Predicting the tissue depth for remote triggering of drug delivery systems

Area of Science:

• Biomedical Engineering
• Drug Delivery Systems
• Nanotechnology

Background:

• Externally triggerable drug delivery systems offer precise control over treatment timing and intensity, potentially reducing side effects and enhancing efficacy.
• A key challenge for clinical translation is predicting the safe tissue depth for in vivo activation of these systems using clinically safe energy dosages.
• Current methods lack a reliable approach to evaluate the in vivo performance and safety of externally triggered drug delivery systems at varying tissue depths.

Purpose of the Study:

• To develop and validate a predictive method for determining the maximum safe tissue depth for externally triggered drug release in vivo.
• To assess the influence of energy penetration and system sensitivity on the efficacy of triggered drug delivery systems.
• To provide a framework for evaluating the clinical potential of ultrasound- and near-infrared light-triggered liposomal drug delivery systems.

Main Methods:

• Combined in vitro and ex vivo experiments with mathematical modeling to predict drug release at different tissue depths.
• Developed models for liposomal drug delivery systems activated by ultrasound and near-infrared light in muscle and fat tissues.
• Validated the predictive method in vivo using a triggered sciatic nerve block model in rats.

Main Results:

• Identified tissue energy penetration and system sensitivity as critical parameters for triggered drug delivery.
• The developed method accurately predicted activated drug release at various tissue depths.
• In vivo validation demonstrated a strong correlation between predicted and actual triggered drug release, confirming the approach's accuracy.

Conclusions:

• The developed method provides an accurate estimation of activated drug release at different tissue depths for externally triggered systems.
• This approach facilitates the safe clinical translation of externally triggerable drug delivery systems by predicting safe operating depths.
• The findings support the use of ultrasound and near-infrared light for targeted drug delivery, with improved predictability and safety profiles.