Effect of β-cyclodextrin and its derivatives on caveolae disruption, relationships with their cholesterol extraction capacities

Nanoparticles Incorporating a Fluorescence Turn-on Reporter for Real-Time Drug Release Monitoring, a Chemoenhancer and a Stealth Agent: Poseidon's Trident against Cancer?

The rate and extent of drug release under physiological conditions is a key factor influencing the therapeutic activity of a formulation. Real-time detection of drug release by conventional pharmacokinetics approaches is confounded by low sensitivity, particularly in the case of tissue-targeted novel drug delivery systems, where low concentrations of the drug reach systemic circulation. We present a novel fluorescence turn-on platform for real-time monitoring of drug release from nanoparticles based on reversible fluorescence quenching in fluorescein esters. Fluorescein-conjugated carbon nanotubes (CNTs) were esterified with methotrexate in solution and solid phase, followed by supramolecular functionalization with a chemoenhancer (suramin) or/and a stealth agent (dextran sulfate). Suramin was found to increase the cytotoxicity of methotrexate in A549 cells. On the other hand, dextran sulfate exhibited no effect on cytotoxicity or cellular uptake of CNTs by A549 cells, while a decrease in cellular uptake of CNTs and cytotoxicity of methotrexate was observed in macrophages (RAW 264.7 cells). Similar results were also obtained when CNTs were replaced with graphene. Docking studies revealed that the conjugates are not internalized by folate receptors/transporters. Further, docking and molecular dynamics studies revealed the conjugates do not exhibit affinity toward the methotrexate target, dihydrofolate reductase. Molecular dynamics studies also revealed that distinct features of dextran-CNT and suramin-CNT interactions, characterized by π-π interactions between CNTs and dextran/suramin. Our study provides a simple, cost-effective, and scalable method for the synthesis of nanoparticles conferred with the ability to monitor drug release in real-time. This method could also be extended to other drugs and other types of nanoparticles.

NDS27 combines the effect of curcumin lysinate and hydroxypropyl-β-cyclodextrin to inhibit equine PKCδ and NADPH oxidase involved in the oxidative burst of neutrophils

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The antioxidant effects of curcumin lysinate complexed with two cyclodextrins were compared.

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NDS27 is complexed with hydroxypropyl-β- and NDS28 with γ-cyclodextrin.

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NDS27 but not NDS28 inhibits translocation and activity of PKCδ and NADPH oxidase.

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NDS27 but not NDS28 improved the release of curcumin lysinate and its exchange with membrane lipids.

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NDS27 is a good candidate molecule to inhibit ROS production by neutrophils.

Polymorphonuclear neutrophils (PMNs) are involved in host defence against infections by the production of reactive oxygen species (ROS), but excessive PMN stimulation is associated with the development of inflammatory diseases. After appropriate stimuli, protein kinase C (PKC) triggers the assembly of NADPH oxidase (Nox2) which produces superoxide anion (O₂^•−), from which ROS derive. The therapeutic use of polyphenols is proposed to lower ROS production by limiting Nox2 and PKC activities. The purpose of this study was to compare the antioxidant effect of NDS27 and NDS28, two water-soluble forms of curcumin lysinate respectively complexed with hydroxypropyl-β-cyclodextrin (HPβCD) and γ-cyclodextrin (γ-CD), on the activity of Nox2 and PKCδ, involved in the Nox2 activation pathway. Our results, showed that NDS27 is the best inhibitor for Nox2 and PKCδ. This was illustrated by the combined effect of HPβCD and curcumin lysinate: HPβCD, but not γ-CD, improved the release of curcumin lysinate and its exchange against lipid or cholesterol as demonstrated by the lipid colouration with Oil Red O, the extraction of radical lipophilic probes recorded by ESR and the HPLC measurements of curcumin. HPβCD not only solubilised and transported curcumin, but also indirectly enhanced its action on both PKC and Nox2 activities. The modulatory effect of NDS27 on the Nox2 activation pathway of neutrophils may open therapeutic perspectives for the control of pathologies with excessive inflammatory reactions.

Intra- and extracellular antioxidant capacities of the new water-soluble form of curcumin (NDS27) on stimulated neutrophils and HL-60 cells

Phagocytic cells, especially neutrophils (PMNs) are specialized in the production of reactive oxygen species (ROS) to kill pathogenic agents, but an excessive ROS production is associated with tissue damages and inflammatory diseases. Phagocytes are thus prime therapeutic targets to control inflammatory events associated to ROS production. Nowadays, there is a growing interest for the use of polyphenols to modulate the inflammatory response. The aim of this work was to study the antioxidant effect of NDS27, a highly water-soluble form of the polyphenolic molecule curcumin, on in vitro stimulated equine PMNs and human promyelocytic leukemia cells (HL-60). NDS27 was either pre-incubated with cells and eliminated before their activation (intracellular effect) or let in the medium (extracellular effect). Our results indicate that NDS27 significantly and dose-dependently (10(-6) M-10(-4) M) inhibited the ROS production in both cell types without affecting their viability. NDS27 was able to cross and interact with cell membrane, especially for HL-60 cells, while we observed a better intracellular antioxidant effect with PMNs. The activity of myeloperoxidase (MPO) released by PMNs and HL-60 cells, was decreased by NDS27, but more efficiently for PMNs. These results suggested that the greater efficiency of NDS27 in PMNs is due to an inhibitory effect on cells which are more mature for ROS production, probably by targeting the enzymes implied in respiratory burst like MPO. The modulatory effect of NDS27 on the oxidant activity of cells involved in immune and inflammatory responses opens perspectives for a therapeutic control of pathologies with excessive inflammatory reactions.