Inter-center comparison of good manufacturing practices-compliant stromal vascular fraction and proposal for release acceptance criteria: a review of 364 productions

Abstract

Background Even though the manufacturing processes of the stromal vascular fraction for clinical use are performed in compliance with the good manufacturing practices applying to advanced therapy medicinal products, specifications related to stromal vascular fraction quality remain poorly defined. We analyzed stromal vascular fraction clinical batches from two independent good manufacturing practices-compliant manufacturing facilities, the Swiss Stem Cell Foundation (SSCF) and Marseille University Hospitals (AP-HM), with the goal of defining appropriate and harmonized release acceptance criteria. Methods This retrospective analysis reviewed the biological characteristics of 364 batches of clinical-grade stromal vascular fraction. Collected data included cell viability, recovery yield, cell subset distribution of stromal vascular fraction, and microbiological quality. Results Stromal vascular fraction from SSCF cohort demonstrated a higher viability (89.33% ± 4.30%) and recovery yield (2.54 × 105 ± 1.22 × 105 viable nucleated cells (VNCs) per mL of adipose tissue) than stromal vascular fraction from AP-HM (84.20% ± 5.96% and 2.25 × 105 ± 1.11 × 105 VNCs per mL). AP-HM batches were significantly less contaminated (95.71% of sterile batches versus 74.15% for SSCF batches). The cell subset distribution was significantly different (higher proportion of endothelial cells and lower proportion of leukocytes and pericytes in SSCF cohort). Conclusions Both centers agreed that a good manufacturing practices-compliant stromal vascular fraction batch should exert a viability equal or superior to 80%, a minimum recovery yield of 1.50 × 105 VNCs per mL of adipose tissue, a proportion of adipose-derived stromal cells at least equal to 20%, and a proportion of leukocytes under 50%. In addition, a multiparameter gating strategy for stromal vascular fraction analysis is proposed.

A Closed-system Technology for Mechanical Isolation of High Quantities of Stromal Vascular Fraction from Fat for Immediate Clinical Use

“…the yield obtained by enzymatic isolation, it was similar to the average yield obtained by clinical-grade enzymatic SVF isolation recently reported to be obtained using either the leading commercial enzyme-based Celution System (Cytori Therapeutics Inc.) (n = 70) or by manual isolation (n = 294), 20 making the RBs technique highly relevant to clinical use. Importantly, however, SVF isolation using this nonenzymatic method was achieved in under 15 minutes, a drastically shorter interval than enzymatic isolation.…”

“…19 RBs mechanical isolation technology isolated an average 2.01 × 10 5 ± 1.2 × 10 5 SVF nucleated cells per 1 mL fat (n = 30). The yield was inferior to the yield obtained by enzymatic isolation [4.17 × 10 5 ± 1.8 × 10 5 SVF nucleated cells per 1 mL fat (n = 30)], but was similar to the average yield obtained by clinical-grade enzymatic SVF isolation recently reported to be obtained using either the leading commercial enzyme-based Celution System (Cytori Therapeutics Inc.) (n = 70) or by manual isolation (n = 294) 20 and far superior to that achieved by the wash technique [0.67 × 10 5 ± 0.51 × 10 5 SVF nucleated cells per 1 mL fat (n = 30)] (Fig. 2).…”

“…19,[26][27][28] Tiryaki et al recently claimed to have achieved high yields of SVF cells by mechanical means; however, their findings are somewhat questionable since the SVF quantities isolated by enzymatic isolation in their report were 3.38 × 10 6 /1 mL fat, which is far beyond the average cell quantities obtained via enzymatic methods (~2-6 × 10 5 /1 mL fat). 20 In addition, the authors fail to indicate whether the reported isolated SVF quantity was per 1 mL fat following fat mechanical breakage or per 1 mL of the original fat. 29 In light of the large volume of human samples examined in the study (n = 30) and the repeated ability of the novel RBs technology to extract high quantities of high-quality SVF cells similar to the ones obtained by the gold standard enzymatic SVF isolation, we believe that the technology should be further developed to allow its use in the clinical setting.…”

Clinical, Histologic, and Transcriptomic Evaluation of Sequential Fat Grafting for Morphea

“…It has been reported that SVF cells, especially adiposederived mesenchymal stromal cells, could exert an antisclerotic association with morphea. [29][30][31] SVF gel only requires the mechanical process to eliminate most mature adipocytes and concentrate SVF cells within the adipose tissue, getting rid of using the collagenase and retaining the ECM scaffold. [32][33][34] SVF gel can be injected through a 30-G needle, which enables precise intradermal delivery, as traditional lipoaspirates cannot.…”

Characterization of mesenchymal stromal cells physical properties using acoustic radiation force

“…This is especially the case when the objective is to sort the cells upstream of specific processes. One can find many examples in biomedical research [1,2], clinical diagnostic [3,4] and bioproduction field [5,6]. The common principles for cell separation are based either on the density differences or on specific biological membrane markers.…”