Construction of polybutylcyanoacrylate nanoparticles loaded brain derived neurotrophic factor gene and their expressions in rat brain tissues

Abstract

Objective To prepare the polybutylcyanoacrylate nanoparticles (PBCA-NPs) loaded brain derived neurotrophic factor (BDNF) gene as the gene delivery system and explore their expressions in rat brain tissues so as to observe the influence of PBCA-NPs in BDNF expression. Methods PBCA-NPs were prepared by emulsion polymerization method. Surface of PBCA-NPs was surveyed by transmission electron micrograph (TEM) and zeta potentials of PBCA-NPs were determined with laser grain analyzer. The PBCA-NPs surface was modified by cationic surfactant cetyltrimethylammonium bromide (CTAB). The eukaryotic expression vectors PEGFP-BDNF were constructed; after verification by double enzyme digestion and sequencing, PEGFP-BDNF was packaged by PBCA-NPs. Forty-eight male SD rats were randomly divided into blank-control group, PBCA group, PEGFP-BDNF group and PBCA-PEGFP-BDNF group (n=12), and Feeney's method was used to induce craniocerebral injury models in these rats, and then, one mL normal saline, PBCA-NPs, PEGFP-BDNF plasmids and PBCA-PEGFP-BDNF plasmids were given to the above groups. Seven d after that, peripheral brain tissues of right injury brain tissues were chosen; expressions of BDNF gene were detected by pathological examination, real time-PCR and Western blotting. Results Nps with even size and smooth surface were successfully obtained, holding the high zeta electric potential ([62.23±2.15]%). The new constructed vectors were confirmed by restricted enzyme and sequencing. Real time-PCR indicated significant difference of BDNF mRNA expressions among the four groups (F=112.668, P=0.000); as compared with that in the other three groups, the BDNF mRNA expression in the PBCA-PEGFP-BDNF group was significantly higher (P<0.05). Western blotting indicated significant difference of BDNF protein expressions among the four groups (F=66.629, P=0.000); as compared with that in the blank group and PBCA group, the BDNF protein expression in the PEGFP-BDNF group was significantly higher (P<0.05), and that in the PBCA-PEGFP-BDNF group was significantly higher than the other three groups (P<0.05). Conclusion PBCA-NPs could be a good vector and provide a new way for gene therapy of craniocerebral injury Key words: Polybutylcyanoacrylate nanoparticle; Brain derived neurotrophic factor; Craniocerebral injury