Synthesis of chemical tools to improve water solubility and promote the delivery of salinomycin to cancer cells

LC-MS/MS analysis of coccidiostats in meat supply chain safety

The presence of coccidiostats in meat products represents an important topic because of the animal administration of these substances, authorized as feed additives for targeted species, in order to prevent and inhibit coccidiosis. Coccidiostats include both ionophores and synthetic molecules characterized by different chemical-physical properties such as polarity. Meat is a matrix characterized by many interfering compound groups, such as proteins, phospholipids, and fats. High-performance liquid chromatography (HPLC) coupled to mass spectrometry (MS) analysis allows the required selectivity and sensitivity for discriminating analytes and matrix interferences. For these reasons, an LC-MS/MS method for the analysis of coccidiostats in meat products was developed without SPE purification steps. The correct analyte quantification is allowed by matrix-matched calibration. The method validation was performed by the replicated analysis of spiked meat samples at two different concentration levels (limit of quantification-LOQ-and a 10 times LOQ) in order to evaluate method recovery and repeatability, plus spiked samples at higher concentrations up to 10,000 μg/kg. Moreover, the metrological approach was used for the calculation of method uncertainty. The application of the developed method to real samples evidenced the presence of some non-ionophores coccidiostats in the meat and liver of chicken and rabbit species. Although, the determined concentration was below the established MRLs, the monitoring of coccidiostats in the meat supply chain is confirmed as a good strategy in order to safeguard consumer health.

Salinomycin-Loaded High-Density Lipoprotein Exerts Promising Anti-Ovarian Cancer Effects by Inhibiting Epithelial-Mesenchymal Transition

Background

Effective treatments for ovarian cancer remain elusive, and survival rates have long been considered grim. Ovarian cancer stem cells (OCSCs) and epithelial–mesenchymal transition (EMT) are associated with cancer progression and metastasis, as well as drug resistance and eventual treatment failure. Salinomycin (Sal) has an extensive effect on a variety of cancer stem cells (CSCs); however, its poor water solubility and toxicity to healthy tissues at high doses limit further research into its potential as an anti-cancer drug. We proposed a therapeutic strategy by constructing a tumor-targeting carrier that mimics high-density lipoprotein (HDL) to synthesize salinomycin-loaded high-density lipoprotein (S-HDL). This strategy helps reduce the side effects of salinomycin, thereby improving its clinical benefits.

Methods

OCSCs were isolated from ovarian cancer cells (OCCs) and the uptake of HDL nanoparticles was observed using laser confocal microscopes. After the cell viability analysis revealed the inhibitory effect of S-HDL on OCCs and OCSCs, the main biological processes influenced by S-HDL were predicted with a transcriptome sequencing analysis and verified in vitro and in vivo.

Results

Cellular uptake analysis showed that the HDL delivery system was able to significantly enhance the uptake of Sal by OCCs, tentatively validating the targeting role of recombinant HDL, so that S-HDL could reduce the toxicity of Sal and increase its anti-ovarian cancer effects. Conversely, S-HDL could exert anti-ovarian cancer effects by inhibiting the proliferation of OCCs and OCSCs, promoting apoptosis, blocking EMT, and suppressing stemness and angiogenesis-related protein expression in vitro and in vivo.

Conclusion

S-HDL had stronger anti-ovarian cancer effects than unencapsulated Sal. Thus, it may be a potential agent for ovarian cancer treatment in the future.

Salinomycin-Based Drug Delivery Systems: Overcoming the Hurdles in Cancer Therapy

Cancer stem cells (CSCs) are reportedly responsible for the initiation and propagation of cancer. Since CSCs are highly resistant to conventional chemo- and radiotherapy, they are considered the main cause of cancer relapse and metastasis. Salinomycin (Sali), an anticoccidial polyether antibiotic, has emerged as a promising new candidate for cancer therapy, with selective cytotoxicity against CSCs in various malignancies. Nanotechnology provides an efficient means of delivering Sali to tumors in view of reducing collateral damage to healthy tissues and enhancing the therapeutic outcome. This review offers an insight into the most recent advances in cancer therapy using Sali-based nanocarriers.