Time-of-flight secondary ion mass spectrometry analyses of vancomycin

Abstract

As an antibiotic that prevents and treats infections caused by Gram-positive bacteria such as Staphylococcus aureus, vancomycin incorporated in a biodegradable polymer poly(lactide-co-glycolide) provides opportunities to construct controlled-release drug delivery systems. Developments associated with this promising system have been largely concentrated on areas of drug delivery kinetics and biodegradability. In order to provide surface analytical approaches to this important system, the authors demonstrate applicability of time-of-flight secondary ion mass spectrometry (TOF-SIMS) in three-dimensional molecular imaging for a model system consisting of alternating layers of ploy(lactide-co-glycolide) and vancomycin. TOF-SIMS imaging clarified that the two chemicals can undergo phase separation when dimethyl sulfoxide is used as the solvent. The authors identified two diagnostic ions that are abundant and structural moieties of vancomycin. The results on TOF-SIMS imaging and depth profiling vancomycin provide useful information for further applications of TOF-SIMS in the development of antibiotic drug delivery systems involving the use of vancomycin.

Graphene‐Encapsulated Bifunctional Catalysts with High Activity and Durability for Zn–Air Battery

“…These oxygen‐containing groups can lead to carbon degradation by decarboxylation (R‐(COO)– → R + + CO 2 ), resulting in low performance. [ 54 ] Therefore, 3d‐GMC has excellent potential for high durability due to reduced carbon corrosion in Zn–air batteries because of well‐grown graphene on the surface of metal alloy particles uniformly dispersed within 3D carbon networks.…”