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The local peri‐implant pH changes caused by sterile inflammation and bacterial and fungal infections are studied herein. Then, a sensing electrode based on polyaniline and poly(2‐methyl‐2‐oxazoline) on a titanium alloy support is developed for potentiometric detection of peri‐implant pH changes to enable early detection of the aforementioned pathologies. The infected endoprosthesis area is shown to have an average pH of 0.79 units lower than the aseptic sample. The pH measurements of the individual pathogenic bacteria or pathogenic yeast reveal that Escherichia coli decreased the pH by 1.24 units, Staphylococcus aureus decreased the pH by 1.33 units and the methicillin‐resistant Staphylococcus aureus bacteria decreased the pH from 7.2 to 5.6 during 10 h, followed by a subsequent increase to 6.4. The results are statistically significant (α = 0.01). Pseudomonas aeruginosa is not shown to change pH levels. On the other hand, the pathogenic yeast has the lowest recorded pH, which decreases from 5.8 to 4.8. This difference in pH can be used to identify the nature of the infection. The developed electrodes have a pH response between pH 5 and 8, with a Nernstian slope of −59.6/pH. The developed electrode can contribute to the next generation of biosensors. [ABSTRACT FROM AUTHOR]

Bioinks play a crucial role in tissue engineering, influencing mechanical and chemical properties of the printed scaffold as well as the behavior of encapsulated cells. Recently, there has been a shift from animal origin materials to their synthetic alternatives. In this context, we present here bioinks based on fully synthetic and biodegradable poly( α ,L-amino acids) (PolyAA) as an alternative to animal-based gelatin methacrylate (Gel-Ma) bioinks. Additionally, we first reported the possibility of the visible light photoinitiated incorporation of the bifunctional cell adhesive RGD peptide into the PolyAA hydrogel matrix. The obtained hydrogels are shown to be cytocompatible, and their mechanical properties closely resemble those of gelatin methacrylate-based scaffolds. Moreover, combining the unique properties of PolyAA-based bioinks, the photocrosslinking strategy, and the use of droplet-based printing allows the printing of constructs with high shape fidelity and structural integrity from low-viscosity bioinks without using any sacrificial components. Overall, presented PolyAA-based materials are a promising and versatile toolbox that extends the range of bioinks for droplet bioprinting., (© 2024 IOP Publishing Ltd.)

The use of fluorinated contrast agents in magnetic resonance imaging (MRI) facilitates improved image quality due to the negligible amount of endogenous fluorine atoms in the body. In this work, we present a comprehensive study of the influence of the amphiphilic polymer structure and composition on its applicability as contrast agents in 19 F MRI. Three series of novel fluorine-containing poly(2-oxazoline) copolymers and terpolymers, hydrophilic-fluorophilic, hydrophilic-lipophilic-fluorophilic, and hydrophilic-thermoresponsive-fluorophilic, with block and gradient distributions of the fluorinated units, were synthesized. It was discovered that the CF 3 in the 2-(3,3,3-trifluoropropyl)-2-oxazoline (CF 3 EtOx) group activated the cationic chain end, leading to faster copolymerization kinetics, whereby spontaneous monomer gradients were formed with accelerated incorporation of 2-methyl-2-oxazoline or 2- n -propyl-2-oxazoline with a gradual change to the less-nucleophilic CF 3 EtOx monomer. The obtained amphiphilic copolymers and terpolymers form spherical or wormlike micelles in water, which was confirmed using transmission electron microscopy (TEM), while small-angle X-ray scattering (SAXS) revealed the core-shell or core-double-shell morphologies of these nanoparticles. The core and shell sizes obey the scaling laws for starlike micelles predicted by the scaling theory. Biocompatibility studies confirm that all copolymers obtained are noncytotoxic and, at the same time, exhibit high sensitivity during in vitro 19 F MRI studies. The gradient copolymers provide the best 19 F MRI signal-to-noise ratio in comparison with the analogue block copolymer structures, making them most promising as 19 F MRI contrast agents.