Strategies for Using Polydopamine to Induce Biomineralization of Hydroxyapatite on Implant Materials for Bone Tissue Engineering

In the field of tissue engineering, there are several issues to consider when designing biomaterials for implants, including cellular interaction, good biocompatibility, and biochemical activity. Biomimetic mineralization has gained considerable attention as an emerging approach for the synthesis of biocompatible materials with complex shapes, categorized organization, controlled shape, and size in aqueous environments. Understanding biomineralization strategies could enhance opportunities for novel biomimetic mineralization approaches. In this regard, mussel-inspired biomaterials have recently attracted many researchers due to appealing features, such as strong adhesive properties on moist surfaces, improved cell adhesion, and immobilization of bioactive molecules via catechol chemistry. This molecular designed approach has been a key point in combining new functionalities into accessible biomaterials for biomedical applications. Polydopamine (PDA) has emerged as a promising material for biomaterial functionalization, considering its simple molecular structure, independence of target materials, cell interactions for adhesion, and robust reactivity for resulting functionalization. In this review, we highlight the strategies for using PDA to induce the biomineralization of hydroxyapatite (HA) on the surface of various implant materials with good mechanical strength and corrosion resistance. We also discuss the interactions between the PDA-HA coating, and several cell types that are intricate in many biomedical applications, involving bone defect repair, bone regeneration, cell attachment, and antibacterial activity.