No abstract

In metal-peptide interactions, cations form stable complexes through bonds with coordinating groups as side chains of amino acids. These compounds, among other things, exert a wide variety of antimicrobial activities through structural changes of peptides upon metal binding and redox chemistry. They exhibit different mechanisms of action (MOA), including the modification of DNA/RNA, protein and cell wall synthesis, permeabilization and modulation of gradients of cellular membranes. Nowadays, the large increase in antibiotic resistance represents a crucial problem to limit progression at the pandemic level of the diseases that seemed nearly eradicated, such as tuberculosis (Tb). Mycobacterium tuberculosis (Mtb) is intrinsically resistant to many antibiotics due to chromosomal mutations which can lead to the onset of novel strains. Consequently, the maximum pharmaceutical effort should be focused on the development of new therapeutic agents and antimicrobial peptides can represent a valuable option as a copious source of potential bioactive compounds. The introduction of a metal center can improve chemical diversity and hence specificity and bioavailability while, in turn, the coordination to peptides of metal complexes can protect them and enhance their poor water solubility and air stability: the optimization of these parameters is strictly required for drug prioritization and to obtain potent inhibitors of Mtb infections with novel MOAs. Here, we present a panoramic review of the most recent findings in the field of metal complex-peptide conjugates and their delivery systems with the potential pharmaceutical application as novel antibiotics in Mtb infections.

Background/Aims: There is a lack of data regarding the influence of different laminates for mouthguard reinforcement in the mechanical response during an impact in the orofacial region. The aim of this study was to verify the influence of the laminate framework on the stresses and strains of the anterior teeth and displacement of ethylene-vinyl acetate (EVA) custom-made mouthguards during a simulated impact. The null hypotheses was that the different laminates reinforcement would present the similar effect in maxillary structures, regardless the elastic modulus. Methods: A finite element model of human maxillary central incisors with an antagonist contact was used. A linear quasi-static analysis was used to simulate the force exerted during an impact. A total of 5 different layers were simulated inside the mouthguard at the labial portion according to the Elastic Modulus 1 MPa (Extremely flexible), 9 GPa (Low modulus reinforcement), 18 GPa (Without reinforcement), 50 GPa (Flexible alloy), 100 GPa (Titanium alloy) and 200 GPa (Hard material). The results were evaluated by means of Maximum Principal Stress (in the tooth and bone), Microstrain (periodontal ligament) and Displacement (mouthguard) criteria. Results: The elastic modulus of the material inside the MG influenced the stress distribution on the enamel buccal face. However, it did not affect the bone tissue stress, periodontal ligament strain or root dentin tissue stress. Conclusion: The use of reinforcement inside the custom-made mouthguard can modify the stress generated in the enamel buccal surface without improvement to the root dentin, periodontal ligament or bone tissue.

Dental anxiety is a crucial problem for dentistry because it may represent a significant risk to oral health. Within the framework of the Cognitive Vulnerability Model (CVM), which sheds light on the cognitive vulnerability patterns that may cause dental anxiety, this study aimed to assess the psychometric characteristics of the Italian version of the Dental Fear Maintenance Questionnaire (DFMQ). The DFMQ is a 32-item questionnaire that assesses four cognitive vulnerability patterns, i.e., dangerousness, disgust, unpredictability, and uncontrollability. In a sample of 200 dental patients who had accessed public-university-hospital dental surgery, this study assessed the model fit of the DFMQ and different types of validity (i.e., predictive, convergent, construct, and discriminant validity). In addition, potential differences between DFMQ dimensions were assessed based on gender (men vs. women) and age ranges. All indicators of cognitive vulnerability were significantly associated with high dental anxiety when each variable was included independently. In contrast, when the DFMQ subscales were considered together, only unpredictability and uncontrollability were found to be associated with high dental anxiety. Women had higher scores for unpredictability, uncontrollability, and general dangerousness than men. In addition, older patients had higher scores for some vulnerability cognitive patterns than younger patients. This study provides Italian dentists and researchers with a valid questionnaire to assess cognitive factors associated with dental anxiety.