According to the World Health Organization's World Cancer Report 2014, cancer caused 8.2 million deaths worldwide in 2012, and this number is expected to rise to 22 million by 2035. Along with surgery and radiotherapy, chemotherapy is a mainstay of cancer treatment. Chemotherapy is the most frequently used systemic treatment for suppressing cancer cell proliferation, disease progression and metastasis. However, chemotherapeutic drugs not only kill proliferating cancer cells but also inevitably attack normal cells, causing adverse effects. Therefore, antitumor drug vehicles that maintains or improves the efficacy of chemotherapy while reducing the severity of reactions and side effects are urgently needed. Nanoparticles, which can be adapted to have various biological properties and can be used in a range of settings, provide a safer and effective means of delivering chemotherapy. Nanotechnology is an interdisciplinary field of engineering, physics, chemistry and biology at Nano level. Nano medicine is the medical application of nanotechnology. The present era of Nano medicine has reached to a stage where nanoparticles are applied for treating killer diseases like cancer, HIV and disorders like diabetes, cardiac diseases etc. The ‘Nanos’ meaning dwarf, is a prefix used to describe “one billionth “of something, or 0.000000001. The origins of nanotechnology did not occur until 1959, when Richard Feynman presented ideas for creating Nano scale machines to manipulate, control and image matter at the atomic scale. The term Nanotechnology was first coined by Tokyo Science University professor Norrio Taniguchi in 1974. He used the term ‘nanotechnology’ to represent extra high precision and ultra-fine dimensions, and also predicted improvements in integrated circuits, optoelectronic devices, mechanical devices and computer memory devices. This is called ‘top-down approach’ of carving small things from large structures. In 1986, Drexler discussed the future of nanotechnology, particularly the creation of larger objects from their atomic and molecular components, the so called “bottom-up approach’. Nanotechnology has achieved the status as one of the critical research endeavors of the early 21st century, as scientists harness the unique properties of atomic and molecular assemblages built at the nanometer scale. An important challenge in treating cancer in general is to find a technology for a controlled targeted drug delivery and release to eradicate tumor cells while sparing normal cells. The circulatory system can deliver a drug to almost every cell in the body; however, delivering the drug specifically into the tumor cell past its membrane and then releasing the drug into the tumor cells on demand without affecting the normal cells remains a formidable task. Modern research attempts to address this fundamental challenge by using nanoparticles as delivery vehicles. Nanoparticles display novel properties due to their (i) unique size, ranging from tens to over one hundred nanometers, to tailor drug delivery into different organs, (ii) wide shape 2 / 2 variation, including spheres, rods, and platelets, to help steer the drug-loaded nanoparticles towards more specific targets, and (iii) amenability to comprehensive surface functionalization to meet a wide range of requirements required for conjugation with specific biomolecules and overcoming numerous biological barriers, with or without exploiting the immune system. Last but not least, nanoparticle drug delivery (NDD) shows promise for overcoming the fundamental problem of multidrug resistance (MDR) in cancer therapies & widespread research & clinical trials are in progress. The latest update in Nano medicine chemotherapy has moved from the realm of research papers to the pre-clinical or clinical testing stage. For example, CytImmune has published the preliminary results of a phase 1 clinical trial of a targeted chemotherapy treatment method. They use gold nanoparticles attached to a molecule of a tumor-killing agent called tumor necrosis factor alpha (TNF) as well as a molecule of Thiol-derivatized polyethylene glycol (PEG-THIOL), which hides the TNF bearing nanoparticle from the immune system. The PEG-THIOL allows the nanoparticle to flow through the blood stream without being attacked. The combination of a gold nanoparticle, TNF and PEG-THIOL is named Aurmine. Several other treatments are under development using nanoparticles combined with TNF and other chemotherapy drugs. It will take a while to bring these treatments through all the phases required for qualification with the FDA; however it is exciting that they have progressed from the realm of research papers to trials that will lead to targeted treatment for patients & will contribute in a revolutionary change chemotherapeutic treatment.
Muqueet Mohsen Chowdhury
Senior Editor, Science & Technology
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