Novel Photodynamic/Photothermal Treatment of Fungal Keratitis Using Rose Bengal-Loaded Polypyrrole-Gold Nanoparticles...

Area of Science:

• Ophthalmology
• Nanotechnology
• Microbiology

Background:

• Fungal keratitis is a serious corneal infection with limited treatment options due to poor drug penetration and resistance.
• Standard antifungals face challenges in treating fungal keratitis effectively.
• Rose bengal (RB) photodynamic therapy shows potential but is hindered by poor corneal penetration.

Purpose of the Study:

• To evaluate a novel treatment protocol for fungal keratitis using polypyrrole-coated gold nanoparticles (AuPpy NP) loaded with rose bengal (RB).
• To investigate the combined photodynamic and photothermal effects of RB-AuPpy NP for enhanced corneal penetration and efficacy.
• To assess the therapeutic potential of this combined approach against Candida albicans and Aspergillus niger infections in a rat model.

Main Methods:

• Albino Wistar rats were infected with Candida albicans and Aspergillus niger.
• Treatment groups included RB (photodynamic), AuPpy NP (photothermal), and RB-AuPpy NP (combined photodynamic/photothermal) followed by radiation.
• Histopathological examination and slit lamp imaging were used to evaluate treatment outcomes.

Main Results:

• The combined photodynamic/photothermal treatment with RB-AuPpy NP demonstrated superior corneal improvement compared to monotherapies.
• Significant healing was observed in corneas treated with the novel nanoparticle system three weeks post-treatment.
• The RB-AuPpy NP effectively overcame limitations associated with RB's hydrophilicity.

Conclusions:

• The combined photodynamic/photothermal effect of RB-AuPpy NP represents a promising strategy for fungal keratitis management.
• This novel nanoparticle-based protocol offers a potential solution to overcome microbial resistance issues in fungal keratitis.
• Further research into this approach could lead to improved clinical treatments for fungal eye infections.