Fabrication of inhaled hybrid silver/ciprofloxacin nanoparticles with synergetic effect against Pseudomonas aeruginosa

Ciprofloxacin (CFX) is a fluroquinolone antibiotic used as a first line treatment against infections caused by Pseudomonas aeruginosa and Streptococcus pneumonia that are commonly acquired by cystic fibrosis (CF) patients. However, no inhalation formulation is currently available for ciprofloxacin. Hybrid silica coated silver nanoparticles were prepared using Stöber reaction and the optimum ratio of chitosan and sodium tripolyphosphate was used to encapsulate CFX. Particle deposition was assessed in vitro using twin stage impinger while antimicrobial activity was evaluated based on the planktonic growth of P. aeruginosa as well as against P. aeruginosa sp biofilm formation. In vitro deposition results showed significant deposition in stage 2 using twin stage impinger (TSI) (∼70%). Compared to CFX, the formed hybrid nanoparticles were 3-4 folds more effective against inhibiting growth and biofilm formation by P. aeruginosa PAO1 and P. aeruginosa NCTC 10662

Comparison study of iron preparations using a human intestinal model

Iron deficiency and related iron deficiency anaemia (IDA) are the most prevalent nutritional disorders worldwide. The standard treatment involves supple-mentation with solid or liquid iron supplement preparations, usually based on a ferrous salt such as ferrous sulphate, ferrous fumarate, or ferrous gluconate. In the present study, we compared iron uptake and absorption from various solid and liquid iron supplement preparations currently available in the United Kingdom using the well-characterised human epithelial adenocarcinoma cell line Caco-2. Intracellular ferritin protein formation by the Caco-2 cell was considered an indicator of cellular iron uptake and absorption. We investigated the effects of formulation ingredients at a defined pH on iron uptake and absorption, and designed a novel two-stage dissolution-absorption protocol that mimicked physiological conditions. Our experiments revealed wide variations in the rate of dissolution between the various solid iron preparations. Conventional-release ferrous iron tablets dissolved rapidly (48 ± 4 mins to 64 ± 4 mins), whereas modified-released tablets and capsules took significantly longer to undergo complete dissolution (274 ± 8 to 256 ± 8 mins). Among the solid iron preparations, ferrous sulphate conventional-release tablets demon-strated the highest iron absorption, whereas modified-release ferrous prepa-rations demonstrated uniformly low iron absorption, as compared to the control (P < 0.05). Taken together, our results demonstrate that there are wide-ranging variations in dissolution times and iron uptake from oral iron preparations, with the physical characteristics of the preparation as well as the form of iron playing a key role

Iron bioavailability of sweet potato and moringa leaves in comparision with leafy green vegetables commonly consumed in Ghana

Introduction: Iron deficiency anaemia (IDA) is a significant public health problem in Northern Ghana especially amongst women and children. Leafy green vegetables are major contributors to iron intake in this part of the world; poor iron bioavailability from these food sources may be part of the reason for the high prevalence of IDA. Evidence suggests that sweet potato and Moringa leaves might be better sources of bioavailable iron, compared with other leafy green vegetables, as both have high levels of iron, and also beta−carotene − a dietary factor that has been suggested to improve iron bioavailability. Aims/Hypothesis: Our research aims were to evaluate iron bioavailability of sweet potato and Moringa leaves in comparison with other leafy green vegetables commonly consumed in Ghana. We hypothesized that iron uptake from sweet potato and Moringa leaves would be higher compared with the other tested vegetables. Methods: We used the Caco−2 cell/in vitro digestion system; Caco−2 cell ferritin formation was used as a surrogate marker of iron bioavailability. In addition, we also measured levels of other nutrients and dietary factors known to affect iron bioavailability: beta−carotene, iron, calcium, zinc, ascorbate, phytates and polyphenols. Results: Iron bioavailability from all tested vegetables was poor despite relatively high absolute levels of iron in the leaf samples (14.5 − 24.6 mg/100 grams dry weight); there was no statistically significant difference in iron uptake between any of the tested varieties or the control sample with no added iron. Levels of phytates and polyphenols, known inhibitors of iron uptake, were high and probably accounted for the low iron bioavailability of tested leaves. As expected, beta−carotene levels were highest in the sweet potato and Moringa leaves (ranging from 47−98 micrograms retinol activity equivalent)/gram freeze dried leaf) − approximately 100% more compared with the other leafy green vegetables, with the exception of the purple leafed sweet potato variety tested that had approximately the same amount of beta−carotene as the commonly consumed vegetables. Conclusion: In our in vitro model neither sweet potato nor Moringa leaves demonstrated good iron bioavailability suggesting that increased consumption of these vegetables would not lead to improved iron status. However, both leaves were good sources of beta−carotene, and further testing in vivo to evaluate whether they could impact on vitamin A status may be warranted

Ascorbyl palmitate/DSPE-PEG nanocarriers for oral iron delivery: Preparation, characterisation and in vitro evaluation

The objective of this study was to encapsulate iron in nanocarriers formulated with ascorbyl palmitate and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine polyethylene glycol (DSPE-PEG) for oral delivery. Blank and iron (Fe) loaded nanocarriers were prepared by a modified thin film method using ascorbyl palmitate and DSPE-PEG. Surface charge of the nanocarriers was modified by the inclusion of chitosan (CHI) during the formulation process. Blank and iron loaded ascorbyl palmitate/DSPE nanocarriers were visualised by transmission electron microscopy (TEM) and physiochemical characterisations of the nanocarriers carried out to determine the mean particle size and zeta potential. Inclusion of chitosan imparted a net positive charge on the nanocarrier surface and also led to an increase in mean particle size. Iron entrapment in ascorbyl palmitate-Fe and ascorbyl palmitate-CHI-Fe nanocarriers was 67% and 76% respectively, suggesting a beneficial effect of chitosan on nanocarrier Fe entrapment. Iron absorption was estimated by measuring Caco-2 cell ferritin formation using ferrous sulphate as a reference standard. Iron absorption from ascorbyl palmitate-Fe (592.17 ± 21.12 ng/mg cell protein) and ascorbyl palmitate-CHI-Fe (800.12 ± 47.6 ng/mg, cell protein) nanocarriers was 1.35-fold and 1.5-fold higher than that from free ferrous sulphate, respectively (505.74 ± 23.73 ng/mg cell protein) (n = 6, p < 0.05). This study demonstrates for the first time preparation and characterisation of iron loaded ascorbyl palmitate/DSPE PEG nanocarriers, and that engineering of the nanocarriers with chitosan leads to a significant augmentation of iron absorption

Annexin-A1 protein and its relationship to cortisol in human saliva

Salivary cortisol is commonly used as a clinical biomarker of endocrine status and also as a marker of psychosocial stress. Annexin-A1 (AnxA1) is an anti-inflammatory protein whose expression is modulated by glucocorticoids. Our principal objectives were to (i) detect the presence of and (ii) measure AnxA1 protein in whole human saliva and to (iii) investigate whether salivary cortisol and AnxA1 are correlated in healthy humans. A total of 37 healthy participants (male and female) were used in the study. Saliva was collected using salivette tubes. Salivary cortisol and AnxA1 protein were sampled at between 3 and 6 time points over 24 h and measured for cortisol and AnxA1 protein using specific ELISA's. The presence of salivary AnxA1 protein was confirmed by Western blotting. AnxA1 protein is detectable in whole human saliva, as detected by Western blot analysis and ELISA. A diurnal rhythm was evident in both salivary cortisol (P 0.05), whereas salivary cortisol was significantly elevated between time 0 and 30 min post waking (P < 0.001). AnxA1 protein correlates positively with salivary cortisol, indicating that cortisol is most likely a regulator of AnxA1 in human saliva

A new era of pulmonary delivery of nano-antimicrobial therapeutics to treat chronic pulmonary infections

Pulmonary infections may be fatal especially in immunocompromised patients and patients with underlying pulmonary dysfunction, such as those with cystic fibrosis, chronic obstructive pulmonary disorder, etc. According to the WHO, lower respiratory tract infections ranked first amongst the leading causes of death in 2012, and tuberculosis was included in the top 10 causes of death in low income countries, placing a considerable strain on their economies and healthcare systems. Eradication of lower respiratory infections is arduous, leading to high healthcare costs and requiring higher doses of antibiotics to reach optimal concentrations at the site of pulmonary infection for protracted period. Hence direct inhalation to the respiratory epithelium has been investigated extensively in the past decade, and seems to be an attractive approach to eradicate and hence overcome this widespread problem. Moreover, engineering inhalation formulations wherein the antibiotics are encapsulated within nanoscale carriers could serve to overcome many of the limitations faced by conventional antibiotics, like difficulty in treating intracellular pathogens such as mycobacteria spp. and salmonella spp., biofilm-associated pathogens like Pseudomonas aeruginosa and Staphylococcus aureus, passage through the sputum associated with disorders like cystic fibrosis and chronic obstructive pulmonary disorder, systemic side effects following oral/parenteral delivery and inadequate concentrations of antibiotic at the site of infection leading to resistance. Encapsulation of antibiotics in nanocarriers may help in providing a protective environment to combat antibiotic degradation, confer controlled-release properties, hence reducing dosing frequency, and may increase uptake via specific and non-specific targeting modalities. Hence nanotechnology combined with direct administration to the airways using commercially available delivery devices, is a highly attractive formulation strategy to eradicate microorganisms from the lower respiratory tract, which might otherwise present opportunities for multi-drug resistance

A novel approach to oral iron delivery using ferrous sulphate loaded solid lipid nanoparticles

Iron (Fe) loaded solid lipid nanoparticles (SLN’s) were formulated using stearic acid and iron absorp-tion was evaluated in vitro using the cell line Caco-2 with intracellular ferritin formation as a marker ofiron absorption. Iron loading was optimised at 1% Fe (w/w) lipid since an inverse relation was observedbetween initial iron concentration and SLN iron incorporation efficiency. Chitosan (Chi) was included toprepare chitosan coated SLN’s. Particle size analysis revealed a sub-micron size range (300.3 ± 31.75 nmto 495.1 ± 80.42 nm), with chitosan containing particles having the largest dimensions. As expected,chitosan (0.1%, 0.2% and 0.4% w/v) conferred a net positive charge on the particle surface in a concen-tration dependent manner. For iron absorption experiments equal doses of Fe (20 �M) from selectedformulations (SLN-FeA and SLN-Fe-ChiB) were added to Caco-2 cells and intracellular ferritin proteinconcentrations determined. Caco-2 iron absorption from SLN-FeA (583.98 ± 40.83 ng/mg cell protein)and chitosan containing SLN-Fe-ChiB (642.77 ± 29.37 ng/mg cell protein) were 13.42% and 24.9% greaterthan that from ferrous sulphate (FeSO4) reference (514.66 ± 20.43 ng/mg cell protein) (p ≤ 0.05). Wedemonstrate for the first time preparation, characterisation and superior iron absorption in vitro fromSLN’s, suggesting the potential of these formulations as a novel system for oral iron delivery

Study on the pulmonary delivery system of apigenin loaded albumin nanocarriers with antioxidant activity

Background: Respiratory diseases are mainly derived from acute and chronic inflammation of the alveoli and bronchi. The pathophysiological mechanisms of pulmonary inflammation mainly arise from oxidative damage that could ultimately lead to acute lung injury (ALI). Apigenin (Api) is a natural polyphenol with prominent antioxidant and anti-inflammatory properties in the lung. Inhalable formulations consist of nanoparticles (NPs) have several advantages over other administration routes therefore this study investigated the application of apigenin loaded bovine serum albumin nanoparticles (BSA-Api-NPs) for pulmonary delivery. Methods: Dry powder formulations of BSA-Api-NPs were prepared by spray drying and characterized by laser diffraction particle sizing, scanning electron microscopy, differential scanning calorimetry and powder X-ray diffraction. The influence of dispersibility enhancers(lactose monohydrate and L-leucine) on the in vitro aerosol deposition using a next generation impactor (NGI) was investigated in comparison to excipient-free formulation. The dissolution of Api was determined in simulated lung fluid by using Franz cell apparatus. The antioxidant activity was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH˙) free radical scavenging assay. Results: The encapsulation efficiency and the drug loading was measured to be 82.61 ± 4.56% and 7.51 ± 0.415%. The optimized spray drying conditions were suitable to produce particles with low residual moisture content. The spray dried BSA-Api-NPs possessed good the aerodynamic properties due to small and wrinkled particles with low mass median aerodynamic diameter, high emitted dose and fine particle fraction. The aerodynamic properties was enhanced by leucine and decreased by lactose, however, the dissolution was reversely affected. The DPPH˙ assay confirmed that the antioxidant activity of encapsulated Api was preserved. Conclusion: This study provides evidence to support that albumin nanoparticles 49 are suitable carriers of Api and the use of traditional or novel excipients should be taken into consideration. The developed BSA-Api-NPs is a novel delivery system against lung injury with potential antioxidant activity

Dimensionality and dynamics in the behavior of C. elegans

A major challenge in analyzing animal behavior is to discover some underlying simplicity in complex motor actions. Here we show that the space of shapes adopted by the nematode C. elegans is surprisingly low dimensional, with just four dimensions accounting for 95% of the shape variance, and we partially reconstruct "equations of motion" for the dynamics in this space. These dynamics have multiple attractors, and we find that the worm visits these in a rapid and almost completely deterministic response to weak thermal stimuli. Stimulus-dependent correlations among the different modes suggest that one can generate more reliable behaviors by synchronizing stimuli to the state of the worm in shape space. We confirm this prediction, effectively "steering" the worm in real time.Comment: 9 pages, 6 figures, minor correction