Hospital wastewater treatment using eco‐friendly eugenol nanostructured lipid carriers: Formulation, optimization, and in vitro study for antibacterial and antioxidant properties

Abstract

In this study, nano‐formulation has been used to tackle one of the most important environmental problems which can be considered a major threat to human health. We prepared some eco‐friendly nanostructured lipid carriers (NLCs) as delivery agents to properly deliver an antibacterial agent (eugenol) into hospital wastewater in order to control bacterial growth. Eugenol‐loaded nanostructured lipid carriers were prepared by hot high‐speed homogenization. Then, the prepared nanocarriers were characterized using different techniques such as transmission electron microscopy, Fourier transform infrared, and dynamic scanning calorimetry. The turbidity assay and colony counting method were used to determine the ability of the prepared eugenol‐loaded nanostructured lipid carriers to inhibit bacterial growth rate in the culture media and hospital wastewater, respectively. The mean size and zeta potential of NLC‐eugenol were 78.12 ± 6.1 nm and −29.43 ± 2.21 mV, respectively. The results showed that the highest inhibitory effect of NLC‐eugenol in culture media was seen in standard and wild Staphylococcus aureus strains (43.42% and 26.41%, respectively) with a concentration of 0.125 μM. The antibacterial activity of NLC‐eugenol in sterile wastewater on wild strains of bacteria showed that the most effective concentration to reduce bacterial amounts was 0.125 μM on wild S. aureus and Enterococcus faecalis strains (38% and 33.47%, respectively) at 37°C. The NLC‐eugenol with a concentration of 0.125 μM showed the greatest effect of reducing total microbial agents by 28.66% in hospital wastewater at 25°C. The highest antibacterial effect achieved using the 0.125 μM concentration is due to the egel phenomenon. Also, the mechanism of action of NLC‐eugenol is cell wall destruction and eventually cell death. The results showed that NLC‐eugenol with a concentration of 0.125 μM can reduce wild bacterial strains in sterilized wastewater and hospital wastewater, which can prove the great potential of the prepared eugenol‐loaded nanostructured lipid carriers to control bacterial growth. Practitioner Points NLC is one of the safest biodegradable and environmentally friendly carriers, which is nontoxic for humans and the environment. Eugenol is a natural compound, which makes it less toxic for the environment while being toxic for bacteria. Therefore, our method has the least side effect in comparison with existing methods for wastewater treatment. The gradual release of eugenol from NLC nanoparticles can effectively control the pathogenic factors of wastewater.

Eugenol works synergistically with colistin against colistin-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae isolates by enhancing membrane permeability

“…Therefore, further studies are needed to evaluate the safety of eugenol for clinical use. Currently, several eugenol-related nanocapsules, including nanocoated, nanoparticle, and liposome formulations, have been extensively developed to improve the biocompatibility, stability, and bioactivity of eugenol ( 41 , 42 ). The development of eugenol nanopreparations will optimize its performance as an antibiotic adjuvant.…”

Monitoring hospital effluents through physico‐chemical characterization and genotoxic testing

“…Microorganisms act as the indicators of water quality and determine the particular pathogens and their relative risk in wastewater (Shajari et al, 2022). For example, fecal Streptococci and Escherichia coli are the indicators of fecal contamination and bacteriophages for viral contamination (Eze et al, 2016).…”

“…In this direction, Mathur et al, 2022 performed battery of bioassays to check the efficiency of the treatment plants installed at various health care establishments. Likewise, Shajari et al, 2022 had prepared ecofriendly nanostructured lipid carriers (NLCs) to deliver antibacterial agent Eugenol to control bacterial growth in hospital wastewater. Such studies are an effort to monitor and provide safe recycled water.…”

Sewage Treatment Using Nanoparticles

“…The antibacterial activity of NLC-eugenol in sterile wastewater on wild bacteria strains revealed that 0.125 M was the most effective concentration to reduce bacterial quantities on wild S. aureus and Enterococcus faecalis strains (38% and 33.47%, respectively) at 37°C. At 25°C, NLC-eugenol at 0.125 M had the best impact, lowering total microbiological agents by 28.66% in hospital wastewater as shown in Table 1 [57].…”