Xeno-free production of human embryonic stem cells in stirred microcarrier systems using a novel animal/human-component-free medium.

Currently, stem cell research faces a major bottleneck related to the low efficiency of methods to produce large quantities of human embryonic stem cells (ESC) for use in clinical trials. Most culture media currently employed for human ESC cultivation contain animal compounds, and cells are grown in static flasks. Besides the immediate contamination with nonhuman compounds, cell expansion in flasks tends to be laborious and nonefficient. Here we cultured human ESC in stirred microcarrier (MC) systems using an animal/human-component-free medium, to overcome both issues. The method developed to culture cells on suspended beads combined the use of polymeric MCs in stirred vessels with an optimized culture medium free of supplements of animal and human origin. This approach generated approximately 160 million cells within 6 days, which were shown to remain pluripotent. The process developed herein provides a step forward toward therapy due to the economic advantages in the production of human ESC and to their consequent low immunogenic potential.