Antibacterial Activity of Boron Compounds Against Biofilm-Forming Pathogens

Activity of zinc oxide and zinc borate nanoparticles against resistant bacteria in an experimental lung cancer model

BACKGROUND

Recent research indicates a prevalence of typical lung infections, such as pneumonia, in lung cancer patients. Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii stand out as antibiotic-resistant pathogens. Given this, there is a growing interest in alternative therapeutic avenues. Boron and zinc derivatives exhibit antimicrobial, antiviral, and antifungal properties.

OBJECTIVES

This research aimed to establish the effectiveness of ZnO and ZB NPs in combating bacterial infections in lung cancer cell lines.

METHODS

Initially, this study determined the minimal inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) of zinc oxide nanoparticles (ZnO NPs) and zinc borate (ZB) on chosen benchmark strains. Subsequent steps involved gauging treatment success through a lung cancer-bacteria combined culture and immunohistochemical analysis.

RESULTS

The inhibitory impact of ZnO NPs on bacteria was charted as follows: 0.97 µg/mL for K. pneumoniae 700603, 1.95 µg/mL for P. aeruginosa 27853, and 7.81 µg/mL for Acinetobacter baumannii 19,606. In comparison, the antibacterial influence of zinc borate was measured as 7.81 µg/mL for Klebsiella pneumoniae 700603 and 500 µg/mL for both P. aeruginosa 27853 and A.baumannii 19606. After 24 h, the cytotoxicity of ZnO NPs and ZB was analyzed using the MTT technique. The lowest cell viability was marked in the 500 µg/mL ZB NPs group, with a viability rate of 48.83% (P < 0.001). However, marked deviations appeared at ZB concentrations of 61.5 µg/mL (P < 0.05) and ZnO NPs at 125 µg/mL.

CONCLUSION

A synergistic microbial inhibitory effect was observed when ZnO NP and ZB were combined against the bacteria under investigation.

Quantum dots: a next generation approach for pathogenic microbial biofilm inhibition; mechanistic insights, existing challenges, and future potential

Quantum Dots (QDs) have emerged as versatile nanomaterials with origins spanning organic, inorganic, and natural sources, revolutionizing various biomedical applications, particularly in combating pathogenic biofilm formation. Biofilms, complex structures formed by microbial communities enveloped in exopolysaccharide matrices, pose formidable challenges to traditional antibiotics due to their high tolerance and resistance, exacerbating inefficacy issues in antibiotic treatments. QDs offer a promising solution, employing physical mechanisms like photothermal or photodynamic therapy to disrupt biofilms. Their efficacy is noteworthy, with lower susceptibility to resistance development and broad-spectrum action as compared to conventional antibiotic methods. The stability and durability of QDs ensure sustained biofilm activity, even in challenging environmental conditions. This comprehensive review delves into the synthesis, properties, and applications of Carbon Quantum Dots (CQDs), most widely used QDs, showcasing groundbreaking developments that position these nanomaterials at the forefront of cutting-edge research and innovation. These nanomaterials exhibit multifaceted mechanisms, disrupting cell walls and membranes, generating reactive oxygen species (ROS), and binding to nucleic materials, effectively inhibiting microbial proliferation. This opens transformative possibilities for healthcare interventions by providing insights into biofilm dynamics. However, challenges in size control necessitate ongoing research to refine fabrication techniques, ensure defect-free surfaces, and optimize biological activity. QDs emerge as microscopic yet potent tools, promising to contribute to a brighter future where quantum wonders shape innovative solutions to persistently challenging issues posed by pathogenic biofilms. Henceforth, this review aims to explore QDs as potential agents for inhibiting pathogenic microbial biofilms, elucidating the underlying mechanisms, addressing the current challenges, and highlighting their promising future potential.

Boron Compound-Based Treatments Against Multidrug-Resistant Bacterial Infections in Lung Cancer In Vitro Model

Multidrug-resistant bacteria is one of the most important public health problems. Increasing rates of antibacterial resistance also affect the outcomes of medical approaches. Cancer treatment because of immune system deficiency (chemotherapy or steroids usage) commonly can cause infection. Lung cancer is the dominant cause of cancer-related deaths, and infection is the most common cause of death among those patients. In this study, it was aimed to determine the antimicrobial, antibiofilm, and anticancer activity of boron compounds. A549 lung cancer cell line was infected with Acinetobacter baumannii (ATCC 19606), Klebsiella pneumoniae (ATCC 700603), and Pseudomonas aeruginosa (ATCC 27853). In order to determine the fractional inhibitory concentration (FIC) index, antibiotics and boron compound concentrations prepared according to the minimum inhibitory concentration (MIC) values were determined by the checkerboard method. In our study results, the antibiofilm activity was an average of 46% in A. baumannii+boron compounds, 45% in P. aeruginosa+boron compounds, and 43% in K. pneumoniae. Cell culture analysis results show a decrease in viability and antioxidant capacity and an increase in total oxidant status after adding boron compounds to the culture. Immunofluorescence results show a correlation with MTT, and boron compounds increased 8-OHdG expression in comparison to antibiotic administration. In conclusion, boron compounds have promising effects on bacteria, especially in resistant bacteria spp.