Mechano-bactericidal anisotropic particles for oral biofilm treatment.

Bacterial biofilms play a major etiological role in dental diseases worldwide. Currently, toothpastes with bactericidal chemicals and abrasive materials are used as preventive care methods. However, chemicals can cause adverse side effects, with the use of antibiotics, fluorides, and antiseptics drastically reducing quality of life. At the same time, the rational design of bulk toothpaste materials has remained unexplored. In this work, we demonstrated a mechano-bactericidal strategy as an antibiotic-free and tooth-safe approach for dental biofilm elimination based on shape-anisotropy CaCO3 (cubic-, stick-, and urchin-shaped). As proof-of-concept, we demonstrated superior efficiency during biofilm eradication from ex vivo teeth using urchin- and stick-shaped microparticles involving both Escherichia coli K12 (227 ± 32.6% and 215 ± 33%, respectively) and Staphylococcus aureus ATCC 209P (210 ± 54.7% and 202 ± 55.5%, respectively) compared to the spherical particles that are employed in conventional toothpastes. These findings will potentially give rise to the development of novel and safer toothpastes with antibiotic-free bactericidal activity for the prevention of dental diseases.

Metal-derived nanoparticles in tumor theranostics: Potential and limitations.

Initially, metal derived nanoparticles have been used exclusively as contrasting agents in magnetic resonance imaging. Today, green routes of chemical synthesis together with numerous modifications of the core and surface gave rise to a plethora of biomedical applications of metal derived nanoparticles including tumor imaging, diagnostics, and therapy. These materials are an emerging class of tools for tumor theranostics. Nevertheless, the spectrum of clinically approved metal nanoparticles remains narrow, as the safety, specificity and efficiency still have to be improved. In this review we summarize the major directions for development and biomedical applications of metal based nanoparticles and analyze their effects on tumor cells and microenvironment. We discuss the advantages and possible limitations of metal nanoparticle-based tumor theranostics, as well as the potential strategies to improve the in vivo performance of these unique materials.