Bioprintable Janus Base Nano-Matrix for Improved Cartilage Tissue Engineering

Bioprinting is an additive manufacturing technique used to print living cells within a three-dimensional scaffold that mimics natural tissue microenvironments. There are several disadvantages to using hydrogel-based biomaterials for bioprinting including limited cell adhesion and functionality. To address this, we have developed a library of Janus base Nano-Matrices (JBNms) which are novel nanoscale scaffolds self-assembled from DNA-inspired Janus base nanotubes (JBNts) and ECM molecules. In this study, JBNms are incorporated in bioprinting by printing a cartilage-specific JBNm with human mesenchymal stem cells (hMSCs) into a 3D alginate scaffold to selectively improve chondro-lineage cell adhesion and differentiation.

Human mesenchymal stem cells (hMSCs) were combined with a cartilage-specific JBNm and printed within an alginate-based bioink. They were maintained in chondrogenic media and were characterized at 7 and 28 days. Reverse transcription quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) and histological staining were used to determine the presence of cartilage-specific genes and proteins.

The bioprinted structures with the cartilage-specific JBNm showed significantly greater expression of chondrogenic-related marker genes and glycosaminoglycan (GAG) expression after 28 days compared to the negative control group, indicating successful chondrogenesis. The cells were viable within the structures and showed significant proliferation after 28 days.

Cartilage-specific JBNm scaffolds successfully promote enhanced hMSC adhesion, growth, and chondrogenic differentiation within bioprinted constructs.