It seems that the biological effect of silver (antibacterial effect) The ability of silver to kill or inhibit pathogenic microorganisms has been confirmed by many studies [5-8]. Among antibacterial drugs, silver is unique because of its broad spectrum, and it is effective for all kinds of microorganisms, including G+ bacteria, G- bacteria, sporogenous bacteria, fungi, viruses, mycoplasma and so on. According to Scientific Abstracts 1978, "One antibiotic can kill about 6 kinds of pathogens, while silver can kill 650 kinds of microorganisms without drug resistance." After silver enters the body, it is quickly absorbed by reticuloendothelial tissue and deposited on reticuloendothelial cells [9]. Reticular endothelial cell is a part of the immune system and a scavenger of the body, which is responsible for removing foreign bodies, cell fragments and invading bacteria. Reticular endothelial cells ingest silver particles as foreign bodies and invasive pathogens, so silver comes into direct contact with pathogens and plays a role. The mechanism of silver killing microorganisms is generally believed that silver can inactivate specific enzymes in pathogens, block the respiratory pathway of cells and kill microorganisms. Regarding the sterilization mechanism of silver, researchers have put forward several hypotheses, the most representative of which are: 1, the combination of silver and sulfhydryl groups in the metabolic enzymes of pathogens inactivates the enzymes, and pathogens cannot metabolize and die. 2. Cell wall reaction [10, 1 1]: The cell wall of bacteria is a protein structure connected by amino acids, which is called peptidoglycan in protein. Silver reacts with exposed peptidoglycans to form reversible complexes, which prevent them from transporting oxygen (energy) to cells, prevent bacteria from moving, and lead to bacterial death. 3.DNA binding: It is found that [12, 13], silver can bind to DNA in germs or spores of germs. Silver ions combine with DNA bases to form cross-linking, which replaces the hydrogen bond between adjacent nitrogen in purine and pyrimidine, leading to structural degeneration of bacterial DNA, inhibiting DNA replication and inactivating bacteria. (2) Promoting wound healing Becker found that [14] silver plus weak current can make fibroblasts poorly differentiated. Fibroblast is a common cell type, which can significantly promote tissue repair and regeneration when transformed into other types of cells. Recent studies have also confirmed [15] that simple silver administration accelerates epithelial regeneration of local non-infected acute wounds. It can be seen that silver not only has antibacterial properties, but also has the characteristics of promoting wound healing. The specific mechanism of action is not clear at present, which may be related to the anti-inflammatory properties of silver and the reduction of wound exudation. (3) Anti-inflammatory properties Because silver has strong antibacterial and wound healing properties, it is difficult to accurately define its anti-inflammatory properties. It was found that [15, 16], silver can reduce the activity of metalloproteinases. Metalloproteinase (MMP) is a kind of protease, which exists in wounds and can decompose necrotic tissues. Under normal circumstances, MMP is in equilibrium with natural inhibitors and growth factors. The structure of MMP contains sulfhydryl groups, and the activation requires the participation of zinc ions [17, 18]. When burn or chronic trauma occurs, MMP activity increases [19]. Excessive MMP activity will destroy growth factors and new tissues and hinder wound healing. However, silver can combine with sulfhydryl groups in MMP structure, or reduce excessive MMP activity by reducing zinc ions in wound surface [20,265,438+0]. It is also reported that silver can increase the amount of calcium in wounds, and calcium can accelerate epithelial regeneration [22]. In addition, it has been reported in literature that [23] silver can increase white blood cells. Second, the medical application forms of modern silver (1) surgical silver: silver needle for acupuncture, silver thread for suture of injured bone and connective tissue, and silver drainage tube. Silver alloy is used for bone replacement (especially skull). Covering fresh wounds with silver foil can accelerate the healing of open wounds. Ag-Pd alloy is widely used in optic nerve repair devices, ear foil nerve stimulation devices, spinal cord stimulation devices for incontinent people, spinal cord bending devices for children and so on. Using electro-biological stimulation, silver can promote the growth of bones and skin. (2) Dental materials. It can be divided into dental casting alloy and dental amalgam. Cast silver-based dental alloys include: Ag-Cu-Sn, Ag-Cu-Sn-Zn, Ag-Cu-Zn-Ni, Ag-Pd-Au, Ag-In-Zn-Pd and other materials. Silver palladium is used in denture base and short-span bridge. Dental amalgam is a filling material for dental restoration. The former silver-tin amalgam is no longer used, but now it is silver-copper-tin amalgam. The alloy is made into spherical powder and mixed with irregular powder. This mixed powder has better packaging firmness and better carving viscosity. High-lead silver alloy powder and mercury-free dental filling materials (such as silver-gallium-based alloy and gallium alloy materials) have attracted people's attention. (3) Silver can be used for diagnosis and analysis. Silver staining technique is useful in diagnosis, and its Lou sensitivity is 100 times higher than other methods. Silver can be used for prenatal diagnosis and pathological monitoring of fetal malformation, changes in pathogenic physiology, chromosome diagnosis of hereditary diseases, identification of hormone and urinary polypeptide levels and evaluation of drug treatment, and can also be used for daily analysis of natural foods. Can protein analysis of silver provide a clear image? Quot Fingerprint protein "to identify other protein. The silver complex can be used to determine and observe the smallest component of human cells, to diagnose cancer and indicate the existence of antibodies in multiple sclerosis, and to accurately identify the deformation of protein by electrophoresis. Silver nitrate is used to identify oestrophobia and diagnose early breast cancer. A thin film made of silver is used to determine the concentration of glucose in urine and diagnose diabetes. Using Ag/AgCl electrode, biosensor can be made to measure syphilis antibody and blood type, as well as the concentration and PH value of O2 and CO2 in blood. (4) Silver halide optical fiber CO2 laser scalpel. Silver halide polycrystalline fiber [AgClXBR (1x)] (0 ≤ x ≤1) has good infrared spectrum signal and mid-infrared laser energy performance. The newly developed silver halide optical fiber CO2 laser scalpel in China has been applied to oral cavity, throat, gynecology, anorectal and other aspects. After clinical application, it will enter the stage of industrialization. (5) X-ray films, CT films and magnetic resonance imaging films of medical images. B. Application of silver in medicine (1) Silver in traditional Chinese medicine: Some traditional Chinese medicine formulas contain silver foil. Some Chinese herbal medicines also contain trace amounts of silver. For example, the content of silver in raw astragalus is 4.665438 0.05 μ g/g (2) Soluble silver salts: such as silver nitrate and silver citrate. The most commonly used soluble silver salt is silver nitrate, which can be used as astringent, irritant or corrosive drug, and its effect is related to the concentration and duration of deep solution. The wart, growth and inner bud can be removed by solid rod silver nitrate (containing 1 ~ 3% AgCl) or silver nitrate solutions with different concentrations. Silver citrate can be used to treat burns and dermatoses. Eye drops of 1% silver nitrate solution can prevent neonatal eye mucosa from being infected by streptococcus. (3) Insoluble compounds: such as oxides and halide salts (oxides, iodides). Colloidal silver can be used as ointment for treating odor burn and skin infection. (4) Silver sulfadiazine and silver fluoperate: This is a major medical silver compounds. Treat burns and African sleeping sickness. (5) Silver Sol: Colloidal solutions such as AgI(Neosilvol), Protargol (strong), Argyrol (weak) and Crede plaster (containing natural silver) can be used as effective local anti-infective drugs. Colloidal silver is used for gynecological washing, disinfection and sterilization. (6) Electrogenerated Silver Ion Technology (EGSI). In vivo experiments show that it has obvious anti-infection effect and broad-spectrum antibacterial effect on all kinds of bacteria, gram-positive bacteria, gram-negative bacteria, aerobic bacteria and anaerobic bacteria. Four silver-containing drugs, silver nitrate, protein silver, silicon carbon silver and sulfadiazine silver, have been included in modern pharmacopoeia, which are used to treat conjunctivitis, gonorrhea, cystitis, dysentery, enteritis, burns and other diseases. 3. The application of silver in life. Silver tableware food is not easy to ferment and turn sour; Silver chopsticks can detect sulfur-containing poisons in food. No one knows when humans discovered metallic silver, but our ancestors have long known that this metal has magical purification ability: 2,500 years ago, King cyrus the great of Persia ordered all his troops to hold water in silver jars, because the water released by silverware was cleaner than other containers. In ancient Rome, silver nitrate was used as medicine, which was recorded in the Pharmacopoeia of Rome Publishing House in 69 BC. In 78 AD, Pliny Sr described the characteristics of silver in his book Natural History: "It has therapeutic effect ... especially in promoting wound healing. "Rich Romans used silver wine glasses and silverware every day, not only because silver was a symbol of wealth: aristocratic families fed their babies with silver spoons, but they also thought it could drive away diseases." At that time, people did not know the sterilization mechanism of silver. Said a Bart fleek, a plastic surgeon and trauma rehabilitation expert in Clayton, Georgia. Frick often uses silver to treat local wounds. He said: "Obviously, silver is good for people's health, and it was not harmful at that time. Therefore, people regard silver as a "safe metal". Today, more than half of the airlines in the world have used silver water filters. The water in swimming pools in many countries is also purified with silver. Unlike chemicals, this purified water will not irritate the swimmer's skin and eyes. Silver is one of the earliest metals used by human beings. Herders in Inner Mongolia grassland have long noticed that horse milk in a silver bowl will not turn sour for a few days. Modern research has further revealed the mystery: silver can kill bacteria. As long as a small amount of silver is dissolved in water and becomes silver ions, it has high bactericidal ability. Scientists have done experiments. Twenty-three liters of sewage (containing more than 7,000 Escherichia coli per milliliter) were treated with silver electrode for three hours, and all the Escherichia coli died. A few parts per billion of silver can make a liter of water clean. According to the experiment, typhoid bacilli can only survive 18 hours on silver tablets, and diphtheria bacilli can only survive for 3 days on silver tablets. If the skin is scratched and there is no medicine for a while, put silverware on the wound immediately to prevent infection. Nearly half of families in Korea eat with silver tableware, which is not extravagant, because silverware has health care function and is beneficial to health. Li Shizhen, a medical scientist in the Ming Dynasty, recorded in Compendium of Materia Medica that silver has the functions of "calming the five internal organs, calming the mind, stopping convulsions and eliminating evil spirits". Modern science has proved that silver is a natural and permanent bactericide, and silver ions dissolved in water will adsorb bacteria on it, making its colloid converge and solidify until death. As long as there is 50 billionth of a gram of silver ion in a liter of water, it is enough to make bacteria unable to survive. Drinking water in a silver pot can last for several months without corruption. The ancient Egyptians knew to cover wounds with silver more than 2000 years ago to sterilize and prevent suppuration. Silver ion can not only kill more than 60 kinds of harmful bacteria such as Escherichia coli and typhoid Bacillus, but also promote detoxification and health preservation, accelerate metabolism and enhance resistance to diseases. Long-term use of pure silver products can enhance energy and prolong life. Since ancient times, silver has been a symbol of wealth. Pure silver health cup, pure silver wine set, pure silver tea set, pure silver tableware ... The flashing silverware silently shows the noble taste of the host and shows respect for the visiting guests. The silverware in the Tang Dynasty was closely related to the banquet of dignitaries. Time flies, time flows. The former royal family and noble silver have now entered people's homes. Silver is not unassuming, only introverted; There is no shabby, only vicissitudes. Noble and natural, quality is passed down from generation to generation. You can regain your former elegance in the calm and gentle silverware, and life is worth slowing down and savoring.