Polydopamine used as Hollow Capsule and Core–Shell Structures for Multiple Applications

Abstract

Polydopamine (PDA) capsule and core-shell structures with tailored structures and properties are of particular interests due to their multifunctions and potential applications as new colloidal structures in diverse¯elds. Among the available fabrication methods, PDA¯lm onto colloidal particles followed by selective template removal has attracted extensive attention due to its advantages of precise control over the size, wall thickness and functions of the obtained capsules. The past several years has witnessed a rapid increase of research concerning the new fabrication strategies, functionalization and applications of this kind of capsules and core-shell structures, particularly in many¯elds such as drug delivery, catalysis, antibacterial, etc. In this review, the very recent progress of the capsule and core-shell structures based on PDA are summarized. There are basically two sections, including the fabrication process of PDA capsules, core-shell structures, and the various applications based on PDA.

Chemistry of polydopamine analogues

“…Furthermore, electrochemical oxidation of DA can lead to PDA films . By the application of sacrificial templates or folic acid as an additive in the oxidation of DA, it was also possible to obtain PDA objects of various morphologies such as spheres, hollow spheres, double layered PDA capsules and PDA fibers, which recently attracted much attention …”

“…However, considering the structure and the mechanism of formation of PDA (Scheme ) there are crucial situations. Electron withdrawing substituents R at the N‐atom can hamper indole formation or additional substituents R in the aromatic ring prevent indole formation or incorporation of the DA units via the common 1,4‐connection (see Schemes , 12 later). On the other hand, substituents R and R found in the side chain of DA should be tolerated in oxidative polymerizations similar to the formation of PDA.…”

“…Since the pioneer work of the Messersmith group polydopamine (PDA) obtained by oxidative polymerization of dopamine (DA) has attracted enormous interest from chemists, materials scientists and biologists . Compared with PDA, analogues of polydopamine (PDANAs) either contain additional functional groups (e.g.…”

Efficient single photon emission from a high-purity hexagonal boron nitride crystal

“…The resulting high-purity crystals have released the engineering potential of this material for the development of efficient light-emitting devices in the deep ultraviolet [5,6]. More recently, hBN has even attracted a renewed interest because it exhibits a two-dimensional (2D) honeycomb structure similar to graphene, which can be used as a building block for the design of complex van der Waals heterostructures [7][8][9][10]. Given this wide range of promising applications, it is essential to precisely characterize intrinsic defects hosted in the hBN crystal in order to further optimize the properties of this material.…”

Current Advances in the Utilization of Polydopamine Nanostructures in Biomedical Therapy

“…The fabrication of PDA hollow nanostructures mainly relies on the polymerization of a DA monomer on sacrificial templates, followed by template removal. In this manner, the sacrificial cores could be either emulsion droplets or solid particulates, with the majority being of spherical shape . The utilization of PDA hollow capsules for biomedical applications has been demonstrated in various reports.…”