Comparison of in vivo adipogenic capabilities of two different extracellular matrix microparticle scaffolds.

BACKGROUND: The extracellular matrix is an essential microenvironment for cell survival activity. The adipose tissue extract microparticle scaffolds from human adipose tissue and small intestine submucosa microparticle scaffolds from porcine jejunum were prepared. Their effects on the adipogenic capabilities of human adipose-derived stem cells were compared in vivo. METHODS: A combination of physical and chemical methods was used to decellularize human fat and porcine jejunum. Expression of CD molecules on the adipose-derived stem cell surface was determined by flow cytometry. The stem cells were then cultured with the scaffold materials in vitro. The cell-scaffold complexes were implanted subcutaneously into nude mice, and samples were collected 4 and 8 weeks later. The adipogenic differentiation capabilities of adipose-derived stem cells were studied by histologic methods and real-time polymerase chain reaction. RESULTS: The authors observed high expression of CD90 and CD44; no expression of CD34, CD45, CD31, or CD106; and weak positive expression of CD49d on the extracted cells, which indicates that the cells were adipose-derived stem cells. The main constituent of the decellularized adipose tissue extract and small intestine submucosa microparticles was collagenous fiber, and the cells proliferated faster on the adipose tissue extract than on small intestine submucosa. Formation of adipocytes in the adipose tissue extract group was closer to that of normal human fat tissue compared with that of the small intestine submucosa group. CONCLUSIONS: Extracellular matrix microparticle scaffolds could promote proliferation, adhesion, and adipogenic differentiation of adipose-derived stem cells. The role of the adipose tissue extract microparticle scaffold in promoting adipogenesis was stronger and more suitable as a vector in fatty tissue engineering.

[Allograft antigenicity of human ear cartilage and effect of cell extraction on antigenicity].

OBJECTIVE: To study the allograft antigenicity of human ear cartilage and the effect of the cell extraction on antigenicity. METHODS: The human ear cartilage was acellular by cell extraction with Triton X-100. Then the cartilage and the acellular cartilage were analyzed by anti-MHC-I immunohistochemical staining, the reaction of the peripheral blood mononuclear(PBM) cells to the cartilage and the acellular cartilage and the migration of the PBM cells toward the cartilage and the acellular cartilage. RESULTS: The result of human ear cartilage was positive for the anti-MHC-I immunohistochemical staining, whereas that of the acellular cartilage was negative for the staining. The reactive proliferation of the PBM cells was more when they were co-cultured with human ear cartilage than that when they were cultured alone in vitro(P < 0.05), but the acellular cartilage did not show the same phenomena (P > 0.05); when the cartilage and the acellular cartilage were co-cultured with the PBM cells, the PBM cells migrated to the cartilage much more than that to acellular cartilage(P < 0.01). CONCLUSION: Human ear cartilage has allograft antigenicity and its antigenicity can be removed by cell extraction with Triton X-100.