Amoebicidal Activity of Poly-Epsilon-Lysine Functionalized Hydrogels.

Abstract

Purpose:

To determine the amoebicidal activity of functionalized poly-epsilon-lysine hydrogels (pɛK+) against Acanthamoeba castellanii.

Methods:

A. castellanii trophozoites and cysts were grown in the presence of pɛK solution (0-2.17 mM), pɛK or pɛK+ hydrogels, or commercial hydrogel contact lens (CL) for 24 hours or 7 days in PBS or Peptone-Yeast-Glucose (PYG) media (nutrient-deplete or nutrient-replete cultures, respectively). Toxicity was determined using propidium iodide and imaged using fluorescence microscopy. Ex vivo porcine corneas were inoculated with A. castellanii trophozoites ± pɛK, pɛK+ hydrogels or commercial hydrogel CL for 7 days. Corneal infection was assessed by periodic acid-Schiff staining and histologic analysis. Regrowth of A. castellanii from hydrogel lenses and corneal discs at 7 days was assessed using microscopy and enumeration.

Results:

The toxicity of pɛK+ hydrogels resulted in the death of 98.52% or 83.31% of the trophozoites at 24 hours or 7 days, respectively. The toxicity of pɛK+ hydrogels resulted in the death of 70.59% or 82.32% of the cysts in PBS at 24 hours or 7 days, respectively. Cysts exposed to pɛK+ hydrogels in PYG medium resulted in 75.37% and 87.14% death at 24 hours and 7 days. Ex vivo corneas infected with trophozoites and incubated with pɛK+ hydrogels showed the absence of A. castellanii in the stroma, with no regrowth from corneas or pɛK+ hydrogel, compared with infected-only corneas and those incubated in presence of commercial hydrogel CL.

Conclusions:

pɛK+ hydrogels demonstrated pronounced amoebicidal and cysticidal activity against A. castellanii. pɛK+ hydrogels have the potential for use as CLs that could minimize the risk of CL-associated Acanthamoeba keratitis.

• Authors: Stephnie M Kennedy, Pallavi Deshpande, Andrew G Gallagher, Malcolm J Horsburgh, Heather E Allison, Stephen B Kaye, Donald A Wellings, Rachel L Williams
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 63 Issue 1 Pg. 11 (01 03 2022) ISSN: 1552-5783 [Electronic] United States
• PMID: 34994769 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amebicides
• Contact Lens Solutions
• Hydrogels
• Polylysine

Topics

• Acanthamoeba Keratitis (drug therapy, parasitology)
• Acanthamoeba castellanii (drug effects)
• Amebicides (pharmacology, toxicity)
• Animals
• Cells, Cultured
• Contact Lens Solutions (pharmacology)
• Cornea (parasitology)
• Disease Models, Animal
• Epithelium, Corneal (drug effects)
• Eye Infections, Parasitic (drug therapy, parasitology)
• Humans
• Hydrogels (pharmacology, toxicity)
• Microscopy, Fluorescence
• Polylysine (pharmacology, toxicity)
• Swine
• Trophozoites (drug effects)