Bactericidal activity under UV and visible light of cotton fabrics coated with anthraquinone-sensitized TiO2

Inactivation and Degradation of Influenza a Virus on the Surface of Photoactive Self-Cleaning Cotton Fabric Functionalized with Nanocrystalline TiO2

Chemical modification of cotton-rich fabrics with TiO2 nanoparticles results in photoactive self-cleaning textiles, which can provide, under UV or solar radiation, complete oxidation of low-molecular compounds, degradation of supramolecular structures, and inactivation of microorganisms due to the photocatalytic effect. In this paper, we describe, based on the example of influenza A (H1N1) virus, a photoinduced antiviral effect of cotton fabric functionalized with nanocrystalline TiO2. Fast inactivation of influenza virus occurs on the irradiated surface of photoactive fabric due to adsorption and photocatalytic degradation. The TiO2 component in the prepared fabric increases the adsorption effect compared to initial cotton due to a high specific area of TiO2 nanocrystallites. Long-term irradiation leads to destruction of all virion structures to the point of RNA molecules. In contrast to pristine cotton, no virus RNA is detected using the polymerase chain reaction (PCR) technique after long-term irradiation of photoactive fabric. The results of this study underline the potential of photoactive self-cleaning fabrics for application in air purification systems and personal protective clothes to provide permanent protection of people against harmful chemical and biological pollutants.

An approach to the photocatalytic mechanism in the TiO2-nanomaterials microorganism interface for the control of infectious processes

The approach of this timely review considers the current literature that is focused on the interface nanostructure/cell-wall microorganism to understand the annihilation mechanism. Morphological studies use optical and electronic microscopes to determine the physical damage on the cell-wall and the possible cell lysis that confirms the viability and microorganism death. The key parameters of the tailoring the surface of the photoactive nanostructures such as the metal functionalization with bacteriostatic properties, hydrophilicity, textural porosity, morphology and the formation of heterojunction systems, can achieve the effective eradication of the microorganisms under natural conditions, ranging from practical to applications in environment, agriculture, and so on. However, to our knowledge, a comprehensive review of the microorganism/nanomaterial interface approach has rarely been conducted. The final remarks point the ideal photocatalytic way for the effective prevention/eradication of microorganisms, considering the resistance that the microorganism could develop without the appropriate regulatory aspects for human and ecosystem safety.

Conjugating biomaterials with photosensitizers: advances and perspectives for photodynamic antimicrobial chemotherapy

Antimicrobial resistance is threatening to overshadow last century's medical advances. Previously eradicated infectious diseases are now resurgent as multi-drug resistant strains, leading to expensive, toxic and, in some cases, ineffective antimicrobial treatments. Given this outlook, researchers are willing to investigate novel antimicrobial treatments that may be able to deal with antimicrobial resistance, namely photodynamic therapy (PDT). PDT relies on the generation of toxic reactive oxygen species (ROS) in the presence of light and a photosensitizer (PS) molecule. PDT has been known for almost a century, but most of its applications have been directed towards the treatment of cancer and topical diseases. Unlike classical antimicrobial chemotherapy treatments, photodynamic antimicrobial chemotherapy (PACT) has a non-target specific mechanism of action, based on the generation of ROS, working against cellular membranes, walls, proteins, lipids and nucleic acids. This non-specific mechanism diminishes the chances of bacteria developing resistance. However, PSs usually are large molecules, prone to aggregation, diminishing their efficiency. This review will report the development of materials obtained from natural sources, as delivery systems for photosensitizing molecules against microorganisms. The present work emphasizes on the biological results rather than on the synthesis routes to prepare the conjugates. Also, it discusses the current state of the art, providing our perspective on the field.

Materials for selective photo-oxygenation vs. photocatalysis: preparation, properties and applications in environmental and health fields

Photosensitizing materials made of organic dyes embedded in various supports are compared to usual supported TiO₂-based photocatalysts.

Antibacterial textiles functionalized by layer-by-layer assembly of polyelectrolytes and TiO2photocatalyst

Antibacterial photocatalytic textiles with high self-decontaminating activity under solar light againstE. colihave been prepared by sprayed layer-by-layer assembly of TiO₂and polyethylenimine or polyanionic poly(styrene sulfonate) polyelectrolyte.