In order to deliver and/or release anti-cancer therapeutics at the tumor sites, novel environment-responsive drug delivery systems are designed to specifically respond to tumor microenvironment （such as low pH and hypoxia）. Due to their extraordinary advantages, these environment-responsive drug delivery systems can improve antitumor efficacy, and most importantly, they can decrease toxicity associated with the anti-cancer therapeutics. This review highlights different mechanisms of environmentresponsive drug delivery systems and their applications for targeted cancer therapy.
We encapsulated vincristine into folic acid-conjugated PEGylated liposomes to improve the anti-tumor efficacy on multidrug resistant cancers.It was observed that the drug delivery system we constructed exhibited maximum cytotoxicity on KBv200 cells(multidrug resistant variant)compared with any other formulations.The semi-quantitative analysis of region of interest revealed that there was a great increase in area under curve(AUC)of a near-infrared fluorescein in solid tumors due to folic acid-mediated accumulation.Folic acid-conjugated PEGylated liposomes showed a significant tumor growth inhibiting effect in vitro and in vivo.TUNEL assay revealed that folic acid-conjugated PEGylated liposomes could induce cell apoptosis much more greatly than others.This study demonstrated that it had potential application prospective for the treatment of multidrug resistant cancer.
Chenyu WangLinglin FengXiangkun YangFei WangWeiyue Lu
The lymphatic system has an important defensive role in the human body. The metastasis of most tumors initially spreads through the surrounding lymphatic tissue and eventually forms lymphatic metastatic tumors; the tumor cells may even transfer to other organs to form other types of tumors. Clinically, lymphatic metastatic tumors develop rapidly. Given the limitations of surgical resection and the low effectiveness of radiotherapy and chemotherapy, the treatment of lymphatic metastatic tumors remains a great challenge. Lymph node metastasis may lead to the further spread of tumors and may be predictive of the endpoint event. Under these circumstances, novel and effective lymphatic targeted drug delivery systems have been explored to improve the specificity of anticancer drugs to tumor cells in lymph nodes. In this review, we summarize the principles of lymphatic targeted drug delivery and discuss recent advances in the development of lymphatic targeted carriers.
