Pegylated Curcumin with Gold Nanoparticles: Antimicrobial Agent Evaluation

Abstract

Curcumin is a polyphenol derived from the Curcuma longa plant. Curcumin exhibits a variety of therapeutic properties, including antioxidant, analgesic, anti-inflammatory, anticancer and antiseptic activities. Curcumin acts as photosensitizer in photodynamic therapy (PDT), which is an alternative way to kill pathogenic microorganisms. The use of gold nanoparticles (AuNPs) as the vehicle for curcumin delivery increases photodynamic ability. Therefore, the aim the present study is to investigate the effect of the photodynamic action of LED-activated curcumin gold nanoparticles, on cell viability of Staphylococcus aureus (Sa), Staphylococcus epidermidis (Se), Pseudomonas aeruginosa (Pa), Escherichia coli (Ec), Citrobacter freundii (Cf) and Klebsiella pneumoniae (Kp). To prepare Curcumin gold nanoparticles (Curc:AuNps) solutions, 3.2 mg of HAuCl4 was mixed with 1.5 mg Curcumin and Polyethylene glycol (PEG) in Mili-Q water. This solution was exposed to light from a mercury metal halide lamp. The resulting solutions were characterized by UV-Vis and transmission electron microscopy (TEM). The in vitro antibacterial activity of Curc:AuNps was evaluated against Sa, Se, Pa, Ec, Cf and Kp using the broth dilution assay. The effects of exposure to yellow LED light with ~38 J/cm 2 fluence and variations in the Curc:AuNPs concentrations (38, 50, 75 and 100% dilutions) were studied. The presence of a surface plasmon resonance band at ~560 nm indicated the formation of spherical gold nanoparticles. In the presence of PEG, the solution color changed some minutes after the mixing of reagents, and solution size homogeneity was improved with the mercury metal halide lamp illumination. TEM analyses showed ~17±2 nm nanoparticles. The results indicate that PDT with curcumin gold nanoparticles inhibits the development of Gram positive and Gram negative bacteria. This study revealed antibacterial probability of inhibition >80% with 32 mM of Curc:AuNPs and light against Sa, Se, Cf and Kp strains after 18 hours of incubation. NOVA/Tukey's tests were conducted to compare groups curcumin/Curc:AuNPs, with and without photodynamic excitation.

Synergizing Immune Balance: Curcumin Gold Nanoparticles and Ultrasound Irradiation for Macrophage Down-Regulation

“…Kurdi et al prepared AuNPs with different shapes and sizes using curcumin and several surfactants [38]. Courrol et al proposed photoreduction as a simple and rapid approach to generating curcumin gold nanoparticles [39].…”