We disclose a particle comprising a matrix coated thereon and having a positive charge, the particle being of a size to allow aggregation of
primate or human stem cells attached thereto. The particle may comprise a substantially elongate, cylindrical or rod shaped particle having a longest dimension of between 50 μm and 400 μm, such as about 200 μm. It may have a cross sectional dimension of between 20 μm and 30 μm. The particle may comprise a substantially compact or
spherical shaped particle having a size of between about 20 μm and about 120 μm, for example about 65 μm. We also disclose a method of propagating
primate or human stem cells, the method comprising: providing first and second
primate or human stem cells attached to first and second respective particles, allowing the first primate or human
stem cell to contact the second primate or human
stem cell to form an aggregate of cells and culturing the aggregate to propagate the primate or human stem cells for at least one passage. A method of propagating human embryonic stem cells (hESCs) in long term
suspension culture using microcarriers coated in
Matrigel or
hyaluronic acid is also disclosed. We also disclose a method for differentiating stem cells.