Gold Nanoparticles and Femtosecond Laser System for Enhanced Drug Delivery in Fungal Cells

Background

“Fungal infections are becoming a global health problem. A major limiting factor for the development of antifungals is the high impermeability of the rigid and thick fungal cell wall. Compared to mammalian cells, fungal cells are more resilient to perforation due to the presence of this carbohydrate armor. While a few methods have been reported to penetrate the fungal cell wall, such as electroporation, biolistics, glass beads, and the use of monovalent cations, such methods are generally time-consuming, compromise cell viability, and often lead to low permeation rates. In addition, their use remains limited to in vitro applications due to the collateral damage that these techniques could cause to healthy living tissues.

Current approaches to dealing with fungal infections fall short in several areas. Methods like electroporation and biolistics are not only inefficient but also damage the cells they aim to treat. This issue is exacerbated by the fact that these techniques are primarily suitable for in vitro applications, making them impractical for clinical use where they could harm healthy tissues. Additionally, chemical and viral vector methods used in mammalian cells are less effective due to the unique structural challenges posed by fungal cell walls. As a result, there is a significant unmet need for a reliable, efficient, and biocompatible method to penetrate fungal cells for therapeutic purposes.”

Technology

The technology described leverages the combination of gold nanoparticles and femtosecond infrared laser irradiation to create transient pores in the rigid cell walls of fungi, facilitating the delivery of otherwise impermeable molecules such as calcein and plasmid DNA. This method, known as nanoparticle-mediated photoporation, generates cavitation and shock waves that temporarily disrupt the fungal cell wall, allowing molecules to penetrate the cell without causing significant damage to the cells themselves. The approach has shown effectiveness in both Saccharomyces cerevisiae and the pathogenic Candida albicans, with high biocompatibility and the potential for clinical applications in treating fungal infections, particularly in scenarios where current treatments fail due to adverse host reactions, poor penetration, or antifungal resistance.

What differentiates this technology is its reliance on the precise and controlled disruption of the fungal cell wall using ultrafast pulsed wave lasers with or without gold nanoparticles. Unlike traditional methods such as electroporation or chemical treatments, which can be time-consuming, often compromise cell viability, and are limited to in vitro applications, this technique is efficient and minimizes collateral damage. The method utilizes the unique properties of ultrafast pulsed wave lasers with or without gold nanoparticles to enhance the interaction with the laser’s electromagnetic field, resulting in more consistent and reproducible pore formation. Moreover, the non-toxic nature of both the laser and nanoparticles makes this approach highly suitable for preclinical evaluations, marking a significant advancement in the field of drug delivery for fungal pathogens.

Benefits

• Enhanced delivery of membrane-impermeable molecules into fungal cells.
• High biocompatibility with minimal cell damage.
• Potential for clinical applications in treating fungal infections.
• Effective drug and nucleic acid delivery without significant cell viability loss.
• Optimization of nanoparticle size, shape, and concentration for improved photoporation.
• Potential to reduce adverse reactions and resistance development in current treatments.
• Stable nanoparticle solutions with long shelf life.
• Non-toxic effects of AuNPs and laser irradiation on cells.
• Efficient gene silencing in pathogenic fungi using siRNA delivery.

Applications

• Clinical antifungal treatments
• Drug delivery systems
• Gene therapy applications
• Biomedical research tools

Additional info

Nanoparticle-mediated photoporation employs gold nanoparticles and femtosecond infrared lasers to generate pores in rigid fungal cell walls. This technique enables the delivery of membrane-impermeable molecules, such as calcein and plasmid DNA, into fungi like Saccharomyces cerevisiae and Candida albicans. It offers high biocompatibility and minimal cell viability loss, showing potential for clinical applications in treating fungal infections, especially where current treatments fall short.