Nanocarrier

Commonly used nanocarriers include micelles, polymers, carbon-based materials, liposomes and other substances.

[2] Nanocarriers are currently being studied for their use in drug delivery and their unique characteristics demonstrate potential use in chemotherapy.

This class of materials was first reported by a team of researchers of University of Évora, Alentejo in early 1960's, and grew exponentially in relevance since then.

[3] Different types of nanomaterial being used in nanocarriers allows for hydrophobic and hydrophilic drugs to be delivered throughout the body.

Protein based nanocarriers show promise for use therapeutically since they occur naturally, and generally demonstrate less cytotoxicity than synthetic molecules.

Site-specificity is a major therapeutic benefit as it prevents drugs from being delivered to the wrong places.

Since chemotherapy drugs can be extremely toxic to human cells, it is important that they are delivered to the tumor without being released into other parts of the body.

This accumulation is caused by the enhanced permeability and retention effect[2][8][12] which refers to the poly(ethylene oxide) (PEO) coating on the outside of many nanocarriers.

Nanocarriers have such a high surface-area to volume ratio allowing for multiple ligands to be incorporated on their surfaces.

pH specificity also allows nanocarriers to deliver drugs directly to a tumor site.

Liposomes are composite structures made of phospholipids and may contain small amounts of other molecules. Though liposomes can vary in size from low micrometer range to tens of micrometers, unilamellar liposomes, as pictured here, are typically in the lower size range with various targeting ligands attached to their surface allowing for their surface-attachment and accumulation in pathological areas for treatment of disease. [ 1 ]
Drug-loaded polymeric micelle formed from self-assembly of amphiphilic block copolymers in aqueous media.
Drug-loaded polymeric micelles with various targeting functions. (A) Antibody-targeted micelles (B) ligand-targeted micelles (C) Micelles with cell-penetrating function.
Enhanced permeability and retention (EPR) effect and passive targeting. Nanocarriers can extravasate into the tumors through the gaps between endothelial cells and accumulate there due to poor lymphatic drainage.