Preparation And Properties Study Of The Folate Receptor-Madiated Delivery System Of Carbon Nanotubes

The use of nanotechnology for cancer treatment is one of the most cutting-edge biotechnology research topics. To date, laboratory cell model studies and pre-clinical animal models research have made significant progress, nano-bio-technology will become an effective manner following the surgery, chemotherapy and radiotherapy treatment of tumors. Surgery, chemotherapy and radiotherapy treatment of cancer have strong side effects. Thus, in the course of clinical treatment of diseases, we need to improve the drug targeting, with a view to maximize drug efficacy, while adverse drug side effects to a minimum. While because of the high purity and size identity , the carbon nanotubes make less toxic to the human body and the large surface area of the structure makes the carbon nanotubes carry large amounts of drugs. It is found that carbon nanotubes can smoothly enter the cell, which makes carbon nanotubes may be used as one of the best candidates of the active targeting nanoparticles carriers which are used as the carrier of the anti-cancer drugs.Here the water-soluble carbon nanotubes were prepared, then 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide/N-Hydroxysuccinimide (EDC/NHS) or Dicyclohexylcarbodiimide/N-Hydroxysuccinimide(DCC/NHS) were used as active agents to folic acid, the activated folic acid was conjugated with the water-soluble carbon nanotubes to prepare the tumor targeting systerm MWNTs-PEG-Folic acid. Finally, the tumor targeting systerms were used to absorb anti-cancer drug 5-fluorouracil(5-FU) and then the drug release behavior was systematically studied in vitro.The following aspects were included:1) Carboxyl groups (MWNTs-COOH) were introduced at defect sites on both ends and sidewalls of the carbon nanotubes by using nitric acid or mixed acid as oxidation agents. MWNTs-COOH was characterized by FTIR spectra.2)SOCl2,DCC/NHS and EDC/NHS were used as active agents to activate the carboxyl group on MWNTs, then polyethylene glycol derivatives were conjugated to the activated carboxylic group on MWNTs. The water-soluble carbon nanotubes were characterized by FTIR spectra.3) Folic acid was activated by EDC/NHS and was connected to the water-soluble carbon nanotubes to prepare the tumor targeting system which was characterized by FTIR spectra and UV absorption spectra.4) The tumor targeting system was used to adsorb anti-cancer drug, 5-fluorouracil (5-FU), and then the drug release behavior was systematically studied in vitro.The products of each step were analysed by SEM,FTIR and UV absorption spectra to determine the groups which had been connected to the carbon nanotubes. Through the release experiments, it can be determined that the targeting system has the delayed release effect.