Research On Inhibition Of Antibacterial Peptieds And TiO₂ Nanoparticle Spray In Influenza A (H1N1) Virus

The first case of human infection of Influenza A (H1N1) was found in Mexican in March 2009. Immediately, the cases were found in California and Texas of the USA. And the Influenza A (H1N1) swept through 214 countries of the Americas, Europe and Asia, with almost 20 thousand people losing their lives due to the infection of the virus and up to 100 million persons were infected. The influenza was a disaster of the whole society. Although in August 2010 WHO has declared that the influenza pandemic is over, the world has stepped into post-pandemic period. Due to the high variability and unpredictability of the Influenza A(H1N1), new type of strain would appear any time. Experience shows that the virus will act similarly as the seasonal influenza virus and would exist in few years. At present, effective Oseltamivir and Zanamivir are being used, and the strain of resistance against Zanamivir has been found. So as keeping vigilant, every country should press on with the work of research and development of new type of medicine.Antibacterial peptide, also called antimicrobial peptides or peptide antibiotics, is a kind of defensive small peptide developed by organisms when it is defense against the pathogenic microorganisms. This peptide is a kind of antibiotic molecules developed by genetic code and host cell, and a kind of congenital immune reactive molecules developed by organism during evolution for acclimatization. The molecular weight of it is lower, generally is 4kD. As the research is going further, people found that the antibacterial peptides possess strong effect against some fungus, protozoa, virus or cancer cell. Due to abuse of the antibiotic, more and more microorganisms have developed resistance. Thus the discovery of the antibacterial peptides provides a new cue method. It takes effect through membrane passageways of bacterial to kill it. So the prospect of its use is quite considerable, with its not being so easy to develop resistance.There are some reports about the antiviral property of the antibacterial peptides. Some report figures that the antiviral activity of the antibacterial peptides depends on the concentration of the virus, the completion of disulfide bond of the molecule, and it may be affected by time of injection, pH value, temperature and the component of the culture medium. The antibacterial peptides can also interfere the replication, packaging and combination of the virus. The antibacterial peptides can also be used as chemo-attractants to inhibit the virus. It has been found that some antibacterial peptides can chemo-attract the T cell, mononuclear and immature DC cell to move towards the parts of infected by virus. Besides, it can also stimulate the mononuclear cell and the epithelial cell to develop cytokine, and regulate the immune system of the organism with the immune components to achieve the goal of inhabitation of virus infection.The antibacterial peptides can take action in the following two aspects. Firstly, the antibacterial peptides can develop ion channel on the surface of virus, letting the material in virus outgo, destroying the basic structure of the virus, to change the osmotic pressure in and out the membrane of the virus to kill the virus. Or, the antibacterial peptides can combine with some receptor of the surface of the virus to prevent the virus from distinguishing and combining with other cell, thus prevent the virus from affection. Secondly, the antibacterial peptides can interact with the target cell which is affected by the virus by changing some structure or signal pathway of the target cell to prevent the virus from distinguishing or combining with the target cell to spread and replicate. Or, it can strengthen the biochemical performance of organism cell which is affected by the virus, to strengthen the ability of antivirus.Now the exact effective mechanism of the antibacterial peptides has been lack of detail and exact clue. And the way of affection vary a lot. Maybe the different antibacterial peptides take effect in different way, but this need prove further.TiO₂, commonly referred to as titanium, the particle diameter of the nano TiO₂ referred in this paper is smaller than the traditional TiO₂, only 10～50nm.It possesses a higher transmittance to visible light, stronger ability of absorbing and shielding to ultraviolet rays. Besides, the performance in mechanics of the nano TiO₂ is more stable than that of traditional TiO₂.The use of nano TiO₂ is now concentrated on photocatalysis. Now the theory of photocatalysis property of nano TiO₂ has been revealed in detail. When nano TiO₂ is shined by light with wavelength smaller than 387nm, it can develop a great deal of radical groups with high activity, which possesses the good oxidability to transfer the organism to inorganics of CO₂ and H2O, and can go through the membrane of the cell to affect the normal physiological function of cell, thus kill the cell by disturbing the internal balance of it. Some experiment has showed that nano TiO₂ can kill kinds of bacterium. But there are few reports about the antiviral effect of nano TiO₂. With the pandemic of virus such as SARS and Influenza A (H1N1) throughout the world, it becomes quite significant whether this new type of nano TiO₂ could inhibit or kill these virus effectively.On basis of experiments in laboratory, this paper chose three kinds of antibacterial peptides and a kind of nano TiO₂ synthetized in Teacher Chen Yuxin's laboratory, which was proved to possess high performance in antibiosis and anticancer as the study objects. We study on whether they could kill the virus in process of interaction with Influenza A (H1N1). And the result of our experiment shows that the effect to MDCK cell of Influenza A (H1N1) decreases obviously after its being treated with antibacterial peptides. And the survival rate of MDCK cell can increase by treating it with nano TiO₂ spray. This shows that the there kinds of antibacterial peptides and a kind of nano TiO₂ possess the inhabitation effect to Influenza A (H1N1).And this provide certain theatrical basis to development of new medicine. We wish to explain the effect theory of these there kinds of antibacterial peptides and a kind of nano TiO₂ sufficiently by completing later experimental data.