Fig. 1

Schema of production and quality control checks of clinical-grade human deciduous pulp stem cells (hDPSCs). The present procedure for clinical-grade hDPSCs is composed of isolation of colony-forming unit-fibroblast (CFU-F)-based multi-colonies, culture steps, and two-step cell banking. Briefly, dental pulp tissues (DP) of deciduous teeth were extracted and were digested. The cell suspension was seeded into a T-75 culture flask, and the attached multi-colonies were obtained. The formed multi-colonies were collected and were passaged for further expansion. hDPSCs harvested at passages 3 (P3) and P10 were cryopreserved for an master cell bank (MCB) and a working cell bank (WCB), respectively, in a liquid nitrogen (LN) tank. Final hDPSC products were obtained from cells thawed from the WCB batch. To manufacture high numbers, safety, and quality of the final cell products for the patients, multi-step validation for quality, safety, and preclinical check was employed as indicated at each step. The final hDPSC products should meet all criteria. Full details are described in the “Results” and “Materials and methods” sections of this manuscript