Fabrication of core-shell Ag@pDA@HAp nanoparticles with the ability for controlled release of Ag+ and superior hemocompatibility

Silver nanoparticles (Ag-NPs) are a type of crucial bactericide due to their excellent antibacterial properties. However, the application of Ag-NPs in clinics and in bone tissue engineering is hampered because of their unabiding antibacterial efficacy and undesirable biological properties such as cytotoxicity and inferior hemocompatibility. In this study, Ag-NPs were modified with polydopamine (pDA) and hydroxyapatite (HAp) to prepare novel and multifunctional core (Ag-NPs)-shell (pDA)-shell (HAp) nanoparticles (Ag@pDA@HAp-NPs). The Ag+ release rate was reduced by about 80% on the first day, and then Ag+ was slowly released, which implied that the core-shell Ag@pDA@HAp-NPs could effectively control the release of Ag+. The core-shell Ag@pDA@HAp-NPs could obviously inhibit the growth of E. coli and S. aureus, and the bactericide rate of the Ag@pDA@HAp-NPs was up to 99.99% after being cultured for 24 h. Furthermore, the synthesized Ag@pDA@HAp-NPs exhibited superior hemocompatibility due to the favorable blood compatibility of the pDA coating and HAp shell as well as the controlled release of Ag+. Thus, the core-shell Ag@pDA@HAp-NPs, with the ability for the controlled release of Ag+ and superior hemocompatibility, are promising for reducing cytotoxicity and achieving long-term antibacterial properties, and could have potential applications in clinics and in bone tissue engineering.