负载肝素及生物素化肝素修饰的纳米粒子的基质介导基因传递系统

首先通过静电作用将带负电荷的肝素及生物素化肝素和带正电荷的PAMAM/DNA自组装,分别制备了PAM AM/DNA/heparin和PAMA M/DNA/heparin-biotin复合物,然后用快速降解胆酸功能化星型聚(DL-丙交酯)作为基质、并加入水溶性高分子α,β-聚(N-2-羟乙基)-L-天冬酰胺(PHEA)作...

STUDY ON SUBSTRATE-MEDIATED GENE DELIVERY SYSTEMS LOADED WITH HEPARIN AND HEPARIN-BIOTIN MODIFIED NANOPARTICLES

The negatively charged heparin and heparin-biotin were complexed with the positively charged PAMAM/DNA via electrostatic interactions to prepare PAMAM/DNA/heparin and PAMAM/DNA/heparin-biotin complexes,respectively.By using a fast degrading cholic acid functionalized star poly(DL-lactide) as a matrix and a water soluble polymer,α,β-poly(N-2-hydroxyethyl)-L-aspartamide(PHEA) as an additive,thin films loaded with PAMAM/DNA,PAMAM/DNA/heparin or PAMAM/DNA/heparin-biotin complexes were prepared.The in vitro substrate-mediated gene transfections were carried out in HeLa cells and 293T cells.The results indicated that the complexes loaded polymer films could effectively mediate sustained transfections.The PAMAM/DNA/heparin-biotin complexes loaded polymer films exhibited improved transfection efficiency because the existence of heparin-biotin on the complex surface resulted in an enhanced cellular uptake for HeLa cells due to the specific interaction between the biotin moiety and the biotin-specific receptors on HeLa cells.By adding the water soluble polymer PHEA,which could keep the bioactivity of DNA during the film fabrication,the gene expression levels could be significantly improved.During the cellular transfection,the degradation of the polymer films did not show any negative effects on the gene transfection.