Accurate prediction of drug-induced heterogeneous response of red cell in vivo using a gravity-driven flow cytometry based on a microfluidic chip.

The drug-induced diverse response among patients is a severe problem for improving hemorheological character. However, there is no validated method for personalized therapy to the best of our knowledge. Here, we apply a gravity-driven deformability cytometry platform (GD-DCP) to profile the drug response of the red cell deformability (RCD) at the single-cell level using pentoxifylline (PTX) as a model drug, the effect of different concentrations of PTX (0, 2, 20, 200 µg mL-1, the clinical dosage of PTX is 20 µg mL-1) on RCD in patients with cardiovascular disease was explored. Based on the GD-DCP, about 38 and 56% of the acute phase of acute myocardial infarction (AMI) patients in the acute phase and coronary heart disease (CHD) patients respond positively to PTX, respectively, indicating that PTX has a strong patient dependency on RCD. Moreover, RCD is observed to be significantly inversely correlated with the activation of membrane protein kinase C (PKC) as well as the concentration of Ca2+ (both P < 0.001). The results of animal experiments show that the protective effects of PTX on myocardial ischemia rats have substantial individual variation, too. It is noted that the effect of PTX is highly consistent between RCD in vitro and in vivo outcomes (blood viscosity, myocardial injury, and electrocardiogram (ECG)) in the same rat. All these new findings suggest that the GD-DCP is a promising method that uses deformability in vitro as one of the important criteria in personalized medicine, and our study provides unique insight into the individual-dependent mechanisms of PTX for improving RCD.

Development of Taccalonolide AJ-Hydroxypropyl-ß-Cyclodextrin Inclusion Complexes for Treatment of Clear Cell Renal-Cell Carcinoma.

BACKGROUND: Microtubule-targeted drugs are the most effective drugs for adult patients with certain solid tumors. Taccalonolide AJ (AJ) can stabilize tubulin polymerization by covalently binding to ß-tubulin, which enables it to play a role in the treatment of tumors. However, its clinical applications are largely limited by low water solubility, chemical instability in water, and a narrow therapeutic window. Clear-cell renal-cell carcinoma (cc RCC) accounts for approximately 70% of RCC cases and is prone to resistance to particularly targeted therapy drugs. METHODS: we prepared a water-soluble cyclodextrin-based carrier to serve as an effective treatment for cc RCC. RESULTS: Compared with AJ, taccalonolide AJ-hydroxypropyl-ß-cyclodextrin (AJ-HP-ß-CD) exhibited superior selectivity and activity toward the cc RCC cell line 786-O vs. normal kidney cells by inducing apoptosis and cell cycle arrest and inhibiting migration and invasion of tumor cells in vitro. According to acute toxicity testing, the maximum tolerated dose (MTD) of AJ-HP-ß-CD was 10.71 mg/kg, which was 20 times greater than that of AJ. Assessment of weight changes showed that mouse body weight recovered over 7-8 days, and the toxicity could be greatly reduced by adjusting the injections from once every three days to once per week. In addition, we inoculated 786-O cells to generate xenografted mice to evaluate the anti-tumor activity of AJ-HP-ß-CD in vivo and found that AJ-HP-ß-CD had a better tumor inhibitory effect than that of docetaxel and sunitinib in terms of tumor growth and endpoint tumor weight. These results indicated that cyclodextrin inclusion greatly increased the anti-tumor therapeutic window of AJ. CONCLUSIONS: the AJ-HP-ß-CD complex developed in this study may prove to be a novel tubulin stabilizer for the treatment of cc RCC. In addition, this drug delivery system may broaden the horizon in the translational study of other chemotherapeutic drugs.

Femtomolar Detection of Lipopolysaccharide in Injectables and Serum Samples Using Aptamer-Coupled Reduced Graphene Oxide in a Continuous Injection-Electrostacking Biochip.

A method for microfluidic sample preconcentration to detect femtomolar level of lipopolysaccharide (LPS) is introduced, enabled by 6-carboxyfluorescein (6-FAM) labeled aptamer-LPS binding along with reduced graphene oxide (rGO). The free FAM-aptamers can be adsorbed onto the surface of rGO, resulting in fluorescence quenching of background signals. Conversely, the aptamer-LPS complex cannot be adsorbed by rGO, so the fluorescence is maintained and detected. When an electric field is applied across the microchannel with Nafion membrane in the chip, only the fluorescence of aptamer-LPS complex can be detected and stacked by continuous injection-electrostacking (CI-ES). The method shows a high selectivity (in the presence of pyrophosphate, FAD+, NAD+, AMP, ADP, ATP, phosphatidylcholine, LTA, and ß-d-glucans which respond positively to LAL) to LPS and an extreme sensitivity with the limit of detection (LOD) at 7.9 fM (7.9 × 10-4 EU/mL) and 8.3 fM (8.3 × 10-4 EU/mL) for water sample and serum sample, respectively. As a practical application, this method can detect LPS in injections and serum samples of human and sepsis model mouse and quickly distinguish Gram-negative bacteria Escherichia coli ( E. coli) from Gram-positive bacteria Staphylococcus aureus ( S. aureus) and fungus Candida albicans ( C. albicans). More importantly, by changing the aptamers based on different targets, we can detect different analytes. Therefore, aptamer-coupled rGO in a CI-ES biochip is a universal, sensitive, and specific method. For TOC only.