ABSTRACT
To optimize the formulation and technology of oxymatrine-astragaloside IV coloaded liposomes (Om-As-Lip) based on quality by design (QbD) principles, and further to verify the feasibility of its amplification process, Om-As-Lip was prepared by ethanol injection combined with pH gradient method. The critical material attributions of Om-As-Lip were evaluated by dual-risk analysis tools and Plackett-Burman design (PBD). The formulation of Om-As-Lip was further optimized with the Box-Behnken design (BBD). The design space was also established based on the contour plots of BBD. In order to further investigate the amplification process of Om-As-Lip, the critical process parameters of high-pressure homogenization (HPH) were optimized by single-factor test, and the quality of the final product was also evaluated. The results of risk analysis and PBD confirmed that the astragaloside concentration, cholesterol concentration, and phospholipid ratio (HSPC∶SPC) were the ctitical material attributes. The model established by BBD had a good predictability, and the optimized mass ratio of As to phospholipids was 1∶40, cholesterol to phospholipids was 1∶10, HSPC to SPC was 51∶9. The design space of Om-As-Lip was as follows: the ratio of cholesterol to phospholipids was 1∶12-1∶5 and HSPC to SPC was 1∶7-17∶3. The optimized high-pressure homogenization pressure was 600 bar, temperature was 4 ℃, and cycle times was 6 times for HPH-Om-As-Lip. The quality of Om-As-Lip prepared based on the QbD concept can meet the expected CQAs, and the formulation and technology established can provide a reliable experimental basis for its future development and applications.
ABSTRACT
Size and surface modification are the two key factors affecting the effect of macrophages polarization induced by superparamagnetic iron oxide nanoparticles (SPIONs). The smaller the particle size, the better the polarization effect of SPIONs. Besides, the reasonable SPIONs surface modification method can also be used to enhance the polarization effect. In this study, SPIONs was prepared by solvothermal method and optimized by Box-Benhnken center combination design and response surface method. Furthermore, astragalus polysaccharide-superparamagnetic iron oxide nanocomplex (APS-SPIONs) was successfully constructed by EDC/NHS esterification method. The structure of APS-SPIONs was confirmed by dynamic light scatter and infrared spectrometer, and the contents of iron and polysaccharide were characterized by spectrophotometry. The effect of APS-SPIONs on inducing mouse macrophages RAW264.7 polarization was investigated by flow cytometry. The RAW264.7 macrophages-HepG2 human hepatoma cancer cells Transwell co-culture system was established to investigate APS-SPIONs improve anti-tumor function of macrophages in vitro, and the proliferation activity of APS-SPIONs on RAW264.7 detected by cell counting kit-8 (CCK-8) method. The results showed that the average particle size and zeta potential of APS-SPIONs were (82.93 ± 1.47) nm and (-24.00 ± 0.47) mV. Polysaccharide and Fe content were 8.69% and 7.04%, respectively. APS-SPIONs effectively induced the polarization of RAW264.7 into M1 type in vitro, improving the anti-tumor ability of macrophages in a co-culture system, without effecting the proliferation of macrophages. Our study provides a drug development strategy and preliminary research results to educate macrophages and reshape the tumor immune microenvironment to achieve tumor-killing effects.