In the past, oral insulin has been developed to reduce the suffering of diabetic patients. However, the physiological barriers in gastrointestinal (GI) tract are the major challenges in oral delivery of insulin. In this study, a novel oral delivery system of insulin called NiM (NPs in MPs) has been developed to overcome the GI barriers, which based on a three‐dimensional system of biocompatible chitosan/alginate/casein. Alginate/chitosan nanoparticles (AC‐NPs) were firstly prepared by ionic pre‐gel method and complexation with polyelectrolytes. Then, they were subsequently coated with casein as a protective agent to form NiM, which could keep stability and physiological activity of insulin in gastric tract. The characterization of NiM showed stable hydrodynamic parameters, and the entrapment efficiency of insulin reached 51.1%. In vitro, only 13.5% of insulin was released in the simulated gastric fluid for the first 2 h. But about 57.4% of insulin was slowly released in the simulated intestinal fluid for 10 h. These results indicated that the coating of casein could increase stability of insulin in gastric tract and control release of insulin in intestinal tract. Furthermore, NiM provided a sustained and significant reduction of the blood glucose levels of diabetic mice. Overall, the results demonstrated that our formed NiM may be a promising oral delivery system of insulin for diabetic patients.

Silver nanoparticles (Ag NPs) and the titanium dioxide (TiO 2 ) dielectric layer produced by magnetron sputtering and subsequent annealing treatment, were integrated at the front side of crystalline silicon (c-Si) solar cells. A photovoltaic device was realized based on the c-Si substrate and stacked Ag NPs/TiO 2 /n/p/Ag layer. The results show that the energy conversion efficiency (ECE) can be improved by 9.9% with the introduction of well-sized Ag NPs and an ultrathin TiO 2 dielectric layer to the c-Si solar cells. The presence of the dielectric layer enables Ag NPs to fully exert the advantage of localized surface plasmon resonance (LSPR) and light scattering, and the recombination of the photogenerated carriers originating from Ag NPs is effectively avoided at the surface or in the vicinity of Ag NPs. Moreover, COMSOL Multiphysics simulations were performed to investigate the reflection and absorption of incident light in the c-Si. The simulation results match well with the experimental data.

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