Mussel‐Inspired Polydopamine Coating as a Universal Route to Hydroxyapatite Crystallization

Abstract

Bone tissue is a complex biocomposite material with a variety of organic (e.g., proteins, cells) and inorganic (e.g., hydroxyapatite crystals) components hierarchically organized with nano/microscale precision. Based on the understanding of such hierarchical organization of bone tissue and its unique mechanical properties, efforts are being made to mimic these organic–inorganic hybrid biocomposites. A key factor for the successful designing of complex, hybrid biomaterials is the facilitation and control of adhesion at the interfaces, as many current synthetic biomaterials are inert, lacking interfacial bioactivity. In this regard, researchers have focused on controlling the interface by surface modifications, but the development of a simple, unified way to biofunctionalize diverse organic and inorganic materials remains a critical challenge. Here, a universal biomineralization route, called polydopamine‐assisted hydroxyapatite formation (pHAF), that can be applied to virtually any type and morphology of scaffold materials is demonstrated. Inspired by the adhesion mechanism of mussels, the pHAF method can readily integrate hydroxyapatites on ceramics, noble metals, semiconductors, and synthetic polymers, irrespective of their size and morphology (e.g., porosity and shape). Surface‐anchored catecholamine moieties in polydopamine enriches the interface with calcium ions, facilitating the formation of hydroxyapatite crystals that are aligned to the c‐axes, parallel to the polydopamine layer as observed in natural hydroxyapatites in mineralized tissues. This universal surface biomineralization can be an innovative foundation for future tissue engineering.

Polydopamine-based synthesis of a zeolite imidazolate framework ZIF-100 membrane with high H2/CO2 selectivity

“…34 Then the PDA-modied surface can be used as a versatile platform for further reactions. [35][36][37] Recently, PDA-based synthesis of ZIF-8 and zeolite LTA membranes has been developed to improve their gas separation performance and reproducibility. [38][39][40] It can be expected, therefore, that ZIF-100 membranes prepared on PDA-functionalized supports will show higher gas separation performances and reproducibility of membrane preparation.…”

In situ preparation and protein delivery of silicate–alginate composite microspheres with core-shell structure

“…We have tested the stability of the CS shell by an ultrasonic shaking method described previously [30]. After 1 h of ultrasonic treatment, the CS shell was still present on the surface of the in situ 30CS -A microspheres and showed no evidence of delaminating from the microspheres (see the electronic supplementary material, figure S2), indicative of a high degree of stability.…”

Recent biomedical applications of bio-sourced materials

“…Therefore, a major focus of tissue engineering research is the design of bio-materials that provide information about cells and tissues. Inspired by mussel adhesion, scientists found that dopamine self-polymerized under alkaline conditions [63,65]. The reaction provides a universal coating for metals, polymers, and ceramics, regardless of their chemical and physical properties.…”