Construction of Aptamer-siRNA Chimera/PEI/5-FU/Carbon Nanotube/Collagen Membranes for the Treatment of Peritoneal Dissemination of Drug-Resistant Gastric Cancer.

Due to extensive metastasis, poor blood supply, and drug-resistant, there is still no effective clinical means to treat peritoneal dissemination of gastric cancer. Here, an aptamer-siRNA chimera (Chim)/polyethyleneimine (PEI)/5-fluorouracil (5-FU)/carbon nanotube (CNT)/collagen membrane is constructed, which could be divided into 15 layers with a thickness of 70-100 µm. Sustained release experiments show that the collagen membranes can control 5-FU release for more than 2 weeks. Aptamer-siRNA chimera can specifically bind to gastric cancer cells, enabling targeted delivery of 5-FU and silencing drug-resistant gene. In vitro experiments demonstrated that Chim/PEI/5-FU/CNT nanoparticles promoted the apoptosis of 5-FU-resistant gastric cancer cells, inhibited their invasion and proliferation. Animal experiments show that Chim/PEI/5-FU/CNT/collagen membrane significantly inhibits the expression of mitogen-activated protein kinase (MAPK), and effectively treats peritoneal dissemination of 5-FU-resistant gastric cancer. Compared with siRNA/PEI/5-FU/CNT group, ki-67 proliferation index, and matrix metallopeptidase 9 (MMP9) expression are significantly decreased in the Chim/PEI/5-FU/CNT group, while the proportion of apoptotic cells is markly increased. In conclusion, a chimera/PEI/5-FU/CNT/collagen membrane is constructed, which can effectively treat peritoneal dissemination of drug-resistant gastric cancer. The study provides a new therapeutic approach for relevant clinical treatment.