Feasibility and Stability of Polyelectrolyte Complex Formed by WSLP with siRNA.
Then, the stability of the complex in serum was evaluated, as it was previously reported that WSLP conjugation would protect nucleic acid from degradation.
The results showed that there were no obvious alterations between the NS and sWSLP groups in NR2B expressions, while NR2B expressions in mRNA and protein levels in the PEI and WSLP groups were notably decreased as compared to the NS and sWSLP groups (Figures 1(c) and 1(d)).
To confirm that NR2B-siRNA is able to effectively silence NR2B when it is complexed with WSLP, we transfected PC12 cells with NR2B-siRNA (NT group), WSLP/scRNA (CT group), or WSLP/NR2B-siRNA (WT group) and assessed their NR2B mRNA and protein levels with PCR and western blot assays, respectively.
We found that compared to the control NS group, the CFA, PEI, WSLP, and sWSLP groups showed significantly higher NR2B protein levels 3 days after administration of the intrathecal injection (p < 0.01; Figure 3(a)).
The increase in MWT and TWL compared with that in the CFA group was the greatest in the WSLP group (p < 0.01).
Recent lines of evidence discovered that WSLP has shown promise as a genetic carrier with high efficiency and low toxicity .
NR2B expressions at mRNA and protein levels in the PEI and WSLP groups were lower than those in the NS and sWSLP groups.
In the present study, we synthesized WSLP based on the method mentioned by Lee for example,  and discovered that this polymer can effectively bind NR2B-siRNA when they were mixed at a mass ratio of 5 : 1.
In this study, we investigated whether WSLP could deliver NR2B-siRNA to successfully inhibit NR2B gene expression in cells and consequently reduce chronic inflammatory pain in the rat model.
In contrast, injection of WSLP complexed with control scRNA or of PEI with NR2B-siRNA did not produce this inhibitory effect, indicating that the intrathecal injection of WSLP/NR2B-siRNA complexes can specifically inhibit NR2B gene expression in rats with chronic inflammatory pain.