General descriptionGold nanoparticles (AuNPs) ranging from 2-200nm in diameter find applications in diverse fields. They show excellent biocompatibility and attractive physicochemical properties. Poly (ethylene) glycol (PEG) surface coatings on gold nanoparticles help in the reduction of protein adsorption, reduce nonspecific interactions with cells and greatly improve the pharmokinetics of these nanoparticles and reduce aggregation of the nanoparticles. PEG layer density depends inversely on the AuNP curvature. Denser coating was possible on smaller AuNPs. AuNPs coated with PEG 5000 exhibited highest colloidal stability. Amine functionalized GNPs which have Poly Ethylene Glycol (PEG) as the ligand or carrier molecule forms a conjugate with siRNA and is extremely useful in RNAi technology. Since it adheres to cell membranes, it may find use in cellular and intracellular targeting in targeted drug delivery applications and also used in biodistribution studies.
Application
Functionalized particles have been extensively used to study cellular uptake of nanoparticles and targeted drug delivery.
Several other specific applications have been listed below:
- Since they adheres to cell membranes, AuNPs are used in cellular and intracellular targeting in targeted drug delivery applications and may also be used in biodistribution studies
- AuNPs may also be used in photothermal therapy and radiotherapy.
- They may also be used in carrying siRNA which acts against human prostate carcinoma cells by inhibiting a specific cancer gene.
Features and Benefits
- A negatively charged siRNA-PEG complex attached to a positively charged GNPs is easily cleavable in reductive cytosolic environment thus enabling the release of siRNA into cytosol.
- The PEG coating decreases the cytotoxicity and increases effciciency of GNPs. PEG increases the stability of the nanoparticles and prevents agglomeration.
