Biophysical and molecular characterization of the immobilization of biomimetic peptide-polymer conjugates as building blocks for antimicrobial catheter surfaces to prevent infectious diseases.

Abstract

Catheter-associated urinary tract infections (CAUTIs) are the most common type of healthcare-associated infection. The World Health Organization recently reported that patients with a catheter had a 5% greater probability of acquiring a urinary tract infection per day of being catheterized and in a month this probability increased up to a 100%. This work explores the catheter surface immobilization and characterization of the MH5C modified with acysteine (MH5C-Cys) and coupled to polyethylene glycol to serve as a surface protective coating. First, purification method by size exclusion chromatography (SEC) was performed followed by analytical SEC and SDS-PAGE and MALDI-ToF to confirm the reaction. Also, we immobilized on the catheter surface the MH5C-Cys-PEG and it was confirmed by the appearance of the characteristic peaks of 3,264 cm−1for N-H stretching, 1,532 cm−1for N-H bending and 1,157 cm−1for C-N stretching at the FTIR spectrum of the catheter with the immobilized peptide. Additionally, for this study, we have performed a Circular Dichroism (CD) technique for evaluating the secondary structure of the peptide-polymer conjugates. The CD spectra illustrated that conjugates possessed α-helical structures. Subsequently, we evaluated the efficacy of MH5C-Cys-PEG conjugate via scanning electron microscopy, minimum biofilm inhibition concentration (MBIC), assays to evaluate their ability to prevent the biofilms. Interestingly, this work demonstrated a critical PEG polymer weight of 5 kDa as ideal when coupled to the MH5C-Cysto achieve inhibition and eradication of the biofilm formation in Escherichia coli. According to theMBICs (300 μM), we can conclude that MH5C-Cys-PEG has an action that prevents the formation of biofilms. This type of study serves to improve progress toward new methods to counteract antimicrobial resistance of many of the bacteria known to cause CAUTIs.