The bionic artificial acetabular cup used in the experiment is mainly composed of medical titanium alloy.
Can the new biomaterial kill bacteria after "charging"? Recently, the research team of the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences (hereinafter referred to as "Shenzhen Advanced Institute"), together with the City University of Hong Kong and the Beijing Institute of Nanoen of the Chinese Academy of Sciences, has developed a new type of biological material based on capacitive coating and effective antibacterial through charging and discharging, and the sterilization efficiency after repeated charging can exceed 90%, which has the characteristics of high efficiency, low risk and wide application space.
The technology is expected to be applied to dental and orthopedic implant materials to reduce the risk of postoperative infection in patients, and the related paper "A new antibacterial platform based on the capacitance characteristics of carbon-doped titanium dioxide nanotubes" was recently published in the internationally renowned academic journal Nature Communications. Wang Huaiyu, a researcher at the Biomedical Materials and Interface Research Center of Shenzhen Advanced Institute, introduced that the research and development of related products has recently been approved as a key project of the Science and Technology Service Network Program Area (STS Program) of the Chinese Academy of Sciences.
Sterilization efficiency exceeds 90% after repeated charging
Public information shows that titanium and its alloys as surgical implant materials, very widely used, with small density, high strength, good toughness, good biocompatibility, non-toxic and other advantages, but its shortcomings are also very obvious: the material itself is not antibacterial, more prone to infection after implantation in the human body, most need to take antibiotics, silver ions, etc. to resist bacteria, the former acting on a small area of antibacterial efficiency is not high and easy to make bacteria resistant, the latter itself has a certain toxicity, there are certain safety risks.
How to make full use of the advantages of titanium alloy materials, but also to ensure that it can be antibacterial? Wang Huaiyu and wang Guomin, one of the project executives and a guest doctoral student at the Shenzhen Advanced Institute of the Chinese Academy of Sciences, found in previous studies that by introducing carbon elements to replace the oxygen elements in titanium dioxide, it can improve the capacitance and achieve capacitance regulation, "With the continuous increase of capacitance, its antibacterial effect also increases, which is a good way to control."
In fact, the principle that cations have antibacterial properties is not complicated, it is based on positive charge, which adheres to the surface of negatively charged bacteria through electrostatic action, and eventually leads to bacterial decay. Based on this mature research background, the team made a further bold hypothesis: after the elemental replacement of the titanium alloy material, the sample only needs to be charged for 15 minutes at 2 volts, which can maintain the sterilization effect for 3 hours, and after repeated charging and discharging, its sterilization efficiency can be raised to more than 90%.
In the future, wireless charging technology may be added
For example, in the past, when titanium alloys were used as dental materials, the gum area was prone to plaque attachment, forming a biofilm (an organized group of bacteria wrapped in extracellular macromolecules), making it difficult to eradicate bacteria. "Now we are studying the way to kill bacteria through charging, and in the future, we will add wireless charging technology to improve charging efficiency and convenience." Wang Huaiyu said.
Taking bone implant surgery as an example, the first month after surgery is more likely to occur infection, this technology is suitable for use during this period, and if wireless charging technology is added in the future, postoperative care will be more convenient and safe. "This concept is great, if the product is formed in the future, there will be a lot of market space," Wang Huaiyu said bluntly, the study may encounter many problems in the future, such as how to control efficiency, the human body's blocking of wireless signals, etc.
The study hasn't been all smooth sailing, either. Wang Huaiyu introduced that the sterilization efficiency of antibiotics can often reach 99%, and the new biological materials that achieve effective sterilization through charging and discharging can exceed 80% at a time, and repeated use can reach more than 90%, from a numerical point of view, it is still lower than antibiotics, "In the future, we will optimize the material to achieve a similar effect to antibiotics, which is the biggest difficulty we are currently encountering." Wang Huaiyu said.
Wang Guomin said that the advantage of the material of her research is that the side effects are small and highly targeted, "antibiotics often act on the whole body, we only need to be targeted to charge and discharge, will not trigger side effects throughout the body", she introduced, this method and other antibacterial methods are not the same mechanism, so there is no risk of cross-resistance.
At present, the physical antibacterial method has been extensively verified on strains such as E. coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, etc., and has been proved to be able to achieve effective inhibition of the bacterial membrane through cyclic charge and discharge.
Interdisciplinary collision with new materials "spark"
In addition to being used in medical fields such as orthopedics and dentistry, this new biomaterial has a broader application space in the future. "For example, fish ponds for fish farming also need to be sterilized, and if we apply our metal materials, sterilization by charging and discharging is also a way to consider; for example, rapid sterilization under harsh conditions, such as surgery near the battlefield, can also apply our technology." The material has more room to play in the future. Wang Huaiyu said.
"By realizing the bactericidal properties of biological materials through charging and discharging, we are at the forefront of scientific research, and there is no similar research in the international community at present." Wang Guomin told reporters that the study of this technology requires energy, biology, materials and other multidisciplinary intersection, and the cooperation between the City University of Hong Kong and the Shenzhen Advanced Institute provides a suitable platform, "We are currently doing animal experiments, and seeking cooperation from orthopedic-related enterprises, follow-up efficiency and so on to reach a satisfactory level, will really carry out clinical application."
Wang Huaiyu also holds the same view, he believes that biomaterials themselves are interdisciplinary, it is a fusion of many disciplines, everyone has their own strengths, can learn from each other's strengths, and finally make better work. "Biomaterials is an interdisciplinary discipline, and researchers need to understand knowledge that cannot be limited to the fields of biology and chemistry. When I first started doing research, I strengthened my knowledge of materials and broadened my knowledge. ”
Southern Network all-media reporter Su Ziwei photographed Lu Li