Recent Advances and Progress on Melanin-like Materials and Their Biomedical Applications.

Melanins are well-known biopolymers that are ubiquitous in nature, distributed widely in microorganisms, plants, and animals, and play significant physiological roles. They are mostly biopolymers formed from phenolic compounds by polymerization via quinones. Poly(dopamine) (PDA), a melanin-like material, is similar in structure and properties to eumelanin and has attracted considerable interest for various types of biological applications. This review outlines the recent advances in the structure and synthesis of PDA and discusses applications of PDA in many biological fields, such as biological imaging, photothermal therapy, and drug delivery systems. The purpose of this review is to give a brief overview of the synthesized procedures, structure, biomedical applications, and prospects of melanin-like materials.