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Aliivibrio fischeri is a heterotrophic marine bacterium capable of bioluminescence which is controlled by quorum sensing. Quorum sensing is a population density dependent communication method for the bacteria to coordinate their activities by producing and detecting low-molecular-weight signal molecules. The effective infectivity of the bacteria is based on various virulence factors controlled by quorum sensing. Cyclodextrins, a family of toroidal-shaped oligosaccharides, reversibly encapsulate in their hydrophobic interior the fatty acid acyl chain of the signal molecules, thus preventing their binding to the receptors and interrupting the bacterial communication consequently the expression of various properties including different virulence factors.Short-term tests were performed to examine the potential quorum quenching ability of newly prepared cyclodextrin derivatives: α- and β-cyclodextrins monosubstituted with alkylthio moieties. In these derivatives one of the modifiable hydroxyl groups of the cyclodextrin molecule is substituted with an alkylthio group of six, ten, twelve or sixteen carbon atoms. Cyclodextrins at 1.563–12.5 mM concentrations were added to A. fischeri culture in exponential growth phase, then the bioluminescence intensity, the population growth and the cell viability were kept under systematic review.According to our results, the cyclodextrins have inhibitory effect on the quorum sensing system of A. fischeri, the alkylthio-substitution improves this effect compared to the native molecules and the length of the alkyl chain has significant influence on the quorum quenching efficiency.

Cancer and drug-resistant bacterial infections are two of the biggest health threats that humankind is facing. In fact, cancer causes nowadays 9.6 million deaths/year and drug-resistantinfections are expected to reach the same figures by 2050. EC engages in supporting anincreasing number of research projects for innovative solutions to overcome drawbacks ofcurrently employed therapeutics. The ITN CyclonHit and the MSCA-IF Polar Star projects aretwo examples of EC commitment and focus on cyclodextrin (CD)-based nanocarriers toencapsulate, protect and potentiate known drugs to fight resistant bacteria and prostate cancer,respectively.In the frame of CyclonHit project, we developed biocompatible and biodegradablepolymeric CD nanoparticles (pCD NPs) able to coencapsulate by a “green” method two potentanti-tuberculosis molecules which are insoluble in biologically-compatible solvents. Theformulation process was complicated by the completely different physico-chemical properties ofthe two active agents and by the strong tendency to crystallize of one of them. The developedcarriers were spectroscopically characterized proving that the drugs were encapsulated at amolecular level not only in the CD cavities but also in the intermingled polymeric chains. Theefficacy of the developed NPs was demonstrated in vitro and in vivo. In particular, theaerosolized NPs suspension led to a 3-log decrease of the pulmonary bacterial load of infectedanimals after only 6 administrations. Interestingly, the unloaded pCD NPs exhibited themselvesa good antibacterial effect contributing to the action of the two active molecules.In the frame ofPolar Star, CD-based NPs are tailored to increase the effectiveness and the specificity ofknown drugs against castrate-resistant prostate cancer. The NPs are composed of innovativemixed polymers combining α, β and γ-CD in single polymers to improve loading capacity fordifferent therapeutic agents. The final goal is to exploit multicargo NPs able to act acrossmultiple oncogenic pathways.

Osteoarthritis is one of the most widespread diseases worldwide, with a progressive damage to cartilage and bone. In this context, the choice of biocompatible materials mimicking the cellular microenvironment is of the utmost importance to develop new drug carriers. Cyclodextrins (CDs) and hyaluronic acid (HA) are promising candidates for intra-articular injection in the joint synovial fluid because of the high biocompatibility and effectiveness of HA, empowered by the presence of the CD units able to entrap therapeutic agents for the regenerative process. Nano and micro scale polymeric assemblies based on cationic ?-CD polymers (PolyCDNH3+ or PolyCDNR3+) and HA have been developed by using both supramolecular and/or covalent approaches. Supramolecular nanoassemblies made from PolyCDNH3+ were obtained by using a crosslinker bearing two terminal adamantane moieties. Spongy hydrogels based on PolyCDNR3+/HA were prepared through amide formation. The nanoassemblies were loaded with fluorescent probe, with diclofenac and were characterized by complementary spectroscopic techniques including 1H-NMR, UV-Vis, steady-state and time-resolved fluorescence, DLS and ?-potential measurement. Release profiles were investigated in vitro in media mimicking the physiological conditions to ensure control over time and efficacy. Biocompatibility studies were performed by placing primary human bone marrow-derived mesenchymal stromal cells in contact with the nanosystems and testing cell viability by WST-1 assay. With these premises, this study might open novel routes to exploit original CD-based nanobiomaterials for OA treatment.

Clofazimine (CLZ) is an antibiotic with a promising behavior against Gram-positive bacteria; however, the drug is completely insoluble in water and accumulates in fat tissues. We explored nanocarriers, labeled and not labeled with rhodamine, consisting of negatively charged sulfobutylether-β-cyclodextrins for CLZ loading. A new oligomeric carrier was obtained cross-linking βCyD with epichlorohydrin followed by sulfonation in a strongly alkaline aqueous medium. The oligomeric carrier has a MW of 53 kDa and forms small nanoparticles of a few tens of nm. With aqueous solutions containing a 25 mg/mL oligomeric carrier, we loaded up to 0.5 mg/mL of drug. The oligomers exhibited a 10-fold better loading capacity compared to monomers and formed nanoparticles with a size in the 20-60 nm range after drug loading. Circular dichroism confirmed encapsulation of the CLZ in the nanocarriers. All carriers with or without CLZ are not cytotoxic up to 1 μM, while CLZ alone is highly cytotoxic at the same concentration. The drug has IC

Tuberculosis remains a major global health problem. The use of ethionamide (ETH), a second line drug, is associated to severe side-effects due to its low therapeutic index. We addressed this problem by loading ETH in ?-cyclodextrin (?CyD)-based carriers. The drug was incorporated in a molecular state avoiding crystallization even for long-term storage and obtaining a tenfold increased solubility up to 25 mM. The binding of ETH to polymeric ?CyD nanoparticles (p?CyD NPs) labelled and not with fluorescein (FITC) was investigated in neutral aqueous medium by means of solubility phase diagrams, circular dichroism (CD) and UV-Vis absorption and compared with the corresponding ?CyD monomer. The binding constants and the absolute CD spectra of the drug complexes were determined by global analysis of multiwavelength data from spectroscopic titrations. The spectroscopic and photophysical properties of the complexes evidenced an alcohol-like environment for ETH included in the cavity. Additionally, ETH was found to be located not only in ?CyD cavities, but also in confined microdomains inside the crosslinked NPs. This double modality of complexation together with a slightly higher binding constant makes the utilization of p?CyD NPs preferable over the monomeric ?CyDs. The ?CyD-based polymeric carrier appeared as versatile "green" system for efficient incorporation and future delivery of ETH. Finally, the drug-loaded NPs were passed through a Microsprayer® to evaluate the feasibility to administer p?CyD NPs by pulmonary route.

Cyclodextrins (CDs) are widely used compounds in pharmaceutical industry. They enhance solubility, bioavailability and stability of many drugs. Recently, several of CD derivatives have been synthetized in order to improve their physicochemical properties and inclusion capacities. Based on their pharmaceutical importance, many studies demonstrated the activity of CDs in drug complexation, however, there is limited information available about their cytotoxic effects. The aim of our study was to investigate the cytotoxic properties of various CD derivatives. We performed MTT cell viability assays on the Caco-2 human colon carcinoma cell system. In addition, we investigated cholesterol-CD complexation by an HPLC method, which determined the cholesterol content of the cholesterol-CD complex. The viability tests showed significant differences between the cytotoxicity of the CD derivatives. Cell toxicity of methylated CDs decreases DIMEBTRIMEBRAMEB. The anionic carboxymethylated derivative (CMBCD) and cationic quaternary amino beta-cyclodextrin (QABCD) proved to be less toxic than the methylated ones. Most of the second generation CD derivatives, which contain ionic substituents beside the methyl groups, showed less cytotoxicity than the parent compounds, only succinyl random methylated beta-CD (SU-RAMEB) and RAMEB represent the similar toxicological properties on Caco-2 cells. Harmful attributes of RAMEB, DIMEB and their cholesterol complexes were also investigated in our in vitro system. RAMEB and DIMEB cholesterol complex derivatives showed slight cytotoxic effects compared to the parent compounds. In conclusion, our studies demonstrated a significant correlation between the cytotoxic effect and the cholesterol complexation attributes of CD derivatives.

Large number of sulfated derivatives of cyclodextrin (CD) monomers have been described in the literature [1], for preparation of water soluble CD polymer sulfates, however, only two references can be found [2,3]. Sulfated derivatives can be prepared by reacting the CD with chlorosulfonic acid or SO3 complexes. The average degree of substitution (DS) of the product can be calculated based on sulfur content or from the results of MS, NMR, IR or titrimetric measurements.

The effectiveness of cyclodextrin polymer as a disintegrating agent for directly compressed tablets containing furosemide, cyclodextrin polymer and microcrystalline cellulose was investigated. Regression analysis based on statistically designed experiments made it possible to determine how various tablet characteristics are affected by the amount of excipients. As a result of computer optimization an optimum formulation was obtained exhibiting high dissolution rate, sufficient dissolution stability, fast disintegration, high hardness immediately after preparation and adequate hardness after ageing.

The binding and disintegrating properties of cyclodextrin polymer as well as its effect on the dissolution of a poorly soluble drug have been evaluated on the basis of the hardness, friability and disintegration time of directly compressed tablets. The hardness of tablets containing cyclodextrin polymer in addition to potato starch or lactose was lower than that of tablets with microcrystalline cellulose indicating that cyclodextrin polymer has a relatively poor binding capacity. The disintegrating action of cyclodextrin polymer was compared to those of potato starch and lactose, with microcrystalline cellulose as a binder. Equal disintegration times were obtained with 2.5% cyclodextrin polymer, 12.5% potato starch, and 25% lactose. The dissolution rate of furosemide was greatly accelerated by as little as 2.5% cyclodextrin polymer added to microcrystalline cellulose. A somewhat lower dissolution rate was observed with 12.5% potato starch. As a result it was shown that cyclodextrin polymer, which has excellent disintegrating properties as well as some binding capacity, can be used advantageously in direct compression systems as a binder-disintegrant.

Clofazimine (CLZ) is an antibiotic with a promising behavior against Gram-positive bacteria; however, the drug is completely insoluble in water and accumulates in fat tissues. We explored nanocarriers, labeled and not labeled with rhodamine, consisting of negatively charged sulfobutylether-beta-cyclodextrins for CLZ loading. A new oligomeric carrier was obtained cross-linking beta CyD with epichlorohydrin followed by sulfonation in a strongly alkaline aqueous medium. The oligomeric carrier has a MW of 53 kDa and forms small nanoparticles of a few tens of nm. With aqueous solutions containing a 25 mg/mL oligomeric carrier, we loaded up to 0.5 mg/mL of drug. The oligomers exhibited a 10-fold better loading capacity compared to monomers and formed nanoparticles with a size in the 20-60 nm range after drug loading. Circular dichroism confirmed encapsulation of the CLZ in the nanocarriers. All carriers with or without CLZ are not cytotoxic up to 1 mu M, while CLZ alone is highly cytotoxic at the same concentration. The drug has IC50 values below 100 nM against S. epidermidis. The same holds true also for clinical isolates of S. epidermidis, some displaying MDR So, the selectivity index significantly increased for CLZ/carrier systems compared to the drug alone. Taken all together, our results open new avenues for the clinical application of this antibiotic.