پیشرفت هایی در غیر فعالسازی واکنش باکتریایی کاتالیزگر نوری
Abstract
1- Introduction
1-1- Ag as antimicrobial particles
1-2- Surface Ag-NPs characteristics
1-3- Ag-NPs leading to bacterial inactivation in the dark
1-4- Ag-NPs surfaces leading to bacterial inactivation
1-5- Microstructure of nanoparticles on surfaces sputtered by DCMS, DCPMS and HIPIMS: Critical issues
1-6- Nitride selection when using antimicrobial metal nitrides under light irradiation: TEM-microstructure of Ag-nitride films
1-7- Evidence for the interfacial charge transfer (IFCT) mechanism in semiconductors under light leading to bacterial inactivation
1-8- Dependence of the Ag-nitride mediated bacterial inactivation kinetics on the applied light dose
1-9- Effect of the sputtering energies on the film microstructure and the bacterial inactivation kinetics
2- Introduction
2-1- Cu as antimicrobial particles (Cu-NPs) and Cu-films: Critical issues
2-2- Cu-surfaces and catheter devices obtained by sol-gel methods
2-3- Sputtered films leading to bacterial inactivation in the dark and under light
2-4- Cu bacterial inactivation under light and in the dark: Scientific bases
2-5- Features of antimicrobial Cu-decorated surfaces under light and in the dark
2-6- Effects of the Cu/TiO2 films microstructure on bacterial inactivation kinetics
2-7- Protection of the Cu-ion release in sputtered films increases the sample stability
2-8- Inactivation of Gram-positive methicillin resistant staphylococcus aureus (MRSA) and other pathogens on Cu-surfaces
2-9- Cu-sputtered surfaces: Implications of the applied deposition energy
3- Introduction
3-1- Ag-Cu as antibacterial bimetal materials
3-2- Colloidal loaded Ag-Cu NPs and films leading to bacterial inactivation
3-3- Ag-Cu films leading to bacterial inactivation with a quasi-instantaneous kinetics
3-4- Mechanism suggested for the bacterial inactivation of Ag-Cu films
3-5- Surface potential and pH-changes during bacterial inactivation
3-6- TEM imaging and XPS analysis of Ag-Cu films
3-7- E. coli and MRSA inactivation on Ag-Cu films: corrosion of the film during the bacteria/fungi inactivation
3-8- Effect of the Ag, Cu and Ag-Cu films on normal and porinless E. coli. Differentiation of ionic and surface-contact effects
3-9- Infrared spectroscopy of the functional groups abatement leading to bacterial lysis
3-10- Mechanism of the interfacial charge transfer (IFCT) during bacterial inactivation
3-11- Conclusions
3-12- Outlook
References
Abstract
The design, synthesis, fundamentals and evaluation of 2D/3D antimicrobial surfaces are addressed in detail in the current review. Recent advances in the antimicrobial mechanism, kinetics and properties of Ag, Cu and Ag-Cu surfaces in the dark and under light irradiation are described and discussed. The structure-reactivity relations in the catalyst/photocatalyst layers were described by way of the surface characterization and the observed antibacterial kinetics. Escherichia coli (E. coli) and Methicillin resistant Staphylococcus aureus MRSA bacteria are selected as model pathogens to evaluate the antimicrobial inactivation kinetics. The separate antimicrobial properties of ions and the antimicrobial surface-contact effects are presented in a detailed way. The interfacial charge transfer (IFCT) mechanism and the identification of the most relevant reactive oxygen species (ROS) leading to bacterial disinfection are considered. The recently developed monitoring of the changes of the film surface potential (Eigenvalues) during bacterial inactivation and the redox reactions associated with catalyst/photocatalyst surfaces are also presented. The potential for practical applications of these innovative 2D films and 3D sputtered medical devices in health-care facilities are accounted for in the present review.
Introduction
Since decades, nano-silver has been used as an antibacterial material. Ag-nanoparticles cannot be compared to conventional chemicals or bulk materials when trying to elucidate its bactericide action. Products containing nano-silver particles have been commercially available for over 100 years and have been used in different applications [1]. The medical uses of Ag-suspensions, Ag-healing pads and Ag-ions have been reported for the last few decades. Lately, there has been a renewed interest in silver coatings for antimicrobial purposes due to the increased resistance of bacteria to antibiotics [2]. The bacterial inactivation by Ag proceeds by the release of silver-ions penetrating the bacteria cytoplasm through the bacterial porins and by the silver nanoparticles in contact with the bacterial outer-wall [2]. Also, silver nanoparticles (Ag-NPs) have been reported to inactivate bacteria and other pathogens through the oligodynamic effect involving the diffusion of 10−6 -10-9 mol/l (ppm-ppb) amounts in contact with the bacterial outer cell envelope [2–6]. Ag-NPs disinfection proceeds in suspension or deposited on films through the destruction of cell wall by reactive oxygen species (ROS) [1–9]. The Ag-toxicity towards bacteria, viruses and fungi is significantly higher compared to the toxicity reported for mammalian cells [4,5]. Silver ions have an affinity towards sulfhydryl groups located at the cell wall, interfering with the electron transport chain through the cell wall porins diffusing to the interior of the bacteria. Ag-ions have also been reported to block the respiratory chain of microorganisms without inducing resistance to silver ions with a few exceptions [7]. The concentrations required for bactericidal activity are in the ppb range (10−9 mol/l). Metallic silver particles react with moisture, releasing highly oxidative Ag-ions. These Ag-ions complex with DNA and RNA, which inhibit the microorganism replication [8]. Recent reviews report that the size, shape and concentration of Ag-NPs control their antimicrobial kinetics and efficiency [9].