Dicationic Imidazolium-Based Ionic Liquid Coatings on Zirconia Surfaces: Physico-Chemical and Biological Characterization

In the present work, dicationic imidazolium-based ionic liquids (ILs) were investigated as multi-functional coatings on a zirconia (ZrO2) surface to prevent biofilm formation and enhance the wear performance of zirconia while maintaining the material’s compatibility with host cells. ILs containing phenylalanine and methionine were synthesized and deposited on zirconia. Intermolecular interactions driving IL deposition on zirconia were studied using X-ray photoelectron spectroscopy (XPS). Anti-biofilm activity and cell compatibility were evaluated in vitro after one and seven days, and wear performance was tested using a pin-on-disk apparatus. ILs were observed to form strong hydrogen bonds with zirconia. IL containing phenylalanine formed a stable film on the surface after one and seven days in phosphate-buffered saline (PBS) and artificial saliva and showed excellent anti-biofilm properties against Streptococcus salivarius and Streptococcus sanguinis. Compatibility with gingival fibroblasts and pre-osteoblasts was maintained, and conditions for growth and differentiation were preserved. A significantly lower coefficient of friction and wear volume loss were observed for IL-coated surfaces as compared to non-coated substrates. Overall, zirconia is an emerging alternative to titanium in dental implants systems, and this study provides additional evidence of the materials’ behavior and IL coatings as a potential surface treatment technology for improvement of its properties

Ibuprofen-loaded PCL meshes manufactured using rapid tooling for ocular orbital repair

This study investigated the manufacture of resorbable polycaprolactone/ibuprofen (PCL/IBP) meshes by injection molding for application in ocular orbital repair. The pore dimension sizes used demonstrate that micro-porous meshes can be manufactured by injection molding using a prototype mold. The mechanical properties were observed to be dependent on the material composition and morphology. Lower stiffness, strength and elongation at failure were observed for the 8 mm pore sized samples. The PCL/Ibuprofen meshes initially showed a fast drug release but after 3 days the release was slow and controlled. The cytotoxicity test results of the PCL/Ibuprofen meshes indicated that the large initial quantity of Ibuprofen released was too high and resulted in cell toxicity. However, after this initial release, the PCL/Ibuprofen meshes showed a good interaction with the cells seeded on their surface. The presence of a low concentration of Ibuprofen does not negatively influence cell viability in culture

Ionic Liquid Coatings for Titanium Surfaces: Effect of IL Structure on Coating Profile

Dicationic imidazolium-based ionic liquids (ILs) having bis­(trifluoromethylsulfonyl)­imide (NTf₂) and amino acid–based (methionine and phenylalanine) anionic moieties were synthesized and used to coat titanium surfaces using a dip-coating technique. Dicationic moieties with varying alkyl chains (8 and 10 carbons) and anions with distinct characteristics were selected to understand the influence of IL structural features on deposition profile. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were used in this study to help elucidate intermolecular interactions within ILs as well as between ILs and TiO₂ surfaces and to investigate IL coating morphology. Charge concentration on IL moieties, as well as the presence of functional groups that can interact via hydrogen bond, such as carboxylate and amino groups, were observed to influence the deposition profile. ILs containing amino acids as the anionic moiety were observed to interact strongly with TiO₂, which resulted in more pronounced changes in Ti 2p binding energy. The higher hydrophobicity of the IL having NTf₂ as the anionic moiety resulted in higher adhesion strength between the IL coating and TiO₂

Modeling Gastrointestinal Tract Wet Pool Size in Small Ruminants

The gastrointestinal tract (GIT) wet pool size (GITwps) refers to the total amount of wet contents in GIT, which in small ruminants can reach up to 19% of their body weight (BW). This study aimed to develop models to comprehensively predict GITwps in small ruminants using a meta-regression approach. A dataset was created based on 21 studies, comprising 750 individual records of sheep and goats. Various predictor variables, including BW, sex, breed, species, intake level, physiological states, stages and types of pregnancy, dry matter intake, and neutral detergent fiber intake (NDFI), were initially analyzed through simple linear regression. Subsequently, the variables were fitted using natural logarithm transformations, considering the random effect of the study and residual error, employing a supervised forward selection procedure. Overall, no significant relationship between GITwps and BW (p = 0.326) was observed for animals fed a milk-based diet. However, a strong negative linear relationship (p p p < 0.0001). Overall, this study sheds light on the factors influencing GITwps in small ruminants, providing valuable insights into their digestive processes and nutritional requirements

Preparation of TiO₂ Nanoparticles Coated with Ionic Liquids: A Supramolecular Approach

Coated TiO₂ nanoparticles by dicationic imidazolium-based ionic liquids (ILs) were prepared and studied by differential scanning calorimetry (DSC), dynamic light scattering (DLS), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and scanning electron microscopy (SEM). Three ILs with different hydrophobicity degrees and structural characteristics were used (IL-1, IL-2, and IL-3). The interaction between IL molecules and the TiO₂ surface was analyzed in both solid state and in solution. The physical and chemical properties of coated nanoparticles (TiO₂ + IL-1, TiO₂ + IL-2, and TiO₂ + IL-3) were compared to pure materials (TiO₂, IL-1, IL-2, and IL-3) in order to evaluate the interaction between both components. Thermal behavior, diffraction pattern, and morphologic characteristics were evaluated in the solid state. It was observed that all mixtures (TiO₂ + IL) showed different behavior from that detected for pure substances, which is an evidence of film formation. DLS experiments were conducted to determine film thickness on the TiO₂ surface comparing the size (hydrodynamic radius, <i>R</i>_h) of pure TiO₂ with coated nanoparticles (TiO₂ + IL). Results showed the thickness of the film increased with hydrophobicity of the IL compound. TEM images support this observation. Finally, X-ray diffraction patterns showed that, in coated samples, no structural changes in TiO₂ diffraction peaks were observed, which is related to the maintenance of the crystalline structure. On the contrary, ILs showed different diffraction patterns, which confirms the hypothesis of interactions happening between IL and the TiO₂ nanoparticles surface

How Mechanical and Chemical Features Affect the Green Synthesis of 1<i>H</i>‑Pyrazoles in a Ball Mill

This work investigated the chemical and mechanical factors that affect cyclocondensation reactions in a ball mill. Chemical characteristics such as the use or non-use of a catalyst, amount of catalyst and reactants, and product formation, as well as the yield and mechanical factors such as rotation frequency and the number, diameter, and material of the milling balls were evaluated. It was found that a rotation frequency of 450 rpm is efficient for energy transfer to the reactants because the conversion is higher at this rotation. The reaction was highly dependent on the time (3 min) and amount of <i>p</i>-TSA (<i>p</i>-toluenesulfonic acid) utilized as catalyst (10 mol %). Five steel balls of 10 mm were considered to be the ideal number for the efficient mixing of the particles. For this work, the ideal conditions determined were used for the green synthesis of a series of 1<i>H</i>-pyrazoles