In vitro heterogeneous degradation of alginate and its validation of different molecular weight on blood bio-compatibility

In the present work, sodium alginate (ALG) was degraded by heterogeneous phase acid degradation. The molecular weight distribution of ALG after degradation was close to homogenization. Then the blood bio-compatibility of ALG with different molecular weights (ALG-0h 50,075, ALG-0.5h 20,680, ALG-2h 13,170 and ALG-96h 1170 kDa) was evaluated in vitro and vivo. The human umbilical vein endothelial cells were used to assess the cytotoxicity of ALGs, ALG-0.5h and ALG-2h exhibited greater increment in percentage of cell viability comparing with ALG-0h and ALG-96h. With increasing of molecular weight of ALG, the blood clotting time was shortened and the hemolysis rate was slightly decreased. The different degree aggregation of red blood cells (RBCs) was observed in the ALG with different molecular groups and ALG-0h caused a severe aggregation of RBCs. Hematology analysis in vivo behavior after intraperitoneal (i.p.) injection indicated ALG-0h could cause blood solidification. Above results provided a reference for molecular weight selection in different applications.