Liposomes coated with thiolated chitosan as drug carriers of curcumin

- We have synthesized thiolated chitosan and coated liposomes.
- The nanoliposomes coating with thiolated chitosan can encapsulate the curcumin.
- Liposome could improve the bioactivity and water solubility of curcumin.
- The coating liposomes can reduce the curcumin release rate and become more stable.
- Furthermore, the thiolated chitosan can form hydrogel which can be prepared liposome hydrogel.

Liposome is one of a promising delivery system to improve water solubility, stability, and bioavailability of curcumin. But its instability is not favorable for long-circulating treatment, controlled release or conservation. To overcome the disadvantages, thiol derivatised chitosan (CSSH) were synthesized and utilized to coat liposomes. The CSSH coated curcumin liposomes (Cur-Lip-CSSH) had an encapsulation efficiency (EE) of 93.95%, a drug loading (DL) of 7.95%, an average particle size of 406.0 nm, and a positive zeta-potential of 36.6 mV, which were all higher than that of Cur-Lip. Cur-Lip-CSSH showed slower in vitro release than Cur-Lip at pH 5.5 and pH 7.4, and the higher retention of curcumin would be remained for the following uptake of cells. The stability of the both liposomes at 4 °C was almost the same, but Cur-Lip-CSSH displayed a higher stability at room temperature and higher temperature by DSC characterization. Curcumin can inhibit the growth of cancer cells under certain conditions. MCF-7 cell line was used to study its inhibition and proliferation after treating with curcumin and Cur-Lip-CSSH. Treatment of MCF-7 with curcumin and Cur-Lip-CSSH showed dose and time dependent cytotoxicity, with growth suppression at 200 μM, 72 h, obviously. These results indicate that the proper coating of liposomes is able to improve the stability of liposomes and the Lip-CSSH can function as potential drug delivery system.

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