Hospital-acquired infections (HAIs) are responsible for over 40% of cases in acute-care hospitals and commonly associated with catheter-sassociated urinary tract infections (CAUTIs). Current nanotechnology approach focus on improving the aseptic procedures for medical devices and manage the HAIs risk. TiO2 and ZnO nanoparticles (NPs) have been widely reported independently, to have a photocatalytic killing potential. The present study evaluates the antibacterial activity of heterojunction between TiO2 and ZnO NPs on several types bacterial pathogens model including Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The antibacterial screening test on TiO2/ZnO nanoparticles (NPs) were done under dark and light conditions with different molar ratio 25T75Z, 50T50Z and 75T25Z according to Clinical Laboratory Standards Institute (CLSI) guidelines MO2-A11. ZnO and TiO2/ZnO (25T75Z and 50T50Z) NPs at the highest concentration (1000µg/µL) showed mean diameters of the zones of inhibition (mm); (12.5 ± 0.58), (12.13 ± 0.85), and (7.25 ± 1.44) in dark condition. Increment in inhibition zones was obtained under light condition; (21.38 ± 0.48), (17.50 ± 1.0), and (12.38 ± 1.80). Findings from this study highlights the heterogeneous TiO2 and ZnO NPs could become a promising bacteriostatic and/or bactericidal agent to combat against the HAIs.
There is a growing concern in using zinc oxide nanoparticles (ZnO NPs) for medical devices as alternative options in reducing hospital-acquired infections (HAIs). The commensal HAIs; Staphylococcus aureus (S.aureus) infect patients and lead to increased rates of morbidity and mortality. This study aims to investigate the antibacterial action of ZnO NPs in three different shapes; nanorod, nanoflakes and nanospheres impregnated in low-density polyethylene (LDPE) against S.aureus ATCC 25923. Methods: The antibacterial efficiency of ZnO NPs was studied through two standard test methods included were based on Clinical Laboratory Standards Institute (CLSI) guidelines MO2-A11 under light conditions of 5.70 w/m2 and American standard test method (ASTM) E-2149. Results: Preliminary screening did show a significant growth inhibition against S.aureus with ZnO NPs nanorod and nanoflakes, approximately in 7 to 8 mm zones of inhibition. Further analysis using ASTM E-2149 in dynamic conditions revealed variable activity depending on incubation treatment periods. It demonstrated the ZnO NPs in nanoflakes and nanosphere shape showed better inhibition against S.aureus with maximum reduction (100%). The FESEM results strongly suggest that the structure of ZnO nanoflakes and nanosphere played an importance role in nanomaterial-bacteria interaction which consequently cause cell membrane damage. Additionally, the irradiation under light treatment also enhance the generation of ROS and free radicals which helps the bactericidal activity against S.aureus. Conclusion: This study provides new insights for the antibacterial action of ZnO NPs/LDPE thin films in future biomedical appliances to reduce HAIs risks.
Metal oxide-polymer nanocomposite has been proven to have selective bactericidal effects against the main and common pathogens (Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli)) that can cause harmful infectious diseases. As such, this study looked into the prospect of using TiO₂/ZnO with linear low-density polyethylene (LLDPE) to inactivate S. aureus and E. coli. The physical, structural, chemical, mechanical, and antibacterial properties of the nanocomposite were investigated in detail in this paper. The production of reactive species, such as hydroxyl radicals (•OH), holes (h⁺), superoxide anion radicals (O₂•¯), and zinc ion (Zn2+), released from the nanocomposite were quantified to elucidate the underlying antibacterial mechanisms. LLDPE/25T75Z with TiO₂/ZnO (1:3) nanocomposite displayed the best performance that inactivated S. aureus and E. coli by 95% and 100%, respectively. The dominant reactive active species and the zinc ion release toward the superior antibacterial effect of nanocomposite are discussed. This work does not only offer depiction of the effective element required for antimicrobial biomedical appliances, but also the essential structural characteristics to enhance water uptake to expedite photocatalytic activity of LLDPE/metal oxide nanocomposite for long term application.