Tissue engineering chambers (TECs) represent a new and attractive in vivo tissue engineering model that can successfully generate mature adipose tissue. However, the newly formed adipose tissue is not able to fill the...Tissue engineering chambers (TECs) represent a new and attractive in vivo tissue engineering model that can successfully generate mature adipose tissue. However, the newly formed adipose tissue is not able to fill the volume of the chamber as expected. To investigate whether the capsule surrounding the newly formed adipose tissue limits the adipose tissue volume in the chamber, we detected fibrotic parameters two months after these chambers were implanted into rats. The results showed that the newly formed adipose tissue was surrounded by a thick layer of capsule, and the protein levels of transforming growth factor-<em>β</em>1 (TGF-<em>β</em>1), phosphorylated Smad2 (p-Smad2), connective tissue growth factor (CTGF), collagen type I (COL-I) and α-smooth muscle actin (<em>α</em>-SMA) in the capsule were increased. The levels of these proteins decreased following systemic administration of P144 (a peptide inhibitor of TGF-<em>β</em>1). Furthermore, the capsule thickness was significantly reduced, and the adipose tissue volume was markedly greater when using P144. These findings indicate that capsule formation, which is mediated through a TGF-<em>β</em>1 signaling pathway, restricted the volume of the engineered adipose tissue that was formed. This study may provide a new approach to regenerate amounts of adipose tissue for the reconstruction of large soft tissue defects.展开更多
Recent years, it has attracted more attentions to increase the porosity and pore size of nanofibrous scaffolds to provide the for the cells to grow into the small-diameter vascular grafts. In this study, a novel bi-la...Recent years, it has attracted more attentions to increase the porosity and pore size of nanofibrous scaffolds to provide the for the cells to grow into the small-diameter vascular grafts. In this study, a novel bi-layer tubular scaffold with an inner layer and an outer layer was fabricated. The inner layer was random collagen/poly （ L-lactide-co-caprolactone ） I P （ LLA- CL） ] nanofibrous mat fabricated by conventional electrospinning and the outer layer was aligned collagen/P （LLA-CL） nanoyarns prepared by a dynamic liquid dectrospinning method. Fourier transform infrared spectroscopy （FTIR） was used to characterize the chemical structure. Scanning electron microscopy （ SEM ） was employed to observe the morphology of the layers and the cross- sectioned bi-layer tubular scaffold. A liquid displacement method was employed to measure the porosities of the inner and outer layers. Stress-strain curves were obtained to evaluate the mechanical properties of the two different layers and the bi-layer membrane. The diameters of the nanofibers and the nanoyarns were （480 ± 197 ） nm and （ 19.66 ± 4.05 ） μm, respectively. The outer layer had a significantly higher porosity and a larger pore size than those of the inner layer. Furthermore, the bi-layer membrane showed a good mechanical property which was suitable as small-diameter vascular graft. The results indicated that the bi-layer tubular scaffold had a great potential application in small vascular tissue engineering.展开更多
文摘Tissue engineering chambers (TECs) represent a new and attractive in vivo tissue engineering model that can successfully generate mature adipose tissue. However, the newly formed adipose tissue is not able to fill the volume of the chamber as expected. To investigate whether the capsule surrounding the newly formed adipose tissue limits the adipose tissue volume in the chamber, we detected fibrotic parameters two months after these chambers were implanted into rats. The results showed that the newly formed adipose tissue was surrounded by a thick layer of capsule, and the protein levels of transforming growth factor-<em>β</em>1 (TGF-<em>β</em>1), phosphorylated Smad2 (p-Smad2), connective tissue growth factor (CTGF), collagen type I (COL-I) and α-smooth muscle actin (<em>α</em>-SMA) in the capsule were increased. The levels of these proteins decreased following systemic administration of P144 (a peptide inhibitor of TGF-<em>β</em>1). Furthermore, the capsule thickness was significantly reduced, and the adipose tissue volume was markedly greater when using P144. These findings indicate that capsule formation, which is mediated through a TGF-<em>β</em>1 signaling pathway, restricted the volume of the engineered adipose tissue that was formed. This study may provide a new approach to regenerate amounts of adipose tissue for the reconstruction of large soft tissue defects.
基金National Natural Science Foundations of China，Science and Technology Commission of Shanghai Municipality,China，Ph.D.Programs Foundation of Ministry of Education of China
文摘Recent years, it has attracted more attentions to increase the porosity and pore size of nanofibrous scaffolds to provide the for the cells to grow into the small-diameter vascular grafts. In this study, a novel bi-layer tubular scaffold with an inner layer and an outer layer was fabricated. The inner layer was random collagen/poly （ L-lactide-co-caprolactone ） I P （ LLA- CL） ] nanofibrous mat fabricated by conventional electrospinning and the outer layer was aligned collagen/P （LLA-CL） nanoyarns prepared by a dynamic liquid dectrospinning method. Fourier transform infrared spectroscopy （FTIR） was used to characterize the chemical structure. Scanning electron microscopy （ SEM ） was employed to observe the morphology of the layers and the cross- sectioned bi-layer tubular scaffold. A liquid displacement method was employed to measure the porosities of the inner and outer layers. Stress-strain curves were obtained to evaluate the mechanical properties of the two different layers and the bi-layer membrane. The diameters of the nanofibers and the nanoyarns were （480 ± 197 ） nm and （ 19.66 ± 4.05 ） μm, respectively. The outer layer had a significantly higher porosity and a larger pore size than those of the inner layer. Furthermore, the bi-layer membrane showed a good mechanical property which was suitable as small-diameter vascular graft. The results indicated that the bi-layer tubular scaffold had a great potential application in small vascular tissue engineering.
