ABSTRACT
This study aimed to construct an intelligent fluorescent nanocarrier for tumor cell tracing. Doxorubicin (DOX) was used as a model drug, and the gene targeting siBcl-2 was loaded to achieve synergistic inhibition of tumor cells. Mesoporous silicon nanoparticles (MSN) were prepared by a sol-gel method, and acetaldehyde cystine (AC) and polyethyleneimine (PEI) were covalently modified. The prepared nanocarrier MSN-AC-PEI was uniformly dispersed, with a particle size of 235.53 nm and a potential of 14.63 mV. The carrier material MSN-AC-PEI could load siRNA with the mass ratio of 60∶1 (Wvectors∶WsiRNA) and protect siRNA from RNase I degradation. To simulate the microenvironment of tumor, DOX release in phosphate buffer (pH 5) including 10 mmol·L-1 glutathione (GSH) was investigated. The cumulative release rate of DOX at 120 h is 35 times that of the normal physiological environment, which lays the foundation for the intelligent release of DOX in tumor cells. The results of cell experiments showed that the carrier material MSN-AC-PEI had significant green fluorescence, and the traceability can be maintained for 24 h after taken up by MCF-7 cells. After 24 hours of administration of the nano drug delivery system MSN-AC-PEI@DOX/siBcl-2, the inhibition rate of tumor cell proliferation reached 40.91%, and the late apoptosis rate was 60.84%. The Western blot results showed that compared with free DOX and siBcl-2, the nano-delivery system MSN-AC-PEI@DOX/siBcl-2 can significantly reduce the expression of anti-apoptotic protein Bcl-2, thereby enhancing its anti-tumor ability.