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

Abstract

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 μg/mL. The Ce6-loaded CSO-SA micelles were then prepared by a dialysis method, and the properties and drug release profiles of Ce6-loaded 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 ~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.

Keywords::

• Chitosan oligosaccharide
• stearic acid
• polymeric micelle
• chlorine e6
• in vitro drug release
• cellular uptake

Acknowledgments

We thank the Nature Science Foundation of Zhejiang province under contract Y207785 and Jiaxing Science and Technology Bureau under contract 2008AY2039-6.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.