**5. Chronic obstructive pulmonary disease (COPD)**

COPD is the fourth leading cause of death in the United States and Europe, with COPD mortality more than doubling in the last two decades (Mannino et al., 2002). COPD can be defined as a preventable and treatable disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking. Although COPD affects the lungs, it also produces significant systemic consequences (Celli & MacNee, 2004). It is interesting to point out how the definition of COPD has evolved including the systemic consequences of the disease. The natural history of the disease reveals numerous extrapulmonary manifestations and comorbidity factors that complicate the evolution of COPD, thereby altering the prognosis and quality of life of patients (Barnes & Celli, 2009; Agusti & Soriano, 2008). Many extrapulmonary effects of COPD have been described over the last two decades, including renal and hormonal abnormalities, muscle wasting (Remels et al., 2007), osteoporosis, anemia and reduction in circulating bone marrow progenitors (Palange et al., 2006). Although these systemic manifestations have been described for years in COPD patients, it is still unclear whether they represent consequences of the pulmonary disorder, or whether COPD should be considered as a systemic disease. The importance of establishing the distinction between a respiratory disease with extrapulmonary manifestations and a systemic inflammatory state with multiple compromised organs is justified by different therapeutic options: in the first definition, therapy is primarily centred on the lungs, whereas in the second, therapy could aim at the systemic inflammatory state. Both submucosal gland hypertrophy and airway surface goblet cell metaplasia are prominent features of the chronic bronchitis that occurs in most COPD patients. While cough and chronic expectoration helps to remove excess mucus from the large airways, impaired mucociliary function in COPD causes ineffective mucus clearance from small airways (≤2 mm diameter) which are not well cleared by cough. Like asthma and CF, COPD is strongly associated with the accumulation of inflammatory mucous exudates in the lumens of small airways (Hogg et al., 2004). Accordingly, declining lung function, respiratory infections, hospital admission, and mortality are significantly associated with chronic expectoration.

Among the numerous extrapulmonary effects of COPD, systemic inflammation has been widely studied and considered as an important key between the pulmonary disease and the related systemic manifestations. Many studies reported changes in various inflammatory cells and mediators, including neutrophils, lymphocytes, acute-phase reactants, and cytokines. Recently it was shown that systemic inflammation is present during COPD exacerbations and stable phases of the disease: increased numbers of leukocytes, levels of acute-phase response proteins (C-reactive protein and fibrinogen), cytokines such as interleukin (IL)-6, and tumor necrosis factor (TNF)- are present in the peripheral blood of COPD patients (Gan et al., 2004). Systemic inflammation has been implicated in the pathogenesis of the majority of COPD systemic effects, including weight loss (Wouters, 2002), skeletal muscle dysfunction, cardiovascular diseases (Sin & Man, 2003), and osteoporosis, although it is still controversial whether this so called low-grade systemic inflammation represents the consequence of pulmonary inflammation into the systemic vascular bed (Agust` et al. 2003), or whether it is a systemic inflammation. Although inflammation is certainly one of the major features of COPD, we still need to understand

COPD is the fourth leading cause of death in the United States and Europe, with COPD mortality more than doubling in the last two decades (Mannino et al., 2002). COPD can be defined as a preventable and treatable disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking. Although COPD affects the lungs, it also produces significant systemic consequences (Celli & MacNee, 2004). It is interesting to point out how the definition of COPD has evolved including the systemic consequences of the disease. The natural history of the disease reveals numerous extrapulmonary manifestations and comorbidity factors that complicate the evolution of COPD, thereby altering the prognosis and quality of life of patients (Barnes & Celli, 2009; Agusti & Soriano, 2008). Many extrapulmonary effects of COPD have been described over the last two decades, including renal and hormonal abnormalities, muscle wasting (Remels et al., 2007), osteoporosis, anemia and reduction in circulating bone marrow progenitors (Palange et al., 2006). Although these systemic manifestations have been described for years in COPD patients, it is still unclear whether they represent consequences of the pulmonary disorder, or whether COPD should be considered as a systemic disease. The importance of establishing the distinction between a respiratory disease with extrapulmonary manifestations and a systemic inflammatory state with multiple compromised organs is justified by different therapeutic options: in the first definition, therapy is primarily centred on the lungs, whereas in the second, therapy could aim at the systemic inflammatory state. Both submucosal gland hypertrophy and airway surface goblet cell metaplasia are prominent features of the chronic bronchitis that occurs in most COPD patients. While cough and chronic expectoration helps to remove excess mucus from the large airways, impaired mucociliary function in COPD causes ineffective mucus clearance from small airways (≤2 mm diameter) which are not well cleared by cough. Like asthma and CF, COPD is strongly associated with the accumulation of inflammatory mucous exudates in the lumens of small airways (Hogg et al., 2004). Accordingly, declining lung function, respiratory infections, hospital admission, and mortality are

Among the numerous extrapulmonary effects of COPD, systemic inflammation has been widely studied and considered as an important key between the pulmonary disease and the related systemic manifestations. Many studies reported changes in various inflammatory cells and mediators, including neutrophils, lymphocytes, acute-phase reactants, and cytokines. Recently it was shown that systemic inflammation is present during COPD exacerbations and stable phases of the disease: increased numbers of leukocytes, levels of acute-phase response proteins (C-reactive protein and fibrinogen), cytokines such as interleukin (IL)-6, and tumor necrosis factor (TNF)- are present in the peripheral blood of COPD patients (Gan et al., 2004). Systemic inflammation has been implicated in the pathogenesis of the majority of COPD systemic effects, including weight loss (Wouters, 2002), skeletal muscle dysfunction, cardiovascular diseases (Sin & Man, 2003), and osteoporosis, although it is still controversial whether this so called low-grade systemic inflammation represents the consequence of pulmonary inflammation into the systemic vascular bed (Agust` et al. 2003), or whether it is a systemic inflammation. Although inflammation is certainly one of the major features of COPD, we still need to understand

**5. Chronic obstructive pulmonary disease (COPD)** 

significantly associated with chronic expectoration.

whether the local inflammation is sufficient to induce systemic effects, or whether a second pathogenetic event is required (Evans & Koo, 2009; Huertas & Palange 2011).

Over the years it was evidenced that mucus hypersecretion is an important manifestation of COPD. In the classical phenotype of chronic bronchitis, mucus hypersecretion is the key presenting symptom that appears independent of airflow obstruction. A more recent work demonstrated that obstruction of the small airways by inflammatory exudates containing mucus is predictive of early death after volume reduction surgery in patients with advanced COPD (Hogg et al., 2007). It was suggested that such occlusion enhanced the probability of infection in the lower respiratory tract. In addition, several epidemiological studies showed an association between mucus hypersecretion and outcomes in patients with COPD. Mucus hypersecretion is not an innocent disorder. However, despite these observations, until now few studies have focused on the effects of mucolytic drugs in patients with COPD, even though some of these mucolytic drugs also appear to have antioxidant properties (Dekhuijzen, 2004; Rahman et al., 1997; Rahman & Kilty 2006; Decramer & Janssens, 2010).

Histopathological findings from surgical specimens clearly show that increased goblet cell numbers and increased MUC5AC and MUC5B production and secretion are found in the lumen of small airways in COPD patients (Caramori et al., 2004). These findings are inversely associated with pre-surgical Forced Expiratory Volume in the 1st second (FEV1). Thus, patients with higher FEV1 have less goblet cell metaplasia than patients with lower FEV1, suggesting that the presence of mucin-producing cells in the airways is related to increased airflow obstruction. The presence of a prominent goblet cell phenotype also negatively correlates with FEV1 improvement following lung volume reduction surgery (Kim et al., 2005). Collectively, these results show that mucus secretion may be significant enough to result in physiologically and clinically measurable mechanical obstruction of small airways, and it may significantly impact disease pathogenesis and prognosis. The main cause of COPD in humans is cigarette smoking. In mice, chronic cigarette smoke exposure causes strain dependent mucous metaplasia. Cigarette smoke itself has also been shown to promote mucin synthesis directly in vitro by activation of the EGFR cascade (Shao et al., 2004). Inhalation, of one of the many potential toxicants present in cigarette smoke, acrolein (acrylic aldehyde), induces mucous metaplasia and MUC5AC production in animals. Acrolein also induces MUC5AC production in human airway epithelial cell lines, and it is found at significantly elevated levels in the induced sputum and exhaled breath condensates of COPD patients, (Deshmukh et al., 2008).

It has been suggested that mucus can also serve as a suitable medium for adherence and growth of some bacterial pathogens, such as non-typeable H. influenzae. Gram positive and gram negative bacteria products up-regulate MUC5AC and MUC2 gene expression and mucin secretion in human respiratory epithelial cell lines in vitro, and the same effect can be seen in some animal models in vivo. Viral infections are also closely associated with COPD exacerbations in humans (Wedzicha & Donaldson, 2003; Beckham et al., 2005). Surgical specimens from smokers with COPD show increased goblet cell numbers in the epithelium of peripheral airways compared to non-smokers. This is accompanied by increased macrophages and CD8 positive T-lymphocytes, both of which are indicative of viral. Roles for IL-6 and virus-induced mucin overproduction have been suggested. In vivo, IL-6 production is enhanced during the early phase of bacterial or viral-induced inflammation.

synthetic phospholipids are usually expensive and, on the other side, natural phospholipids

An alternative approach to the liposomal approach is the use of liposome-like vesicles made up of non-ionic surfactants, the so-called niosomes. These carriers were proposed for both topical (Carafa et al., 2000; Carafa et al., 2004; Paolino et al., 2007; Paolino et al., 2008) and

Here we report the evaluation of the possible advantages of a new type of non-phospholipid vesicle system for pulmonary drug delivery that can lead to an improved mucus permeation. Vesicles consisting of one or more surfactant bilayers enclosing aqueous spaces (non ionic surfactant vesicles NSVs), are of particular interest because they offer several advantages with regard to chemical stability, lower cost and availability of materials

In the formulation of inhaled drugs for the treatment of asthma and COPD, considerable attention has been devoted to new aerosol morphologies which can either enhance the local effect and/or increase the penetration through the mucus, secreted in bronchial inflammatory diseases. In diseases characterized by bronchial hypersecretion, lipophilic substances, such as corticosteroids, can be remarkably impeded in reaching their receptors,

In particular, alveolar macrophages are important target cells for the therapeutic action of glucocorticoids, because these cells are the major source of both proinflammatory and antiinflammatory cytokines. The action of glucocorticoids is mediated by an intracellular receptor belonging to the steroid thyroid/retinoic acid receptor superfamily (Oakley et al.,

With the purpose of carrying out research leading to an innovative formulation for lung delivery capable of permeating the mucous layer and of an efficient delivery to alveolar macrophages, beclomethasone dipropionate (BDP), clinically used for the treatment of

BDP, as a reference model drug, was encapsulated in vesicular structures obtained with polysorbate 20. The aim of the study was to evaluate *in vitro* the effectiveness of such delivery system that should enhance permeation through mucosal barriers because of the presence of vesicles formed with a remarkably hydrophilic non-ionic surfactant usually considered as unsuitable for the formation of vesicular structures because of its high HLB

The intracellular availability of BDP and the safety of the delivery system are the two main issues to be addressed to propose these innovative non-ionic surfactant vesicles as carriers for the pulmonary delivery of this drug to be effectively used for the treatment of pulmonary inflammatory diseases. Therefore, the aim of this investigation was the evaluation of the interaction between our innovative non-ionic surfactant vesicles and human lung fibroblast (HLF) cells, the carrier tolerability, the vesicle localization within the

Unilamellar vesicles were obtained from a non-ionic surfactant/BDP aqueous dispersion (Hepes pH 7.4) by means of the "film" method as previously reported (Santucci et al., 1996),

which are localized within the cytoplasm of bronchial epithelial cells.

asthma and COPD, was entrapped in non-phospholipid vesicles.

cells and the amount of BDP actually internalized by the cells.

according to the compositions reported in Table 1.

show a variable degree of purity (Desai & Finlay, 2002).

systemic administration (Cosco et al., 2009).

compared to conventional liposomes

value (HLB 16.7) (Santucci et al., 1996).

1999).

Accordingly, IL-6 levels are increased in COPD patients (Bucchioni et al., 2003), and during experimental respiratory viral infections in humans and mice (Decramer & Janssens, 2010).
