Photodynamic Antimicrobial Polymers for Infection Control

Abstract

Hospital-acquired infections pose both a major risk to patient wellbeing and an economic burden on global healthcare systems, with the problem compounded by the emergence of multidrug resistant and biocide tolerant bacterial pathogens. Many inanimate surfaces can act as a reservoir for infection, and adequate disinfection is difficult to achieve and requires direct intervention. In this study we demonstrate the preparation and performance of materials with inherent photodynamic, surface-active, persistent antimicrobial properties through the incorporation of photosensitizers into high density poly(ethylene) (HDPE) using hot-melt extrusion, which require no external intervention except a source of visible light. Our aim is to prevent bacterial adherence to these surfaces and eliminate them as reservoirs of nosocomial pathogens, thus presenting a valuable advance in infection control. A two-layer system with one layer comprising photosensitizer-incorporated HDPE, and one layer comprising HDPE alone is also described to demonstrate the versatility of our approach. The photosensitizer-incorporated materials are capable of reducing the adherence of viable bacteria by up to 3.62 Log colony forming units (CFU) per square centimeter of material surface for methicillin resistant Staphylococcus aureus (MRSA), and by up to 1.51 Log CFU/cm2 for Escherichia coli. Potential applications for the technology are in antimicrobial coatings for, or materials comprising objects, such as tubing, collection bags, handrails, finger-plates on hospital doors, or medical equipment found in the healthcare setting.

Optimization of singlet oxygen production from photosensitizer‐incorporated, medically relevant hydrogels

“…Knowledge of the most efficient wavelength and light source to select, to provide the most efficient production of 1 O 2 will allow more efficient photosensitisation in, for example, photodynamic therapy and photodynamic materials. 21 In the power range studied, the rate of 1 O 2 production is linearly related to the power applied. The halogen source is more efficient at producing 1 O 2 than the white LED array.…”

Thiol-Capped Gold Nanoparticles Swell-Encapsulated into Polyurethane as Powerful Antibacterial Surfaces Under Dark and Light Conditions

“…One alternative approach involves the photosensitisation of bacteria via reactive oxygen species (ROS) using light-active surfaces such as TiO 2 11 or photosensitised dye-modified materials121314. A photosensitisation approach is promising since this form of antibacterial technology can be easily incorporated to polymer surfaces15 for applications in healthcare environments such as hospital surfaces and/or medical devices such as catheters. Photosensitised dyes including crystal violet (CV), methylene blue (MB) and toluidine blue O (TBO), in addition to nanoparticles, can be incorporated into medical grade polymers using a simple swell-encapsulation-shrink method151617.…”

“…A photosensitisation approach is promising since this form of antibacterial technology can be easily incorporated to polymer surfaces15 for applications in healthcare environments such as hospital surfaces and/or medical devices such as catheters. Photosensitised dyes including crystal violet (CV), methylene blue (MB) and toluidine blue O (TBO), in addition to nanoparticles, can be incorporated into medical grade polymers using a simple swell-encapsulation-shrink method151617. Upon illumination, the polymer-immobilised dye molecule is promoted to an excited singlet state, which can then undergo inter-system crossing to the triplet state, after which it can partake in a series of different photochemical reactions.…”

Antimicrobial photodynamic active biomaterials for periodontal regeneration

“…In the present study the photosensitizer mTHPC was incorporated into the biomaterials to achieve antimicrobial activity upon illumination with red light at 652 nm. Up to now, there are only a few reports available, where photosensitizers were used to create antimicrobial activity on the surface of solid materials [49,50]. In photodynamic therapy, application of suitable light causes a photosensitizer to enter a triplet state which subsequently leads to the formation of highly reactive oxygen radicals that cause lethal damage to the microbes.…”