RESUMO
The joint application of traditional Chinese medicine injection containing chlorogenic acid (CA) and cefotaxime sodium (CS) is sometimes appeared in clinical practice, but the scientific basis of drug molecular compatibility is still weak. This study proposes a sequential analysis strategy based on isothermal titration calorimetry (ITC), cold-spray ionization mass spectrometry (CSI-MS) and antibacterial activity test to evaluate the molecular interactions between CA and CS. The results of ITC experiments showed that the Gibbs free energy ΔG < 0 and it was driven by enthalpy change when CA titrated CS, suggesting CA could spontaneously chemically react with CS. Subsequently, the parent ions (m/z 808.143 5) of binding molecular of CA and CS was detected by CSI-MS, indicating CA could chemically bond with CS. Furtherly, the antibacterial experiments found the antibacterial ability of CS against Klebsiella pneumonia was significantly reduced (P < 0.01) by CA in mixed solution. Finally, molecular docking technology showed CA and CS have a common target of penicillin binding protein 3 (PBP3), suggesting that the phenomenon of CA reduced the antibacterial ability of CS may be related to the competitive binding of two components with PBP3. Our studies have shown that CA could spontaneously chemically bond to CS and reduced its antibacterial ability, providing scientific data for molecular interaction evaluation of CA and CS.
RESUMO
La aplicación de adhesivos dentarios autograbantes que contienen 10-metacriloxidecilfosfato dihidrogenado supera la resistencia a la biodegradación de la interfase adhesiva de los sistemas tradicionales de grabado total. El mecanismo de acción se basa en la formación de múltiples nanocapas de calcio unido a 2 moléculas 10-metacriloxidecilfosfato dihidrogenado sobre la dentina; estas múltiples capas de 3,5 nm son las que protegerían las fibras colágenas del fenómeno de hidrólisis. Las nanocapas explicarían su alta estabilidad en el tiempo y la fortaleza de la unión, probadas tanto en estudios clínicos como de laboratorio. La interacción con la hidroxiapatita sucede con ácidos de pH bajos, pero mayores que los tradicionales, por lo que surge la necesidad de recomendar el grabado selectivo previo del esmalte. El uso de metacriloxidecilfosfato dihidrogenado permite el cambio de filosofía adhesiva desde el grabado total a la integración adhesiva de la dentina.
Applying self-etching dental adhesives containing 10-MDP overcomes the resistance to biodegradation of the adhesive interface of traditional total etch. The mechanism of action is based on the formation of multiple nano-layers of calcium and two molecules of 10-MDP on the dentin surface. These multiple layers of 3.5 nm protect the collagen fibers from hydrolysis phenomenon. The nano-layer explains its high stability and bond strength over time, tested both by clinical and laboratory studies. Hydroxyapatite interaction occurs with acids of low pH, but are higher than traditional, thus increasing the need to recommend the previous selective etching of the enamel. The use of MDP allows a change of philosophy from the total-etch adhesive to adhesive integration of the dentin.