Gold nanoparticles in chemotherapy

This article is about gold nanoparticles in chemotherapy and radiotherapy. For colloidal gold, see colloidal gold.

Gold nanoparticles in chemotherapy and radiotherapy is the use of colloidal gold in therapeutic treatments, often for cancer or arthritis. Gold nanoparticle technology shows promise in the advancement of cancer treatments. Some of the properties that gold nanoparticles possess, such as small size, non-toxicity and non-immunogenicity make these molecules useful candidates for targeted drug delivery systems. With tumor-targeting delivery vectors becoming smaller, the ability to by-pass the natural barriers and obstacles of the body becomes more probable. To increase specificity and likelihood of drug delivery, tumor specific ligands may be grafted onto the particles along with the chemotherapeutic drug molecules, to allow these molecules to circulate throughout the tumor without being redistributed into the body.

Gold nanoparticles range in size depending on which therapy they are being used for. In photothermal cancer therapy, many gold nanoparticle molecules are used in each test and they must all be uniform in size. Including PEG coating, the nanoparticles measured to be ~130 nm in diameter. Gold nanoparticles that act as drug delivery systems in conjugation with chemotherapeutic drugs typically range in size from 10 to 100 nm.

Drug vectorization requires greater specificity, and are synthesized within the single digit measurements ranging from 3-7 nm.

Antibacterial treatments are testing different sizes for cell type targeting; 10, 20 and 40 nm.

Due to the ability to tune the size and absorption of AuNPs, these molecules can vary in the colors they emit. Colors of AuNP solutions typically range from vibrant red to pale blue. These colors play a necessary role in the synthesis of AuNPs as indicators of reduction.

For more on synthesis of AuNPs for medical use, see Colloidal gold

Other synthesis may include cell type targeting. A tumor consists of a multitude of cell types, and thus targeting a single type of cell is ineffective and potentially dangerous. At most, this type of targeting would only have a minor effect on killing the tumor. Tumors are constantly changing and thus phenotype targeting is rendered useless. Two main problems persist: how to get to the target and how to destroy a variety of cells.

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