Surface Grafted Antimicrobial Polymer Networks with High Abrasion Resistance

Abstract

In this work, we have investigated a quaternary ammonium compound that exhibits excellent antimicrobial activity and can be permanently grafted to substrates containing C−H bonds to form a durable polymeric film within 1 min. The compound consists of a biocidal component, dodecyl-alkylated quaternary ammonium, and a benzophenone moiety that, under mild UV irradiation, generates a densely cross-linked network and covalently attaches to a variety of substrates, including plastics, fabrics, and alkyl-modified glass surfaces. The surface attachment is 1 order of magnitude faster than that of previously reported benzophenone-associated cross-linkers, due to the electronwithdrawing effect of quaternary ammonium on the benzophenone chromophore. The modified surfaces are nonleaching and exhibit contact-killing and highly effective antimicrobial activity against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) using cell count and live/dead staining methods. The charged ammonium group also promotes photoreaction efficiency with respect to network robustness, leading to a thin film that can sustain high shear forces and abrasion when compared to commercially available silanebased quaternary ammonium compounds. The biocidal activity is also retained after exposure to mechanical stress and abrasion.

A multi-defense strategy: Enhancing bactericidal activity of a medical grade polymer with a nitric oxide donor and surface-immobilized quaternary ammonium compound

“…This process was monitored by the decrease in absorbance of the n-π * transition of BP using UV-vis spectrometry (Figure 2 (A)). Before exposure to UV light, the λ max absorbance at 255 nm was observed, which is the characteristic n-π * transition of BPAM [20]. A spectrum shoulder ranging from 310–350 nm is assigned to the UV absorbance (λ max ) of SNAP [64].…”

“…The benzophenone based antimicrobial molecule (BPAM) was prepared using the previously reported procedure of Gao et al, [20]. Briefly, 4-methylbenzopheone (6.0 g, 30.6 mM), NBS (6.0 g, 33.6 mM), AIBN (1.0 g, 6.1 mM), and cyclohexane (100 mL) were added to a round-bottom flask under nitrogen atmosphere.…”

“…Designing surfaces containing covalently bound poly “oniums” is one of the most successful strategies to date used to overcome surface microbial in fections [15–18]. Among these polycations, the benzophenone chromophore has been utilized to develop photochemically grafted quaternary ammonium coatings [19, 20]. Benzophenone based quaternary ammonium cations (BPAM) has been shown to exhibit instant contact killing and high biocidal activity against both Gram-positive and Gram-negative bacteria.…”

“…Benzophenone based quaternary ammonium cations (BPAM) has been shown to exhibit instant contact killing and high biocidal activity against both Gram-positive and Gram-negative bacteria. BPAM also exhibits rapid surface attachment (within 1 min) to the polymer with mild UV irradiation and good mechanical durability (survives Taber abrasion testing) due to the high photochemical efficiency of benzophenone and cross-linked network structure with polymer post irradiation [20]. …”

Tailoring Macromolecular Structure of Cationic Polymers towards Efficient Contact Active Antimicrobial Surfaces

“…[7][8] Alternatively, the polymers can be covalently anchored to the surfaces, which in most of the cases do not entail losing their biological activity. [9][10] In recent years, a variety of antimicrobial polymeric systems have been investigated including quaternary ammonium compounds, polymeric quaternary phosphonium salts, guanidine containing polymers and halogen polymers (i.e. N-halamines) among others.…”