Antimicrobial function of Ag nanoparticles (NPs) has a strong correlation with the released Ag⁺ cations that are produced by oxidation of Ag NPs in a solution state under ambient condition. Therefore, in order to develop anti-infective materials for biomedical applications, one needs to include Ag NPs inside biocompatible materials, which can allow slow release of Ag⁺ cations. Hydrogels of natural polymers could be an ideal choice for the purpose because (a) the physicochemical properties of hydrogels resemble with biological tissue, and (b) the inclusion of Ag NPs inside hydrogels prevents the direct release of Ag NPs, while allowing the release of Ag⁺ cations out of the hydrogels. In this regard, we present a simple strategy for producing Ag NPs-containing hydrogel based on natural alginate polymers. The chemical modification of alginate, blending with Ag NPs, gelation by photo-crosslinking process have been discussed in connection with antimicrobial reaction on model bacterium. GRAPHICAL ABSTRACT

Polydopamine was utilized an adhesive interface for the uniform coating of Au nanoparticles in the pores of polydimethylsiloxane to enhance the output performance of triboelectric nanogenerators.

In this study, diselenide (Se–Se) and disulfide (S–S) redox-responsive core-cross-linked (CCL) micelles were synthesized using poly(ethylene oxide)_2k-b-poly(furfuryl methacrylate)_1.5k (PEO_2k-b-PFMA_1.5k), and their redox sensitivity was compared. A single electron transfer-living radical polymerization technique was used to prepare PEO_2k-b-PFMA_1.5k from FMA monomers and PEO_2k-Br initiators. An anti-cancer drug, doxorubicin (DOX), was incorporated into PFMA hydrophobic parts of the polymeric micelles, which were then cross-linked with maleimide cross-linkers, 1,6-bis(maleimide) hexane, dithiobis(maleimido) ethane and diselenobis(maleimido) ethane via Diels–Alder reaction. Under physiological conditions, the structural stability of both S–S and Se–Se CCL micelles was maintained; however, treatments with 10 mM GSH induced redox-responsive de-cross-linking of S–S and Se–Se bonds. In contrast, the S–S bond was intact in the presence of 100 mM H₂O_2, while the Se–Se bond underwent de-crosslinking upon the treatment. DLS studies revealed that the size and PDI of (PEO_2k-b-PFMA_1.5k-Se)₂ micelles varied more significantly in response to changes in the redox environment than (PEO_2k-b-PFMA_1.5k-S)₂ micelles. In vitro release studies showed that the developed micelles had a lower drug release rate at pH 7.4, whereas a higher release was observed at pH 5.0 (tumor environment). The micelles were non-toxic against HEK-293 normal cells, which revealed that they could be safe for use. Nevertheless, DOX-loaded S–S/Se–Se CCL micelles exhibited potent cytotoxicity against BT-20 cancer cells. Based on these results, the (PEO_2k-b-PFMA_1.5k-Se)₂ micelles can be more sensitive drug carriers than (PEO_2k-b-PFMA_1.5k-S)₂ micelles.