Cell labeling approaches for tracking stromal vascular fraction fate

The stromal vascular fraction (SVF) of adipose tissue is a heterogeneous cell population with significant regenerative, paracrine, and immunomodulatory potential, positioning it as a promising therapeutic platform in regenerative medicine and oncology. As SVF-based strategies advance toward preclinical and clinical application, robust methods to label and track transplanted cells have become essential for elucidating their biodistribution, engraftment, survival, differentiation, and functional roles in vivo. A wide spectrum of SVF labeling approaches has been developed, including fluorescent dyes, magnetic and inorganic nanoparticles, radiotracers, and genetically encoded reporters. While these techniques have enabled important biological insights, they differ markedly in sensitivity, stability, biocompatibility, detection modality, and translational feasibility, and each presents distinct methodological limitations such as signal dilution, cytotoxicity, or challenges in distinguishing viable from non-viable cells. In this review, we provide a comprehensive and critical synthesis of current SVF labeling strategies, detailing their mechanistic principles, technical workflows, and applications in in vitro and in vivo tracking studies. Moreover, we highlight the advantages, limitations, and appropriate uses of each modality. By consolidating and evaluating the existing literature, this review aims to support informed selection of labeling techniques and to facilitate the design of rigorous, reproducible, and clinically relevant SVF tracking studies.