Treatment Of Helicobacter Pylori By Amoxicillin-loaded Magnetic Nanoparticles:In Vitro Study

Background:Helicobacter pylori (H. pylori, HP) infection has become a major public health problem in our country. With the popularization of standard treatment for HP and over-application of antibiotics, the probability of failure on radical cure of HP is rising and the refractory patients with HP infection are increasing year by year. This study intends to explore the magnetic nanoparticles as a new carrier to carry antibiotics, which can produce heat and release drugs in an alternating magnetic field to inhibit the growth of HP. Our study intends to provide experimental evidence for a new treatment for HP.Methods:We used a reverse microemulsion method to prepare MnFe2O4@SiO2 and observed its ultrastructure and physical properties. CCK-8 assays were used to detect the cytotoxicity of MnFe2O4@SiO2 on human gastric cancer cell line SGC-7901. We put amoxicillin and MnFe2O4@SiO2 together to get amoxicillin-loaded MnFe2O4@SiO2. High performance liquid chromatography (HPLC) was used to detect the drug loading efficiency and drug release. We put the magnetic nanoparticles into an alternating magnetic field and observed its hyperthermia effect (41 ± 0.5 ?) against HP. Bacterial counts, urease test, bacterial adhesion, and vacuolating activity were detected to evaluate the inhibition efficiency of amoxicillin-loaded MnFe2O4@SiO2 against HP. TEM was used to observe the morphology of HP before and after hyperthermia treatment.Results:1. We prepared MnFe2O4@SiO2 using a reverse microemulsion method. The core/shell-structured microspheres with a diameter of 26-30nm (core,20-22nm) was observed by TEM. We coated SiO2 on the surface of MnFe2O4 and observed better water solubility and almost no difference in magnetism compare with naked nuclei.2. Low concentration of MnFe2O4@SiO2 had no cytotoxicity on SGC-7901 cells. When the concentration ?250?g/ml and contacting time more than 48h. MnFe2O4@SiO2 nanoparticles exhibited growth inhibition of gastric cancer cells.3. We successfully prepared amoxicillin-loaded MnFe2O4@SiO2 and zeta potential analysis suggested that the positive and negative charge adsorption was involved in the formation of the composite microspheres. HPLC detection revealed the loading efficiency was 10.4% and the drug can release from the nanoparticles.4. The MnFe2O4@SiO2 magnetic nanoparticles can rapidly heat water and Campylobacter Agar to 42? and can make them stabilized at a specific temperature by adjusting the frequency of the alternating magnetic field.5. The antibacterial effect of amoxicillin-load MnFe2O4@SiO2 with heating, which were put into an alternating magnetic field, was much better than amoxicillin or MnFe2O4@SiO2 heating treatment. The results of bacterial counts, urease test, bacterial adhesion test and vacuolating activity test revealed the superior antibacterial ability of amoxicillin-load MnFe2O4@SiO2.6. TEM revealed that the HP with hyperthermia treatment showed unique characters, bending body, decreased electron density and disappearance of biological membrane and flagellum, compared with common HP.Conclusion:The hyperthermia effect of MnFe2O4@SiO2 can inhibit the growth of HP. Our studies suggested that amoxicillin-loaded MnFe2O4@SiO2 produced a great effect on HP eradication, which were characterized by drug release and physical heating.