The Use of Artificial Gel Forming Bolalipids as Novel Formulations in Antimicrobial and Antifungal Therapy

Abstract

The alarming growth of multi-drug resistant bacteria has led to a quest for alternative antibacterial therapeutics. One strategy to circumvent the already existing resistance is the use of photodynamic therapy. Antimicrobial photodynamic therapy (aPDT) involves the use of non-toxic photosensitizers in combination with light and in situ oxygen to generate toxic radical species within the microbial environment which circumvents the resistance building mechanism of the bacteria. Hydrogels are used ubiquitously in the biological and pharmaceutical fields, e.g., for wound dressing material or as drug delivery systems. Hydrogels formed by water-insoluble low-molecular weight gelators may potentially provide the much-needed benefits for these applications. Bolalipids are a superior example of such gelators. In the present work, two artificial bolalipids were used, namely PC-C32-PC and Me2PE-C32-Me2PE, which self-assemble in water into long and flexible nanofibers leading to a gelation of the surrounding solvent. The aim of the study was to create stable hydrogel formulations of both bolalipids and to investigate their applicability as a novel material for drug delivery systems. Furthermore, methylene blue—a well-known photosensitizer—was incorporated into the hydrogels in order to investigate the aPDT for the treatment of skin and mucosal infections using a custom designed LED device.

Keywords

• hydrogel
• drug delivery system
• self-assembly
• bolaform amphiphilic lipids
• bolalipids
• aerogel
• chorioallantoic membrane model
• antimicrobial photodynamic therapy