Calcium phosphate nanoparticles as intrinsic inorganic antimicrobials: In search of the key particle property

Abstract

One of the main goals of materials science in the 21st century is the development of materials with rationally designed properties as substitutes for traditional pharmacotherapies. At the same time, there is a lack of understanding of the exact material properties that induce therapeutic effects in biological systems, which limits their rational optimization for the related medical applications. This study sets the foundation for a general approach for elucidating nanoparticle properties as determinants of antibacterial activity, with a particular focus on calcium phosphate nanoparticles. To that end, nine physicochemical effects were studied and a number of them were refuted, thus putting an end to frequently erred hypotheses in the literature. Rather than having one key particle property responsible for eliciting the antibacterial effect, a complex synergy of factors is shown to be at work, including (a) nanoscopic size; (b) elevated intracellular free calcium levels due to nanoparticle solubility; (c) diffusivity and favorable electrostatic properties of the nanoparticle surface, primarily low net charge and high charge density; and (d) the dynamics of perpetual exchange of ultrafine clusters across the particle/solution interface. On the positive side, this multifaceted mechanism is less prone to induce bacterial resistance to the therapy and can be a gateway to the sphere of personalized medicine. On a more problematic side, it implies a less intense effect compared to single-target molecular therapies and a difficulty of elucidating the exact mechanisms of action, while also making the rational design of theirs for this type of medical application a challenge.

Ultrasmall FeS2 Nanoparticles‐Decorated Carbon Spheres with Laser‐Mediated Ferrous Ion Release for Antibacterial Therapy

“…So, the ultrasmall nature of FeS 2 nanoparticles is critical here because it presents a prerequisite for their exhibition of the antibacterial mode of action. [ 35 ] Taken together, these results provide direct evidence that CNSs@FeS 2 possess an effective antibacterial ability, and Fe 2+ ions released from CNSs@FeS 2 and their stable existence are the critical factors in exerting antibacterial activity.…”

A trilogy antimicrobial strategy for multiple infections of orthopedic implants throughout their life cycle

“…Thus, the antibacterial effect of Sr–Zn0@CaP group was not caused by the presence of Sr, suggesting that intrinsic property and morphology of CaP coating may contribute to the observed antimicrobial property. Many precious reports have confirmed that the unique topological morphology and corrugated surface structure could damage the microorganism through intrinsic bacteriostatic process [ 39 , [45] , [46] , [47] , [48] ]. In addition, increased surface roughness at the microscale significantly inhibit bacterial adhesion and biofilm formation on its surface [ 48 , 49 ].…”

From molecules to nanoparticles to functional materials

“…One of the studies had as its objective the delineation of the exact properties of calcium phosphate nanoparticles that are responsible for their exhibiting a moderate antibacterial activity. 28 This conceptually novel study proceeded by designing experimental conditions for testing nine sep-Available on line at www.shd.org.rs/JSCS/ ________________________________________________________________________________________________________________________ (CC) 2020 SCS.…”

“…(Reproduced with the permission of the American Institute of Physics). 28 In late 2015, work began on a book the goal of which was to gather world--renowned experts from the field of nanomedicine and have them contribute with either their opinions as to whence and where to this field develops or up-to-date reviews of their and their peers' work in this field. The book was eventually issued by Elsevier in 2018, with the title "Nanotechnologies in Preventive and Regenerative Medicine: An Emerging Big Picture", 29 containing the work of 58 different authors from five continents of the world.…”