Gold Nanoparticles and Chitosan as Innovative Compounds in Medicine and Cosmetology: A Review of Current Applications.

The medical and cosmetic industries have developed in recent years, and there has been a growing demand for new materials. Gold nanoparticles (AuNPs) and chitosan (CS) have been known and used for many years. Unfortunately, despite their numerous advantages and possible applications, such materials may possess certain disadvantages and limitations that constitute a problem in medical or cosmetic applications. Au NPs may have potential toxicity depending on their size, shape, charge, surface coatings, and tendency to agglomerate into larger clusters. On the other hand, the CS production process requires strict control due to the possibility of uncontrolled hydrolysis or chemical modifications during polymer isolation. The combination of Au NPs and CS that differ in chemical and phase in one composite (Au NPs/CS) allows for acquiring of new material with many advantages. The obtained composite has good mechanical properties and is biocompatible due to the presence of CS and the antibacterial properties of Au NPs. Therefore, it can be successfully used in many branches of medicine, including gene delivery, cell encapsulation, wound healing process, or as a preservative ingredient of cosmetics. Moreover, Au/CS nanocomposites are used in the food industry and environmental protection. This review highlights the preparation routes, properties, and applications of Au NPs and CS as separate materials. Moreover, the last part presents the advantages of combining these two materials into one nanocomposite. Specifically, we described the role of CS in the synthesis of Au NPs and possible subsequent applications of such nanomaterials as an element of biosensors, scaffolds, and an intelligent drug release system or tissue engineering.