Injectable, Cryopreservable Mesenchymal Stromal Cell-Loaded Microbeads for Pro-Angiogenic Therapy: In Vitro Proof-of-Concept

This study demonstrates an injectable and cryopreservable hydrogel microbead system encapsulating human mesenchymal stromal cells (hMSCs) for pro-angiogenic therapy. Using stirred emulsification, microbeads composed of chitosan (CH), chitosan–gelatin (CH–Gel), and alginate (ALG) were produced with controlled size (~500 μm diameter). CH–Gel microbeads showed superior viability (80%), higher vascular endothelial growth factor (VEGF) secretion (11× vs ALG), and maintained mechanical integrity after cryopreservation. Celastrol preconditioning further enhanced cell viability and proangiogenic function. The system enables a scalable, oil-based process to generate injectable microbeads suitable for minimally invasive, off-the-shelf cell therapies.