Immobilization of chlorophyll by using layer-by-layer technique for controlled release systems and photodynamic inactivation

Growth models of fractal interfaces in the description of microorganism colony growth: effect of photodynamic inactivation

Candida albicans is responsible for most of the nosocomial infections that affect immunocompromised individuals. We investigated the application of eosin in photodynamic inactivation as a strategy in the inhibition of the growth of C. albicans and the morphological variation and growth dynamics in light of fractal theory. The damage caused to fungal structures alters the roughness of the colony, and these changes were described by parameters that were defined by mathematical models. Proliferation of the fungi should be inhibited in the center of the colonies and the analysis of the edges gives an indication about the dynamics of growth and cell reproduction.

Latex membranes with methylene blue dye for antimicrobial photodynamic therapy

The search for new materials that can be applied in the treatment of injured human tissues has led to the development of new dressings. Membranes have potential as dressing materials because they can be fitted to and interact with the tissue surface. In this study, we analyze the morphological properties and wettability of latex membranes, along with the incorporation of the photosensitizer methylene blue, in the context of the utility of the membranes in curative applications involving photodynamic therapy (PDT). It was observed that deposition of the photosensitizer into latex membranes increased both the surface roughness and wettability. Antifungal testing indicated that antimicrobial PDT assisted by the latex membranes incorporating methylene blue effectively inactivated Candida albicans.

Revisiting Current Photoactive Materials for Antimicrobial Photodynamic Therapy

Microbial infection is a severe concern, requiring the use of significant amounts of antimicrobials/biocides, not only in the hospital setting, but also in other environments. The increasing use of antimicrobial drugs and the rapid adaptability of microorganisms to these agents, have contributed to a sharp increase of antimicrobial resistance. It is obvious that the development of new strategies to combat planktonic and biofilm-embedded microorganisms is required. Photodynamic inactivation (PDI) is being recognized as an effective method to inactivate a broad spectrum of microorganisms, including those resistant to conventional antimicrobials. In the last few years, the development and biological assessment of new photosensitizers for PDI were accompanied by their immobilization in different supports having in mind the extension of the photodynamic principle to new applications, such as the disinfection of blood, water, and surfaces. In this review, we intended to cover a significant amount of recent work considering a diversity of photosensitizers and supports to achieve an effective photoinactivation. Special attention is devoted to the chemistry behind the preparation of the photomaterials by recurring to extensive examples, illustrating the design strategies. Additionally, we highlighted the biological challenges of each formulation expecting that the compiled information could motivate the development of other effective photoactive materials.