The polysaccharides (PS) have been widely used as biomaterials in drug delivery, due to their excellent biocompatibility, ease of functionalization, and intrinsic biological activities. Among the various PS-based biomaterials, the self-assembled PS nanogels (NG) featuring facile preparation are attracting evergrowing interests in various biomedical applications. Specifically, NG derived from the self-assembly of natural PS well maintain both the physicochemical and biological properties of PS while avoiding the chemical modification or alteration of PS structure, representing a potent drug delivery system for various therapeutic agents. In this review, the natural PS, such as chitosan, alginate, and hyaluronan, for self-assembled NG construction and their advantages in the applications of drug delivery have been summarized. The residues, such as amine, carboxyl, and hydroxyl groups, on these PS provide multiple sites for both ionic cross-linking and metal coordination, which greatly contribute to the formation of self-assembled NG as well as the drug loading, thus enabling a wide biomedical application of PS NG, especially for drug delivery. Future developments and considerations in the clinical translation of these self-assembled PS NG have also been discussed.

Transition metal phosphides (TMP)-based oxygen evolution reaction (OER) catalysts constructed by interface engineering strategy have a broad prospect due to their low cost and good performance. Herein, a novel CeO2/NiCoP nanoarray with intimate phosphide (NiCoP)-oxide (CeO2) interface was developed via in situ generation on nickel foam (NF). This structure is conducive to increasing active sites and accelerating charge transfer, and may be conducive to regulating electronic structure and adsorption energy. As expected, optimal 1.4-CeO2/NiCoP/NF delivers a low overpotential of 249 mV at the current density of 10 mA cm−2 with a Tafel slope of 77.2 mV dec−1. CeO2/NiCoP/NF boasts one of the best OER catalytic materials among recently reported phosphides (TMP)-based OER catalysts and composite catalysts involving CeO2. This work provides an effective strategy for the construction of hetero-structure with CeO2 with oxygen vacancies to improve the OER performance of phosphides.

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An integration hydrogen adsorption benign component such as a metal with an oxygen-containing reactant adsorption benign component such as metal oxide allows for efficient overall water splitting in alkaline solutions and yet remains a considerable challenge. Herein, 5d transition metal oxide WO2 and WO3 (denoted as WO x ) nanoparticles are purposely integrated with a porous Ni nanosheet array grown on nickel foam (NF) to design a strongly coupled Ni/WO x /NF porous nanosheet array electrocatalyst. Through the anion exchange of Ni­(OH)2 nanosheets with tungstate, followed by hydrogenation treatment, abundant Ni/WO x interfaces with strong coupling interaction are generated. Benefiting from the strong synergies between Ni and WO x and the unique nanostructure, Ni/WO x /NF only requires the overpotentials of 42 mV for hydrogen evolution reaction (HER) and 395.7 mV for oxygen evolution reaction (OER) to achieve the current densities of 10 and 100 mA cm–2, respectively. Furthermore, the Ni/WO x /NF can achieve a current density of 10 mA cm–2 at a low cell voltage of 1.54 V in a two-electrode system. This work opens a novel avenue for the design of high-performance but low-cost electrocatalysts for overall water splitting.