The introduction and evaluation of novel decellularized extracellular matrix/gellan gum bioprinting scaffolds for cartilage tissue engineering

Cartilage demonstrated limited self-regeneration; and there is a need for developing new compounds. Here, gellan gum was selected due to its hydrophilicity, biocompatibility, and native cartilage environmental resemblance, and cartilage decellularized extracellular matrix (dECM) was added (GG/dECMb) to improve the cellular interactions. The decellularization was performed using freeze-thaw cycles and sodium dodecyl sulfate and a hematoxylin-eosin and Bradford assays showed successful decellularization with low extracellular matrix damage. The GG/dECMb compound was formulated, and the gellan gum was considered as the control (GGb). The rheological evaluations demonstrated the shear-thinning and bioprinting capability, while the GG/dECMb had a lower cross-linking degree (5.04 ± 0.79%) in comparison to GGb (6.65 ± 0.48%). Both bioinks were successfully bioprinted. The mechanical test demonstrated the GG/dECMb had a damping feature, which is essential for cartilage regeneration. Furthermore, it has a higher hydrophilic nature (44.27 ± 6.0° contact angle), swelling ratio, and biodegradation ratio in comparison to GGb. The cellular tests confirmed the high capability of GG/dECMb dried scaffolds in cell viability based on the cell viability test (97.41 ± 1.02%) and live/dead assays. The Alcian blue staining proved the glycosaminoglycans deposition and cartilage differentiation of GG/dECMb. Therefore, it seems that GG/dECMb can be effective in cartilage regeneration, although needs further in-vivo studies in the future.