Preparations and properties of drug-eluting embolization microspheres based on modified gelatin

Embolization using microspheres plays an important role in interventional cancer therapy. The drug-eluting embolization microspheres were prepared via reverse suspension crosslinking of gelatin, followed by modification of the cross-linked microspheres. The microspheres displayed regular spherical shapes with size distribution ranging from 180 μm to 350 μm. The negatively charged groups (COO⁻) were introduced into the microspheres which could load positively charged doxorubicin with loading rates as high as 26.1% and 34.0% in 1 and 12 h, respectively. The high drug-loading rates were ascribed to ionic interaction between carboxyl groups and doxorubicin. The drug release profile showed the modified microspheres (MMS) have a sustained release manner compared with non-MMS in phosphate buffered saline (PBS). The MMS were almost completely degradated after 20 days. Cytotoxicity assay certified that the MMS were non-cytotoxic, and could be potentially used as biocompatible materials.