Biofabricated Fatty Acids-Capped Silver Nanoparticles as Potential Antibacterial, Antifungal, Antibiofilm and Anticancer Agents

Abstract

The current study demonstrates the synthesis of fatty acids (FAs) capped silver nanoparticles (AgNPs) using aqueous poly-herbal drug Liv52 extract (PLE) as a reducing, dispersing and stabilizing agent. The NPs were characterized by various techniques and used to investigate their potent antibacterial, antibiofilm, antifungal and anticancer activities. GC-MS analysis of PLE shows a total of 37 peaks for a variety of bio-actives compounds. Amongst them, n-hexadecanoic acid (21.95%), linoleic acid (20.45%), oleic acid (18.01%) and stearic acid (13.99%) were found predominately and most likely acted as reducing, stabilizing and encapsulation FAs in LIV-AgNPs formation. FTIR analysis of LIV-AgNPs shows some other functional bio-actives like proteins, sugars and alkenes in the soft PLE corona. The zone of inhibition was 10.0 ± 2.2–18.5 ± 1.0 mm, 10.5 ± 2.5–22.5 ± 1.5 mm and 13.7 ± 1.0–16.5 ± 1.2 against P. aeruginosa, S. aureus and C. albicans, respectively. LIV-AgNPs inhibit biofilm formation in a dose-dependent manner i.e., 54.4% ± 3.1%—10.12% ± 2.3% (S. aureus), 72.7% ± 2.2%–23.3% ± 5.2% (P. aeruginosa) and 85.4% ± 3.3%–25.6% ± 2.2% (C. albicans), and SEM analysis of treated planktonic cells and their biofilm biomass validated the fitness of LIV-AgNPs in future nanoantibiotics. In addition, as prepared FAs rich PLE capped AgNPs have also exhibited significant (p < 0.05 *) antiproliferative activity against cultured HCT-116 cells. Overall, this is a very first demonstration on employment of FAs rich PLE for the synthesis of highly dispersible, stable and uniform sized AgNPs and their antibacterial, antifungal, antibiofilm and anticancer efficacy.

Counteraction of Biofilm Formation and Antimicrobial Potential of Terminalia catappa Functionalized Silver Nanoparticles against Candida albicans and Multidrug-Resistant Gram-Negative and Gram-Positive Bacteria

“…The results of the SEM were confirmed by TEM analysis, as discussed elsewhere [ 10 ]. Briefly, MRSA, MDR-PA, and C. albicans cells grown in the presence of MIC values of TCE-Ag-3 were centrifuged, washed with MQ water, fixed in 2.5% glutaraldehyde and 1% osmium tetraoxide, and embedded in Epon resin (Polybed 812).…”

“…The role of bio-actives molecules contributed by animal, microbial, and plant cells and tissues in bio-inspired nanomaterial synthesis has been recognized, with the ultimate potential to reduce a wide range of metal cations to nano size particles [ 34 , 35 , 36 ]. Benign extracts of explants such as leaves, root, stem, bark, and seed typically act as bio-factory for the synthesis of a wide range of bio-actives including long and short hydrocarbon chains (saturated/unsaturated), aromatic complex cyclic compounds, polyphenols, alkaloids, flavonoids, terpenoids, sugars, proteins, and enzymes naturally [ 8 , 10 , 30 , 31 ]. Besides, easy availability, inexpensiveness, low toxicity, and indigenous therapeutic effects of plant bio-actives have attracted the nanotechnologies towards green synthesis approaches while developing their intended nanoconstructs.…”

“…The plates were then incubated for 24 h at 37 and 28 °C, respectively. The MBC/MFC endpoint is defined as the lowest concentration of antimicrobial agent that kills 100% of the initial microbial population [ 10 ].…”

“…The 96-well microtiter plate method was used to evaluate the antibiofilm activity of TCE-Ag-3 NPs against MRSA, MDR-PA, and C. albicans [ 10 ]. Precisely, the wells seeded with 100 μL of bacteria (~1 × 10 7 CFU/mL) and C. albicans (~5 × 10 6 CFU/mL) were treated with 0.95, 1.95, 3.90, and 7.8 µg/mL of TCE-Ag-3 at 37 °C for 24 h. The wells were washed with phosphate buffer saline (PBS) after taking out the NPs suspensions.…”

“…Such nanoscale fabrication of organic, inorganic, metallic, and biological structures is generally done by following either bottom-up or top-down approaches. In modern times, green approaches for NPs synthesis have gained immense interest due to its eco-friendly processing and low-cost input [ 10 , 11 , 12 ]. Furthermore, NPs derived from various plant extracts contain a variety of indigenous bio-active molecules such as polyphenols, alkaloids, terpenoids, sugars, proteins, and enzymes that act as reducing, capping, and stabilizing agents.…”