Conjugating biomaterials with photosensitizers: advances and perspectives for photodynamic antimicrobial chemotherapy

Photochem Photobiol Sci. 2020 Apr 1;19(4):445-461. doi: 10.1039/c9pp00398c. Epub 2020 Feb 27.

Abstract

Antimicrobial resistance is threatening to overshadow last century's medical advances. Previously eradicated infectious diseases are now resurgent as multi-drug resistant strains, leading to expensive, toxic and, in some cases, ineffective antimicrobial treatments. Given this outlook, researchers are willing to investigate novel antimicrobial treatments that may be able to deal with antimicrobial resistance, namely photodynamic therapy (PDT). PDT relies on the generation of toxic reactive oxygen species (ROS) in the presence of light and a photosensitizer (PS) molecule. PDT has been known for almost a century, but most of its applications have been directed towards the treatment of cancer and topical diseases. Unlike classical antimicrobial chemotherapy treatments, photodynamic antimicrobial chemotherapy (PACT) has a non-target specific mechanism of action, based on the generation of ROS, working against cellular membranes, walls, proteins, lipids and nucleic acids. This non-specific mechanism diminishes the chances of bacteria developing resistance. However, PSs usually are large molecules, prone to aggregation, diminishing their efficiency. This review will report the development of materials obtained from natural sources, as delivery systems for photosensitizing molecules against microorganisms. The present work emphasizes on the biological results rather than on the synthesis routes to prepare the conjugates. Also, it discusses the current state of the art, providing our perspective on the field.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Bacteria / drug effects*
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / pharmacology*
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Photochemotherapy*
  • Photosensitizing Agents / chemistry
  • Photosensitizing Agents / pharmacology*
  • Reactive Oxygen Species / metabolism

Substances

  • Anti-Bacterial Agents
  • Biocompatible Materials
  • Photosensitizing Agents
  • Reactive Oxygen Species