Gold Nanoparticle for Medicine

Abstract

Gold nanoparticles were synthesized by reducing aqueous chloroauric acid (HAuCl4) with three different bacteria. Various microorganisms were verified to see how feasible they will be in synthesizing gold nanoparticles. Three microorganisms were screened and found to produce gold nanoparticles effectively. These bacteria include; Bacillus megaterium, Bacillus subtilis and serratia mercensis mercensis. Microorganisms in the synthesis of nanoparticles appear as an environmentally friendly and exciting approach. Different sizes and shapes of gold nanoparticles are produced by the various microorganisms used. The particle sizes and shapes were controlled by pH. The microorganisms and the HAuCl4 were incubated at pH of 3 and 7. It was observed that spherical nanoparticles were observed at of pH 7 whiles nanoplates were observed at pH 3. Poor bioavailability and intrinsic toxicity are some of the problems facing conventional therapies and as a result have compromised the therapeutic efficacy of many otherwise beneficial drugs. Some of these shortcomings of the conventional therapies are been overcome by the design of nanoscopic systems to change the pharmological and therapeutic properties of molecules. In order to enhance the bioavailability of targeted site, nanosystems are often accumulated at higher concentrations than normal drugs. Systems toxicity is greatly reduced when the enhanced drug is targeted to the diseased tissue. Diagnosis of cancer is often late as most of them are hidden or known metastasis. The ability of gold nanoparticles to absorb light in the visible and near-infra red (NIR) region depends strongly on the shape and size of the nanostructure. Moreover, the amount of cells that can be taken by gold nanoparticles is size dependent with optimal diameter of 50 nm for spherical nanoparticles.