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Background:: Mesenchymal stem cells (MSCs) are used for tissue regeneration due to their wide differentiation capacity and anti-inflammatory effects. Extracellular vesicles (EVs) derived from MSCs are also known for their regenerative effects as they contain nucleic acids, proteins, lipids, and cytokines similar to those of parental cells. There are several studies on the use of MSCs or EVs for tissue regeneration. However, the combinatorial effect of human MSCs (hMSCs) and EVs is not clear. In this study, we investigated the combinatorial effect of hMSCs and EVs on cartilage regeneration via co-encapsulation in a hyaluronic-acid (HA)-based hydrogel. Methods:: A methacrylic-acid-based HA hydrogel was prepared to encapsulate hMSCs and EVs in hydrogels. Through in vitroand in vivoanalyses, we investigated the chondrogenic potential of the HA hydrogel-encapsulated with hMSCs and EVs. Results:: Co-encapsulation of hMSCs with EVs in the HA hydrogel increased the chondrogenic differentiation of hMSCs and regeneration of damaged cartilage tissue compared with that of the HA hydrogel loaded with hMSCs only. Conclusion:: Co-encapsulation of hMSCs and EVs in the HA hydrogel effectively enhances cartilage tissue regeneration due to the combinatorial therapeutic effect of hMSCs and EVs. Thus, in addition to cartilage tissue regeneration for the treatment of osteoarthritis, this approach would be a useful strategy to improve other types of tissue regeneration.

To improve electrical characteristics of high-kgate dielectrics, post-deposition annealing (PDA) was performed in high-pressure (10atm)pure hydrogen ambient. High-pressure PDA samples show excellent electrical characteristics such as low fixed charge density, and reduced interface state density confirmed by capacitance-voltage analysis and conductance technique, respectively. They also showed no frequency dependency and a hysteresis of 2.9mV. The leakage current decreases remarkably from 0.23 to 2.44×10−7Ampere∕cm2at the gate voltage of 1Vbelow VFB. The excellent electrical characteristics of high-pressure hydrogen annealed sample can be explained by enhanced hydrogen passivation of defects in high-kdielectric.