Characterization and bioactivity of self-assembled anti-angiogenic chondroitin sulfate-ES2-AF nanoparticle conjugate

Xing, Liang; Sun, Feng; Wang, Zhendong; Li, Yan; Yang, Zhifang; Wang, Fengshan; Zhai, Guangxi; Tan, Haining

To study the targeting properties, the modified product and ES2-AF were labeled with FITC according to a previous protocol. 9 The tumor model was established by subcutaneous injection of B16 cells (5×10 6 /mL) into the right armpit of each nude mouse (approval number by ethical committee: 2017-D040). When the tumor volume reached approximately 200 mm 3 , the nude mice were injected with the FITC-labeled compounds FITC-ES2-AF, FITC-CS-ES2-AF, and CS&FITC-ES2-AF via tail vein. All animal experiments in this study were approved by the Ethics Committee of School of Nursing of Shandong University and performed following ethical guidelines for the care and use of animals. Saline was used as the control and the dose of the experimental group was 25 mg/kg (concentration refers to the ES2-AF portion only). The In Vivo Imaging System kinetics system was used to visualize the nude mice at 0.5, 1, 2, and 4 hours after administration, and the distribution of the drugs was observed in the mice at each time point. 22, 35, 36 Pharmacokinetic study BALB/c mice (~20 g) that were fasted for 12 hours were randomly divided into three groups. Then, 200 μL of FITC-ES2-AF or FITC-CS-ES2-AF was injected via the tail vein at a peptide dose of 20 mg/kg (concentration refers to the ES2-AF portion only). Blood samples were collected through the fundus venous plexus, 0.5-24 hours after administration. The samples were allowed to stand for 2 hours and the supernatants were collected by centrifugation at 4°C for 10 minutes. Then, an equal volume of 0.1% SDS solution was added to the supernatants as a fluorescent sensitizer. Finally, the fluorescence intensity of the samples was measured by a fluorescence spectrophotometer (excitation at 280 nm and emission at 350 nm). 37, 38 Results synthesis of cs-es2-aF conjugate