Green Synthesis of Antileishmanial and Antifungal Silver Nanoparticles Using Corn Cob Xylan as a Reducing and Stabilizing Agent

Abstract

Corn cob is an agricultural byproduct that produces an estimated waste burden in the thousands of tons annually, but it is also a good source of xylan, an important bioactive polysaccharide. Silver nanoparticles containing xylan (nanoxylan) were produced using an environmentally friendly synthesis method. To do this, we extracted xylan from corn cobs using an ultrasound technique, which was confirmed by both chemical and NMR analyses. This xylan contained xylose, glucose, arabinose, galactose, mannose, and glucuronic acid in a molar ratio of 50:21:14:9:2.5:2.5, respectively. Nanoxylan synthesis was analyzed using UV–vis spectroscopy at kmax = 469 nm and Fourier transform infrared spectroscopy (FT-IR), which confirmed the presence of both silver and xylan in the nanoxylan product. Dynamic light scattering (DLS) and atomic force microscopy (AFM) revealed that the nanoxylan particles were ~102.0 nm in size and spherical in shape, respectively. DLS also demonstrated that nanoxylan was stable for 12 months and coupled plasma optical emission spectrometry (ICP-OES) showed that the nanoxylan particles were 19% silver. Nanoxylan reduced Leishmania amazonensis promastigote viability with a half maximal inhibitory concentration (IC50) value of 25 μg/mL, while xylan alone showed no effective. Additionally, nanoxylan exhibited antifungal activity against Candida albicans (MIC = 7.5 μg/mL), C. parapsilosis (MIC = 7.5 μg/mL), and Cryptococcus neoformans (MIC = 7.5 μg/mL). Taken together, these data suggest that it is possible to synthesize silver nanoparticles using xylan and that these nanoxylan exert improved antileishmanial and antifungal activities when compared to the untreated polysaccharide or silver nitrate used for their synthesis. Thus, nanoxylan may represent a promising new class of antiparasitic agents for use in the treatment of these microorganisms.

Plant-Based Green Synthesis of Nanoparticles: Production, Characterization and Applications

“…It is essential that these NPs be precisely and thoroughly characterized in order to ensure reproducibility in their production, biological activity, and safety. For this purpose, a wide range of physicochemical methods are used to very precisely characterized the synthesized NPs including ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), attenuated total reflection (ATR), Raman spectroscopy, photoluminescence analysis (PL), dynamic light scattering (DLS), UV-visible diffuse reflectance spectroscopy (UV-DRS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), X-ray diffractometer (XRD), X-ray photoelectron microscopy (XPS), energy dispersion analysis of X-ray (EDAX), thermal gravimetric differential thermal analysis (TG-DTA), or nuclear magnetic resonance (NMR) [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ].…”

“…Plant-based silver nanoparticles (AgNPs) are among the easiest to prepare [ 24 , 26 , 27 , 30 , 35 , 38 ]. For the green synthesis of silver nanoparticles, a silver metal ion solution and a reducing biological agent are required.…”

“…Due to their unique properties, such as bioavailability, reduced toxicity, targeted drug delivery, and biodegradability, a variety of nanotechnology-based techniques and products have emerged as anti-leishmanial drugs, including liposomes, lipid nano-capsules, metal and metallic oxide nanoparticles, polymeric nanoparticles, nanotubes, and nanovaccines [ 2 ]. AgNPs containing xylan (also known as nanoxylan) synthesized in a green synthesis route with corncob xylan as a reducing and stabilizing agent demonstrated effective inhibitory activity against Leishmania amazonensis promastigote viability, whereas xylan alone had no effect [ 35 ]. This work nicely illustrates the potential of the nanoxylan as a promising new type of antiparasitic agent [ 35 ].…”

Salvadora persica mediated synthesis of silver nanoparticles and their antimicrobial efficacy

“…They also exhibit effective antimicrobial efficacy against fungal pathogens 31 . Recently, applications of AgNPs in other biomedical fields have also been reported, for instance, anticoagulant activity 32 , thrombolytic effect 33 , anti-filarial 34 , anti-leishmania 35 , antilarval, anthelmintic, antioxidant activity and anticancer 36 . The applications of AgNPs in biomedical and pharmaceuticals will continue to rise, owing to their potential industrial applications related to global health and eco-benign production requiring cheaper raw materials and cost-effective procedures.…”

Platinum Nanoparticles: Green Synthesis and Biomedical Applications

“…Plant extracts harbor various bioactive metabolites that could act as bio-reductants and stabilizers during the green synthesis of PtNPs [8][9][10][11]. In addition to plants, other biological entities were employed for green synthesis of PtNPs, including microbes (such as bacteria, viruses, fungi, and yeast) and marine algae [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. The use of microbes as a potential biogenic route for the fabrication of PtNPs has some advantages, including their ease of production and capability to reduce Pt ions via enzymatic activity into the zero-valent Pt while maintaining optimum control over the average particle sizes [27].…”