Synthesis of Functional Silver Nanoparticles and Microparticles with Modifiers and Evaluation of Their Antimicrobial, Anticancer, and Antioxidant Activity

Abstract

An accumulating body of evidence reports the synthesis and biomedical applications of silver nanoparticles. However, the studies regarding the use of maleic acid and citric acid in the synthesis of nano-sized silver particles (AgNPs) and micro-sized silver particles (AgMPs) as well as their antibacterial, antifungal, and anticancer activities have not been reported. In the current study, we synthesized AgNPs and AgMPs using maleic acid and citric acid as capping agents and have characterized them by UV-Vis, energy-dispersive X-Ray spectroscopy (EDS), X-Ray diffraction (XRD), and scanning electron microscope (SEM) analysis. The capped silver particles were examined for their antimicrobial activity and cytotoxicity against bacteria, fungi, and brine shrimp. Additionally, the anticancer activity of these particles was tested against human breast and liver cancer cell lines. The free radical scavenging activity of capped silver particles was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. SEM analysis revealed a round plate-like morphology of maleic acid capped particles with an average size of 39 ± 4 nm, whereas citric acid capped particles display flower-shaped morphology with rough surfaces and an average size of 250 ± 5 nm. The uncapped AgMPs were hexagonal with 500 ± 4 nm size. EDS and XRD analysis confirmed the presence of Ag and face-centered cubic crystalline nature, respectively. Functionally, capped silver particles exhibited antibacterial activity against Gram-positive (Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteus) and Gram-negative bacteria (Salmonella setubal, Enterobacter aerogenes, and Agrobacterium tumefaciens). The bactericidal activity was more active against Gram-negative bacteria with minimum inhibitory concentration (MIC) as low as 5 ppm as compared to 25 ppm for Gram-positive. Similarly, the silver particles demonstrated antifungal activity by inhibiting the growth of five fungal strains (Mucor species, Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, and Fusarium solani) up to 50% at the concentration of 500 ppm. Additionally, these particles showed substantial toxicity against brine shrimp and also significantly inhibited the proliferation of breast cancer (MCF7) and liver cancer (HePG2) cell lines (IC50 8.9–18.56 µM). Uncapped AgMPs were less effective, inhibiting only the proliferation of MCF7 cells with IC50 46.54 µM. Besides cytotoxicity, these particles acted as potential antioxidants, showing free radical scavenging up to 74.4% in a concentration-dependent manner. Taken together, our results showed that the modifiers affect the shape and size of silver particles and may, in part, contribute to the antimicrobial and antioxidant activity of silver particles. However, the contribution of maleic acid and citric acid in enhancing the antimicrobial, anticancer, and antioxidant potential independent of silver nano and microparticles needs to be studied further. In vivo experiments may determine the therapeutic effectiveness of silver particles capped with these modifiers.

Nanomaterial-Based Antifungal Therapies to Combat Fungal Diseases Aspergillosis, Coccidioidomycosis, Mucormycosis, and Candidiasis

“…This behavior was also observed in the MIC determinations, where Ag 2 Fe 2 O 2 antifungal effects were observed at 50 mg/mL, Ag 2 Cr 2 O 4 at 12.5 mg/mL, and fluconazole at 25 mg/mL against all four fungal species. Dilshad et al [74] observed the antimicrobial effect of citric acid-and maleic acid-capped AgNPs against A. niger, A. flavus, A. fumigatus, and Fusarium solani. The authors observed that the maleic acid-capped NPs exhibit better antifungal activity than citric acid-capped NPs.…”

“…AgNPs Growth inhibition at 10 µg/mL [33] 54% growth inhibition at 100 mg/L [92] 75.61% growth inhibition at 150 µg/mL [105] Growth inhibition at 150 µg/mL [106] Growth inhibition at 40 µg/mL [107] 60% growth inhibition at 50 µg/mL [110] Marketed AgNPs 90% growth inhibition at 0.5 µg/mL (clinical isolates) [93] AgO/Ag NPs 75.25% growth inhibition at 50 µg/mL [113] Ag-AuNPs 90.78% growth inhibition at 200 µg/mL [111] Ag 2 Cr 2 O 4 3.1 times higher inhibition than fluconazole [94] Maleic acid capped AgNPs Growth inhibition [74] Milk protein synthesized AgNPs Growth inhibition [95] Fibroin-AgNPs Fungicidal activity at 2 µg/mL [99] Ag-Cu core-shell NPs Growth inhibition at 0.1 M and fungicidal activity at 15 µg/mL [100] CChG/AgNPs Better growth inhibition than AmB at 0.98 µg/mL [101] CuNPs Growth inhibition at 31.67 µg/mL [107] Cu-Ag core-shell NPs Growth inhibition at 0.1M and fungicidal activity at 25 µg/mL [100] Au@5FU NPs Higher inhibition than 5FU [96] Fibroin-AuNPs Fungicidal activity at 10 µg/mL [99] TiO 2 -PLA NPs 99.9% growth inhibition at 8 wt% of NPs [97] pMWCNT-CD/Ag-TiO 2 nanosponge Growth inhibition at 437.5 µg/mL [98] Table 3. Cont.…”

Novel Hybrid Compounds Containing Benzofuroxan and Aminothiazole Scaffolds: Synthesis and Evaluation of Their Anticancer Activity

“…DAPI and propidium iodide were purchased from Sigma. Two fluorescent dyes that selectively penetrate the cell membranes and fluoresce at different wavelengths were used in the 7-Chloro-4,6-dinitrobenzofuroxan 1 was synthesized according to the literature [47], 4,6-dinitro-7-(thiazol-2-ylamino)benzo[c] [1,2,5]oxadiazole 1-oxide 3a was prepared according to [20], and 2-aminothiazoles were purchased by Sigma-Aldrich (Darmstadt, Germany).…”

“…The end result of the action of all antitumor drugs is the inhibition of cell proliferation and the death of tumor cells (tumor regression) [ 5 ]. This effect is achieved by acting on various targets in the cell: DNA; RNA; enzymes necessary for normal DNA replication and repair; pathways for the intracellular transduction of mitogenic signals; the mitotic apparatus of the cell.…”

Green Synthesis of Zinc oxide Nanocomposite Using Fusarium oxysporum and Evaluation of the Anticancer Effect on Hepatocellular Carcinoma

“…It should also provide functional groups which can be further modified to control the drug release or to bind targeting units [11]. Silver nanoparticles based nanosystems were evaluated as suitable carriers of various therapeutic molecules, including antiinflammatory [12,13], antioxidant [14], antimicrobial [15,16] and anticancer [17,18] substances. Coreshell nanoparticles have received a lot of attention, especially as multimodal for medical applications [19][20][21][22].…”