Title : Nanocarriers
Abstract:
A nanocarrier is nanomaterial being used as a transport molecule for another substance, such as a drug. Common examples include micelles, polymers, carbon-based materials, liposomes and other substances. Nanocarriers are currently being investigated for their use in drug delivery and their unique characteristics demonstrate potential use in chemotherapy. Structurally, nanocarriers range from sizes of diameter 1–1000 nm. However, due to the width of microcapillaries being 200 nm, nanomedicine often refers to devices <200 nm. Because of their small size, nanocarriers can deliver drugs to otherwise inaccessible sites around the body and alleviate symptoms leading to treatment of diseases. Since nanocarriers are so small, it is often difficult to provide large drug doses using them. The emulsion techniques used to make nanocarriers also often result in low drug loading and drug encapsulation, providing a difficulty for the clinical use. Nanocarriers to date include polymer conjugates, polymeric nanoparticles, lipid-based carriers, dendrimers, carbon nanotubes, and gold nanoparticles. Lipid-based carriers include both liposomes and micelles. Examples of gold nanoparticles are gold nanoshells and nanocages. Different types of nanomaterial being used in nanocarriers allows for hydrophobic and hydrophilic drugs to be delivered throughout the body. Since the human body contains mostly water, the ability to deliver hydrophobic drugs effectively in humans is a major therapeutic benefit of nanocarriers. This calls for functionalization of nanocarriers with water soluble groups. Micelles are able to contain either hydrophilic or hydrophobic drugs depending on the orientation of the phospholipid molecules. Some nanocarriers contain nanotube arrays allowing them to contain both hydrophobic and hydrophilic drugs.
One disadvantages with nanocarriers is unwanted toxicity from the type of nanomaterial being used. This must be taken into consideration when using the type of nanocarriers. Inorganic nanomaterial are toxic to the human body if it accumulates in certain cell organelles. Research is currently being conducted to invent more effective, durable and safer nanocarriers. In this direction, protein based nanocarriers show promise for use therapeutically, since they occur naturally, and generally demonstrate less cytotoxicity than synthetic molecules. This presentation outlines recent advances in nanocarriers.
