Cancers figure among the leading causes of morbidity and mortality worldwide. Prostate cancer is the first in cancer incidence followed by colorectal, bowel, breast and lung cancers to the extent of 60 per cent. Out of every one lakh people 388 are suffering from prostate cancer. While Denmark occupies the first place in prostate cancer, USA the sixth place and India occupies 128th position. Globally cancer patients spend about Rs seven lakh crores on cancer drugs. About 45 different new cancer drugs have come into market between 2010 and 2014.
The present remedial conditions available for cancer are surgery, chemotherapy and radiotherapy. Scientists are concentrating on another therapy in cancer using bacteria. Chemo and radio therapies lead to the destruction of healthy cells. Now the scientists are concentrating on nanotechnology which leads to the destruction of only cancer cells without causing harm to the surrounding healthy cells.
The Food and Drug Administration in USA has given permission to test nanotechnology-based drugs which leads to the cure of cancer.
A break-through in cancer fight
The British scientists hailed the recent discovery in the treatment of cancer. The researchers at University College, London have developed a way of finding unique markings with in a tumor allowing the body to target and fight the disease. These treatments for patients with advanced cancer could enter the human trials with in two years. The logic of the treatment is that the treatment response should be much more specific than any thing tried so far. It is a game changer for cancer as stated by the lead researcher.
This discovery could mean that instead of being given toxic chemotherapy, patients could in future be given vaccines made from proteins in their own tumors. As only the tumor cells have the particular biological signature, healthy tissue will not be attacked by the immune response which is exciting. Now we can prioritize and target tumor antigens that are present in every cell – the Achilles heel of these complex cancers as stated by Professor Charles Swanton, from the UCL Cancer Institute. The way of working is given below:
- Samples from patient’s tumor are removed and the DNA is read
- Scientists identify clearly the mutations that are common to all cancer cells
- Then they search for disease-fighting white blood cells in the tumor that are perfect match for the mutations.
- These cells are removed from the body and grown in the lab until there are millions of copies.
Nanotechnology and drug delivery
Nanotechnology has immense potential in the therapy of medical diseases like cancer, diabetes, Alzheimer’s disease besides like cardiovascular problems, infections or inflammatory diseases leading to the revolutionary improvement for the quality of life and health of the people.
The latest drug delivery systems combine polymer science, bioconjugate chemistry and molecular biology. The main objective is to attain a control over pharmaco-kinetics and pharmaco-dynamics of the applied medicine besides leading the reduction of toxicity to a great extent. Nanotechnology provides at engineering of drug carriers that include nano particles, nano capsules, lipoproteins and liposomes to slowly decay respond to stimuli and be target specific. Various targeting mechanisms have been developed based on nanotechnology. For example, the special build up of chemotherapeutic agents in solid tumor resulting from the differences in the vascularization of the tumor tissue makes this property of vascularization nano particle specific to target the disease tissue. Another method called active targeting involves a coating on the surface of drug carriers with nano killers thus allowing them to adhere selectively to problematic cells.
The other important aspect of nano based approach to drug delivery is to deal with crossing of blood-brain barrio. The basic aim is to find different suitable roots for the release of nano particle or protein based drugs except for the gastro-intestinal track route where the drugs are subjected to degradation. Thus nanotechnology forms the basis of pioneering delivery techniques that provide several possible advantages to patients and also gives anew definition to drug delivery system.
Dendrimers are nano meter sized polymer macro-molecules with a central core of branching units. The core-chemistry decides the solubilizing properties of the cavity with in the core and the outer chemical groups determine the chemical behavior of the dendrimer itself. Certain linker to the outer surface of the dendrimer that allows it to bind to particular disease site is a way to attain targeting. Nano particles, nano spheres and nano capsules that are amorphous and crystalline are used efficiently as drug carriers. They function by encapsulating or absorbing a drug and provide protection against any kind of degradation. In nano capsules the basic drug is restricted to a cavity covered by a polymer membrane, in nano-spheres, there is a matrix system in which the drug is scattered. The structures are formulated to provide a shield to the drug. The novel introduction of biodegradable polymeric nano particles has been a miracle in the sustained release of drugs that are target specific. This approach has also made nano particles the carriers of DNA (genetic material) in gene therapy and their capability to deliver proteins and genes via oral route.
Liposomes are vesicles that are formed chemically active lipid bilayers that encapsulate the drug molecules and solubilize with in them. Certain proteins can be included in the liposome membrane to act as filters and allow only the transmission of small solutes like ions, nutrients and antibiotics. Thus liposome here acts as a natural nano cage for the drug preventing them from any degradation. The transmission is also allowed when there is a difference of concentration between the internal and external walls of the nano cage.
Usually parental routes like intravenous, intramuscular or subcutaneous routes are used for drug administration. Liposomes are the nano systems that are administered intravenously. The other nano scale drug carriers have a high ability for improving drug delivery through nasal and sublingual routes thus avoiding the initial metabolism and accessing other wise directly the inaccessible areas like brain, and intra-articular cavities. The nasal route is now being used to administer the drug molecules with nano particles thus leading to high improvement of the bioavailability of drugs.
At present the pulmonary problems are accelerating. They account for more than one third of the drug delivery market. Nanotechnology provides the best alternative to make drug delivery efficient. The drugs at present are delivered through inhaler systems, aerosols, powder/capsule inhaler and nebulizers which are now revised to contain nanostructures like dendrimers, micelles, nano particles and liposomes. This route is an effective route for the delivery of protein and peptide drugs. The lung route is the priority route for gene therapy when needed like in untreatable diseases of fibrosis treatment. Nano medicines for pulmonary drug delivery are great at site-targeting for the treatment in respiratory diseases.
Transdermal delivery is a promising field for nano delivery systems as it avoids the troubles of gastro-intestinal problem and the degeneration of drug. The drug delivery rate becomes more efficient. The procedure is non-invasive and can be used for local drug delivery. Trans-tissue drug delivery systems have become popular and need to be adhered to the resected tissue during surgeries.
The nano medicine used produces an eminent pharmacological outcome and minimizes the toxicity that is associated with drug administration. Thus nanotechnology has become an effective drug delivery system that has gained momentum.
Nano silver in drinking water
Nano silver is pure deionized water with silver (Ag) in suspension. About 80 per cent of silver is in the form of metallic silver nano particles while the remaining silver is in ionic form. Though it is similar to colloidal silver as the colloidal suspension is with particles ranging from 10 nm to one micron in diameter, the silver particles in nano silver are less than 2 nm in diameter that is too small to be considered as suspension in much more stable state.
By virtue of small size of the particles, the total surface area of the silver exposed in solution is maximized resulting in the highest possible effect per unit of silver. The 20 ppm (parts per million) concentration of silver in nano silver provides more effectiveness inside the body than silver solutions in the colloidal class, of many times greater concentration.
The other important characteristic feature of nano silver is its high effectiveness inside the body compared to that of common colloidal silver products. The high percentage of silver in nano silver is in metallic particulate form. This feature is the key because ionic silver becomes silver chloride in the stomach or blood stream. The silver chloride is lightly soluble and far less effective than metallic or ionic silver. The metallic particles survive in the hydrochloric acid of the stomach that remains effective inside the blood stream and body tissues. Most of the colloidal silver solutions contain not more than 5 – 10% metallic particles with the remainder in ionic form. Combination of high particulate concentration and ultra small particle size in a silver solution results in high effectiveness which is without a peer.
A comparison between nano silver and common colloidal silver solutions reveals a striking contrast in the surface area of the particles and therefore effectiveness. When we compare the best common colloidal silver product (a theoretical formula of 20 ppm silver; 10 per cent particles of 10 nm) we get eight - fold advantage for percent concentration for nano silver and a five- fold advantage for particle size. Multiplying the two factors of differences in potency we have an advantage of 40 times. With the advantage of 40 to one in potency per unit of silver we can choose to take a dose of 350 mcg (Micro grams) per day as allowed by EPA (USA) as a maximum daily reference while still maintaining a robust component of bioavailable silver in blood stream. Scientists in USA have found effective prophylactic benefit of 1 – 2 tea spoonful of Nano silver in thousands of customers. This equates to 100 – 200 mcg/day well under the amount referred by EPA.
Thus nano silver has become a natural immune system assistant. For the optimum function of the body immunity every one needs nano silver in circulation in their blood stream. Production of nano silver by a fungus was developed by BARC (Bhaba Atomic Research Centre) of the Department of Atomic Energy a decade ago but the central government has not shown any interest in this aspect to implement. Even the private industry did not think of these products in India whereas China is far advancing. Political lethargy in the exploitation of scientific aspect is accelerating in the country.