# Therapeutic Effects of PSL-Loaded PLGA-PEG-PLGA NPs in Allergic Contact Dermatitis Model Mice

## TL;DR

This study evaluates a new nanoparticle drug delivery system for treating allergic contact dermatitis in mice.

## Contribution

A novel PLGA-PEG-PLGA triblock copolymer nanoparticle is proposed as an improved carrier for prednisolone in treating allergic contact dermatitis.

## Key findings

- PSL-loaded PLGA-PEG-PLGA NPs significantly reduced TNF-α and IL-4 levels in a mouse model of allergic contact dermatitis.
- The nanoparticle formulation was as effective as a PSL ointment at a 40 times lower steroid dose.
- The results suggest PLGA-PEG-PLGA NPs may be more effective than traditional PLGA-based drug delivery systems for ACD treatment.

## Abstract

This study focused on the poly(DL-lactide-co-glycolide)-block-poly(ethylene glycol)-block-poly(DL-lactide-co-glycolide) (PLGA-PEG-PLGA) triblock copolymer, which was recently reported as a novel material for polymeric nanoparticles to replace poly(DL-lactide-co-glycolide) (PLGA) as a drug carrier for prednisolone (PSL), and aimed to evaluate the efficacy of PSL-loaded PLGA-PEG-PLGA nanoparticles (NPs) against allergic contact dermatitis (ACD). PSL-loaded PLGA-PEG-PLGA NPs were prepared using the nanoprecipitation method, and their particle size distribution and mean particle size were measured using dynamic light scattering. 1-Fluoro-2,4-dinitrobenzene (DNFB) was used to create a mouse model of contact hypersensitivity (CHS). PSL-loaded PLGA-PEG-PLGA NPs were administered before sensitization with DNFB, and the therapeutic effect was evaluated by quantifying intracutaneous TNF-α and IL-4 levels suing ELISA. When PSL-loaded PLGA-PEG-PLGA NPs were administered before sensitization, TNF-α expression and IL-4 statements were significantly lower in the PSL-loaded PLGA-PEG-PLGA NP group than in the non-treated group. No significant difference was observed between the PSL-loaded PLGA-PEG-PLGA NP and PSL-loaded ointment groups, even though the steroid dose was 40 times lower than in the PSL-containing ointment. These results suggest that PSL-loaded PLGA-PEG-PLGA NPs may have a better effect in the treatment of ACD than PSL-loaded PLGA NPs.