Chitosan-Hyaluronan Nanoparticles for Vinblastine Sulfate Delivery: Characterization and Internalization Studies on K-562 Cells.

In the present study, we developed chitosan/hyaluronan nanoparticles (CS/HY NPs) for tumor targeting with vinblastine sulfate (VBL), that can be directed to the CD44 transmembrane receptor, over-expressed in cancer cells. NPs were prepared by coating with HY-preformed chitosan/tripolyphosphate (CS/TPP) NPs, or by polyelectrolyte complexation of CS with HY. NPs with a mean hydrodynamic radius (RH) of 110 nm, 12% polydispersity index and negative zeta potential values were obtained by a direct complexation process. Transmission Electron Microscopy (TEM) images showed spherical NPs with a non-homogeneous matrix, probably due to a random localization of CS and HY interacting chains. The intermolecular interactions occurring between CS and HY upon NPs formation were experimentally evidenced by micro-Raman (µ-Raman) spectroscopy, through the analysis of the spectral changes of characteristic vibrational bands of HY during NP formation, in order to reveal the involvement of specific chemical groups in the process. Optimized NP formulation efficiently encapsulated VBL, producing a drug sustained release for 20 h. In vitro studies demonstrated a fast internalization of labeled CS/HY NPs (within 6 h) on K-562 human myeloid leukemia cells. Pre-saturation of CD44 by free HY produced a slowing-down of NP uptake over 24 h, demonstrating the need of CD44 for the internalization of HY-based NPs.

Flow cytometry and micro-Raman spectroscopy: Identification of hemocyte populations in the mussel Mytilus galloprovincialis (Bivalvia: Mytilidae) from Faro Lake and Tyrrhenian Sea (Sicily, Italy).

Immunological and structural characteristics of hemocyte populations in the mussel Mytilus galloprovincialis (Bivalvia: Mytilidae), going from two different Sicilian habitats (Faro Lake and Tyrrhenian sea), was investigated by means of two different techniques (flow cytometric and micro-Raman spectroscopy analyses). For this purpose, three hundred and sixty mussels Mytilus galloprovincialis were analyzed during November 2017. They were divided into two equal groups (triplicate sample) on the basis of the site of collection (n = 60 caught in Faro Lake - group A, and n = 60 caught in Tyrrhenian Sea - group B). Some several differences between the species of Faro Lake and Tyrrhenian Sea are observed and ascribed to the disruption of immune parameters induced by the variations of some qualitative water parameters (temperature, salinity, dissolved oxygen, pH, ammonium 10, free chlorine, total chlorine, total phosphate, orthofhosphate) recorded in the two habitats. This study is relevant for monitoring the conditions of the sea and Faro Lake, which is strongly influenced by the currents of the Tyrrhenian Sea. Faro lake is well known for the cultivation of mussels and this is part of a coastal habitat of particular interest, consisted of a peculiar biocenotic complex. Further, for the first time, significant different arrangement in the mussels cell structural organization was evidenced by simply following their highly reproducible Raman biomolecular signatures.

Synthesis and physico-chemical characterization of a ß-cyclodextrin conjugate for sustained release of Acyclovir.

We report the synthesis of an oligomeric prodrug of the antiviral agent Acyclovir (Acy) conjugated to ß-cyclodextrin (ß-CyD). The drug was selectively linked through a succinic spacer to one of the primary hydroxyl groups of ß-CyD by ester linkage in a 1:1 molar ratio. The conjugate was purified by semipreparative reverse-phase chromatography and characterized by FAB mass spectrometry and NMR experiments. The release of Acy from the conjugate was evaluated both in acidic and in neutral conditions and in the presence of porcine liver esterase. In all cases we observed the release of both free Acy and Acy succinate (AcySucc) at differing rates as a function of the hydrolysis conditions. In the presence of esterase the release of free Acy was favoured over AcySucc, showing a release rate of 100% of Acy within 7 days.

A characterization study of resveratrol/sulfobutyl ether-ß-cyclodextrin inclusion complex and in vitro anticancer activity.

A resveratrol/sulfobutylether-ß-cyclodextrin inclusion complex was prepared using the freeze-drying method and characterized in solution through UV-vis spectroscopy, solubility phase studies and Job's plot methods. At the solid state it was characterized using the FTIR-ATR technique. Sulfobutylether-ß-cyclodextrin has a high affinity for the drug, and forms an inclusion complex with a 1:1 molar ratio both in solution and as a solid sample. It also has a high stability constant (Kc, 10,114 M(-1)). Complexation strongly increases the water solubility of resveratrol (from 0.03 mg/ml to 1.1 mg/ml, at 25 °C) and positively influences its in vitro anticancer activity which was observed on a human breast cancer cell line (MCF-7). In solid phase, FTIR-ATR revealed itself as being a useful technique in elucidating the complexation mechanism, which it did by emphasizing the functional groups involved in the activation of non-covalent "host-guest" interactions.

Celecoxib-loaded PLGA/cyclodextrin microspheres: characterization and evaluation of anti-inflammatory activity on human chondrocyte cultures.

PLGA microspheres were prepared as a sustained release system for the intra-articular administration of celecoxib (CCB). The microspheres were prepared in the presence of different concentrations of dimethyl-ß-cyclodextrin (DM-ß-Cyd), by the simple oil-in-water emulsion/evaporation solvent method. The microspheres were evaluated as to surface morphology, size and technological properties (such as encapsulation efficiency, drug loading capacity and drug release). Ex vivo studies on cultures of human chondrocytes were performed in order to evaluate the influence of the polymeric carriers on the pharmacological activity of CCB. All systems ranged from about 1 to 5 µm in size and had a high encapsulation efficiency percentage ranging from about 80% to 90% (w/w), except for CCB-loaded-PLGA microspheres containing the highest amount of DM-ß-Cyd, in which a dramatic drop in the encapsulation efficiency was observed (about 54%, w/w). FIB images evidenced the fact that the microspheres had a porous structure in the presence of the highest amount of DM-ß-Cyd. The macrocycle modulated the release profiles of CCB from the microspheres, producing in some cases a zero-order kinetic release. Ex vivo biological studies demonstrated that DM-ß-Cyd improved the drug's anti-inflammatory activity. Thus, CCB-loaded PLGA/cyclodextrin microspheres may have a potential therapeutic application in the treatment of osteo- and rheumatoid arthritis.

Structural and spectroscopic features of lutein/butanoyl-ß-cyclodextrin nanoassemblies.

Lutein, the primary carotenoid present in the central area of the retina of eye appears to be associated with the protection against age-related macular degeneration (the leading cause of blindness in older adults). Its lipophilicity and consequently its scarce water solubility (1.3×10(-9)M) represent a drawback for bioavailability. To circumvent these unfavorable characteristics, in this work lutein (Lut) have been encapsulated in amphiphilic cyclodextrin (ACyD) by following the well-established strategy of entrapping a lipophilic drug in CyD carriers. Primary face butyrate modified ß-cyclodextrins (C(4:7)) form in water nanoaggregates with a average size of 250nm and a ζ-potential of about -6mV. They are able to entrap lutein at 1:6 Lut/ACyD molar ratio by yielding nanoassemblies of vesicular aspect (320nm and -8mV) such as observed by static, dynamic and electrophoretic light-scattering. UV-vis measurements revealed that electronic properties of lutein were maintained when interact with ACyD nanoaggregates. The monitoring of the entapped carotenoid leaking from ACyD nanostructures was investigated suggesting the potential of Lut/ACyD nanoassemblies in drug delivery.

Gemcitabine-loaded chitosan microspheres. Characterization and biological in vitro evaluation.

This study investigates the potential of chitosan microspheres as delivery systems for the anticancer drug gemcitabine. The microspheres were obtained by spray-drying chitosan-gemcitabine solutions containing different amounts of the polyanion dextran sulphate. Morphological characterization by SEM and FIB analyses showed the presence of porous spherical particles having sizes ranging from about 1 to 5 µm. Dextran sulphate improves the technological parameters of the systems by producing very high encapsulation efficiency (about 96%, w/w) and by influencing the in vitro release of gemcitabine. The immediate drug release observed in the system prepared without dextrane sulphate (complete drug release within 30 min) was somewhat reduced by the polyanion (immediate release of 70% (w/w) of the encapsulated drug within 30 min, and subsequent continued release of the remaining 30% of the drug for over 4 days). The anti-tumoral efficacy of the various formulations was tested in vitro on human lung cancer cells (A549) comparing the effects with those of the free drug or drug/dextran sulfate complex. The carriers improved the cytotoxic activity of the drug, particularly the formulation containing the lowest amount of dextran sulphate after 72 h incubation.

Amphiphilic cyclodextrins as nanocarriers of genistein: A spectroscopic investigation pointing out the structural properties of the host/drug complex system.

Nanoggregates of nonionic amphiphilic cyclodextrin (ACyD) modified with hydrophobic chains of intermediate length [(2-oligo-ethyleneoxide-6-hexylthio)-beta-CyD, SC6OH] were prepared by emulsification-diffusion method. They are able to entrap an isoflavone, genistein (Gen), and the complexed species are studied at different host/guest molar ratio. The increased isoflavone solubility in the presence of the aggregates of SC6OH is investigated by UV-Vis spectroscopy, whereas size, charge, and structure of aggregates and their complexes with Gen are measured by means of static and quasi-elastic light scattering, and electrophoretic mobility measurements. On the other hand, preparing samples by the conventional method used for liposomes (hydration of an organic film of SC6OH and sonication) gives rise to aggregates with different sizes and lower colloidal stability. It is shown that the improved stability in water of ACyD aggregates both in the absence and in the presence of Gen, obtained by emulsification-diffusion is due to the existence of nanodomains of organic solvent (R(H) congruent with 120 nm) which cannot be completely removed by evaporation and freeze-drying and in which host/guest complexes are contained. This result shows that residues of organic solvent from preparation step favor the colloidal stability of the aggregate, but their presence must be taken into account in designing systems for drug delivery.