Obejective In this paper, the thrombins were encapsulated in calcium-alginate microspheres using electrostatic droplet technique to produce a new embolic agents: Thrombin-loaded Alginate-Calcium Microspheres (TACM), which were used chiefly to control bleeding in blunt abdominal trauma. However, the use of the embolisation in clinical practice requires a thorough understanding of the biocompatibility of TACM. The present work examined the biocompatibility of TACM from aspect of a series of in-vitro and in-vivo experiments.

Methods After TACM were successfully prepared, the size distribution and morphology of TACM were evualuated. the biocompatibility of TACM in vitro were examined by assessing the cell viability of vascular endothelial cells (VECs), whole blood hemolysis, and inflammatory potential of TACM. In vivo, a dog liver superselective embolization was performed with TACM, after 48 h, 4 w and 12 w, acute, mid and long term biocompatibility were studied by evualuating clinical, biochemical and tissue response.

Results co-culture with VECs revealed non-cytotoxic of TACM compared to monolayer control (P ≥ 0.05), hemolysis was negligible and cytokines release from PBMC shows significant decrease relative to LPS group (p ≤ 0.05). Furthermore, no measurable clinical and biochemical toxic effects were observed in any of animals. The histological study of liver blood vessels tissue shows low inflammation, and the Banff 97 score was only 0.08 ± 0.18 at 48 h and then decrease to 0.04 ± 0.12 at 12 w. correspondingly, the giant cell score were 0.00 ± 0.00, 0.07 ± 0.25, 0.12 ± 0.18 at 48 h, 4 w and 12 w respectively.

Conclusions Both in vitro and in vivo data shows good biocompatibility of TACM, and it can be applied safely in futher clinical reaserch.