Ultrasound-assisted isolation: A new method to isolate stromal vascular fraction

Abstract

Background: The stromal vascular fraction (SVF), a cluster of stem and progenitor cells isolated from adipose tissue, holds significant promise for application in regenerative medicine. However, the existing methods for SVF isolation are time-consuming and expensive. Thus, in this study, we explored a new method of SVF extraction—ultrasound-assisted SVF isolation (USASI)—and compared the viability and characteristics of SVF isolated using different methods. Methods: SVF extraction methods using different combinations of ultrasound power, ultrasound time, collagenase dosage, and collagenase digestion time were compared with those of the control group (collagenase digestion method). The cell yield and vitality of the SVF were evaluated via cell counting and trypan blue staining. The cell components and immunophenotypes of freshly isolated SVF were analyzed using flow cytometry. The proliferative capacity and differentiation potential of the SVF were also identified. Results: Ultrasonication at 95 ​W-20 kHz for 30 ​s followed by digestion with 0.15% collagenase for 30 ​min was identified as the most suitable parameter for the USASI method in isolating SVF, as recommended based on the evaluation of various tested conditions. The USASI method significantly reduced the collagenase dosage and shortened the digestion time. Compared to the collagenase digestion method, the USASI method had a higher cell yield and cell viability, with no adverse effects on cell components, proliferative capacity, or multipotential differentiation capacity. Conclusion: With reduced processing time, lower collagenase dosage, and increased cell yield without impairing the viability and characteristics of SVF, USASI holds the potential to emerge as a time-saving and cost-effective method for future clinical applications.

Keywords

• Stromal vascular fractions
• SVF isolation
• Mechanical force
• Ultrasound