# Distribution and metabolism of iPSC-MSCs in the joint cavity of an osteoarthritis rat model

## TL;DR

This study tracks where and how long iPSC-MSCs stay in the joints of rats with osteoarthritis, showing they can repair joint damage and remain detectable for up to two weeks.

## Contribution

The study is the first to use Antares2 luciferase labeling to track iPSC-MSC metabolism and distribution in osteoarthritis rat joints.

## Key findings

- iPSC-MSCs significantly reversed joint tissue damage in arthritic rats.
- The fluorescent signal of Antares2-labeled iPSC-MSCs lasted about 2 weeks in osteoarthritis joints.
- iPSC-MSCs first attached to the synovium, then the meniscus and cartilage.

## Abstract

To investigate the metabolism and distribution of iPSC‐MSCs in the joint cavity of rats with knee osteoarthritis (KOA).

The iPSC‐MSCs labeled with the Antares2 luciferase gene were injected into the knee joints of rats, and then the metabolism and distribution of the cells in vivo were revealed by imaging and molecular biomarker methods.

Histopathological results demonstrated that iPSC‐MSCs significantly reversed joint tissue damage of arthritic rats. The fluorescence signal of iPSC‐MSCs labeled with Antares2 luciferase gene was stable and persistent with high detection sensitivity. The fluorescent signal duration of Antares2‐iMSCs in the joint cavity of KOA rats was approximately 2 weeks, which was significantly longer than 1 week in the sham‐operated group. The proportion of iPSC‐MSCs in the synovial fluid gradually decreased over time, and for the first time, the cells were observed to attach to the synovium first, followed by the meniscus and cartilage.

This study was the first to explore the metabolism and distribution of iPSC‐MSCs after intra‐articular injection by labeling the Antares2 luciferase gene, which provides assurance and theoretical basis for the safety of clinical application of iPSC‐MSCs in treating osteoarthritis.