Enhancing Rose Bengal penetration in ex vivo human corneas using iontophoresis

Ther Deliv. 2024;15(8):567-575. doi: 10.1080/20415990.2024.2371778. Epub 2024 Jul 18.

Abstract

Aim: Rose Bengal photodynamic antimicrobial therapy (RB-PDAT) has poor corneal penetration, limiting its efficacy against acanthamoeba keratitis (AK). Iontophoresis enhances corneal permeation of charged molecules, piquing interest in its effects on RB in ex vivo human corneas.Methods: Five donor whole globes each underwent iontophoresis with RB, soaking in RB, or were soaked in normal saline (controls). RB penetration and corneal thickness was assessed using confocal microscopy.Results: Iontophoresis increased RB penetration compared with soaking (177 ± 9.5 μm vs. 100 ± 5.7 μm, p < 0.001), with no significant differences in corneal thickness between groups (460 ± 87 μm vs. 407 ± 69 μm, p = 0.432).Conclusion: Iontophoresis significantly improves RB penetration and its use in PDAT could offer a novel therapy for acanthamoeba keratitis. Further studies are needed to validate clinical efficacy.

Keywords: PK profiles enhancement; Rose Bengal; acanthamoeba keratitis; emerging technologies; iontophoresis; penetration depth; personalized delivery.

Plain language summary

The study aimed to improve a new treatment for eye infections known as photodynamic antimicrobial therapy. It investigated whether the use of electricity through a technique called iontophoresis could help a chemical called Rose Bengal go deeper into the eye in order to target more severe infections. The iontophoresis machine was custom built, with patient-contacting components 3D printed. The experiments were performed using donated human eye tissue and found that iontophoresis significantly improved the penetration depth of Rose Bengal as compared with the current technique of only soaking the eye in Rose Bengal.

MeSH terms

  • Acanthamoeba Keratitis* / drug therapy
  • Cornea* / drug effects
  • Cornea* / metabolism
  • Humans
  • Iontophoresis* / methods
  • Microscopy, Confocal
  • Photochemotherapy / methods
  • Rose Bengal* / administration & dosage

Substances

  • Rose Bengal