Drug delivery systems tumor-targeted

Solid tumors display a reductive environment because of hypoxia and the overproduction of bioreductive enzymes. To take advantage of the characteristics of the environment provided by the solid tumor, a bioreductive, tumor-targeted drug delivery system was designed. The system would undergo 

Metastasis can be treated by the use of the tumor cells as the drug carrier. Doxorubicin-loaded B16-F10 murine melanoma cells were intravenously administered into C557B1 mice preinoculated with live B16-F10 tumor cells. The drug-loaded tumor cell system was able to prevent metastases formation from a control level of 554 in mice injected with saline solution to 4 in doxorubicin-treated mice. The drug-loaded cells were also able to cause remission of metastases after they were formed. 

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This article focuses on tumor-targeted drug delivery systems. It is divided into two major sections an overview of targeting mechanisms, and some application examples that have demonstrated tumor targeting in preclinical and clinical studies. 

Tumor-targeted drug delivery systems can be classified based on three major approaches (i) passive targeting (ii) active targeting (Fig. 1) and (iii) external stimuli triggering. The advantages and challenges of each approach are discussed below. 

Tumor-Speckle MAbs or Fragments. In recent years, MAbs have been identified as effective anticancer agents. Several MAbs have been approved for clinical uses since 1997, and many more are in clinical trials. MAbs are believed to have multifunctional mechanisms. Their high selectivity toward tumors makes them ideal targeting ligands for actively tumor-targeted drug delivery systems. 

APPLICATIONS OF TUMOR-TARGETED DRUG DELIVERY SYSTEMS... 

Table 2 Summary of particulate tumor-targeted drug delivery systems...

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