Design, Construction And Study Of K5Polysaccharide-based Amphipathic Drug Carriers

Polymeride micelles could reduce the side effects and increase the targeting effects ofDoxorubicin (DOX). Herein, we reported the self-assemble micelles based on K5polysaccharide (K5PS) and deoxycholic acid (DOCA)(KD) conjugate and disulfide-boundscontaining K5PS-SS-DOCA (KSD) conjugate for the loading of DOX. The in vitro drugrelease behavior, cytotoxicity as well as cellular uptake ability were investigated.(1) DOX-loaded KD micellesThe chemical structures of KD conjugate was respectively identified by1H NMR and thedegree of substitution (DS) was calculated to be0.29. The KD conjugate was able toself-assemble into micelles in water solution and the Critical Micelle Concentration (CMC)was calculated to be23.4mg/L. This micelle could resist serum adsorption, showingfavorable stability. The DOX loading efficiency and encapsulation efficiency of theDOX-loaded KD micelle were16.71%and62.66%. The In vitro drug release study revealedthat the resulting micelles could achieve sustained drug release at pH7.4, and accelerateddrug release at pH5.0or in the existence of β-glucuronidase as well. In vitro cellular uptakeand cytotoxicity assay confirmed that DOX-loaded micelles could be efficiently internalizedinto HeLa cells, and show significant distinction of IC50between tumor cells and normal cells.(2) DOX-loaded KSD micellesUsing cystamine as the crossing arm, DOCA were conjugated to K5PS to fabricate Twodifferent DS K5PS-SS-DOCA (KSD) conjugates (KSD10and KSD16) was synthesized. Theconjugate was able to self-assemble into micelles in water solution for the encapsulation ofdoxorubicin (DOX). The CMC were69mg/L and84mg/L, and the average sizes were225nm and187nm and hold good biocompatibility. The DOX loading efficiency were11.54%13.14%and encapsulation efficiency were46.17%and54.25%. The micelles exhibitedredox-sensitive drug release behavior as10mM GSH could significantly increase the drugrelease rate. DOX-loaded KSD micelles are more cytotoxic against tumor cells than normalcells. Quantitative analysis by flow-cytometric analysis showed much more intracellularuptake of KSD micelles in HeLa cells than COS7celles. The intracellular endocytosis ofDOX-loaded KSD micelle was mediated mainly by clathrin.Our results suggested that the K5PS-based micelles could resist serum adsorption andshowed favorable biocompatibility, the DOX-loading micelles showed accelerated releasebehavior at pH5.0or in the presence of β-glucuronidase, and10mM GSH could significantlyincrease the drug release rate in disulfide-bounds containing micelles. DOX-loaded K5PSmicelles are more cytotoxic against tumor cells than normal cells. Taken together, K5PSmicelles have great potential to be explored as the drug carrier.