Carboxymethyl chitosan and octadecylamine-coated liposome-containing WPTS: design, optimization, and evaluation

Abstract

Liposomes (LPs) are a delivery system for stabilizing pharmaceuticals with limited use due to their propensity to congregate and fuse. A proposed method of addressing these problems is polymer coating. In this study, the potential of octadecylamine (ODA)-coated liposomes and carboxymethyl chitosan (CMCS/ODA-LPs) for enhancing Wacao pentacyclic triterpene saponin (WPTS) transport capacity was investigated. CMCS/ODA-LPs were produced by electrostatic adsorption and thin-film hydration. Response surface methodology (RSM) was employed to enhance the process and encapsulation efficiency (EE) for optimum drug encapsulation efficiency. The synthesized WPTS-CMCS/ODA-LPs were uniformly dispersed in a circular shape, and during 14 days of storage at 4 °C, the particle size and morphology did not significantly change. Vesicle size, zeta potential, polydispersity index (PDI), and entrapment efficiency (%) were 179.1 ± 7.31 nm, −29.6 ± 1.35 mV, 0.188 ± 0.052, and 75.62 ± 0.43, respectively. The hemolysis test revealed that WPTS-CMCS/ODA-LPs were sufficiently biocompatible. Compared to WPTS-LPs, WPTS-CMCS/ODA-LPs consistently showed a much more significant cytotoxic effect on cancer cells. Early and WPTS-CMCS/ODA-LPs-induced apoptosis resulted in almost seven times more cell death than the control. Compared to physiological pH 7.3, the pH-sensitive CMCS coupled LPs increased drug release at acidic pH 6.5. These findings suggest the efficacy of pH-sensitive CMCS/ODA-LPs as a medication delivery method for WPTS.

Keywords:

• Drug delivery
• polymer coating
• liposome
• CMCS
• ODA

Acknowledgements

The authors would like to thank Zhang San from Shiyanjia Lab (www.shiyanjia.com) for the TEM analysis.

Author contributions

X.W. designed the research; N.W. wrote the manuscript. All authors agreed to be accountable for all aspects of the work, ensuring that questions related to the accuracy or integrity of any part of the work were appropriately investigated and resolved.

Ethical approval

This experiment does not involve human participants and animal testing.

Disclosure statement

The authors declared no conflict of interest.

Additional information

Funding

This work was supported by grants from the National Science & Technology Fundamental Resources Investigation Program of China (2018FY100700), the National Natural Science Foundation of China (81773841), and the Science & Technology Support Plan of Guizhou Province (2017MA6DRXM2320354).