Discovery of new antibiotic candidates is driven by urgent global health needs and evolving resistance to current treatments. In pursuit of novel peptide-based antibiotics, more than 100 dipeptides containing fluorinated phenylalanine (F-Phe) residues were synthesized by undergraduate researchers at eight institutions and evaluated against Pseudomonas aeruginosa (P. aeruginosa) in a primary biofilm formation assay. Inclusion of multistep synthesis experiments in curricular laboratory courses at different institutions prompted the prioritization of robust and adaptable procedures that were effective at generating large compound sets for study. Several dipeptides were identified that inhibited biofilm formation at concentrations of 1 μg/mL or less. Further study of two of them, (S,S)-4-F-Phe-Ala and (S,S)-3,4-diF-Phe-Ala, revealed two distinct biological profiles. Inhibition of biofilm formation by (S,S)-4-F-Phe-Ala was directly associated with growth inhibition. In contrast, (S,S)-3,4-diF-Phe-Ala did not significantly inhibit bacterial growth at concentrations up to 100 μg/mL. Mammalian cell lines treated with either dipeptide at much higher concentrations remained viable, demonstrating selective toxicity for P. aeruginosa. Taken together, these data indicate that dipeptides comprising F-Phe are promising leads for the discovery of new antibiofilm therapeutics.

Background: Commercially available wearable devices, capable of measuring cardiac rhythm, are gaining popularity for convenient heart health monitoring. Accurate measurement of key intervals, specifically RR intervals for rhythm and QT and corrected QT (QTc) intervals for arrhythmia risk, is crucial for assessing potential cardiac morbidity. Objective: This study aimed to evaluate the agreement of RR, QT, and QTc intervals measured by a consumer wearable device (Withings ScanWatch series 1) with those measured using a research-grade 3-lead electrocardiogram (ECG; Biopac) and a clinically approved single-lead patch (Cardea SOLO). Methods: This was a cross-sectional study of 28 healthy adults aged 21 to 65 years, with a mean age of 39.4 (SD 13.0) years. Participants underwent 4 concurrent ECG measurements per device: twice seated at rest, once supine, and once after exercise. All RR and QT intervals were manually measured using standardized caliper software (EP calipers) by trained reviewers, and QTc was calculated using the Bazett formula. Agreement was assessed via repeated-measures correlation ( r _rm ) and linear mixed-effects models (LMMs) for repeated-measures Bland-Altman analysis. Results: Strong agreement was observed for RR intervals when comparing the Withings ScanWatch with both the Biopac ( r _rm =0.84; P< .001) and the SOLO ( r _rm =0.80; P <.001). Agreement was weaker for QT intervals ( r _rm =0.37; P =.001 compared to Biopac and r _rm =0.37; P =.001 compared to SOLO) and QTc intervals ( r _rm =0.27; P =.01 compared to Biopac and r _rm =0.27; P =.03 compared to SOLO). Bland-Altman LMM analysis demonstrated that the Withings ScanWatch systematically underestimated QT intervals, with a mean error (ME) of −42.9 (SD 30.1) milliseconds versus Biopac and −15.8 (SD 20.6) milliseconds versus SOLO. Similarly, QTc intervals were underestimated, with an ME of −51.4 (SD 32.3) milliseconds versus Biopac and −18.8 (SD 21.5) milliseconds versus SOLO. Conclusions: While the Withings ScanWatch showed strong agreement for RR interval measurement, its variability and systematic underestimation in QT and QTc measurements limited its clinical applicability for accurate assessment of arrhythmia risk. The device may serve as a valuable tool for tracking trends over time, but it is currently unreliable for precise interval screening.