Bone volume and tissue mineral density of 5-week ectopic microbead implants. (A) Bone volume (BV) and (B) tissue mineral density (TMD) of cell-microbead containing ectopic implants at 5-weeks. Microbead implant types, according to type of encapsulated cells and culture media, were A_G, F_G, F_O, C_G, C_O, and F + C_O, where A = acellular; F = freshly isolated BMMC; C = culture-expanded MSC; G = growth medium, O = osteogenic medium. n ≥ 5. *p ≤ 0.05. There was a lack of bone formation detected in C_G microbead implants.