Studies on alginate-chitosan microcapsules and renal arterial embolization in rabbits

Spherical and well-dispersed alginate-chitosan microcapsules, with a mean diameter of 77.28+/-0.93 microm (n=3), were prepared by the emulsification-gelation method. Adriamycin hydrochloride (ADM) was used as a model drug to investigate the drug loading capacity and release characteristics of the microcapsules. The drug/carrier ratio and chitosan concentration influenced the encapsulation efficiency of adriamycin. The adriamycin release from microcapsules was obviously different in 0.1 mol/l HCl from that in phosphate-buffered saline (PBS, pH 7.4). The drug was completely and rapidly released in 0.1 mol/l HCl, while it showed a sustained release after a burst release in PBS. The increase in chitosan concentration had no effect on adriamycin release in PBS. Using sulforhodamin B (SRB)-staining survival assay, the inhibition of adriamycin alginate-chitosan microcapsules (ADM-ACM) to different cancer cell lines (human BGC-823 cells, Bel-7402 cells and Hela cells) in vitro was determined. The inhibitory rate of ADM-ACM suspension to the three cell lines significantly outran that of ADM solution, no matter at high or low concentration. The effects of blank alginate-chitosan microcapsules (BACM) on renal arterial embolization were examined with transcatheter arterial embolization in rabbits. The angiogram and histopathological results indicated the blank microcapsules had excellent short- and long-term effects on renal arterial embolization.