# Anti-Angiogenic RNAi-Based Treatment of Endometriosis in a Rat Model Using CXCR4-Targeted Peptide Nanoparticles

## TL;DR

This study explores a new RNAi-based treatment for endometriosis using targeted nanoparticles to reduce abnormal blood vessel growth in a rat model.

## Contribution

A novel CXCR4-targeted peptide nanoparticle delivery system for RNAi-based anti-angiogenic therapy in endometriosis is introduced.

## Key findings

- Ternary polyplexes effectively delivered anti-VEGFA siRNA and reduced endometriotic lesion growth in rats.
- CXCR4-targeted nanoparticles showed significant VEGFA gene silencing and anti-angiogenic effects in vivo.
- The developed system demonstrates potential for efficient RNAi-based endometriosis treatment.

## Abstract

Endometriosis is a common gynecological condition that affects fertility in many women of reproductive age worldwide. This multifaceted disease exhibits a pathogenesis characterized by hormonal and immune system dysregulations, alongside increased angiogenic activity within the peritoneum. The aberrant proliferation of endometrial tissue outside the uterus is associated with vascularization in ectopic endometriotic lesions. Consequently, RNA interference (RNAi)-based angiogenic therapies targeting the VEGFA gene present a promising strategy for the treatment of endometriosis. To ensure the efficacy of RNAi-based therapy, it is critical to develop carriers capable of precisely delivering small interfering RNA (siRNA) to target cells. Additionally, the instability of polyplexes in vivo must be regarded as a pivotal aspect influencing the success of non-viral delivery. In this study, we introduce ternary polyplexes comprising siRNA and a carrier derived from an arginine–histidine-rich peptide, which is further coated with a glutamate–histidine-rich polymer modified using an SDF-1 chemokine-derived ligand for targeting CXCR4-expressing cells. The physicochemical characteristics of the siRNA-polyplexes, along with cellular toxicity and GFP gene silencing efficacy, were assessed in vitro. The anti-angiogenic potential of anti-VEGFA siRNA-polyplexes was evaluated by measuring the size of endometrial lesions, conducting immunohistochemical staining, and analyzing VEGFA gene expression. For in vivo experiment, a rat model of endometriosis induced by subcutaneous auto-transplantation of uterine tissue was utilized. A significant reduction in the growth of endometriotic implants and silencing of VEGFA gene expression was observed when compared to the saline-treated control group. The results of this study strongly suggest that the developed ternary polyplexes have significant potential as an efficient tool for the development of anti-angiogenic RNAi-based therapies for endometriosis.