A Study On The Fabrication Of γ-γ-Fe₃O₄ Magnetic Nano Microspheres-Mitomycin C Complex And Its Cytotoxicity To Bladder Cancer

Objective:Bladder cancer is the most common malignancy of the urinary tract,with approximately 570,000 new cases and 210,000 deaths annually worldwide.Intravesical chemotherapy is an important adjuvant modality after surgery for non-muscle-infiltrating bladder cancer,and the pharmacokinetic limitations of frequent elution and poor uroepithelial retention must be overcome in order to improve drug delivery to the bladder.In this research context,a nanomaterialγ-Fe₃O₄ magnet nanomicrospheres was selected as a nanoparticle delivery system to construct a complex ofγ-Fe₃O₄ magnetic nanomicrospheres and the first-line chemotherapeutic drug mitomycin C,which increases the antitumor effect of chemotherapeutic drugs on bladder cancer and provides new ideas for clinical antitumor therapy,using bladder cancer cells as the main research object.Methods:Firstly,we carried out the fabrication ofγ-Fe3O4 magnetic nanomicrospheres-mitomycin C complexes and compared the UV absorption spectra ofγ-Fe3O4 magnetic nanomicrospheres and mitomycin C at different concentrations using UV enzyme standardization to calculate the drug loading rate and encapsulation rate.The stability and dispersity of the nanocarriers were characterized using a homemade immunoassay analyzer from Shenyang University of Technology.A Malvern particle size meter was used to measure the changes of particle size and zeta potential before and after drug loading,and transmission electron microscopy was used to observe the morphology ofγ-Fe3O4magnetic nanospheres and nano-loaded drug complexes.Next,the biosafety ofγ-Fe3O4magnetic nanomicrospheres was examined using light microscopic observation and CCK8assay.Then the anti-tumor effect ofγ-Fe3O4 magnetic nanomicrospheres-mitomycin C complex was verified.Comparison of the effects ofγ-Fe3O4 magnetic nanomicrospheres-mithramycin C complex and mithramycin C alone on bladder cancer cell proliferation using CCK8 assay.The levels of apoptosis induced by nanocomplex and mitomycin C were compared using flow cytometry assay in bladder cancer cells.The expression of apoptotic proteins was detected at the protein level using Western blot assay to compare the levels of apoptosis induced by nanocomplex and mitomycin C alone in bladder cancer cells.Results:The results of fabrication and characterization ofγ-Fe3O4 magnetic nanomicrospheres-mitomycin C complexes showed thatγ-Fe3O4 magnetic nanomicrospheres could be coupled with mitomycin C.There were no overlapping absorption peaks betweenγ-Fe3O4 magnetic nanomicrospheres and mitomycin C.The signal changes were detected by immunoassay for 72 hours after drug loading without significant differences,which indicated the stability of the nanoparticles.The absolute values of zeta potential were both large before and after drug loading,suggesting that the stability of nanoparticles was good.Transmission electron microscopy observed that the uniform shape and particle size of the nanoparticles before and after drug loading were in accordance with the requirements of nanoformulations.The observation under optical microscope and CCK8 assay,flow cytometry assay and Western Blot all illustrated the biosafety ofγ-Fe3O4 magnetic nanospheres.CCK8 assay and flow cytometry assay proved thatγ-Fe3O4 magnetic nanosphere-mitomycin C complex could induce apoptosis of bladder cancer cells,andγ-Fe3O4 magnetic nanosphere-mitomycin C complex had a stronger toxic antitumor effect on bladder cancer cells than mitomycin C.Conclusion:The biosafety ofγ-Fe₃O₄ magnetic nanomicrospheres was demonstrated to be coupled with mitomycin C.The nano-loaded drug complex induced apoptosis in bladder cancer cells,and the nano-loaded drug complex was more toxic to bladder cancer cells and had better in vitro antitumor effects compared to mitomycin C alone.