Biosynthesis and Potential Applications of Silver and Gold Nanoparticles and Their Chitosan-Based Nanocomposites in Nanomedicine

Abstract

Biosynthesized or biogenic metallic nanoparticles, particularly silver and gold nanoparticles (AgNPs and AuNPs, respectively), have been increasingly used because of their advantages, including high stability and loading capacity; moreover, these nanoparticles are synthesized using a green and cost-effective method. Previous studies have investigated reducing and/or stabilizing agents from various biological sources, including plants, microorganisms, and marine-derived products, using either a one-pot or a multistep process at different conditions. In addition, extensive studies have been performed to determine the biological or pharmacological effects of these nanoparticles, such as antimicrobial, antitumor, anti-inflammatory, and antioxidant effects. In the recent years, chitosan, a natural cationic polysaccharide, has been increasingly investigated as a reducing and/or stabilizing agent in the synthesis of biogenic metallic nanoparticles with potential applications in nanomedicine. Here, we have reviewed the mechanism of biosynthesis and potential applications of AgNPs and AuNPs and their chitosan-mediated nanocomposites in nanomedicine.

The Potential of Silver Nanoparticles for Antiviral and Antibacterial Applications: A Mechanism of Action

“…To overcome the disadvantages of the chemical synthesis of AgNPs, biological methods have been preferred and are thus well studied as an alternative method in preparing silver nanoparticles. The application of biologically-mediated synthesis is proven to be cost-effective, simple, and environmentally friendly as it does not use hazardous or toxic chemicals [37]. This approach has been given much attention as it produces the high yield of AgNPs and it replaces chemicals with bacteria, plant extracts, and small biomolecules such as amino acids.…”

All That Glitters Is Not Silver—A New Look at Microbiological and Medical Applications of Silver Nanoparticles

“…The efficacy of various currently used antibiotics such as amoxicillin, erythromycin, clindamycin and vancomycin methicillin against various pathogenic bacteria such as S. aureus (MRSA), S. epidermidis , E. coli , Streptococcus pyogenes , Salmonella typhi and Klebsiella pneumoniae were grown in the presence of AgNPs [ 30 , 54 ]. Chitosan nanoparticle combined with silver plays a similar role as the described antibiotics, because its synthesis into the Ag polymer promotes the formation of small AgNP which can be added to selective media with a pH range of 6.3–6.5 in the form of silver hydrogel nanocomposites [ 66 , 67 , 68 , 69 ].…”

Biomedical Applications of Green Synthesized-Metallic Nanoparticles: A Review

“…Topical application of chitosancapped AgNPs has been recently shown to accelerate the healing of a burn wound where it decreased the inflammatory reaction and consequently, reducing the length of repair phase [137]. In Katas et al [138], AgNPs was used as excellent healing wound dressings because of the acceleration of reepithelization and increased performance at clearing bacteria from infected wounds.…”

“…The particles also inhibited proinflammatory cytokines such as interferon gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) [138]. AgNPs have been extensively used in the preparation of ointment for burns, dressing for pressure ulcer wound and clinical devices for effective avoidance of microbial infections [139,140].…”