Silver Nanoparticles Stabilized with Phosphorus-Containing Heterocyclic Surfactants: Synthesis, Physico-Chemical Properties, and Biological Activity Determination

Linear-Chain Nanostructured Carbon with a Silver Film Plated on Metal Components Has a Promising Effect for the Treatment of Periprosthetic Joint Infection

Background: Due to the aging of the world population, the number of joint diseases, along with the number of arthroplasties, has increased, simultaneously increasing the amount of complications, including periprosthetic joint infection (PPI). In this study, to combat a PPI, we investigated the antimicrobial properties of the new composite cover for titanium implants, silver-doped carbyne-like carbon (S-CLC) film. Methods: The first assay investigated the antimicrobial activity against Pseudomonas aeruginosa and releasing of silver ions from S-CLC films into growth media covered with S-CLC with a thickness of 1, 2, and 4 mm. The second assay determined the direct antibacterial properties of the S-CLC film’s surface against Staphylococcus aureus, Enterococcus faecalis, or P. aeruginosa. The third assay studied the formation of microbial biofilms of S. aureus or P. aeruginosa on the S-CLC coating. Silver-doped carbyne-like carbon (S-CLC)-covered or titanium plates alone were used as controls. Results: S-CLC films, compared to controls, prevented P. aeruginosa growth on 1 mm thickness agar; had direct antimicrobial properties against S. aureus, E. faecalis, and P. aeruginosa; and could prevent P. aeruginosa biofilm formation. Conclusions: S-CLC films on the Ti surface could successfully fight the most common infectious agent in PPI, and prevented biofilm formation.

Detailed Calorimetric Analysis of Mixed Micelle Formation from Aqueous Binary Surfactants for Design of Nanoscale Drug Carriers

While numerous papers have been published according to the binary surfactant mixtures, only a few articles provide deeper information on the composition dependence of the micellization, and even less work attempts to apply the enhanced feature of the mixed micelles. The most important parameter of the self-assembled surfactants is the critical micelle concentration (cmc), which quantifies the tendency to associate, and provides the Gibbs energy of micellization. Several techniques are known for determining the cmc, but the isothermal titration calorimetry (ITC) can be used to measure both cmc and enthalpy change (Δ_micH) accompanying micelle formation. Outcomes of our calorimetric investigations were evaluated using a self-developed routine for handling ITC data and the thermodynamic parameters of mixed micelle formation were obtained from the nonlinear modelling of temperature- and composition- dependent enthalpograms. In the investigated temperature and micelle mole fractions interval, we observed some intervals where the cmc is lower than the ideal mixing model predicted value. These equimolar binary surfactant mixtures showed higher solubilization ability for poorly water-soluble model drugs than their individual compounds. Thus, the rapid and fairly accurate calorimetric analysis of mixed micelles can lead to the successful design of a nanoscale drug carrier.

Advances in Use of Nanomaterials for Musculoskeletal Regeneration

Since the worldwide incidence of bone disorders and cartilage damage has been increasing and traditional therapy has reached its limits, nanomaterials can provide a new strategy in the regeneration of bones and cartilage. The nanoscale modifies the properties of materials, and many of the recently prepared nanocomposites can be used in tissue engineering as scaffolds for the development of biomimetic materials involved in the repair and healing of damaged tissues and organs. In addition, some nanomaterials represent a noteworthy alternative for treatment and alleviating inflammation or infections caused by microbial pathogens. On the other hand, some nanomaterials induce inflammation processes, especially by the generation of reactive oxygen species. Therefore, it is necessary to know and understand their effects in living systems and use surface modifications to prevent these negative effects. This contribution is focused on nanostructured scaffolds, providing a closer structural support approximation to native tissue architecture for cells and regulating cell proliferation, differentiation, and migration, which results in cartilage and bone healing and regeneration.