Method for producing pluripotent stem cell-derived spherical neural mass having suppressed teratoma formation

A method for producing spherical neural masses having suppressed teratoma formation, the method including the following steps:

• 1) fragmentation of the spherical neural masses to obtain fragmented spherical neural masses;
• 2) adhesion-culturing of the fragmented spherical neural masses in a culturing dish comprising culturing medium for neuronal progenitor cell to obtain adhesion-cultured spherical neural masses;
• 3) performing single-cellularization of the adhesion-cultured spherical neural masses by adding enzyme to obtain single cells;
• 4) inducing spontaneous aggregation of cells by adhesion-culturing of the single cells of step 3) in a culturing dish without an additional substrate coated thereon and without adding a differentiation-inducing factor to obtain aggregates attached to a bottom of the culturing dish;
• 5) removing floating cells after step 4) and inducing spontaneous re-aggregation of single cells by repeatedly suspending the aggregates attached to the bottom of culturing dish to obtain re-aggregated spherical neural masses;
• and
• 6) recovering the spherical neural masses re-aggregated in step 5), wherein the re-aggregated spherical neural masses contain fewer undifferentiated cells compared to the spherical neural masses in step 1).