Toxicity induction by nanomaterials:
Nanodrug produced severe toxicity in living species. The toxicity of nanostructure materials could be reduced by chemical approaches such by surface treatment, fictionalization, and composite formation. This chapter summarizes the sources of various nanostructure materials and their human exposure, biocompatibility in relation to potential toxicological effects, risk assessment, and safety evaluation on human and animal health as well as on the environment. Nanotechnology can generate different type of health issues according to following way
1. Nano gold exposure: The structure and properties of gold nanoparticles make them effective for a wide array of biological applications. Toxicity has been observed at high concentrations using nano based systems. It was found that 2 nm gold nanoparticles cationic particles are showing toxicity in moderate scale but anionic nanoparticles are non-toxic.
2. Nanotube toxicity: Lower sized nanoparticles behave like a gas and can easily penetrate through skin and lung tissue to pass through cell membranes. Once got inside, they become highly toxic and normal function of the cell highly affected. Nanotubes which are structurally thread like structure similar to asbestos fibers that is responsible for lung fibrosis due to inhalation in large amounts over long times.
3. Atmospheric nanoparticles toxicity: The nanoparticles exist in the atmosphere in high concentrations and the release of manufactured nanoparticles into atmosphere and aquatic environment is although insignificant but the scientific community admonished that those nanoparticles cause brain damage in fishes and other aquatic creature.
4. Inhaled nanoparticles toxicity: The nanoparticles have very small size small size and higher specific surface area. As result nanoparticles can easily bind with the suspended particle very easily which can cause a various number of pulmonary diseases in mammals. Inhaled nanoparticles have the ability to translocation in the body as much as 80 % of the deposited mass. Once the nanoparticles enter the body, these can distribute throughout the body and reach the organs like liver, kidney or brain. It can also penetrate deeper into the lungs , bloodstream and may also cross the blood-brain barrier .Skin exposure during handling of the nanoparticles is also a serious issue in human safety.
5. Toxicity in cellular level: The nanoparticles are also unsafe for the living biological system. The investigation on toxicity of nanoparticles shows that various products may penetrate into the human body and show toxicity at the cellular level in the various tissues and organs The nanomaterials may be carcinogenic or allergic but inert nanoparticles also show deleterious effects due to some formation of some hazards and toxic products due to various chemical reactions within the body fluids. Some nanoparticles also exhibited different kind of catalytic properties to generate highly reactive forms of oxidizing agents which can cause serious tissue injury including different type of inflammation and other serious toxic effects. For air born nanoparticles, this tissue damage can cause asthma and other atherosclerotic heart diseases.
7.Nanotoxicity by Fullerenes & bucky balls: Fullerenes & bucky balls type nanoparticles are responsible for attracting electrons and may cause generation of toxic free radicals. Nanotoxicity studies of dendrimer, carbon nanotubes and quantum as quantum dots have been highly investigated and familiar. Literature report reveals that low-solubility nanoparticles are more toxic than that of larger particles.
8. Envirorment toxicity: Environmental exposure for nanoparticles adheres easily and frequently to surfaces which are very difficult to detect. As a result the environment nanoparticles may enter into our food chain system and as a result they affect the biosphere system and influence structural change in liquids like water.
9. Sometimes nanoparticles can enter into the body system through the gastrointestinal tract, skin and lungs. As a result nanomaterial may penetrate inside the body though various cavities.
10. More research investigation is required to establish the toxicity of nanoparticles because ultrafine particles are highly reactive and seriously toxic in their effects. Preliminary studies have revealed that some types of nanoparticles could cause serious lung damage in rodents.
Molecular aspects of nanoparticles for showing toxicity
1. Increased various pro-inflammatory activity and produce cytokines and other mediators
2. Serious side effects on cardio vascular functions
3. Reduced various function of macrophages and phagocytosis of particles themselves, reduced macrophage mobility and produce abnormality in cytoskeletal dysfunction
1. Importance of large surface area for interactions with cells and tissues
2. Complex formation with various biomolecules present in our body
3. Formation of increased level of radical species compared to larger particles
4. Generation of oxidative stress
5. Induction of cellular DNA damage
6. Generation of oxidative stress by mechanism of lipid per oxidation
1. Uptake by cells of respiratory epithelium
2. Deposition characteristics dependent on size
3. Increased exposure of interstitial spaces
4. Access to systemic circulation. Organ system effects, including effects on immune and inflammatory systems