Synergistic Superhydrophobic and Photodynamic Cotton Textiles with Remarkable Antibacterial Activities

Abstract

Pathogenic bacterial contamination is at the root of many persistent and chronic bacterial infections. Synergistic superhydrophobic surfaces functionalized with a cationic antimicrobial agent (e.g., quaternary ammonium components) show promising antimicrobial efficacies, but are inherently contradictory in simultaneously maintaining excellent surface liquid repellency and bactericidal activity due to the compromised low surface energy stemming from the introduced hydrophilic biocides. Herein, we present a synergistic antibacterial cotton textile with superhydrophobic bacterial repellency and photodynamic bactericidal activity for both Staphylococcus aureus and Escherichia coli. The modified cotton textile was constructed by integrating tunable micro/nanoscale roughness, hydrophobic photosensitizer chlorin e6, and surface perfluorination. The triple-scale structured superhydrophobic surfaces exhibited ≲90% reductions in both waterborne and airborne bacterial adhesions. Subsequently, after being exposed to visible light for 45 min, the synergistic surface demonstrated complete inactivation (100% killing) against residual bacterial cells via photodynamic bactericidal capacities. Moreover, the triple-scale structured superhydrophobic surface displayed totally suppressed whole blood adhesion, suggesting potential in preventing plenty of undesirable biomedical forms of contamination. This synergistically antibacterial surface not only improves the antibacterial efficiency but also leads to long-lasting antimicrobial performance, each of which is highly desirable in combating bacterial infections.

Bacteria Adhesion of Textiles Influenced by Wettability and Pore Characteristics of Fibrous Substrates

“…Since the textiles have both roughened surfaces and pores within their volume, they provide a dynamic environment for bacteria to adhere, grow, and form biofilms. Such being the case, researchers were motivated to develop antibacterial textiles that can control bacteria adhesion and growth [ 4 , 5 , 6 , 7 , 8 ]. For example, as a preventative measure to bacterial growth on textiles, various antimicrobial treatments such as quaternary ammonium compounds, triclosan, and chitosan have been incorporated into fibers [ 9 ]; however, those materials often fail to kill every organism effectively.…”

Medical textiles

“…Analyses showed that the antibacterial efficiencies of betainemodified cotton fabrics against E. coli and S. aureus were 99.0% and 99.3%, respectively and that the fabrics were durable to laundering with antibacterial action remaining greater than 91.5% after 20 washing cycles; cytotoxicity tests showed the modified fabrics were safe to wear [240]. In other successful cases, antibacterial action and its durability was achieved with a quaternary ammonium salt plus a sulfopropylbetaine [241,242], or by an isocyanate group using a dip-pad-dry application process [243], or they were coupled with perfluorination to yield both superhydrophobicity and antimicrobial effects [244,245], or were applied in nanoparticulate form [246], and they may also be used in combination with N-halamines [247].…”

“…Multifunctional finishing of medical textiles has drawn considerable attention as shown by reported research [241,242,244,245], with the purpose of capturing a series of beneficial improvements in fabric properties alongside antimicrobial action. One recent piece of research involved applying a thin, elastic xerogel coating as a finish by padding on woven 67% PET/33% cotton fabric by the sol-gel method to achieve antibacterial (vs both gram þ ve and gram -ve bacteria) and antifungal effects, combined with photocatalytic cleaning, a high ultraviolet protection factor (over 50) and high abrasion resistance.…”

Antibacterial Coatings for Improving the Performance of Biomaterials

“…Poly(ethylene glycol) (PEG) segments and zwitterionic units anchored at surfaces are the most representative examples of these kinds of antibacterial hydrophilic surfaces and they have been intensively studied. Alternatively, superhydrophobic surfaces have also demonstrated successful antifouling properties related to an air layer between the aqueous medium and the surface that reduce cells attachment [41]. Accordingly, bacteria repelling action can be described and classified based on three different effects: (i) steric, (ii) electrostatic and (iii) superhydrophobic effect, that can be observed in hydrophilic, charged and superhydrophobic surfaces, respectively.…”