APPLICATION OF NANOPARTICLE IN CANCER TREATMENT

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1 APPLICATION OF NANOPARTICLE IN CANCER TREATMENT Introduction Nanotechnology is the design, characterization, production and application of structures, devices and systems by controlling shape and size at nanometer scale. Nanoparticles are the nanoscale devices that have the potential to radically change cancer therapy for a better and to dramatically increase the number of highly effective therapeutic agents. Figure 1: Nanoscale Description of Nanoparticle A nanoparticle (or nanopowder or nanocluster or nanocrystal) is a microscopic particle with at least one dimension less than 100 nm. Nanoparticles are of great scientific interest as they are effectively a bridge between bulk materials and atomic or molecular structures. Nanoparticles Approaches For Cancer Treatment. Nanoparticles as drug delivery systems enable unique approaches for cancer treatment. Over the last two decades, a large number of nanoparticle delivery systems have been developed for cancer therapy, including organic and inorganic materials. Many liposomal, polymer-drug conjugates, and micellar formulations are part of the state of the art in the clinics, and an even greater number of nanoparticle platforms are 1

2 currently in the preclinical stages of development. More recently developed nanoparticles are demonstrating the potential sophistication of these delivery systems by incorporating multifunctional capabilities and targeting strategies in an effort to increase the efficacy of these systems against the most difficult cancer challenges, including drug resistance and metastatic disease For instance, nanoparticles are used for molecular imaging of malignant lesions show in figure 2. They are targeted to cancer cells for use in the molecular imaging of a malignant lesion. Large numbers of nanoparticles are safely injected into the body and preferentially bind to the cancer cell, defining the anatomical contour of the lesion and making it visible. Figure 2: Nanoparticles used for molecular imaging of malignant lesions Purpose of Nanoparticle The purpose of nanoparticles is ability to see cells and molecules that are invisible during conventional imaging process obtained from cancer patient. It is used to observe the cancer cell, monitor therapeutic intervention and to monitor cancer behavior. Basic Principle of Nanoparticle The scientists have begun to successfully engineered nanoparticles that can effectively evade the immune system and actively target tumors. Active tumor targeting of nanoparticles involves attaching molecules, known collectively as ligands, to the 2

3 outsides of nanoparticles. These ligands are special in that they can recognize and bind to complementary molecules, or receptors, found on the surface of tumor cells. When such targeting molecules are added to a drug delivery nanoparticle, more of the anticancer drug finds and enters the tumor cell, increasing the efficacy of the treatment and reducing toxic effects on surrounding normal tissue (Figure 3). Active Tumor Targeting by nanoparticle Ligands Nanoparticle Tumor Cell Receptor Innovative Aspects of Nanoparticle Nanoparticle chemotherapy is a new approach to cure cancer without harming normal body tissue. Reduction in the size of tools means that many tests can be run on a single small device, make screening faster and more cost-efficient. Nanoparticulate technology can prove to be very useful in cancer therapy allowing for effective and targeted drug delivery by overcoming the many biological, biophysical and biomedical barriers that the body stages against a standard intervention such as the administration of drugs or contrast agents. Figure 3: The ligands (green triangles) on the surface of the nanopaticle fit into to enter the tumor cell after binding. the cell receptors, allowing encapsulated drug molecules Encapsulated Drug Molecules 3

4 Advantages of Adopting the Nanoparticle Nanoparticle-Based Chemotherapy could offer some potential advantages over conventional treatment for cancer. The components will be using in the clinical practice are safe and have been approved by FDA such as drug that is put inside nanoparticles, hydrophilic molecules that coat nanoparticles and molecules used for targeting are nonimmunogenic. The NCI (National Cancer Institute) is supporting nanotechnology research through several funding programs. The effectiveness of this technology are tested on animal such as mouse. Experts believe that this technology may be available for clinical use in five to fifteen years. Recently the scientists were working on how the new nonoparticles perform in eliminating tumors as a potential alternative to the brachytherapy approach. A RNA ( tumor binding molecules) PEG hydrophilic molecules) Controlled-release polymer B Figure 4: (A) Graphifical representation of docetaxel-encapsulated nanopaticles. (B) Scanning electron microscopy image of docetaxel-encapsulated nanopaticles. The average particle size is approximately 150 nanometers in diameter 4

5 Docetaxel-targeted nanoparticles Docetaxel-untargeted nanoparticles Docetaxel alone Untreated Figure 5: Representative mouse at end point (109 days) for each group is shown (left) alongside images of excised tumors (right). For the docetaxeltargeted nanoparticle group, which achieved complete tumor regression, the scar tissue and underlying skin at the site of injection are shown. Black arrows point to the position of the implanted tumor on each mouse. Advantages over Other Similar Devices Nanoparticle-Based existing in a variety of forms: particles, tubes, shells, even a soccer ball-like shape. They also share a common prefix: "nano," connoting their size, a billionth of a meter or roughly 25-millionth of an inch. A nanotube, combined with monoclonal antibodies, is detecting cancer cells, to diagnose whether cells are cancerous or not in a matter of minutes versus hour or days with current methods. Nanoshells, filled with gold particles, are destroying tumor cells when heated with laser light. They also interact with light in specific ways, and can be "tuned" to discrete destructive wavelengths by varying the size of the core and the shell. A nanoparticle combined with a hormone and cell-killing peptide is being tested to image, target and destroy primary and metastatic cancer cells. Issue The grey-goo scenario is based on the fear that nanotechnological devices will either be programmed to self-replicate, or that they will evolve into devices capable of self-replicating, and they may destroy the natural world. The solutions for guarding against grey-goo are as hypothetical as the scenario itself, and this distracts attention away from the current practices of science and technology and the need for careful 5

6 oversight and deliberation that attends to current problems and practices, not imagined future scenarios. Prepared by, Zarina Che Amin CMET Date: 26 September