Construction And Properties Of Antibacterial Urinary Catheter

With the development of modern medical technology, medical interventional catheters have been widely used in recent years. This change has greatly improved the level of medical treatment. As a kind of interventional catheter, urinary catheter has been commonly used. Approximately25%of inpatients need urethral catheterization, and many patients in residential homes need long-term indwelling catheters. However, as an invasive operation, urethral catheterization often induces catheter-associated urinary tract infections, which accounts for approximately40%of all hospital-acquired infections, only less than iatrogenic infection of the respiratory tract infection, and ranking as the fifth-leading cause of hospital patients’deaths. The infection not only brings great pain to the patients, but also consumes a lot of health resources. The main reason of catheter-associated urinary tract infections is that the urethral catheter can inhibit or bypass certain defence mechanisms that would normally prevent or minimise bacteria-epithelial cell interactions, e.g. the biofilm formation. Therefore, it is necessary to give the urinary catheter lasting, excellent antibacterial properties to solve this problem from the source. Three kinds of antibacterial agents were firstly synthesized in this paper, including organic antibacterial agent methacryloxylethyl-benzyl-dimethyl ammonium chloride (DMAE-BC), natural antibacterial agent low molecular weight nano-chitosan and inorganic antibacterial agent O-carboxymethyl chitosan-nano-silver. Then they were mixed separately with natural latex, the raw material of catheter, to prepare the antibacterial latex. By comparison, the O-carboxymethyl chitosan-nano-silver antibacterial latex was chosen as raw materials to prepare the antibacterial catheters. The antibacterial performances of antibacterial catheters were studied systematically.The morphologies and structures of the samples were observed by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, infrared spectrometry and X-ray photoelectron spectroscopy. The antibacterial properties of the samples were tested using bacteria-inhibiting ring method and spectrophotometry. In addition, antimicrobial tests in vitro and animal intraurethral cannula of antibacterial catheter were conducted.The main conclusions are as follows:(1) As-prepared quaternary ammonium salt DMAE-BC had obvious crystal structure, in agreement with the characteristic of metal salt. Natural rubber latex particles after antibacterial treatment were oblate and covered by white cladding material. The antibacterial latex had antibacterial ability because it was grafted with the quaternary ammonium salt antibacterial DMAE-BC(2) The mean grain size of low molecular weight chitosan after nano-processing was20nm. It had94.1%antibacterial rate towards escherichia coli; the bacteria-inhibiting ring test shows that the diameter of the bacteria-inhibiting ring was13.5mm. much greater than antibacterial standard of7mm.(3) O-carboxymethyl chitosan-nano-silver antibacterial agent had excellent antibacterial performance towards staphylococcus aureus and escherichia coli. After mixing with natural rubber latex, it had good dispersibility and compatibility in matrix, and also kept excellent antibacterial performance towards escherichia coli and staphylococcus aureus.(4) As-prepared antimicrobial medical catheter, not only had good antibacterial performance against escherichia coli and staphylococcus aureus, but also had good durability in antibacterial performance, as was proved by immersing for4weeks in urine in vitro. With increasing time of indwelling catheter, the inflammatory reaction of antimicrobial catheter group was significantly lighter than that induced by ordinary catheter group. Comparison of the antimicrobial catheter group at4th week indwelling with the ordinary catheter group at1st week indwelling shows no statistical significance in inflammatory markers. These results show that as-prepared antimicrobial medical catheter had good and lasting antibacterial performance.