Aim: 

Here we introduce the embryoid bodies (EBs) derived from embryonic stem cells, which contain blood vessel-like structures and leukocytes, as a new and reproducible in vitro model system for biocompatibility studies.

Methodology and Results: 

Punched spherical discs of bioabsorbable polymers (BAP) (e- caprolactone and L-lactide; variation in composition) of 2 mm diameter and a thickness of 0.2 mm were inoculated in hanging drops with 10-day-old EBs for co-cultivation. As control material non-bioabsorbable polymer (NBAP) punched discs of a petriPERM membrane, which is fabricated of fluoroethylene- propylene copolymer Teflon membrane, were used. In a second step the co-cultivation was performed in spinner flask culture which achieves a better perfusion of the medium. Co-cultivation with polymers did not affect blood vessel growth on day 13 and day 16 of cell culture, whereas the differentiation of CD68-positive leukocytes was strongly induced upon co-culture of BAP with EBs as compared to NBAP. M-CSF and MCP-1 mRNA expression was significantly increased in BAP- as compared to NBAP-cocultures at days 11, 13 and 16, respectively. In spinner flask culture still increased differentiation of CD68-positive leukocytes as well as increased expression of M-CSF and MCP-1 was observed.

Conclusion: 

EBs are well suited to test the biocompatibility of BAP and NBAP with blood vessels (endothelial cells) formation and leukocytes differentiation in a less (hanging drops) and well perfused (spinner flask culture) cell culture system.