Biophysics Research On Mesoporous Silica Nanoparticles As Gene Carriers

Mesoporous silica nanoparticles(MSN)，which are porous，can be modified withgood biocompatibility and biodegradability characteristics, have attracted more andmore attention in the field of non-viral vectors. So far,research on MSN being usedas drug carriers targeted therapy has gained significant results, however，there is afew study on MSN carrying the gene for the cellular uptake,both domestic andoverseas. Especially the research on using modified MSN as targeting agent to carryout cellular uptake.As we can see,safe and efficient gene carriers play a vital role ingene therapy.In this paper，firstly we modified MSN with amino-group, carboxyl group, folicacid and transferrin.Then a series of characterization of MSN were detected by SEM,TEM, XRD, Zeta potential，FT-IR and SERS-RAMAN.The results indicate that MSNhas the possibility to be a good gene carrier. After that we made a research onMSN-DNA. Using agarose gel electrophoresis and UV spectrophotometer to analyzethe particles’ effect on adsorption,desorption and protection of DNA.Finally we useCLSM and FCM to detect the effect of particle uptake.We can draw that the size of the particles is about200nm and the pore size isabout2.5nm.And they are regular spherical particles with good monodispersity. Theparticle surface are high negatively charged, but after the modification by ligands andtargeting reagent, the particles’ surface becomes positively charged, and the particlesare remain monodisperse. Amino-modified particles adsorption and desorption ratewith the20bp DNA is as high as76.7%, after other modifications it’s still on a goodrate. MSN-DNA has a better protective effect, and there is almost no change on shapeand structure. After modification with ligands and targeting reagent, the partices’biocompatibility and efficiency of cell uptake are both improved.The results provide a good theoretical basis for the application in the biologicalcarrier and the nanoparticles carried siRNA to the targeted cells and play genesilencing effect to get gene diagnosis and treatment. We can also see that the MSN used as gene delivery carriers has a vast potential in gene therapy.