NANOTECHNOLOGY IN TREATMENT OF CANCER
Nano technology is a multidisciplinary field, which recently has emerged as one of the most propitious field in cancer treatment. Nano technology is definitely a medical boon for diagnosis, treatment and prevention of cancer disease. It supports and expands the scientific advances in genomic and proteomics and builds on our understanding of the molecular underpinnings of cancer and its treatment.
There are four major types of treatment of cancer
1. Localized delivery of heat and the localized imaging of biological materials through nanoparticles.
2. pH responses toward the cancer particles
3. Nanoparticles used in combination with radiation.
4. Nano Emulsion to treat cancer cells
Thermal approach of nanoparticles:
In the above three major treatments the first one thermal or heat is involved in killing or destroying the cancer using thermalRadiations produced during the nano particles operations.This method has primary goal of curing cancer growth by producing heat. It is a further object of the present invention to provide methods for using these materials which are minimally invasive and efficacious without systemic side effects. In the therapeutic embodiment, methods are described in which particles are administered to cells and/or tissue, which upon their exposure to light, effect the in vitro or in vivo, local heating of their immediate environment. In the preferred embodiment, the particles consist of a dielectric or semiconductor core and a conducting shell, the dimension of the particles is on a scale of tens to hundreds of nanometers, and the radiation used is infrared radiation, this preferred embodiment is used to treat cancer. In an alternative embodiment, the method is applied to treat non-malignant tumors. In either of these embodiments, the method may be the sole method or it may be used in combination with another therapy. The nanoparticles consist of a silica core and a gold shell. In an alternative embodiment, the nanoparticles consist of a gold sulfide core and a gold shell. In a further embodiment of the general method, the nano particles are targeted to a desired location through the use of appropriate chemical schemes. In the preferred embodiment, antigen-antibody binding is used for targeting .
pH responsive nanoparticles
The second method involves in finding or targeting the place where the tumour cells present and how can the cancer curing drugs are implemented as well. Nanoparticles responsive to the pH gradients are promising for cancer drug delivery. Such pH-responsive nanoparticles consist of a corona and a core, one or both of which respond to the external pH to change their soluble/insoluble or charge states. The novel core-shell polymer nanoparticles are designed with their lower critical solution temperature (LCST) being dependent on the ambient pH. This value is above the nominal physiological temperature of 37°C at pH 7.4, but decreases to a temperature below the physiological temperature with a small decrease in pH. The resulting change in LCST causes the core-shell nanoparticles to deform and precipitate in an acidic environment, triggering the release the chemotherapeutics at low pH. In addition, a biological signal has been conjugated to the shell of the nanoparticles, which can recognize tumor cells. This system may be able to target drugs to tumor cells and release the drugs intracellularly.
Nanoparticles combine with the Radiations:
The third method involves with the nanoparticles with the radiations like ultrasonic electromagnetic radiation.The present invention discloses a method/system utilizing interaction of electromagnetic pulses or ultrasonic radiation with nano- and microparticles for enhancement of drug delivery in solid tumors. These particles can be combined to antibodies to target the antigens existing in the tumor vasculature. Cavitation induced by ultrasonic waves or local heating of the particles by pulsed electromagnetic radiation results in perforation of tumor blood vessels, microconvection in the interstitium, and perforation of cancer cell membrane, and therefore, provides enhanced delivery of macromolecular therapeutic agents from blood into cancer cells with minimal thermal and mechanical damage to normal tissues.
According to this aspect, this invention provides a method of making nanoparticles of substantially insoluble water compounds and more specifically, nanoparticles of a water insoluble pharmaceutical compound (or "drug") from an emulsion in which a solution of said material forms the globules of the dispersed phase. These emulsions are readily transformed into a single uniform liquid phase, in which nanoparticles of the diagnostic or therapeutic agent are suspended, upon further dilution with the external or continuous phase. The resulting dispersed solid nanoparticles are generally less than 200 nm average diameters. The approach of miniemulsion can also be employed in cancer treatment. Miniemulsion polymerization process is typically preformed by subjecting a system of monomer, water, surfactant and a highly water insoluble compound, so-called hydrophobe, to high shear fields. In the present invention, comparing with nanoparticles prepared by emulsion polymerization, poly (n-butyl cyanoacrylate) (PBCA) nanoparticles prepared by miniemulsion polymerization process are higher loading and encapsulation efficiencies for hydrophobic monomers, such as paclitaxel and flutamide. An advantageous feature of this invention is that therapeutic or diagnostic nanoparticles so produced can be utilized for intravascular injections to treat systemic diseases. Another advantageous feature is that extra vascular injections containing these particles can provide controlled release of the drug at the site of injection for prolonged drug effects, and minimize multiple dosing. Yet another advantage of this invention is improved drug transport across absorption barriers such as mucosal gastrointestinal barriers, nasal, pulmonary, ophthalmic, and vaginal membranes, and other distribution barriers, such as the blood--tissue and blood--tumor barriers of various organs and tissues. For example, anti-cancer nanoparticles of less than 50 nm diameter can migrate through the compromised, more permeable vascular bed to reach tumor tissues. Once the nanoparticles are in the tumor tissue they will provide local cytotoxic action against the tumor cells. In the case of highly protected organs such as the brain, with its tight vascular bed surrounding the normal tissues, drug nanoparticles will preferentially concentrate in the tumor tissue, with minimal or no toxicity to the healthy brain tissue. A further advantage of this invention is the improved oral bioavailability of poorly absorbed drugs.
There are various other uses for the naonoparticles in the field of curing the cancer like drugs delivery directly to the tumour cells but the basic appliances are the above methods. Since in future experts says that the nonoparticles will create a new revolution with the cancer treatment and in future no people will die for cancer.
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