In situ Gelling Amphotericin B Nanofibers: A New Option for the Treatment of Keratomycosis

Benedikt Göttel; Henrike Lucas; Frank Syrowatka; Wolfgang Knolle; Judith Kuntsche; Joana Heinzelmann; Arne Viestenz; Karsten Mäder

doi:10.3389/fbioe.2020.600384

In situ Gelling Amphotericin B Nanofibers: A New Option for the Treatment of Keratomycosis

Front Bioeng Biotechnol. 2020 Dec 21:8:600384. doi: 10.3389/fbioe.2020.600384. eCollection 2020.

Authors

Benedikt Göttel¹, Henrike Lucas¹, Frank Syrowatka², Wolfgang Knolle³, Judith Kuntsche⁴, Joana Heinzelmann⁵, Arne Viestenz⁵, Karsten Mäder¹

Affiliations

¹ Pharmaceutical Technology and Biopharmacy, Institute of Pharmacy, Martin-Luther University Halle-Wittenberg, Halle, Germany.
² Interdisciplinary Center of Materials Science, Martin-Luther University Halle-Wittenberg, Halle, Germany.
³ Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany.
⁴ Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark.
⁵ Department of Ophthalmology, Martin Luther University Halle-Wittenberg, Halle, Germany.

Abstract

The purpose of our research was the development of Amphotericin B-loaded in situ gelling nanofibers for the treatment of keratomycosis. Different formulation strategies were applied to increase the drug load of the sparingly water-soluble Amphotericin B in electrospun Gellan Gum/Pullulan fibers. These include bile salt addition, encapsulation in poly(lactic-co-glycolic acid) (PLGA) nanoparticles and formation of a polymeric Amphotericin B polyelectrolyte complex. The Amphotericin B polyelectrolyte complex (AmpB-Eu L) performed best and was very effective against the fungal strain Issatchenkia orientalis in vitro. The complex was characterized in detail by attenuated total reflection infrared spectroscopy, X-ray powder diffraction, and differential scanning calorimetry. A heat induced stress test was carried out to ensure the stability of the polyelectrolyte complex. To gain information about the cellular tolerance of the developed polyelectrolyte complex a new, innovative multilayered-stratified human cornea cell model was used for determination of the cellular toxicity in vitro. For a safe therapy, the applied ophthalmic drug delivery system has to be sterile. Sterilization by electron irradiation caused not degradation of pure Amphotericin B and also for the bile salt complex. Furthermore, the developed Amphotericin B polyelectrolyte complex was not degraded by the irradiation process. In conclusion, a new polyelectrolyte Amphotericin B complex has been found which retains the antifungal activity of the drug with sufficient stability against irradiation-sterilization induced drug degradation. Furthermore, in comparison with the conventional used eye drop formulation, the new AmpB-complex loaded nanofibers were less toxic to cornea cells in vitro. Electrospinning of the Amphotericin B polyelectrolyte complex with Gellan Gum/ Pullulan leads to the formation of nanofibers with in situ gelling properties, which is a new and promising option for the treatment of keratomycosis.

Keywords: PLGA nanoparticle; amphotericin B; electrospinning; hydrogel; in situ forming; keratomycosis; ocular drug delivery; polyelectrolyte complex.