Original title: Hydraulic coated dental device with occupation inhibiting and colony supplying properties
Corresponding author: Han Bing, School of Stomatology, Peking University; Liu Hongliang, Institute of physical and chemical technology, Chinese Academy of Sciences; Wei Yan, School of Stomatology, Peking University; Author: Liying Peng, Li Chang, Mengting Si, Jiuxiang Lin, Yan Wei, Shu Wang, Hongliang Liu, Bing Han and Lei Jiang
Caries and periodontal disease are two of the three major oral diseases, which are the main causes of human tooth defect and tooth loss. The main pathogenic factors of the two diseases are local colony accumulation. At the same time, bacterial infection is also the main reason for the failure of medical materials implantation. Therefore, how to reduce the accumulation of bacteria on the surface of dental equipment and dentures has become a key problem to reduce the prevalence of caries and periodontal disease. One of the feasible solutions to this problem is to modify a layer of antibacterial gel on the surface of dental materials.
There are a lot of researches on the surface modification of materials to achieve anti bacterial adhesion, but there are few reports that can meet the requirements of anti adhesion, antibacterial and biocompatibility at the same time. The Han Bing research group of Peking University School of Stomatology and the Liu Hongliang research group of the Institute of physical and chemical technology of the Chinese Academy of Sciences jointly developed an efficient antibacterial technology for oral biomaterials. Through the silylation and polymerization of anti adhesive polyethylene glycol (PEG) and antibacterial agent chitosan (Chitosan), the composite hydrogel coating has significant anti adhesion and anti bacterial effects.
By means of silylation reaction and polymerization, researchers formed nano grade network cross-linked polyethylene glycol gel structure on the surface of the material, and added chitosan antibacterial active ingredient to form polyethylene glycol / chitosan gel composite coating (Fig. 1). In this study, X-ray photoelectron spectroscopy (XPS) was used to qualitatively analyze the composition of the material surface and AFM was used to observe the surface morphology of the material, which confirmed the successful construction of the composite coating. Scanning electron microscopy, laser scanning confocal microscopy and Image J software were used to observe the counts. The antibacterial rate of the materials at different mass ratios was evaluated. It was found that the polyethylene glycol / chitosan gel structure had the best antibacterial effect when the mass ratio of polyethylene glycol to chitosan was 1/0.1, and the antibacterial rate on the surface of the material was the highest (98.8%, 5 hours) (Fig. 2). In addition, contact angle measurement and zeta potential measurement were used in this study to explore the influence of surface hydrophobicity and charge change on the antibacterial properties of materials (Fig. 3). The results showed that when the mass ratio of PEG / chitosan was 1 / 0.1, combined with the influence of surface wettability and surface potential, the best antibacterial performance of the material was obtained. Further increasing the amount of chitosan led to the decrease of the hydrophilicity of the material, and the surface positive charge was too much, which might be conducive to the adsorption of the negatively charged cell membrane, which was unfavorable to the adhesion inhibition performance. The long-term effectiveness and safety of antibacterial materials are important indicators for evaluating medical materials. By prolonging the soaking time of the materials in the bacterial solution and the plate count method, it is found that the prepared composite nanomaterials have significant long-term inhibitory effect on colonies (93.3%, 7 days) (Fig. 4). It was also found that the gel coating had excellent biocompatibility in CCK-8 cell activity test. These results show that the new nano material has good adhesion resistance, antibacterial and biocompatibility, and is expected to become a safe and effective biomedical antibacterial coating.
Fig. 1. schematic diagram of anti adhesion and antibacterial composite function hydrogel coating. (a) The bacteria on the surface of the unmodified stainless steel were obviously accumulated. (b) Due to the hydrophilic layer formed by polyethylene glycol, the bacterial adhesion on the surface of stainless steel decreased significantly. (c) polyethylene glycol / chitosan gel coating has both anti adhesion and antibacterial properties.
Fig. 2. antibacterial activity of polyethylene glycol / chitosan gel coating with different mass ratios. (a) Under scanning electron microscope. (b) Laser confocal fluorescence microscopy. (c) The bacterial density on the material was quantitatively evaluated according to the fluorescence microscope image. (d) Fluorescent microscope images showed the surface coverage of living and dead bacteria. *P & lt; 0.05; * * P & lt; 0.01 compared with the surface of unmodified material.
Figure 3. Study on the regularity of antibacterial performance. (a) The surface morphology of the material under AFM. (b) Change of contact angle. (c) Surface zeta potential changes. *P & lt; 0.05; * * P & lt; 0.01 compared with the surface of unmodified material.
Figure 4. Long term antibacterial performance study. (a) Image of Streptococcus mutans colony after different culture time. (b) Quantitative evaluation of bacterial colony on the plate, * P & lt; 0.05; * * P & lt; 0.01 compared with the surface of unmodified material. (c) The long-term antibacterial rate of * P & lt; 0.05; * * P & lt; 0.01 was compared with that of polyethylene glycol group.
The results were recently published in ACS Applied Materials & amp; Interfaces, the first author of this paper is Dr. Peng Liying from school of Stomatology, Peking University, and Dr. Chang Li from Institute of physical and chemical technology, Chinese Academy of Sciences. The corresponding authors are Professor Han Bing, associate researcher Liu Hongliang and Professor Wei Yan. This research is supported by the National Natural Science Foundation of China and the young top talents fund of ten thousand people plan.
Original text (scan or long press QR code, and then go to the original page after identification):
Hydrogel-Coated Dental Device with Adhesion-Inhibiting and Colony-Suppressing Properties
Liying Peng, Li Chang, Mengting Si, Jiuxiang Lin, Yan Wei, Shutao Wang, Hongliang Liu, Bing Han, Lei JiangACS Appl. Mater. Interfaces, 2020, DOI: 10.1021/acsami.9b19873Publication Date: February 6, 2020Copyright ? 2020 American Chemical Society
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