Gold Nanoparticles in Nanotechnology
Nanotechnologies use nanoscale features to measure and manipulate molecules at the molecular scale and as such promise to yield improved diagnostic, therapeutic, pharmaceutical, and industrial technologies. One of the fastest growing nanotechnologies involves the use of gold nanoparticles. In addition to increasing the color quality and bacteria resistance of paints, gold nanoparticles are at the forefront of biomedical technologies and are capable of playing diagnostic and therapeutic roles simultaneously, resulting in a field called nanotheranositcs. These types of gold nanoparticles can be used in biomedical applications to increase image contrast for diagnostic applications, to target and kill certain cell types for therapeutic applications, to encapsulate and deliver drugs selectively, and to serve as biosensors in rapid, hand-held diagnostic equipment. To impart this functionality to the particles, gold nanoparticles are typically modified with polymer shells that expose electrically charged chemical groups that can be further conjugated to a desired ligand. These highly charged particles, however, interact with biomolecules nonspecifically. Nanoparticle modified with hydrophillic, electrically neutral polymers prevent these nonspecific interactions but are chemically inert to further conjugation.
Functionable, Electrically Neutral Gold Nanoparticles
Researchers in the Department of Pharmaceutical Sciences at the University of Michigan have developed a block colpolymer for encapsulating gold nanoparticles that improves the performance and functionality of the nanoparticles. The researchers developed the amphiphilic copolymer such that gold nanoparticles are electrically neutral, hydrophilic, and contain functional surface chemistry. The result is a polymer-coated, gold nanoparticle with various highly desirable properties. The authors demonstrated that their fabrication method including the polymer modification step generated uniform nanoparticles that were highly stable under physiologic conditions. The authors demonstrated that these particles are well-suited for further conjugation to desired bioactive molecules and for encapsulating therapeutic drugs.
Applications and Advantages
- Gold nanoparticle platform for conjugation to bioactive molecules
- Imaging contrast agents in the lab
- Therapeutic agents in terms of drug delivery
- Biological sensors
- Molecular diagnostics
- Cell-targeting vectors
- Surface chemistry available for standard conjugation procedures
- Hydrophilic, electrically neutral prevents nonspecific interactions with biomolecules
- Uniform, narrow particle size distribution