Hydroxide ion-mediated synthesis of monodisperse dopamine–melanin nanospheres

Chemistry of polydopamine analogues

“…Oxidation with air in Tris buffer is often applied as a dip coating to create PDA films on various types of surfaces, such as Teflon, aluminium oxide, silica, stainless steel, various polymers and nanostructures like carbon nanotubes, magnetic nanoparticles and gold nanoparticles . The thickness of films on the one hand and the size and shape of PDA objects on the other can be influenced by reaction time, concentration, solvent, additives and pH . The deposition time at surfaces can be shortened by increasing the temperature and by vigorous stirring .…”

The modulation of melanin‐like materials: methods, characterization and applications

“…How to control the size of the PDA NPs obtained is an important topic. Researchers have reported that the size can be changed with detailed experimental conditions, such as solution properties, the pH value of the aqueous solution, reaction time, the addition of surfactant or small molecules and so on. In basic aqueous medium, the diameter of PDA NPs can be controlled in the range 80–490 nm via adjusting the concentration of dopamine.…”

“…In basic aqueous medium, the diameter of PDA NPs can be controlled in the range 80–490 nm via adjusting the concentration of dopamine. The concentration of hydroxide ions is linearly proportional to initial reaction rates that determine the nucleus number of PDA NPs . A mixture of water, ethanol and ammonia has been used in the preparation of PDA NPs with controlled size .…”

“…The concentration of hydroxide ions is linearly proportional to initial reaction rates that determine the nucleus number of PDA NPs. 51 A mixture of water, ethanol and ammonia has been used in the preparation of PDA NPs with controlled size. 53 The size of PDA NPs has been adjusted by tuning the molar ratio of ammonia to dopamine: a higher amount of ammonia corresponds to a small size of PDA NPs (average diameter 70 nm).…”

Interleukin-1β and -6 release from immune cells by DOPA-based melanin as free pigment or complexed to carboxymethylcellulose

“…[9] Using DOPA or CAs as precursors, MNs can readily be synthesized in an alkaline environment in the presence of an oxidizing agent. [10][11][12] However, such synthetic MNs are often insoluble and difficult to characterize or test for biological activities. We have explored the possibility that MNs could be synthesized in the presence of polysaccharides (PS) leading to water-soluble PS/MN complexes, providing more suitable preparations for biological evaluations.…”