The Preparation And Function Appliications Of Nano-carbon Microspheres Made By Beta-cyclodextrin

Intravascular catheter-associated infections (CAIs), which are normally induced by microbial adhesionand subsequent biofilm formation, are a major cause of morbidity and mortality. Therefore, strategies toprevent CAIs are in great demand. In this study, we synthesized nano-carbon microspheres (n-CMS) fromβ-cyclodextrin by hydrothermal carbonization. And then used the material as a drug carrier, connectedpolyethyleneimine (PEI) and heparin onto the material in turn by the way of covalent binding. Next weobserved of the functional groups and morphology on the material surface by laser particle size and zetapotential analyzer, fourier transform infrared spectroscopy (FI-IR), scanning electron microscopy (SEM)and other characterization methods. The carboxyl group content of the material was determined by themethod of acid-base titration. We synthesizes of heparinized n-CM successfully, and the plasmarecalcification time shows that the material has good biocompatibility.Coagulasenegative staphylococci are the most common causes of CAIs, followed by Staphylococcusaureus, including methicillin-resistant S. aureus (MRSA). The latter are more virulent and clinicallyimportant, with infections causing greater morbidity and mortality compared to coagulase-negativestaphylococci. To overcome this problem, we further combined vancomycin on the heparinized n-CMS(Hep-n-CMS). We proved vancomycin was bound covalently to the surface of the material by UVspectrophotometer. At the same time, we used the antibacterial experiments in solid and liquid environmentproved the active residues of the vancomycin conjugates, as well as the antimicrobial properties after thefilm formation. An antibacterial and anticoagulant bifunctinal film was produced after mixing withpoly(methyl methacrylate), which is a commonly used polymer film-forming material, and its antibacterialactivity and anticoagulant property were evaluated lastly. At last, we observed that the platelet adhesionphenomenon is not only does not occur, but also the films have a very clear antibacterial propertiescompared to the blank control groups. Therefore, using the nano-carbonaceous microspheres co-modifiedby heparin and vancomycin as the coating materials of intravascular catheter for preventing theintravascular catheter-associated infection is a good choice.