Targeting nanomaterials: future drugs for cancer chemotherapy

Correspondence: Tianfeng Chen 601, Huangpu Road, Guangzhou 510632, China Tel +86 20 8522 5962 Fax +86 20 8522 1263 Email [email protected] Concerning the recent articles published in your journal on multifunctional nanosystem for cancer chemotherapy. It should be an admirable approach to kill cancer cells, with the least side effects on normal tissues and cells. During the past few decades, various chemotherapeutic agents, such as cyclophosphamide, fluorouracil, platinumbased compounds, anthracycline, hydroxycamptothecin and paclitaxel, have been designed and proved to be effective toward cancer cells. However, regrettably, these drugs are non-targeted to cancer, and thus serious side effects to normal cells or tissues are unavoidable. Therefore, new drugs with selective cytotoxicity become an important research focus in cancer chemotherapy. Another obstacle for chemotherapy is the multidrug resistance. Actually, several targeted drugs such as RTK inhibitors, FTase inhibitors, tumor angiogenesis inhibitors, campath, avastin and erbitux, have been commercialized and widely used clinically. However, drug resistance seriously limited their anticancer efficacy. Nanotechnology-based approaches are anticipated to provide a new breakthrough for targeting cancer cells and bypassing their multidrug resistance. Zhang et al have developed two biodegradable novel drug delivery systems: poly(ethylene glycol)-modified docetaxel-lipid-based-nanosuspensions (pLNS), to increase the cycle time of the drugs within the body and enhance the accumulation of the drugs at the tumor sites, and targeted docetaxel-lipid-based-nanosuspensions (tLNS) using folate as the targeting ligand, which could target cancer cells overexpressing folate receptor (FR). In vitro cytotoxicity was employed to evaluate the effects on human hepatocellular liver carcinoma HepG2 (FR-) and B16 (FR+) cells and the results showed that the cytotoxicity of tLNS against B16 cell lines was superior to pLNS, while no significant difference was observed for HepG2 cells. Moreover, in vivo anticancer efficacy evaluation showed that tLNS exhibited higher efficacy in reducing the tumor volume compared with pLNS. These results reveal the application potential of tLNS to enhance the accumulation of the drugs in cancerous tissues and cells. Similarly, Du et al entrapped RGD peptide with poly(ethylene glycol)-modified stearic acid-grafted chitosan (PEG-CS-SA) nanomicelles via chemical reaction in the presence of N,N′-disuccinimidyl carbonate. Moveover, doxorubicin (DOX) was chosen as a model anticancer drug to investigate the drug entrapment efficiency, in vitro drug-release profile and anticancer activities of drug-loaded RGD-PEGCS-SA micelles in cells overexpressing integrins and integrin-deficient cells. Their results indicated that RGD-modified micelles could significantly increase the Dovepress