# A Minimally Invasive Transthoracic Injection Technique for Reproducible Intrapleural Delivery in Mice

## TL;DR

This paper introduces a simple, minimally invasive technique for reliably delivering substances into the pleural cavity of mice, improving preclinical mesothelioma research.

## Contribution

A new minimally invasive injection technique that eliminates surgery and anesthesia for reliable intrapleural delivery in mice.

## Key findings

- The method achieved a 100% tumour engraftment rate with AE17 tumour cells.
- The technique successfully delivered asbestos fibres for mesothelioma models.
- It reduces animal stress and technical complexity compared to traditional methods.

## Abstract

The development of standardised, reproducible preclinical models is essential for advancing pleural mesothelioma (PM) research. Here, we present a simple and reliable minimally invasive transthoracic intrapleural injection technique that could improve the efficiency of orthotopic PM model generation. By incorporating a simple needle sleeve to control the injection depth, this method eliminates the need for surgery or general anaesthesia, reducing technical complexity and animal stress while ensuring precise delivery into the pleural cavity. We demonstrate the effectiveness of this approach by achieving a 100% tumour engraftment rate following the injection of AE17 tumour cells. Additionally, this technique has been successfully used for asbestos fibre injection in mesothelioma models, highlighting its versatility. By providing a more accessible, standardised alternative to existing methods, this protocol improves the reliability of PM models and facilitates broader adoption by researchers, including those with limited experience in invasive procedures.