Fat Grafting Techniques in Regenerative Medicine: A Narrative Review

Background: Autologous adipose tissue transfer has evolved from simple volumetric augmentation to sophisticated regenerative procedures. Understanding the biological principles underlying fat grafting success is essential for optimal clinical outcomes. Objective: The aim to this study is o provide a comprehensive narrative review of adipose tissue biology, technical variations in fat grafting (macrofat, microfat, nanofat, and microfiltrate), and their clinical applications, with an emphasis on microfiltration parameters that preserve tissue progenitor cells. Methods: A narrative review was conducted by searching the PubMed, Scopus, and Web of Science databases (2010–2025) using terms related to autologous fat grafting, adipose-derived stem cells, and regenerative medicine. Both original research and review articles were included to provide a comprehensive overview of the current evidence. Key Findings from Literature: Current evidence demonstrates that adipose tissue contains approximately 4,500 adipose-derived stem cells per milliliter, representing a 45-fold higher concentration than the bone marrow. Studies indicate that macrofat and microfat provide volumetric restoration with 30% to 60% long-term retention, whereas nanofat improves tissue quality through mechanical emulsification. Emerging evidence supports microfiltration at 20 to 40 microns for the selective isolation of tissue progenitors (17.9 to 30.4 microns), while excluding inflammatory debris that activates Toll-like receptor 4-mediated fibrotic pathways. Graft survival depends critically on atraumatic harvesting, minimal processing, and adequate revascularization within the first 7 d posttransplantation. Conclusion: Successful fat grafting requires biology-based technical choices. Understanding adipose tissue components, cellular viability parameters, and size-selective processing enables rational treatment selection across volumetric, regenerative, and tissue quality applications. Microfiltration at 20 to 40 microns represents an evidence-based approach for regenerative procedures requiring high progenitor concentrations without a volumetric contribution.