CONTEXT: c-Myc plays a key role in glioma cancer stem cell maintenance. A drug 
delivery system, nanoparticles loading plasmid DNAs inserted with siRNA 
fragments targeting c-Myc gene (NPs-c-Myc-siRNA-pDNAs), for the treatment of 
glioma, has not previously been reported.
OBJECTIVE: NPs-c-Myc-siRNA-pDNAs were prepared and evaluated in vitro.
MATERIALS AND METHODS: Three kinds of c-Myc-siRNA fragments were separately 
synthesized and linked with empty siRNA expression vectors in the mole ratio of 
3:1 by T4 DNA ligase. The linked products were then separately transfected into 
Escherichia coli. DH5α followed by extraction with Endofree plasmid Mega kit 
(Qiagen, Hilden, Germany) obtained c-Myc-siRNA-pDNAs. Finally, the recombinant 
c-Myc-siRNA3-pDNAs, generating the highest transfection efficiency and the 
greatest apoptotic ability, were chosen for encapsulation into NPs by the 
double-emulsion solvent-evaporation procedure, followed by stability, 
transfection efficiency, as well as qualitative and quantitative apoptosis 
evaluation.
RESULTS: NPs-c-Myc-siRNA3-pDNAs were obtained with spherical shape in uniform 
size below 150 nm, with the zeta potential about -18 mV, the encapsulation 
efficiency and loading capacity as 76.3 ± 5.4% and 1.91 ± 0.06%, respectively. 
The stability results showed that c-Myc-siRNA3-pDNAs remained structurally and 
functionally stable after encapsulated into NPs, and NPs could prevent the 
loaded c-Myc-siRNA3-pDNAs from DNase degradation. The transfection efficiency of 
NPs-c-Myc-siRNA3-pDNAs was proven to be positive. Furthermore, 
NPs-c-Myc-siRNA3-pDNAs produced significant apoptosis with the apoptotic rate at 
24.77 ± 5.39% and early apoptosis cells observed.
DISCUSSION AND CONCLUSION: 
Methoxy-poly-(ethylene-glycol)-poly-(lactide-co-glycolide) nanoparticles 
(MPEG-PLGA-NPs) are potential delivery carriers for c-Myc-siRNA3-pDNAs.