Gene expression profile of the cartilage tissue spontaneously regenerated in vivo by using a novel double-network gel: Comparisons with the normal articular cartilage

<p>Abstract</p> <p>Background</p> <p>We have recently found a phenomenon that spontaneous regeneration of a hyaline cartilage-like tissue can be induced in a large osteochondral defect by implanting a double-network (DN) hydrogel plug, which was composed of poly-(2-Acrylamido-2-methylpropanesulfonic acid) and poly-(N, N'-Dimetyl acrylamide), at the bottom of the defect. The purpose of this study was to clarify gene expression profile of the regenerated tissue in comparison with that of the normal articular cartilage.</p> <p>Methods</p> <p>We created a cylindrical osteochondral defect in the rabbit femoral grooves. Then, we implanted the DN gel plug at the bottom of the defect. At 2 and 4 weeks after surgery, the regenerated tissue was analyzed using DNA microarray and immunohistochemical examinations.</p> <p>Results</p> <p>The gene expression profiles of the regenerated tissues were macroscopically similar to the normal cartilage, but showed some minor differences. The expression degree of COL2A1, COL1A2, COL10A1, DCN, FMOD, SPARC, FLOD2, CHAD, CTGF, and COMP genes was greater in the regenerated tissue than in the normal cartilage. The top 30 genes that expressed 5 times or more in the regenerated tissue as compared with the normal cartilage included type-2 collagen, type-10 collagen, FN, vimentin, COMP, EF1alpha, TFCP2, and GAPDH genes.</p> <p>Conclusions</p> <p>The tissue regenerated by using the DN gel was genetically similar but not completely identical to articular cartilage. The genetic data shown in this study are useful for future studies to identify specific genes involved in spontaneous cartilage regeneration.</p

Surface Properties of Air-Exposed α-Ti–Pd Alloys via XPS and Cross-Coupling Reaction

To identify the reasons why Ti–Pd alloys for hydrogen storage materials show good hydrogenation properties, X-ray photoelectron spectroscopy and the Suzuki–Miyaura cross-coupling reaction were used to investigate a small amount of Pd added Ti–Pd alloys. Pd in or on Ti oxide films is in a valence state of 0 (Pd0). Catalytic activity was shown by Pd0 in the Suzuki–Miyaura cross-coupling reaction. Therefore, the enhanced hydrogenation properties of Ti–Pd alloys for hydrogen storage materials is due to Pd0\u27s catalytic activity in dissociating hydrogen molecules. In addition, the potential catalytic activity of Ti–Pd alloys was shown to be based on a Pd catalyst.This research was financially supported by the Japan Science and Technology Agency\u27s Matching PlannerProgram, the Kansai University Fund for Supporting Young Scholars (2015) and JSPS KAKENHI Grant Number 17K14837