Xie Jingjing,Wang Jichuang,Chen Hongning,Shen Weiyu,Sinko Patrick J.,Dong Haiyan,Zhao Rongli,Lu Yusheng,Zhu Yewei,Jia Lee
Circulation tumor cells (CTCs) in the bloodstream of early-stage cancer patients carry the important information about valuable biomarkers and biological properties of primary tumor. However, detection and capture of CTCs are challenging owing to their low concentrations. Traditional technologies have the limited detection sensitivity and the low capture efficiency. We, herein, report an effective approach to specifically bind and capture colon cancer HT29 cells by using multiple Sialyl Lewis X antibodies (aSlex)-conjugated PAMAM dendrimers. The conjugation was characterized by using atom force microscope, UV and fluorescence measurements. The capturing and regulating HT29 cells by the aSlex-coated dendrimer conjugate were analyzed by microscopy and flow cytometry. The results indicated that the conjugate showed the enhanced capture of HT29 cells in a concentration-dependent manner and the maximum capture efficiency of 77.88% was obtained within 1 h-exposure. G6-5aSlex-FITC conjugate showed capture efficiency better than FITC-G6-COOH-5aSlex conjugate. G6-5aSlex-FITC conjugate could specifically capture HT29 cells even when the target HT29 cells were diluted with the interfering cells (e.g., RBCs) to a low concentration. The capture resulted in a concentration-dependent restraint of the cell activity. In conclusion, the aSlex-coated dendrimer conjugate displayed the great potential in capturing and restraining colorectal CTCs in blood.
Ulcerative colitis (UC) is a recurring inflammatory bowel disease, in which oxidative stress plays a role in its progression, and regulation of the oxidative/antioxidative balance has been suggested as a potential target for the treatment of UC. The aim of this study was to evaluate the protective effect of andrographolide against UC and its potential antioxidant properties by modulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. Dextran sulfate sodium (DSS) -induced UC mice and the LPS-induced HT29 inflammatory cell model were established to uncover the potential mechanisms of andrographolide. ML385, a Nrf2 inhibitor, was used in both models to assess whether andrographolide exerts a protective effect against UC through the Nrf2/HO-1 pathway. The in vivo experiment showed that andrographolide ameliorated the symptoms and histopathology of DSS-induced mice and restored the expressions of ZO-1, Occludin-1 and Claudin-1. Meanwhile, DSS-induced oxidative stress and inflammation were suppressed by andrographolide treatment, along with the upregulation of key proteins in the Nrf2/HO-1 pathway. In vitro experiments showed that andrographolide attenuated LPS-induced excessive generation of ROS in HT29 cells, reduced inflammatory factors, and upregulated the expression of proteins related to tight junctions and Nrf2/HO-1 pathway. In addition, ML385 abolished the beneficial effect of andrographolide. In conclusion, the protective effect of andrographolide against UC may involve the suppression of oxidative stress and inflammation via the Nrf2/HO-1 pathway.
The aim of this study was to prepare a solid self-microemulsifying drug delivery system (S-SMEDDS) of cinnamaldehyde (CA) by spray drying technique to improve the oral bioavailability of CA. The preparation of CA S-SMEDDS with maltodextrin as the solid carrier, a core-wall material mass ratio of 1:1, a solid content of 20% (w/v), an inlet air temperature of 150 °C, an injection speed of 5.2 mL/min, and an atomization pressure of 0.1 MPa was determined by using the encapsulation rate as the index of investigation. Differential scanning calorimetry (DSC) revealed the possibility of CA being encapsulated in S-SMEDDS in an amorphous form. The in-vitro release showed that the total amount of CA released by S-SMEDDS was approximately 1.3 times higher than that of the CA suspension. Pharmacokinetic results showed that the relative oral bioavailability of CA S-SMEDDS was also increased to 1.6-fold compared to CA suspension. Additionally, we explored the mechanism of CA uptake and transport of lipid-soluble drugs CA by S-SMEDDS in a Caco-2/HT29 cell co-culture system for the first time. The results showed that CA S-SMEDDS uptake on the co-culture model was mainly an energy-dependent endocytosis mechanism, including lattice protein-mediated endocytosis and vesicle-mediated endocytosis. Transport experiments showed that CA S-SMEDDS significantly increased the permeability of CA in this model. These findings suggested that CA S-SMEDDS is an effective oral solid dosage form for increasing the oral bioavailability of lipid-soluble drug CA.
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