Dermatan Sulfate/Chitosan Nanoparticles Loaded with an Anti-Inflammatory Peptide Increase the Response of Human Colorectal Cancer Cells to 5-Fluorouracil.

The gold standard drug for colorectal cancer (CRC) treatment, 5-Fluorouracil (5-FU), induces pharmacological tolerance in long-term management. The transcriptional factor nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) plays a key role in 5-FU resistance. The aim of this work is to study the capability of polyelectrolytes complex nanoparticles of dermatan sulfate (DS) and chitosan (CS), loaded with the anti-inflammatory tripeptide IRW, to sensitize colorectal cancer cells to 5-FU. Fluorescence and flow cytometry studies confirmed the recognition by the nanoformulation, of the cluster of differentiation 44 (CD44) receptor, involved in the initiation and progression of colorectal tumors. Dynamic light scattering (DLS) and flow cytometry reinforced the importance of DS and CD44 receptor in the interaction, as the addition of DS or anti-CD44 antibody blocked the binding. Moreover, the nanoformulation also interacts with 3D colon cancer cultures, namely colonospheres, enriched in cancer stem cells (CSC), subpopulation responsible for drug resistance and metastasis. To evaluate the consequences of this interaction, the subcellular distribution of the transcriptional factor NFκB, is determined by immunofluorescence analysis. Internalization and the intracellular release of IRW inhibited nuclear translocation of NFκB and increased cellular sensitivity to 5-FU. Altogether, the nanoformulation could provide a selective delivery platform for IRW distribution to colorectal tumors, being an innovative strategy toward overcoming 5-FU resistance in CRC therapy.

Cannabidiol (CBD) Inhibited Rhodamine-123 Efflux in Cultured Vascular Endothelial Cells and Astrocytes Under Hypoxic Conditions.

Despite the constant development of new antiepileptic drugs (AEDs), more than 30% of patients develop refractory epilepsy (RE) characterized by a multidrug-resistant (MDR) phenotype. The "transporters hypothesis" indicates that the mechanism of this MDR phenotype is the overexpression of ABC transporters such as P-glycoprotein (P-gp) in the neurovascular unit cells, limiting access of the AEDs to the brain. Recent clinical trials and basic studies have shown encouraging results for the use of cannabinoids in RE, although its mechanisms of action are still not fully understood. Here, we have employed astrocytes and vascular endothelial cell cultures subjected to hypoxia, to test the effect of cannabidiol (CBD) on the P-gp-dependent Rhodamine-123 (Rho-123) efflux. Results show that during hypoxia, intracellular Rho-123 accumulation after CBD treatment is similar to that induced by the P-gp inhibitor Tariquidar (Tq). Noteworthy, this inhibition is like that registered in non-hypoxia conditions. Additionally, docking studies predicted that CBD could behave as a P-gp substrate by the interaction with several residues in the α-helix of the P-gp transmembrane domain. Overall, these findings suggest a direct effect of CBD on the Rho-123 P-gp-dependent efflux activity, which might explain why the CBD add-on treatment regimen in RE patients results in a significant reduction in seizure frequency.

Targeted anti-inflammatory peptide delivery in injured endothelial cells using dermatan sulfate/chitosan nanomaterials.

This work describes a novel delivery system for targeting egg-derived anti-inflammatory tripeptide Ile-Arg-Trp (IRW) to endothelial cells. The nanomedicine is synthesized by a simple and reproducible ionotropic gelification method that results in the efficient loading of the positively charged IRW within the dermatan sulfate/ chitosan matrix, as demonstrated by ss-NMR spectroscopy. The incorporation of IRW results in a stable nanoparticle dispersion with a single size population of 442 ±â€¯43 nm. Fluorescence microscopy studies demonstrate the capacity of the nanomaterial to distinguish between a quiescent and an injured endothelium through the interaction of dermatan sulfate with the CD44 receptor. Remarkably, no additional surface functionalization is required as dermatan sulfate mediates their internalization and the intracellular release of this natural anti-inflammatory tripeptide to modulate endothelial inflammatory response. This simple, scalable, and versatile nanotechnology platform opens new opportunities to apply in the therapy of vascular disease.