Polymorphic Self-Organization of Lauroyl Peptide in Response to pH and Concentration.

Amphipathic peptides are attractive building blocks for the preparation of self-assembling, bio-inspired, and stimuli responsive nanomaterials with pharmaceutical interest. The bioavailability of these materials can be improved with the insertion of d amino acid residues to avoid fast proteolysis in vivo. With this knowledge, a new lauroyl peptide consisting of a sequence of glycine, glycine, d-serine, and d-lysine was designed. In spite of its simple sequence, this lipopeptide self-assembles into spherical micelles at acid pH, when the peptide moiety adopts disordered conformations. Self-aggregates reshape toward fibers at basic pH, following the conformational transition of the peptide region from random coil to ß-sheet. Finally, hydrogels are achieved at basic pH and higher concentrations. The transition from random coil to ß-sheet conformation of the peptide headgroup obtained by increasing pH was monitored by circular dichroism and vibrational spectroscopy. A structural analysis, performed by combining dynamic light scattering, small-angle X-ray scattering, transmission electron microscopy, and molecular dynamic simulations, demonstrated that the transition allows the self-assemblies to remodel from spherical micelles to rodlike shapes, to long fibers with rectangular cross-section and a head-tail-tail-head structure. The viscoelastic behavior of the hydrogels formed at the highest pH was investigated by rheology measurements.

Comorbidities are associated with different features of severe asthma.

BACKGROUND: According to ATS/ERS document on severe asthma (SA), the management of these patients requires the identification and proper treatment of comorbidities, which can influence the control of asthma. METHODS: The aim of this study was to assess the independent effect of different comorbidities on clinical, functional and biologic features of SA. Seventy-two patients with SA according to GINA guidelines were examined. We collected demographic data, smoking habit, asthma history, and assessment of comorbidities. Pulmonary function, inflammatory biomarkers, upper airway disease evaluation, asthma control and quality of life were carefully assessed. RESULTS: The mean age of patients was 59.1 years (65.3% female, 5.6% current smokers). Comorbidities with higher prevalence were: chronic rhinosinusitis with or without nasal polyps (CRSwNP or CRSsNP), obesity and gastro-esophageal reflux (GERD), with some overlapping among them. In an univariate analysis comparing patients with single comorbidities with the other ones, asthmatics with CRSwNP had lower lung function and higher sputum eosinophilia; obese asthmatics had worse asthma control and quality of life, and tended to have lower sputum eosinophils; asthmatics with GERD showed worse quality of life. In multivariate analysis, obesity was the only independent factor associated with poor asthma control (OR 4.9), while CRSwNP was the only independent factor associated with airway eosinophilia (OR 16.2). Lower lung function was associated with the male gender and longer duration of asthma (OR 3.9 and 5.1, respectively) and showed a trend for the association with nasal polyps (OR 2.9, p = 0.06). CONCLUSION: Our study suggests that coexisting comorbidities are associated with different features of SA.

Self-assembly and drug release study of linear l,d-oligopeptide-poly(ethylene glycol) conjugates.

The preparation and structural organisation of new bioinspired nanomaterials based on regular alternating enantiomeric sequence of tetra- and hexapeptides end-linked to poly(ethylene glycol) (PEG) is reported. The peptide moiety is composed of two or three repeats of l-Ala-d-Val units while the PEG has a molecular weight of 2kDa. The self-assembling properties of the two conjugates depend significantly on the length of the peptide. Nanoparticles with different sizes and morphologies are formed, the structural properties of which are compared with the previously studied l-Ala-d-Val octapeptide conjugate that self-assembles into rod-like nanoparticles. The aggregation properties were studied by NMR, circular dichroism, fluorescence spectroscopies and dynamic light scattering. The morphology and size of the nanoparticles were assessed by scanning electron microscopy and dynamic light scattering. The loading and release of a model drug were also investigated. This study demonstrates that, by changing the length of the peptide, it is possible to modulate the self-assembly and loading properties of peptide-PEG conjugates.

Asthma Control and Airway Inflammation in Patients with Eosinophilic Granulomatosis with Polyangiitis.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic necrotizing vasculitis that occurs in patients with asthma, nasal disease, blood and tissue eosinophilia, and extrapulmonary manifestations. OBJECTIVE: The aim of our study was to assess the clinical, functional, and inflammatory status of upper and lower airways in 37 patients with EGPA, examined 6.4 ± 4.7 years after diagnosis, when they were in partial or complete remission from systemic involvement while on treatment with low-dose oral corticosteroids as maintenance therapy. METHODS: All patients performed spirometry and were assessed for bronchial hyperreactivity, sputum eosinophilia, and fractional exhaled nitric oxide; asthma control was evaluated according to the Global Initiative for Asthma (GINA) guidelines and the Asthma Control Test. Markers of systemic disease were compared with the data available at diagnosis. Nasal involvement was evaluated by using the Sino-Nasal Outcome Test, nasal endoscopy, and nasal cytology. The impact on the quality of life was evaluated by using generic (36-item short form health survey) and organ-specific questionnaires. RESULTS: At the time of the study visit, almost all patients were receiving low-dose oral corticosteroids and immunomodulating drugs, but only 50% were being treated with inhaled corticosteroids. Although low systemic disease activity was documented in the large majority of patients, poorly controlled asthma and rhinosinusitis with eosinophilic airway inflammation were demonstrated in almost all patients. A significant correlation was found between sputum and blood eosinophilia and between fractional exhaled nitric oxide and asthma control. The 36-item short form health survey questionnaire results significantly correlated with the Sino-Nasal Outcome Test but not with the Asthma Control Test. CONCLUSIONS: Systemic treatment controls systemic involvement in EGPA, but not asthma and nasal diseases, which negatively affects patients' quality of life.

Synthesis and Antiplasmodial Activity of Novel Chloroquine Analogues with Bulky Basic Side Chains.

Chloroquine is commonly used in the treatment and prevention of malaria, but Plasmodium falciparum, the main species responsible for malaria-related deaths, has developed resistance against this drug. Twenty-seven novel chloroquine (CQ) analogues characterized by a side chain terminated with a bulky basic head group, i.e., octahydro-2H-quinolizine and 1,2,3,4,5,6-hexahydro-1,5-methano-8H-pyrido[1,2-a][1,5]diazocin-8-one, were synthesized and tested for activity against D-10 (CQ-susceptible) and W-2 (CQ-resistant) strains of P. falciparum. Most compounds were found to be active against both strains with nanomolar or sub-micromolar IC50 values. Eleven compounds were found to be 2.7- to 13.4-fold more potent than CQ against the W-2 strain; among them, four cytisine derivatives appear to be of particular interest, as they combine high potency with low cytotoxicity against two human cell lines (HMEC-1 and HepG2) along with easier synthetic accessibility. Replacement of the 4-NH group with a sulfur bridge maintained antiplasmodial activity at a lower level, but produced an improvement in the resistance factor. These compounds warrant further investigation as potential drugs for use in the fight against malaria.

Asthma control in severe asthmatics under treatment with omalizumab: a cross-sectional observational study in Italy.

Few data are available on the proportion of asthmatics achieving a good asthma control (according GINA guidelines) and on the level of airway inflammation during omalizumab treatment. The aim of this cross-sectional national observational study was to assess the level of control (according to GINA guidelines) achieved in a group of asthmatics on omalizumab treatment, and to characterize the factors that influence the lack of control. We studied 306 asthmatics under omalizumab treatment for a median of 32 months (range 4-120). The level of control according to GINA was good in 25.2%, partial in 47.1% and poor in 24.5% of patients (data were missing for the remaining 3.2%). Comparison between poorly controlled and partially or well controlled asthmatics showed a statistically significant higher prevalence of some comorbidities in the first group, namely obesity, gastro-oesophageal reflux disease (GORD), aspirin intolerance and mental disorders (all p < 0.001). Similarly, asthmatics with at least one exacerbation in the last year showed a significantly higher prevalence of obesity, chronic rhinosinusitis, nasal polyps, GORD, and aspirin intolerance (all p < 0.05) than patients without exacerbations. When we selected patients without relevant comorbidities (upper airways disease, GORD, obesity, aspirin intolerance) and not currently smoking (N = 73), the percentage of well or partially controlled asthmatics was significantly higher than in patients with comorbidities (84.9% vs 71.1%, p = 0.02); the rate of asthmatics without exacerbations in the last year was also higher (73.6% vs 51.1%, p = 0.001). During omalizumab treatment, a high percentage of asthmatics obtain a good or partial control of asthma. Comorbidities are associated with the lack of asthma control and persistence of exacerbations.

(+)-Laburnamine, a natural selective ligand and partial agonist for the α4ß2 nicotinic receptor subtype.

(+)-Laburnamine (1), a rare alkaloid extracted from Laburnum anagyroides seeds (∼4 mg from 1 kg), was shown to bind with high affinity (Ki, 293 nM) to the α4ß2 nicotinic receptor subtype, which is, respectively, 126 and 136 times higher than to the α3ß4 (Ki 37 µM) and α7 subtypes (Ki 40 µM). When its ability to release [(3)H]-dopamine from striatal slices was tested in a functional assay, compound 1 behaved as a partial agonist with an EC50 of 5.8 µM and an Emax that was 43% that of nicotine. When incubated with nicotine in the same assay, 1 prevented a maximal effect from being reached.

Baseline airway inflammation may be a determinant of the response to ozone exposure in asthmatic patients.

CONTEXT: It is well known that ozone exposure decreases lung function and increases airway neutrophilia, but large variability has been observed among asthmatic patients. OBJECTIVE: To find possible predictors of functional and inflammatory airway response to ozone in asthmatic patients. MATERIALS AND METHODS: We studied 120 patients with mild-to-moderate asthma, randomly exposed to either air or ozone (0.3 ppm for 2 h) in a challenge chamber. Symptoms and pulmonary function test (PFT) were measured before and immediately after exposure. Six hours after exposure, induced sputum was collected. Patients were evaluated according to their functional (FEV1 responders) or neutrophilic (neutrophil responders) response to ozone. We considered, as possible predictors of response: age, baseline FEV1, previous treatment with inhaled corticosteroids (ICS), baseline sputum neutrophils, baseline sputum eosinophils, methacholine responsiveness, atopy and smoking habit. RESULTS: FEV1 responders had lower baseline FEV1, and a lower percentage of these had received ICS treatment. Neutrophil responders were younger, with lower baseline sputum inflammation and greater methacholine responsiveness. These results were confirmed by multivariate logistic analysis. DISCUSSION AND CONCLUSION: Patients not previously treated with ICS and patients with lower FEV1 are more prone to functional response to ozone. Lower baseline airway inflammation and greater bronchial hyperresponsiveness may predict neutrophilic airway response to ozone in asthmatic patients. Thus, determinants of functional and inflammatory responses to ozone are different.

Efficacy of anticholinergic drugs in asthma.

Although bronchial hyperresponsiveness to cholinergic agents is a main feature of asthma, the role of anticholinergic drugs in chronic asthma management has been largely underestimated. Several single-dose studies comparing acute bronchodilation induced by ipratropium bromide with salbutamol have shown that salbutamol was more effective than ipratropium in asthma treatment. Recently, tiotropium has been studied in asthma, when added to low-dose inhaled corticosteroids in unselected moderate asthmatics or in patients with uncontrolled asthma, or patients with chronic obstructive pulmonary disease and history of asthma. Later, studies on patients with Arg/Arg ß(2)-receptor polymorphism demonstrated a similar efficacy of tiotropium in comparison with salmeterol when both were added to low-dose inhaled corticosteroids. Further long-term studies are currently in progress, for the evaluation of the efficacy of tiotropium on clinical asthma control, and on the rate and severity of asthma exacerbations, as well as the potential modification of inflammatory mechanisms and varying efficacy in specific asthma phenotypes (such as smoking asthmatics).

Efficacy of novel acridine derivatives in the inhibition of hPrP90-231 prion protein fragment toxicity.

Quinacrine is one of the few molecules tested to treat patients affected by prion diseases, although the clinical outcome is largely unsatisfactory. To identify novel derivatives with higher neuroprotective activity, we evaluated the effects of a small library of acridine derivatives. The 6-chloro-2-methoxyacridine derivatives bearing on position 9 a quinolizidin-1-ylamino (Q1, Q2) or a quinolizidin-1-ylalkylamino residue (Q3, Q4, Q6, Q7), the thio-bioisoster of Q3 (Q5), the 9-(N-lupinylthiopropyl)amino derivative (Q8) and simple acridines (Q9 and Q10) were considered. We compared the effects of quinacrine and these novel analogues in the inhibition of the cytotoxic activity and protease K (PK) resistance of the human prion protein fragment 90-231 (hPrP90-231). We demonstrate that quinacrine caused a significant reduction of hPrP90-231 toxicity due to its binding to the fragment and the prevention of its conversion in a toxic isoform. All acridine derivatives analyzed showed high affinity binding for hPrP90-231, but only Q3 and Q10, caused a significant reduction of hPrP90-231 cytotoxicity, with higher efficacy than quinacrine. We attempted to correlate the cytoprotective effects of the new compounds with some biochemical parameters (binding affinity to hPrP90-231, intrinsic fluorescence quenching, hydrophobic amino acid exposure), but a direct relationship occurred only with the reduction of PK resistance, likely due to the prevention of the acquisition of the ß-sheet-rich toxic conformation. These data represent interesting leads for further modifications of the basic side chain and the substituent pattern of the acridine nucleus to develop novel compounds with improved antiprion activity to be tested in in vivo experimental setting.

Organometallic compounds in oncology: implications of novel organotins as antitumor agents.

Since the introduction of cisplatin in cancer therapy, metal complexes and organometallic compounds have been gaining growing importance in oncology. The impressive clinical effectiveness of cisplatin is limited by significant side effects and the emergence of drug resistance. Thus, novel classic and unconventional Pt(II) and Pt(IV) complexes have been introduced in therapy or are presently in advanced clinical trials. Moreover, innovative non-platinum metal-based antitumor agents, whose activity does not rely on direct DNA damage and may involve proteins and enzymes, have been developed. Gold and tin derivatives are enjoying an increasing interest and appear very promising as potential drug candidates.

In vitro cytotoxic activity of tri-n-butyltin(IV)lupinylsulfide hydrogen fumarate (IST-FS 35) and preliminary antitumor activity in vivo.

The cytotoxicity in vitro and antitumor activity in vivo of the organotin compound tri-n-butyltin(IV)lupinylsulfide hydrogen fumarate (IST-FS 35) have been investigated. The IC50 values obtained in a panel of tumor cell lines were compared to those of the parental compound IST-FS 29 in the same cells. IST-FS 35 resulted significantly more active than IST-FS 29 with IC50 values in the range 0.16-1.8 microM. Toxicity studies in vivo, after intravenous administration of escalating concentrations of IST-FS 35, provided the identification of the maximal tolerated dose (3.5 mg/kg) which was employed as therapeutic dose in the antitumor activity experiments. Preliminary results, in transplanted murine tumor models, revealed that both the P388 myelomonocytic leukaemia and the B16-F10 melanoma, implanted subcutaneously in BDF1 mice, were inhibited about 96% in their tumor volume at day 11, following a single intravenous injection of the compound. Additional studies are mandatory to unravel the mechanism of action for the development of IST-FS 35 as potential antitumor drug.

Novel sigma binding site ligands as inhibitors of cell proliferation in breast cancer.

Sigma receptors, namely sigma1 and sigma2, have been shown to be expressed in a variety of human cell lines playing a role in cell growth. In the human breast, they are absent in normal mammary tissue but expressed in tumors, particularly in the proliferating stage. The study presented here concerns nine newly synthesized ligands for sigma receptors. The compounds are of general structure consisting of: five (1alpha/1beta-arylalkyl)quinolizidines including two thioisosteres and four spiro-[3,4-dihydro-1,2,4-benzotriazino-3,4'-(1'-substituted) piperidines]. These compounds exhibited varying degrees of affinity for sigma receptors and were able to inhibit the growth of MCF-7 and MDA-MB 231 human breast cancer cell lines, in vitro. Good to moderate binding to at receptors occurred with all tested ligands. However, affinity for sigma2 appeared more evident with compounds FN/C-2 and FN/C-4 (spiro-[3,4-dihydro-1,2,4-benzotriazino-3,4'-(1'-substituted) piperidines] derivatives). In addition, higher cytotoxic activity of FN/C-2 and FN/C-4 with IC50 values below 100 microM in MCF-7 and lower than 40 microM in MDA-MB 231 was revealed. The data from the current study show that these novel sigma receptor ligands exhibit interesting cytotoxic activity and suggest their potential for development as antitumor agents.

Antitumor activity of a new orally active organotin compound: a preliminary study in murine tumor models.

The toxicity and antitumor activity of the novel organotin compound triethyltin(IV)lupinylsulfide hydrochloride (IST-FS 29), administered by the oral route, have been evaluated against three transplantable murine tumor models: P388 lymphocytic leukemia, B16F10 melanoma and 3LL Lewis lung carcinoma. Mild and reversible signs of acute toxicity such as behavioral symptoms, weight loss and histological alterations were mainly reported at the highest single dose of 28 mg/kg. Conversely, lower concentrations of compound ranging from 7 to 21 mg/kg did not result in major toxic effects, even after repeated dosing. The antitumor activity studies showed that fractionation dosing, rather than single bolus administration, over 1 week, might prove more active and better tolerated by allowing the achievement of the highest therapeutic total dose of IST-FS 29 (42 mg/kg). Indeed, repeated administrations of IST-FS 29 resulted in marked significant improvement of antitumor activity against B16F10 (50% of tumor volume inhibition, p = 0.0003) and, to a greater extent, 3LL (90% of tumor volume inhibition, p = 0.0001) tumors. These results indicate that IST-FS 29 might be a suitable candidate as an orally administrable anticancer drug and support its further development in human tumor xenografts.