First comparison of commercial systems to prepare nanofat: technical performances and biological quality differ among obtained products.

Nanofat is a relatively recent fat grafting technique obtained involving the mechanical emulsification of adipose tissue whose preparation is produced at the patient's bedside. Although it was initially reported to improve skin quality in intradermal applications, it is now increasingly used in regenerative medicine. However, the absence of standardized protocols and the diversity of commercial devices result in nanofat products of variable quality. This study presents the first comprehensive comparison of nanofat obtained from different commercially available preparation systems, combining both their technical performance and biological characterization. Lipoaspirates from five healthy donors were processed using eight commercially available devices for nanofat production using emulsification or micronization techniques. The technical parameters included preparation time, ease of preparation and injection, volumetric yield, and residual aqueous fraction. Biological analyses included stromal vascular fraction isolation with evaluation of cell viability, viable nucleated cell yield, immunophenotypic cell subtype characterization and clonogenic capacity. These parameters were compared using a scoring model that enabled inter-kit ranking, integrating both a technical performance score and a biological quality score. Additionally, nanofat-conditioned media were collected for extracellular vesicles (EVs) quantification and subtyping by flow cytometry, and confocal microscopy was performed to evaluate the preservation of mature adipocytes, capillary networks, and the extracellular matrix. All devices demonstrated satisfactory technical performance, with Puregraft Boost V2 and Emulsfat achieving the highest overall technical scores. Cell viability was consistently high, with median values above 85% across all devices. Adinizer provided the greatest proportion of adipose-derived stromal/stem cells and achieved the highest overall biological score. In contrast, Hy-Tissue Nanofat produced the lowest cell yields together with the highest leukocyte proportions. All nanofats contained clonogenic progenitors. Extracellular vesicles concentrations were comparable between devices, and were mainly influenced by donor variability, although Emulsfat was enriched in adipocyte-derived EVs. Microscopic analysis revealed preservation of adipocytes, vascular networks, and the extracellular matrix across devices, challenging the assumption that emulsification or micronization completely disrupts tissue architecture. Nanofat properties are strongly device dependent, with possible dissociation between technical ease and biological quality. This first comparative study highlights the need for standardized preparation methods and qualification criteria, and provides guidance for selecting devices aligned with specific clinical objectives to optimize regenerative outcomes.