Uncultivated stromal vascular fraction is equivalent to adipose-derived stem and stromal cells on porous polyurethrane scaffolds forming adipose tissue in vivo

Stromal Vascular Fraction and Mesenchymal Stem Cells from Human Adipose Tissue: A Comparison of Immune Modulation and Angiogenic Potential

INTRODUCTION

In recent years, both stromal vascular fraction (SVF) from adipose tissue and mesenchymal stem cells (MSC) from adipose tissues were extensively used in both preclinical and clinical treatment for various diseases. Some studies reported differences in treatment efficacy between SVFs and MSCs in animals as well as in humans. Therefore, this study is aimed to evaluate the immune modulation and angiogenic potential of SVFs and MSCs from the same SVF samples to support an explanation when SVFs or MSCs should be used.

METHODS

The adipose tissue samples from ten female donors with consent forms were collected. SVFs from these samples were isolated according to the published protocols. The existence of mesenchymal cells that positive with CD44, CD73, CD90, and CD105 and endothelial progenitor cells that positive with CD31 and CD34 was determined using flow cytometry. Three samples of SVFs with similar percentages of mesenchymal cell portion and endothelial progenitor cell portion were used to isolate MSCs. Obtained MSCs were confirmed as MSCs using the ISCT minimal criteria. To compare the immune modulation of SVF and MSCs, the mixed lymphocyte assay was used. The lymphocyte proliferation, as well as IFN-gamma and TNF-alpha concentrations, were determined. To compare the angiogenic potential, the angiogenesis in quail embryo assay was used. The angiogenesis efficacy was measured based on the vessel areas formed in the embryos after 7 days.

RESULTS

The results showed that all SVF samples contained the portions of mesenchymal cells and endothelial progenitor cells. MSCs from SVFs meet all minimal criteria of MSCs that suggested by ISCT. MSCs from SVFs efficiently suppressed the immune cell proliferation compared to the SVFs, especially at ratios of 1:4 (1 MSCs: 4 immune cells). MSCs also inhibited the IFN-gamma and TNF-alpha production more efficiently than SVFs (p < 0.05). However, in quail embryo models, SVFs triggered the angiogenesis and neovessel formation better than MSCs with more significant vessel areas after 7 days (p < 0.05).

CONCLUSION

This study suggested that SVFs and MSCs have different potentials for immune modulation and angiogenesis. SVFs help the angiogenesis better than MSCs, while MSCs displayed the more significant immune modulation. These results can guide the usage of SVFs or MSCs in disease treatment.

4D polycarbonates via stereolithography as scaffolds for soft tissue repair

3D printing has emerged as one of the most promising tools to overcome the processing and morphological limitations of traditional tissue engineering scaffold design. However, there is a need for improved minimally invasive, void-filling materials to provide mechanical support, biocompatibility, and surface erosion characteristics to ensure consistent tissue support during the healing process. Herein, soft, elastomeric aliphatic polycarbonate-based materials were designed to undergo photopolymerization into supportive soft tissue engineering scaffolds. The 4D nature of the printed scaffolds is manifested in their shape memory properties, which allows them to fill model soft tissue voids without deforming the surrounding material. In vivo, adipocyte lobules were found to infiltrate the surface-eroding scaffold within 2 months, and neovascularization was observed over the same time. Notably, reduced collagen capsule thickness indicates that these scaffolds are highly promising for adipose tissue engineering and repair.

Shape memory scaffolds are needed for minimally invasive tissue repair and void filling. Here the authors report on the development of 4D printed polycarbonate-based scaffolds with surface degradation properties which fill voids without deforming tissue and allow for tissue ingrowth with reduced immune response.