[Preparation, characterization and antitumor effect of iron-based organic framework nano preparations loaded with piperlongumine].

The preparation processes of iron-based organic framework(FeMOF) MIL-100(Fe) and MIL-101(Fe) with two different ligands were optimized and screened, and the optimized FeMOF was loaded with piperlongumine(PL) to enhance the biocompatibility and antitumor efficacy of PL. The MIL-100(Fe) and MIL-101(Fe) were prepared by solvent thermal method using the optimized reaction solvent. With particle size, polymer dispersity index(PDI), and yield as indexes, the optimal preparation processes of the two were obtained by using the definitive screening design(DSD) experiment and establishing a mathematical model, combined with the Derringer expectation function. After characterization, the best FeMOF was selected to load PL by solvent diffusion method, and the process of loading PL was optimized by a single factor combined with an orthogonal experiment. The CCK-8 method was used to preliminarily evaluate the biological safety of blank FeMOF and the antitumor effect of the drug-loaded nano preparations. The experimental results showed that the optimal preparation process of MIL-100(Fe) was as follows: temperature at 127.8 ℃, reaction time of 14.796 h, total solvent volume of 11.157 mL, and feed ratio of 1.365. The particle size of obtained MIL-100(Fe) nanoparticles was(108.84±2.79)nm; PDI was 0.100±0.023, and yield was 36.93%±0.79%. The optimal preparation process of MIL-101(Fe) was as follows: temperature at 128.1 ℃, reaction time of 6 h, total solvent volume of 10.005 mL, and feed ratio of 0.500. The particle size of obtained MIL-101(Fe) nanoparticles was(254.04±22.03)nm; PDI was 0.289±0.052, and yield was 44.95%±0.45%. The optimal loading process of MIL-100(Fe) loaded with PL was as follows: the feed ratio of MIL-100(Fe) to PL was 1∶2; the concentration of PL solution was 7 mg·mL~(-1), and the ratio of DMF to water was 1∶5. The drug loading capacity of obtained MIL-100(Fe)/PL nanoparticles was 68.86%±1.82%; MIL-100(Fe) was nontoxic to HepG2 cells at a dose of 0-120 μg·mL~(-1), and the half-inhibitory concentration(IC_(50)) of free PL for 24 h treatment of HepG2 cells was 1.542 μg·mL~(-1). The IC_(50) value of MIL-100(Fe)/PL was 1.092 μg·mL~(-1)(measured by PL). In this study, the optimal synthesis process of MIL-100(Fe) and MIL-101(Fe) was optimized by innovatively using the DSD to construct a mathematical model combined with the Derringer expectation function. The optimized preparation process of MIL-100(Fe) nanoparticles and the PL loading process were stable and feasible. The size and shape of MIL-100(Fe) particles were uniform, and the crystal shape was good, with a high drug loading capacity, which could significantly enhance the antitumor effect of PL. This study provides a new method for the optimization of the nano preparation process and lays a foundation for the further development and research of antitumor nano preparations of PL.