# Improved Murine Model for the Intravital Microscopic Examination of Manifest Tumors

## TL;DR

Researchers developed a new mouse model to study tumor growth and blood vessel changes over time using advanced microscopic techniques.

## Contribution

The study introduces an improved mouse dorsal skinfold chamber model for long-term, high-resolution in vivo observation of tumor vascularization.

## Key findings

- Tumors developed successfully with sustained vascular supply over six weeks.
- IVM enabled detailed assessment of microvascular parameters and leukocyte–endothelial interactions.
- The polydioxanone membrane simplified chamber preparation but may affect angiogenesis and cause inflammation.

## Abstract

Animal models are essential for studying tumor pathophysiology; however, most lack the capacity for repeated in vivo observation of tumor growth and vascularization over extended periods. This study aimed to establish a novel in vivo model using the mouse dorsal skinfold chamber. Tumor induction was performed using different membrane types (two polytetrafluoroethylene meshes and a polydioxanone plate), followed by monitoring of tumor vascularization via intravital fluorescence microscopy (IVM). Tumors developed successfully over six weeks, demonstrating sustained vascular supply and enabling, for the first time, the investigation of vascular networks in advanced tumors. Among the membranes tested, the polydioxanone membrane facilitated easier chamber preparation but may negatively affect angiogenesis and promote inflammation. IVM revealed persistent microcirculation in manifested tumors over six consecutive days, allowing detailed assessment of microvascular parameters, leukocyte–endothelial interactions, and functional capillary density. This model enables repetitive, high-resolution visualization of tumor microcirculation dynamics in vivo. In conclusion, this improved mouse dorsal skinfold chamber combined with IVM provides a powerful tool for investigating tumor angiogenesis and evaluating therapeutic interventions in advanced tumors.