They start out as spherical cells, which then collapse into mature red blood cells following exposure to various substances.
Read more: Scientists Use Polymers to Create Fake Red Blood Cells With Agility of Real Cells - Page 2 | Medindia http://www.medindia.net/news/Scientists-Use-Polymers-to-Create-Fake-Red-Blood-Cells-With-Agility-of-Real-Cells-62407-2.htm#ixzz2ebSZZ7ch