ABSTRACT
This research evolves into a comparative study of three different phenolic composites as coatings for rigid contact lenses, with a particular emphasis on enhancing their antifouling properties and hydrophobicity. The primary layer, comprised of diverse phenolic compounds, serves as a sturdy foundation. An exclusive secondary layer, featuring synthetic peptoids, is introduced to further minimize biofouling. Validated through X-ray photoelectron spectroscopy, the surface analysis confirms the successful integration of the polyphenolic layers and the subsequent grafting of peptoids onto the lens surface. The efficacy of the proposed coatings is substantiated through protein adsorption tests, providing definitive evidence of their antifouling capabilities. This research employs a nuanced assessment of coating performance, utilizing the quantification of fluorescence intensity to gauge effectiveness. Additionally, contact angle measurements offer insights into wettability and surface characteristics, contributing to a comprehensive understanding of the coating's practicality.
ABSTRACT
Different static properties have been calculated with COMPASS force field for polyacrylamide, poly(2-hydroxyethylacrylate) (HEA), poly(2-hydroxyethylmethacrylate) (HEMA), poly(glycidylmethacrylate) (GMA), polyethylene glycol (PEG), and poly(2,2,2-trifluoroethylmethacrylate) (TFEM). For each polymers, the calculated values were averaged on five equilibrated configurations of amorphous cell composed of one atactic chain containing 100 repeat units. The ranking obtained from the densities calculated at 300 K is TFEM > HEA ≈ xpolycrylamide > HEMA ≈ GMA > PEG. Concerning the glass transition temperature we have obtained polyacrylamide > HEMA ≈ GMA ≈ HEA > PEG, and polyacrylamide > HEMA ≈ HEA > GMA ≈ PEG > TFEM for the bulk modulus. The calculated results, when available, have been compared with experimental data coming from literature.
Subject(s)
Biocompatible Materials/chemistry , Hydrogels/chemistry , Mechanical Phenomena , Polymers/chemistry , Thermodynamics , Acrylic Resins/chemistry , Algorithms , Computer Simulation , Methacrylates/chemistry , Methylmethacrylates/chemistry , Models, Chemical , Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Solubility , TemperatureABSTRACT
Despite advanced sterilization and aseptic techniques, infections associated with medical implants have not been eradicated. Most present coatings cannot simultaneously fulfil the requirements of antibacterial and antifungal activity as well as biocompatibility and reusability. Here, we report an antimicrobial hydrogel based on dimethyldecylammonium chitosan (with high quaternization)-graft-poly(ethylene glycol) methacrylate (DMDC-Q-g-EM) and poly(ethylene glycol) diacrylate, which has excellent antimicrobial efficacy against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Fusarium solani. The proposed mechanism of the antimicrobial activity of the polycationic hydrogel is by attraction of sections of anionic microbial membrane into the internal nanopores of the hydrogel, like an 'anion sponge', leading to microbial membrane disruption and then microbe death. We have also demonstrated a thin uniform adherent coating of the hydrogel by simple ultraviolet immobilization. An animal study shows that DMDC-Q-g-EM hydrogel coating is biocompatible with rabbit conjunctiva and has no toxicity to the epithelial cells or the underlying stroma.
Subject(s)
Anti-Bacterial Agents/chemistry , Biocompatible Materials/chemistry , Chitosan/analogs & derivatives , Hydrogels/chemistry , Polymethacrylic Acids/chemistry , Animals , Anti-Bacterial Agents/pharmacology , Chitosan/chemistry , Chitosan/pharmacology , Escherichia coli/drug effects , Microbial Sensitivity Tests , Polyamines/chemistry , Polyelectrolytes , Polyethylene Glycols/chemistry , Polymethacrylic Acids/pharmacology , Rabbits , Staphylococcus aureus/drug effects , Sterilization , Surface PropertiesSubject(s)
Escherichia coli Proteins/analysis , Escherichia coli/drug effects , Isotope Labeling/methods , Proteome/analysis , Tandem Mass Spectrometry/methods , alpha-Defensins/pharmacology , Anti-Infective Agents/pharmacology , Chromatography, Liquid/methods , Escherichia coli/metabolism , Escherichia coli Proteins/metabolism , Humans , Kinetics , Metabolic Networks and Pathways , Microbial Sensitivity Tests , Proteome/drug effects , Proteome/metabolismABSTRACT
Short antimicrobial peptides with nine and eleven residues were developed against several clinically important bacterial and fungal pathogens (specifically Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Fusarium solani). Twelve analogues of previously reported peptides BP76 (KKLFKKILKFL) and Pac-525 (KWRRWVRWI) were designed, synthesized, and tested for their antimicrobial activities. Two of our eleven amino acid peptides, P11-5 (GKLFKKILKIL) and P11-6 (KKLIKKILKIL), have very low MICs of 3.1-12.5microg ml(-1) against all five pathogens. The MICs of these two peptides against S. aureus, C. albicans and F. solani are four to ten times lower than the corresponding MICs of the reference peptide BP76. P9-4 (KWRRWIRWL), our newly designed nine-amino acid analogue, also has particularly low MICs of 3.1-6.2microg ml(-1) against four of the tested pathogens; these MICs are two to eight times lower than those reported for Pac-525 (6.2-50microg ml(-1)).These new peptides (P11-5, P11-6 and P9-4) also exhibit improved stability in the presence of salts, and have low cytotoxicity as shown by the hemolysis and MTT assays. From the results of field-emission scanning electron microscopy, membrane depolarization and dye-leakage assays, we propose that these peptides exert their action by disrupting membrane lipids. Molecular dynamics simulation studies confirm that P11-6 peptide maintains relatively stable helical structure and exerts more perturbation action on the order of acyl tail of lipid bilayer.
