Enhanced cellular uptake of chlorine e6 mediated by stearic acid-grafted chitosan oligosaccharide micelles

Chlorines are attractive compounds for photodynamic therapy because of their high absorption in the red wavelength region. The stearic acid-grafted chitosan oligosaccharide (CSO-SA) micelles have been presented as potential candidates for intracellular drug delivery carrier because of their special structure. In this study, CSO-SA micelles were prepared to encapsulate chlorine e6 (Ce6). The physicochemical properties of synthesized CSO-SA micelles were characterized. The critical micelle concentration (CMC) of CSO-SA with 4.96% amino substituted degree (SD %) was about 36.27 +/- 1.51 mu g/mL. The Ce6-loaded CSO-SA micelles were then prepared by a dialysis method, and the properties and drug release profiles of Ce6loaded CSO-SA micelles (CSO-SA/Ce6) were investigated. The loading of Ce6 in the CSO-SA micelles could reach higher drug encapsulation efficiency (%), which was similar to 100%. The size of CSO-SA/Ce6 decreased after the loading of Ce6. The zeta potential of CSO-SA/Ce6 and the drug release rate decreased with the loading content of drug. After the Ce6 molecules were encapsulated into the micelles of CSO-SA, the cellular uptake percentage of Ce6 was much more than that of the free drug. And the cellular uptake percentage of CSO-SA/Ce6 micelles was increased with the incubation time in a short period.