A Multi-Institution Biobanking Pipeline for Primary Human Satellite Cells and Fibro-Adipogenic Progenitors.

Satellite Cells (SCs) and Fibro-Adipogenic Progenitors (FAPs) are muscle-resident cell populations crucial for maintaining skeletal muscle homeostasis and coordinating regeneration after injuries. However, primary human SCs and FAPs are difficult to co-isolate, and their broad use in translational research has been limited by a lack of standardized biobanking protocols. Recently, we published a protocol for efficient co-isolation of SCs and FAPs from human skeletal muscle. Here, we extend those efforts to establish a comprehensive pipeline for the cryopreservation, cold-chain transport, and independent-site utilization of human SCs and FAPs. Cells taken through this pipeline maintained lineage-specific markers, including Pax7, MyoD and CD56 for SCs, and PDGFRα and TE7 for FAPs, indicating retention of their pre-biobanking phenotype. Furthermore, SCs demonstrate robust myogenic differentiation capacity, and FAPs demonstrate both fibrogenic and adipogenic differentiation capacity post-transport. Finally, previously biobanked SCs were incorporated into in vitro 3D muscle constructs, demonstrating their utility for human-based New Approach Methodologies (NAMs). This framework for multi-site collaboration facilitates broader access to human primary muscle cells, which will improve the scalability and translatability of human-based NAMs for skeletal muscle research.