Donor Variability and Stromal Vascular Fraction Isolation Outcomes: Implications for Adipose Tissue-Derived ATMP Manufacturing

Stromal vascular fraction (SVF) isolated from adipose tissue is an important source of starting material for adipose tissue-derived advanced therapy medicinal products (ATMPs); however, the influence of donor- and harvesting-related factors on SVF isolation outcomes remains unclear. In this study, SVF was isolated from adipose tissue samples obtained from 100 adult donors undergoing elective liposuction using a standardized enzymatic digestion protocol. Donor age, body mass index (BMI), waist-to-hip ratio (WHR), and harvesting sites were evaluated in relation to SVF yield and viability using correlation and non-parametric statistical analyses. SVF was successfully isolated from all samples. Mean SVF yield was 16.7 ± 9.68 × 106 cells per 100 mL of lipoaspirate, with a mean viability of 80.92 ± 9.91%. Donor age, BMI, and WHR were not significantly associated with SVF yield or viability. In contrast, thigh-derived samples demonstrated significantly higher SVF yield and viability than sub-abdominal samples. Although BMI showed a weak positive correlation with SVF yield, it did not reach statistical significance (ρ = 0.181, p = 0.086). In the cultured subset, the viability of culture-expanded adherent cells at passage 1 was significantly higher than that of freshly isolated SVF cells. These findings suggest that quantitative SVF isolation outcomes are largely independent of the donor-related characteristics evaluated in this cohort, while harvesting sites may influence cell recovery and viability. Importantly, only quantitative SVF isolation parameters were assessed; therefore, potential qualitative differences between donor groups remain unknown.