 3 The RESTORE VGR-SUH team from left; Chirag Jain Mysore Shanthinathan, Tahsin Akhter, Carl Lindahl, Sebastian Concaro, Stina Simonsson, Paula Büttner and Meike Meike Große-Elshoff. Picture taken at the 3D bioprinting journal club & international food event.