Performance Study Of Mesoporous Silica Nanoparticles With Three-dimensional Structure As Nucleic Acid Vectors

Mesoporous Silica Nanoparticles(MSNs),a new type of nucleic acid drug carriers,have been receiving a lot of attention from researchers and are an important development direction in the field of nanomaterials in recent years.In this study,double cationic group modification of MSNs was chosen to carry small fragments of nucleic acids for safe and efficient cell transfection to achieve efficient nucleic acid therapy,and this method provides a new direction and idea for the development of inorganic nano-drug carriers.In this study,two mesoporous silicon oxide nanomaterials were selected for modification to synthesize functionalized nanoparticle carriers.Mobil Composition of Matter No.48(MCM-48)and Dendritic Mesoporous Silica Nanoparticles(DMSN)with a three-dimensional Ia3d cubic structure.On the surface of the nanoparticles,the amino groups(N-MSNs)and the double-modified sulfonium positive ions(S~+-MSNs)were successively modified to obtain nanoparticle carriers with regular morphology and greatly improved drug loading performance.The composition,structure,and important properties of the nanoparticles were investigated by X-ray diffraction,Fourier transforms infrared spectroscopy,BET detection,zeta potential,and dynamic light scattering at the physical and chemical characterization stage of the prepared multiple nanoparticles,respectively.The morphological appearance and pore structure of the synthesized nanoparticles were characterized using transmission electron microscopy and scanning electron microscopy.The adsorption,release,and protection properties of small fragment nucleic acids on the carriers were tested using micro-UV spectrophotometry and agarose gel electrophoresis.In the in vitro cellular assay part,the ability of the vector to transfect functionalized siRNA into tumor cells and the actual effect on target gene silencing eventually causing apoptosis were examined by laser confocal microscopy and flow cytometry.According to the results,the nanocarriers before and after modification were morphologically spherical nanoparticles with particle sizes ranging from 100 to 230 nm,pore sizes ranging from 2.5 to 10 nm,and orderly pore channel dispersion,and the amino group and matte positive ion were confirmed to have been successfully modified on the carriers by infrared and other detections,and the surface charge of the carriers and the pore size of the carriers were successfully changed;for the small fragment DNA of 20 bp,S~+-MCM-48 and The adsorption amounts of S~+-MCM-48 and S~+-DMSN reached 42.22μg/mg and 49.85μg/mg,respectively,with release efficiencies of 50.6%and 57.3%;the protective effect was also best for the nanoparticles with the final double-modified functional groups.In vitro experiments,the effect of nanoparticle uptake was tested on two types of tumor cells(HepG2 and He La cells),and different modified MSNs were taken up by the cells in different amounts,and the results showed that HepG2 cells had the greatest uptake efficiency for S~+-MCM-48 and S~+-DMSN in the same uptake system,with average uptake rates of 39.10%,54.86%.In the cytotoxicity assay,unmodified MSNs,amino-modified N-MSNs,and S~+-MSNs further modified with sulfonium positive ions showed low cytotoxicity at each concentration gradient set the relative activities of experimental cells were higher than 85%at high concentrations of nanoparticle treatment.Finally,S~+-MSNs carrying siRNAs into the cells were tested for targeted silencing of Survivin gene.siRNAs transfected with S~+-MCM-48 resulted in an average apoptosis rate of 47.01%in HepG2 cells,and 52.89%in S~+-DMSN treatment.In this study,amino modification and matte positive ion modification were achieved on MSNs,and small fragment nucleic acid drugs were successfully and efficiently loaded on them.The S~+-MCM-48 and S~+-DMSNs showed good uptake efficiency in tumor cells and overall showed very low cytotoxicity by functionalized modification extracellularly to provide good drug adsorption,slow-release,and protection against apoptosis by their mediated nucleic acid transfection.This paper provides the direction and research basis for such modified silica nanocarriers to enhance their performance as drug carriers.In summary,this paper investigated MCM-48 nanoparticles and DMSN nanoparticles with three-dimensional structures,and the relationship between their structures and carrier performance.The advantages and disadvantages of sulfonium-positive ions as nucleic acid carrier modification groups were demonstrated,and their carrier performance for small nucleic acid loading,transfection,and induction of apoptosis in hepatocellular carcinoma cells was verified experimentally.