Biomimetic fabrication of antibacterial calcium phosphates mediated by polydopamine

Abstract

In this work we developed new antibacterial composite materials using polydopamine (PDA) to trigger the deposition of silver nanoparticles (AgNPs) onto calcium phosphates, namely octacalcium phosphate (OCP) and α-tricalcium phosphate (αTCP). Functionalization of OCP and αTCP with a self-polymerized polydopamine layer was obtained by soaking the calcium phosphates in dopamine solution. The PDA surface of functionalized calcium phosphates (OCPd and αTCPd) promoted the deposition of AgNPs by reducing silver ions when soaked in a silver nitrate solution. The amount of deposited AgNPs can be modulated by varying the concentration of silver nitrate solution and the type of substrate. The results of in vitro tests carried out with osteoblast-like MG63 cells indicate that the combination of AgNPs with OCP provides more biocompatible materials than those obtained using αTCP as substrate. In particular, the study of osteoblast activity and differentiation was focused on the samples OCPdAg5 (silver content=8.2wt%) and αTCPdAg5 (silver content=4.7wt%), which did not show any cytotoxicity, and compared with those obtained on pure OCP and αTCP. The results demonstrate that the AgNPs loaded materials support osteoblast viability and differentiation, whereas they significantly inhibit the growth of relevant antibiotic-resistant pathogenic bacteria.

Effect of strontium substituted ß‐TCP associated to mesenchymal stem cells from bone marrow and adipose tissue on spinal fusion in healthy and ovariectomized rat

“…Although the material is very crystalline, no crystal faces and edges are appreciable, which is not surprising for TCP materials prepared at high temperature (Forte et al, 2018) whose preparation passes through the molten phase.…”

Studies on Cell Compatibility, Antibacterial Behavior, and Zeta Potential of Ag-Containing Polydopamine-Coated Bioactive Glass-Ceramic

“…It is possible to observe calcein-stained cells, which means that cells are alive but under high stress. Forte et al [24] used polydopamine as an interface between calcium phosphate and silver. It was also found that for certain samples coated with silver, cell toxicity occurred [24].…”

“…Forte et al [24] used polydopamine as an interface between calcium phosphate and silver. It was also found that for certain samples coated with silver, cell toxicity occurred [24]. Therefore, more research efforts should be undertaken to optimize the silver dose to obtain an effective dual-function material.…”

“…Coatings, based on polydopamine incorporating silver particles, represent an attractive approach to obtain dual-functional composite layers on the surface of biomaterials. Such composites should facilitate interactions with biological tissues without showing cytotoxicity and also exhibit antibacterial capability [21,22,23,24,25]. In our previous study [26], Ag-containing polydopamine coatings on bioactive glass-ceramic surfaces were developed; however, only a limited characterization of the coatings has been reported.…”

Bio‐inspired nanofunctionalisation of biomaterial surfaces: a review

“…The dual-functional surfaces can prevent the infection of biomaterials during the infection during the tissue regeneration process. Forte et al [112] used PDA to functionalise the CaP surfaces. PDA acts as a reducing agent and can reduce the silver ions to the silver nanoparticles (Ag NPs) on the CaP surfaces in a silver nitrate solution.…”