Investigation on Adipose-derived Stromal Cells for Soft Tissue Augmentation and Repair

• Main Authors: Li-Ting Li, 黎莉婷
• Other Authors: Hsu-Wei Fang
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/jrvavy

博士 === 國立臺北科技大學 === 工程學院工程科技博士班 === 104 === Many patients need for augmentation and wound healing of soft tissue defects caused by traumatic injuries or cancer. Adipose tissue-derived stromal vascular cells (SVF cells) are multipotent progenitor cells present in adipose tissue. Since SVF cells are abundant, and easily and safely accessible by liposuction, they have become a promising adult stem cell source for use in clinical cell therapy for wound healing and in autologous fat implantation for soft tissue augmentation and repair. As the need for SVF cells has increased, so has the need for effective cell isolation technology for clinical use. However, the current isolation methods are tedious and time-consuming, associated with increased medical costs, and affect the quality of life of the patients; hence, they are not suitable for clinical applications. One of the future challenges is the development of an effective cell isolation technology for efficient production of SVF cells. The objective of this study was to optimize the accelerated procedure for the isolation of SVF cells. An accelerated protocol for obtaining effectively transplanted adipose tissues with a high amount of SVF cells was developed. We optimized the operational parameters and used these for the extraction of SVF cells. The optimized rapid procedure involved washing lipoaspirate samples once, adding collagenase, incubating in a water bath for 30 minutes at 37°C, and then centrifuging at 1200×g for 3 minutes. Furthermore, the animal study demonstrated that SVF cells isolated by the optimized rapid procedure reduced fibrosis and inflammation of the fat grafts, while promoting angiogenesis in soft tissue augmentation. In addition, we constructed a cell isolation machine for obtaining SVF cells, and this has been approved as a Class I medical device by TFDA. The validatory results of cells isolated by the cell isolation machine called ProCeller indicated that they have characteristics of adipose-derived stem cells (ADSCs). As compared to the manual method, the ProCeller system required less time (< ⅓), gave a higher yield of SVF cells, and increased the number of ADSCs in the SVF cells. Moreover, we estimated the effects of various dosages of SVF cells on fat grafts. We hypothesized that the improvement in fat transplantation quality due to the use of SVF cells would be dose-dependent. Various dosages of SVF cells isolated by the ProCeller system were mixed into adipose tissue, and the SVF cell-enriched adipose tissues were implanted subcutaneously into nude mice after 30 days. The histological findings showed that the neoangiogenesis and integrity of grafted fat cells significantly increased with increasing dosages of SVF cells. Higher dosages of SVF cells also significantly reduced the side effects of the fat grafts, including inflammation, cell infiltration, fibrosis, and cyst formation. Our results suggest that the amount of fat aspirated for isolating supplemental SVF cells should be equal to or more than the amount of fat tissue to be transplanted. SVF cells isolated by the ProCeller system proved effective for use in fat transplantation. Furthermore, we explored the feasibility of the combined use of cells isolated by the ProCeller system and collagen inducible polylactic acid microspheres developed in a previous study, for wound healing. A large, full-thickness wound area of 10 mm diameter with an o-ring for preventing contraction was estimated on the back of nude mice. The analysis of the wound appearance showed that use of 2.5 × 104 SVF cells increased wound closure time at day 10 post wounding, but at day 14 in PLA alone or in the SVF-PLA group. SVF cells also improved scar formation after 21 days post wounding, while the PLA or SVF-PLA groups did not. Thus, SVF cells isolated by the ProCeller system can promote the neoangiogenesis and reduce side effects in the transplanted tissue; they can accelerate wound closure time and reduce scar formation in wound healing. Therefore, the cell isolation machine is ready for use in a clinical setting for SVF cell- and ADSC-related applications. It can be further used in soft tissue augmentation and wound healing applications.