Curcumin is a natural polyphenol with anti-oxidative, anti-inflammatory and anti-cancer properties but its therapeutic potential is substantially hindered by the rather low water solubility and bioavailability. Thus, in this work, a new soluble inclusion complex of curcumin with sulfobutylether--cyclodextrin (SBE-β-CD) was prepared in solution and at the solid state using different preparation techniques and characterized by FT-IR, NMR, DSC, SEM, phase solubility studies and Job’s plot method. Results clearly indicate that curcumin reacts with SBE-β-CD to form a host-guest complex with an apparent formation constant of 1455 M-1. Moreover, SBE-β-CD strongly increases water solubility of curcumin (from 0.56 to 102.78 g/ml, at 25◦C) and lyophilization method seems to be the best preparation technique to obtain the complex at the solid state. Finally, an in vitro test on a human hepatic cancer cell line (HepG-2) shows that complexation positively influences curcumin anticancer and antioxidant activity

Solid inclusion complex between hydroxypropyl-β-cyclodextrin (HP-β-CD) and minoxidil (MXD) was prepared by freeze-drying and characterized by yield, drug loading and dissolution rate. Moreover, the complex was formulated as alginate gel (GEL HP-β-CD)/MXD 3.5% w/w). The efficacy of the novel GEL HP-β-CD)/MXD 3.5% w/w and of MXD 3.5% w/w ethanolic/propylene-glycol solution (MXD solution) were evaluated by monitoring the hair growth of dorsal skin 1-4 weeks after depilation followed by histological analysis and gene expression in skin biopsies in male rat. Patch-clamp experiments and cell-dehydrogenase activity (CDA) were performed to evaluate the capability of the formulations to activate "in vitro" the ATP-sensitive K(+)-channels (KATP) and their effects on cell viability in skin fibroblasts. After 3 weeks, the MXD solution and MXD/HP-β-CD GEL enhanced the hair growth, respectively, of 80.1±2% and 84.3±4% vs controls. After 4 weeks, the MXD/HP-β-CD GEL significantly enhanced the hair length and bulb diameter vs others groups. The MXD/HP-β-CD GEL significantly enhanced the mRNA levels of the SUR2 and Kir6.1 subunits of the KATP channels and AKT2 vs other groups. The AR gene was down-regulated vs controls following the treatment with either MXD formulations. Either MXD (10(-4)M) formulations were effective in potentiating the KATP currents. The MXD solution and its vehicle after 9 h of incubation time, but not MXD/HP-β-CD, reduced CDA in fibroblasts. In sum, the MXD/HP-β-CD GEL shows a favorable profile following topical long-term use.

The main aim of the present study was to estimate the carrier characteristics affecting the dissolution efficiency of Griseofulvin (Gris) containing blends (BLs) using partial least squares (PLS) regression analysis. These systems were prepared at three different drug/carrier weight ratios (1/5, 1/10, and 1/20) by the solvent evaporation method, a well-established method for preparing solid dispersions (SDs). The carriers used were structurally different including polymers, a polyol, acids, bases and sugars. The BLs were characterised at the solid-state by spectroscopic (Fourier transform infrared spectroscopy), thermoanalytical (differential scanning calorimetry) and X-ray diffraction studies and their dissolution behaviours were quantified in terms of dissolution efficiencies (log DE/DEGris). The correlation between the selected descriptors, including parameters for size, lipophilicity, cohesive energy density, and hydrogen bonding capacity and log DE/DEGris (i.e., DE and DEGris are the dissolution efficiencies of the BLs and the pure drug, respectively) was established by PLS regression analysis. Thus two models characterised by satisfactory coefficient of determination were derived. The generated equations point out that aqueous solubility, density, lipophilic/hydrophilic character, dispersive/polar forces and hydrogen bonding acceptor/donor ability of the carrier are important features for dissolution efficiency enhancement. Finally, it could be concluded that the correlations developed may be used to predict at a semiquantitative level the dissolution behaviour of BLs of other essentially neutral drugs possessing hydrogen bonding acceptor groups only.

Mitochondria represent an attractive subcellular target due to its function particularly important for oxidative damage, calcium metabolism and apoptosis. However, the concept of mitochondrial targeting has been a neglected area so far. The translocator protein (TSPO) represents an interesting subcellular target not only to image disease states overexpressing this protein, but also for a selective mitochondrial drug targeting. Recently, we have delivered in vitro and in vivo small molecule imaging agents into cells overexpressing TSPO by using a family of high-affinity conjugable ligands characterized by 2-phenyl-imidazo[1,2-a]pyridine acetamide structure. As an extension, in the present work we studied the possibility to target and image TSPO with dendrimers. These nano-platforms have unique features, in fact, are prepared with a level of control not reachable with most linear polymers, leading to nearly monodisperse, globular macromolecules with a large number of peripheral groups. As a consequence, they are an ideal delivery vehicle candidate for explicit study of the effects of polymer size, charge, composition, and architecture on biologically relevant properties such as lipid bilayer interactions, cytotoxicity, cellular internalization, and subcellular compartments and organelles interactions. Here, we present the synthesis, characterization, cellular internalization, and mitochondria labeling of a TSPO targeted fourth generation [G(4)-PAMAM] dendrimer nanoparticle labeled with the organic fluorescent dye fluorescein. We comprehensively studied the cellular uptake behavior of these dendrimers, into glioma C6 cell line, under the influence of various endocytosis inhibitors. We found that TSPO targeted-G(4)-PAMAM-FITC dendrimer is quickly taken up by these cells by endocytosis pathways, and moreover specifically targets the mitochondria as evidenced from subcellular fractionation experiments and co-localization studies performed with CAT (Confocal-AFM-TIRF) microscopy.

Succinic derivatives of inulin (INU-SA) with two different degrees of derivatization (20% and 30%, mol/mol) were cross-linked with alpha,beta-polyaspartylhydrazide (PAHy) to obtain INUPAHy hydrogels. Crosslinking was performed using N-ethyl-N-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (NHSS) as coupling agents and by varying the reaction time (4 h, 8 h and 24 h). All samples prepared were characterized by FT-IR analysis and swelling measurements in different media. In vitro assays, performed in the presence of inulinase, demonstrated the degradability of the prepared hydrogels. Cell compatibility was evaluated using Caco-2 cells through both direct and indirect assay. Glutathione (GSH) and oxytocin (OT), both potential agents for the treatment of colonic inflammation, were entrapped into a INUPAHy hydrogel and their release was evaluated in simulated gastrointestinal fluids. The obtained results suggest that GSH- and OT-loaded INUPAHy hydrogels are potentially useful for the oral treatment of inflammatory bowel disease. (C) Koninklijke Brill NV, Leiden, 2011

New conjugates between inulin (INU) and vitamin E (VITE) able to form amphiphilic systems self-assembling in nanostructures thought for biomedical applications such as the therapy of urinary tract affections were prepared. This work, shows the syntheses, characterization and self-assembling properties of the obtained polymeric conjugates (INVITE). The reaction between VITE and INU has been carried out in bulk, without isolation of intermediate products leading to a convenient one-step reaction. To tailor the physical-chemical characteristics of the INVITE bioconjugate, six different INVITE conjugates were obtained by varying the relative amount of bonded VITE respect to INU repeating units. The obtained products were characterized by 1H-NMR, 13C-NMR, FT-IR and DSC. Furthermore, to verify that VITE does not undergo any oxidation during the reactions, UV-VIS analyses have been performed and the ability of the new conjugates to form nanoparticulate systems in water or 0.9 % saline was performed by dynamic light scattering. Furthermore, in the same media, was evaluated the stability of the INVITE nanosystems after incubation at 25 °C up to 12 days, by measuring at different time points their size variation. The degree of derivatization was found not influenced by the temperature, but it mostly depend from the different molar ratios. Interestingly, the introduction of VITE in the inulin backbone resulted almost quantitative. All conjugates resulted self-assembling in water forming nanosystems sized below 100 nm. The nanosystems are stable and do not aggregate after 12 days incubation. These results strongly encourage to prove these systems for drug delivery applications.

Aim of this project is the synthesis and characterization of nanostructured drug delivery systems (DDS) to be used in the therapy of urinary tract affections. The main idea is based on the synthesis of a bioconjugate between inulin and vitamin E (INVITE) able to produce amphiphilic systems self-assembling in nanostructured DDS even at low concentrations. A so ideated system should solubilize, incorporate and protect lipophilic drugs while targeting them in the urinary tract [1,2].

The transport of dopamine across the blood brain barrier represents a challenge for the management of Parkinson's disease. The employment of central nervous system targeted ligands functionalized nanocarriers could be a valid tactic to overcome this obstacle and avoid undesirable side effects. In this work, transferrin functionalized dopamine-loaded liposomes were made by a modified dehydration-rehydration technique from hydrogenated soy phosphatidylcoline, cholesterol and 1,2-stearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(poly(ethylene glycol)-2000)]. The physical features of the prepared liposomes were established with successive determination of their endothelial permeability across anin vitromodel of the blood-brain barrier, constituted by human cerebral microvascular endothelial cells (hCMEC/D3). Functionalized dopamine-loaded liposomes with encapsulation efficiency more than 35% were made with sizes in a range around 180 nm, polydispersity indices of 0.2, and positive zeta potential values (+7.5 mV). Their stability and drug release kinetics were also evaluated. The apparent permeability (Pe) values of encapsulated dopamine in functionalized and unfunctionalized liposomes showed that transferrin functionalized nanocarriers could represent appealing non-toxic candidates for brain delivery, thus improving benefits and decreasing complications to patients subjected to L-dopa chronical treatment.

Translocator protein 18 kDa (TSPO) is a promising target for molecular imaging and for targeted drug delivery to tumors overexpressing TSPO. In our previous work, new macromolecular conjugates with a high affinity and selectivity for TSPO were prepared by conjugating the biodegradable poly(d,l-lactic-co-glycolic acid) (PLGA) polymer with two potent and selective TSPO ligands, namely, compounds 1 and 2. Based on this, nanoparticle delivery systems (NPs), employing TSPO ligand-PLGA conjugated (PLGA-TSPO) polymers, were prepared. Furthermore, to evaluate the ability of the new NPs to be used as a drug delivery systems for anticancer therapy, PLGA-TSPO NPs were loaded with 5-fluorouracil (5-FU), chosen as a model hydrophilic anticancer drug. The main goal of this work was to investigate the synergistic potential of using NP conjugates PLGA-TSPO, TSPO ligands being pro-apoptotic agents, to simultaneously deliver a cytotoxic anticancer drug. To better highlight the occurrence of synergistic effects, dual drug loaded PLGA NPs (PLGA NPs/5-FU/1) and dual drug loaded PLGA-TSPO NPs (PLGA-TSPO NPs/5-FU/1), with 5-FU and TSPO ligand 1 physically incorporated together, were also prepared and characterized. The particle size and size distribution, surface morphology, and drug encapsulation efficiency, as well as the drug release kinetics, were investigated. In vitro cytotoxicity studies were carried out on C6 glioma cells overexpressing TSPO, and to evaluate the potential uptake of these nanoparticulate systems, the internalization of fluorescent labeled PLGA-TSPO NPs (FITC-PLGA-TSPO NPs) was also investigated by fluorescence microscopy. Results demonstrated that PLGA-TSPO NPs/5-FU and dual drug loaded PLGA NPs/5-FU/1 and PLGA-TSPO NPs/5-FU/1 could significantly enhance toxicity against human cancer cells due to the synergistic effect of the TSPO ligand 1 with the anticancer drug 5-FU.