Rapid and Sensitive Fluorescence Detection of Staphylococcus aureus Based on Polyethyleneimine-Enhanced Boronate Affinity Isolation

Formulations with Boric Acid or Aryl-Organoboron Compounds for Treating Diabetic Foot Ulcers

Boron-containing compounds (BCCs) have been proposed for the treatment of diabetes and its complications. Recent studies have reported an improvement in the design and development of pharmaceutical formulations (often gels) containing boric acid applied to the foot ulcers of humans diagnosed with diabetes. The proposed mechanisms of action of boric acid include antimicrobial effects, the modulation of inflammation and metabolism, and the induction of cell differentiation. On the other hand, recent studies have suggested that boronic acids are potent antibacterial and antifungal compounds, effective modulators of inflammation, and inducers of vascular regeneration as well as inducers of healing, and they confer attractive properties such as adhesion, interaction, and the formation of complexes in formulations. Moreover, only a handful of studies conducted in animals have suggested the effective role of some BCCs as potent enhancers of wound healing, including their actions on induced and/or infected wounds in animals with disrupted metabolism. Also, it should be mentioned that no strong interactions between boric acid and the boronic acids present in formulations have been described. The developed combination could act as an additive and complementary therapy in the treatment of diabetic ulcers in humans. Further studies are required to support the hypothesis that this combination acts through diverse mechanisms to improve healing while avoiding or limiting a local or disseminated infection. Furthermore, the safety of BCCs used for foot ulcers should be established, as should the role of these formulations as a complementary therapy in current protocols for treating patients with diabetic foot ulcers.

Europium Ion-Based Magnetic-Trapping and Fluorescence-Sensing Method for Detection of Pathogenic Bacteria

Europium ions (Eu3+) have been utilized as a fluorescence-sensing probe for a variety of analytes, including tetracycline (TC). When Eu3+ is chelated with TC, its fluorescence can be greatly enhanced. Moreover, Eu3+ possesses 6 unpaired electrons in its f orbital, which makes it paramagnetic. Being a hard acid, Eu3+ can chelate with hard bases, such as oxygen-containing functional groups (e.g., phosphates and carboxylates), present on the cell surface of pathogenic bacteria. Due to these properties, in this study, Eu3+ was explored as a magnetic-trapping and sensing probe against pathogenic bacteria present in complex samples. Eu3+ was used as a magnetic probe to trap bacteria such as Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Acinetobacter baumannii, Bacillus cereus, and Pseudomonas aeruginosa. The addition of TC facilitated the easy detection of magnetic Eu3+-bacterium conjugates through fluorescence spectroscopy, with a detection limit of approximately ∼104 CFU mL-1. Additionally, matrix-assisted laser desorption/ionization mass spectrometry was employed to differentiate bacteria tapped by our magnetic probes.