Synthesis Of Folate-Decorated Carbon Nanotubes And Its Drug Release Properties

The using of nanotechnology for malignancy treatment is one of the most leading edge biotechnology research topics. Chemotherapy, surgery and radiotherapy treatment of cancer have strong side effects for living beings. Thus, in the process of later clinical treatment, improving the drug targeting, enhancing the drug curative effect while adverse drug side effects to minimum is needed. Multi-walled carbon nanotubes (MWCNTs), have attracted tremendous interest in numerous fields such as hydrogen storage, reinforce, electric conduction and biomedicine due to their excellent physical and chemical properties. Most recently, CNTs have been explored as nano-vectors for targeted drug delivery systems, and mainly focused on the following aspects:(1) biological modification;(2) Design, synthesis and evaluation of carbon nanotubes based drug delivery system. In this paper, we used folate-chitosan conjugate (FA-CS) decorated multi-walled carbon nanotubes as targeted drug delivery system, and quantitatively evaluated the effect of functional group of the polysacchrides on the cyto-toxicity of MWCNTs. The details are as follows:1) Multi-wallled carbon nanotubes (MWCNTs) were treated through Mixed acid oxidation method, and then decorated with chitosan. The cyto-compatibility of the decorated MWCNTs was investigated by cyto-toxicity tests. The results indicated that the cell viability was affected by the surface properties, the concentration of CNTs. And the cyto-toxicity positively correlated with the concentrations of CNTs. After decorated with FA-CS, the biocompatibility would improved.2) Using irinotecan as drug model, and encapsulated it onto the surface of the functional decorated MWCNTs to prepare a slow release, targeted MWCNTs-based drug delivery system. Such a system have high drug loading efficiency, and the cell viability test indicates that the decorated CNTs have little effects on the cell proliferation rates in HT-29cells, and the irinotecan loaded CNTs drug system proved to be the most cytotoxic.3) Enteric coating materials Eudragit S-100was microencapsulated onto the drug loaded MWCNTs to prepare MWCNTs-based microspheres. The in vitro drug release behavior was studied by changing pH medium, and the results of the Eudragit S-100coated micospheres showed that no drug was released in acidic pHs, and, once the coating layer of Eudragit was dissolved at pH7.4, a controlled release of irinotecan was observed. Therefore, the Eudragit S-100microencapsulated MWCNTs-based drug delivery systems can protect drug from releasing in acidic pHs, and such a system have high potential to be used as drug delivery carrier for the chemotherapy of cancer.