oa Editorial [Hot Topic: Nano Drugs: Novel Agents for Cancer Chemo-Therapy (Guest Editor: Imran Ali)]

This is the special issue of Current Cancer Drug Targets with emphasis on “Novel Agents for Cancer Chemo-Therapy”. The papers were submitted from all over the world including USA, Europe and Asia. This is one of the current areas of research in cancer treatment, which started during the last decade and, hence, only a few Scientists are working in it. Eight articles were accepted for publication because the contents of these describe the state-of-the-art of cancer treatment by nanoparticles-based anti-cancer drugs including drug delivery through hyperthermia for tumor-targeted therapy. Nanoparticles also have the potential to play key roles in the diagnosis and imaging of brain tumors by revolutionizing both preoperative and intraoperative brain tumor delineation. This allows early detection of pre-cancerous cells, and provides real-time, longitudinal, non-invasive monitoring/ imaging of the effects of treatment. The development of nanoparticles-based anti-cancer drugs seems to be effective, providing low side effects and targeted action on only cancer cells. The most commonly used and future nanoparticles are dendrimers, polymers, liposomes, micelles, inorganic (magnetic iron oxide nanoparticles, silica etc.), organic nanoparticles etc. It has been observed that dendrimers have a bright future in this area for proper imaging, diagnostics, with multi-functional nanoparticulate systems combining targeting and therapy. Recently, molecular targeting of liposome to the lymphatic system may enhance therapeutic efficacy by improvement of initial lymphatic uptake and lymph node retention of liposomes such as ligand receptor and antibody binding on the surface of liposomes. The important molecules used for preparation of nano-drugs include cisplatin, carboplatin, bleomycin, 5-fluorouracil, doxorubicin, dactinomycin, 6-mercaptopurine, paclitaxel, topotecan, vinblastin, etoposide. The mechanisms of nanoparticles-based anti-cancer drugs have not been fully elucidated. Major challenges for applying therapeutic nanoparticles (TNPs) in the clinic are to understand precisely how chemotherapeutic agents are released from TNPs and delivered to the targeted tumor tissues/cells, and how the TNPs' biodistribution affects toxicity in major organs. However, attempts have been made to discuss the exploration of these unresolved issues with comparisons between free drugs and therapeutic TNPs and targeted and non-targeted TNPs. Of course, nanoparticles-based anti-cancer drugs may be the choice of future therapeutics but they have certain side effects and toxicities. This aspect has also been discussed in this issue so that the ongoing research can consider them and try to avoid or remove them in the future. Adverse effects of nanoparticles on human health depend on individual factors such as genetics and existing disease, as well as exposure, and nanoparticle chemistry, size, shape, charges, agglomeration state and electromagnetic properties. Briefly, these drugs have many beneficial properties such as targeted drug delivery and gene therapy modalities. I believe that nano-anti-cancer drugs may be magic bullet drugs for cancer treatment leading to a bright future for cancer therapeutics world wide.