Antibacterial Activity of Rose Bengal Entrapped in Organically Modified Silica Matrices

Abstract

Photosensitizers (PSs) are known as powerful antibacterial agents that are activated by direct exposure to visible light. PSs can be noncovalently entrapped into the silica gel network for their controlled release into a contaminated area. The immobilization of PS-containing gel matrices on a polymer support expands their possible applications, such as antibacterial surfaces and coatings, which can be used for the disinfection of liquids. In the current study, we report the use of Rose Bengal (RB) incorporated into organically modified silica matrices (RB@ORMOSIL matrices) by the sol-gel technique. The RB matrices exhibit high activity against Gram-positive and Gram-negative bacteria under illumination by white light. The amount and timing of solidifier addition to the matrix affected the interaction of the latter with the RB, which in turn could affect the antibacterial activity of RB. The most active specimen against both Gram-positive and Gram-negative bacterial cells was the RB6@ORMOSIL matrix immobilized on a linear low-density polyethylene surface, which was prepared by an easy, cost-effective, and simple thermal adhesion method. This specimen, RB6@OR@LLDPE, showed the low release of RB in an aqueous environment, and exhibited high long-term antibacterial activity in at least 14 rounds of recycled use against S. aureus and in 11 rounds against E. coli.

Antibacterial Properties of Rose Bengal Conjugated to Hyaluronic Acid

“…RB immobilized in polystyrene films effectively destroyed S. aureus and E. coli under illumination by white light for a week [ 29 ], and wastewater bacteria—for a month [ 30 ]. In addition, organically modified silica matrices with incorporated RB illuminated with white light kept high activity against bacteria for more than 10 cycles of use [ 31 ].…”

Fluorescence-Coupled Techniques for Determining Rose Bengal in Dermatological Formulations and Their Application to Ex Vivo Skin Deposition Studies

“…Research has been focused on developing advanced drug delivery systems that could help augment the efficacy of RB in dermatology ( Figure 1 ) to obviate RB shortcomings, including low bioavailability and scarce permeation of biological membranes [ 1 , 28 ]. Some of these drug delivery systems include liposomes [ 29 ], transfersomes [ 30 ], micellar platform [ 31 ], microemulsion [ 32 ], hydrogel [ 33 ], upconversion particles [ 34 , 35 ], inorganic nanoparticles (NP) [ 36 , 37 ], hybrid NP [ 24 ] and dissolving polymeric microneedles [ 38 ].…”

Síntesis y caracterización de nuevos fotocatalizadores heterogéneos para degradación de contaminantes y/o desinfección en medio acuoso

“…La rápida inactivación de E. faecalis en comparación con E. coli en presencia del RB se ha reportado desde finales de los años 80 por Dahl et al, [191] donde reportaron una cinética de inactivación un 200% más rápida para bacterias Gram positivas (Streptococcus salivarius, S. faecalis, S. aureus) en comparación con una bacteria Gram negativa (Salmonella typhimurium) mediante RB irradiada. Recientemente, Gurianov et al, [192] demostraron una mayor actividad antibacteriana de RB inmovilizado en sílice usando luz blanca visible, contra S. aureus en comparación con E. coli.…”