MAGNETIC 3D BIO-PRINTING FOR DEVELOPING SALIVA-SECRETING ORGANOIDS TO TREAT DRY MOUTH PATIENTS
Christabella Adine1, Hui Min, Adeline Koh2, Riasat Hasan1, Sujatha Muthu1, Glauco R. Souza3,4, Joao Nuno Andrade Requicha Ferreira1
1National University of Singapore, Singapore;
2Nanyang Polytechnic, Singapore;
3University of Texas MD Anderson Cancer Center, USA;
4Nano3D Biosciences, Inc, USA
Radiotherapy, the preferred therapy for head and neck cancers, can irreversibly damage the salivary glands (SG) saliva secreting cells in about 40-60% of patients. This damage results in dry mouth, which increases the susceptibility to oral infections, decreasing the quality of life of patients. Current options for dry mouth therapies are heavily dependent on the limited number of residual SG secretory cells. Hence, organoid-based transplantation of secreting SG cells in a threedimensional (3D) structure is potentially a viable option. Thus, our aim was to generate new saliva-secreting epithelial cells arranged in 3D organoids using a novel culture system, the magnetic 3D bio-printing (M3DB). Methods: Human dental pulp stem cells were expanded as 3D spheroids followed by epithelial differentiation step using two systems: M3DB and force aggregation (a conventional 3D system). Cellular ATP and caspase 3/7 levels were assessed in the 3D spheroids to study viability and cell survival. Then, these spheroids were transplanted into decellularized SG biomatrices to create ex vivo organoid-like structures and assess viability and functional secretion (α-amylase). 3D organoids were also characterized using qPCR, immunofluorescence and flow cytometry. Results: 3D spheroids using M3DB system exhibited higher proliferation after 3 days in vitro. Moreover, these 3D spheroids also showed similar viability when grown in decellularized SGs. The differentiated 3D organoids showed increase expression of α-amylase at gene and protein levels. Furthermore, these constructs also showed increase expression of K14 and Chrm3, which indicate the presence of ductal epithelial and cholinergic receptor markers in epithelial cells. In summary, our novel M3DB system was able to create differentiated cellular 3D spheroids that were feasible to transplant into biomatrices, and form 3D organoids with functional saliva secreting properties. Conclusion: This project offers a promising 3D bioprinting therapeutic solution to alleviate dry mouth in cancer patients subject to RT.