Carriers for the Targeted Delivery of Aerosolized Macromolecules for Pulmonary Pathologies.

INTRODUCTION: Macromolecules with unique effects and potency are increasingly being considered for application in lung pathologies. Numerous delivery strategies for these macromolecules through the lung, have been investigated to improve the targeting and overall efficacy. Areas covered: Targeting approaches from delivery devices, formulation strategies and specific targets are discussed. Expert opinion: Although macromolecules are a heterogeneous group of molecules, a number of strategies have been investigated at the macro, micro and nanoscopic scale for the delivery of macromolecules to specific sites and cells of lung tissues. Targeted approaches are already in use at the macroscopic scale through inhalation devices and formulations, but targeting strategies at the micro and nanoscopic scale are still in the laboratory stage. The combination of controlling lung deposition and targeting after deposition, through a combination of targeting strategies could be the future direction for the treatment of lung pathologies through the pulmonary route

Evaluation of fentanyl disposition and effects in newborn piglets as an experimental model for human neonates.

BACKGROUND: Fentanyl is widely used off-label in NICU. Our aim was to investigate its cerebral, cardiovascular and pulmonary effects as well as pharmacokinetics in an experimental model for neonates. METHODS: Fentanyl (5 µg/kg bolus immediately followed by a 90 minute infusion of 3 µg/kg/h) was administered to six mechanically ventilated newborn piglets. Cardiovascular, ventilation, pulmonary and oxygenation indexes as well as brain activity were monitored from T = 0 up to the end of experiments (T = 225-300 min). Also plasma samples for quantification of fentanyl were drawn. RESULTS: A "reliable degree of sedation" was observed up to T = 210-240 min, consistent with the selected dosing regimen and the observed fentanyl plasma levels. Unlike cardiovascular parameters, which were unmodified except for an increasing trend in heart rate, some of the ventilation and oxygenation indexes as well as brain activity were significantly altered. The pulmonary and brain effects of fentanyl were mostly recovered from T = 210 min to the end of experiment. CONCLUSION: The newborn piglet was shown to be a suitable experimental model for studying fentanyl disposition as well as respiratory and cardiovascular effects in human neonates. Therefore, it could be extremely useful for further investigating the drug behaviour under pathophysiological conditions

MgSO\u3csub\u3e4\u3c/sub\u3e Treatment Preserves the Ischemia-Induced Reduction in S-100 Protein Without Modification of the Expression of Endothelial Tight Junction Molecules

The aim of this work was to evaluate the effect of magnesium sulphate (MgSO4) administration on blood-brain barrier (BBB) permeabilization after cerebral hypoxia-ischemia (HI) induced by partial occlusion of the umbilical cord of premature fetal lambs. We also characterized BBB dysfunction in terms of the levels of expression of a panel of BBB proteins; Occludin, Claudin, Zona Occludens-1, Zonula Occludens-2, VE-cadherin and beta-catenin. Lambs were assigned to: Control group: non-injured animals, 0 h post-partial cord occlusion (0h-PCO) group: animals subjected to 60 min HI and sacrificed just after the insult, 3h-PCO group: HI injured animals resuscitated and managed on ventilation for 3 hours and MgSO4 group: animals which received a dose of 400 mg/kg MgSO4 after the HI event and managed on ventilation for 3 hours. Brains were fixed and blocks processed for S-100 protein immunohistochemistry. Other brains were dissociated and processed for S-100 and BBB protein immunochemistry for analysis by flow cytometry. The percentage of S-100 positive cells was found to be dramatically reduced in all studied brain tissues in the 3h-PCO group with respect to the other groups. No differences were found in the percentage or mean intensity of BBB protein immunolabeled cells among the groups. In the MgSO4 group, the percentage of S-100 positive cells 3 h after the HI event was similar to the control group. These results suggest that MgSO4 treatment preserves the ischemia-induced reduction in S-100 protein without modification in the expression of endothelial tight junction molecules. We speculate that MgSO4 treatment confers neuroprotection by restoration of blood brain permeability in hypoxia-ischemia

MgSO\u3csub\u3e4\u3c/sub\u3e Treatment Preserves the Ischemia-Induced Reduction in S-100 Protein Without Modification of the Expression of Endothelial Tight Junction Molecules

The aim of this work was to evaluate the effect of magnesium sulphate (MgSO4) administration on blood-brain barrier (BBB) permeabilization after cerebral hypoxia-ischemia (HI) induced by partial occlusion of the umbilical cord of premature fetal lambs. We also characterized BBB dysfunction in terms of the levels of expression of a panel of BBB proteins; Occludin, Claudin, Zona Occludens-1, Zonula Occludens-2, VE-cadherin and beta-catenin. Lambs were assigned to: Control group: non-injured animals, 0 h post-partial cord occlusion (0h-PCO) group: animals subjected to 60 min HI and sacrificed just after the insult, 3h-PCO group: HI injured animals resuscitated and managed on ventilation for 3 hours and MgSO4 group: animals which received a dose of 400 mg/kg MgSO4 after the HI event and managed on ventilation for 3 hours. Brains were fixed and blocks processed for S-100 protein immunohistochemistry. Other brains were dissociated and processed for S-100 and BBB protein immunochemistry for analysis by flow cytometry. The percentage of S-100 positive cells was found to be dramatically reduced in all studied brain tissues in the 3h-PCO group with respect to the other groups. No differences were found in the percentage or mean intensity of BBB protein immunolabeled cells among the groups. In the MgSO4 group, the percentage of S-100 positive cells 3 h after the HI event was similar to the control group. These results suggest that MgSO4 treatment preserves the ischemia-induced reduction in S-100 protein without modification in the expression of endothelial tight junction molecules. We speculate that MgSO4 treatment confers neuroprotection by restoration of blood brain permeability in hypoxia-ischemia

MgSO4 treatment preserves the ischemia-induced reduction in S-100 protein without modification of the expression of endothelial tight junction molecules

The aim of this work was to evaluate the effect of magnesium sulphate (MgSO4 ) administration on blood-brain barrier (BBB) permeabilization after cerebral hypoxia-ischemia (HI) induced by partial occlusion of the umbilical cord of premature fetal lambs. We also characterized BBB dysfunction in terms of the levels of expression of a panel of BBB proteins; Occludin, Claudin, Zona Occludens-1, Zonula Occludens-2, VE-cadherin and ß-catenin. Lambs were assigned to: Control group: non-injured animals, 0 h post-partial cord occlusion (0h-PCO) group: animals subjected to 60 min HI and sacrificed just after the insult, 3h-PCO group: HI injured animals resuscitated and managed on ventilation for 3 hours and MgSO4 group: animals which received a dose of 400 mg/kg MgSO4 after the HI event and managed on ventilation for 3 hours. Brains were fixed and blocks processed for S-100 protein immunohistochemistry. Other brains were dissociated and processed for S-100 and BBB protein immunochemistry for analysis by flow cytometry. The percentage of S-100 positive cells was found to be dramatically reduced in all studied brain tissues in the 3h-PCO group with respect to the other groups. No differences were found in the percentage or mean intensity of BBB protein immunolabeled cells among the groups. In the MgSO4 group, the percentage of S-100 positive cells 3 h after the HI event was similar to the control group. These results suggest that MgSO4 treatment preserves the ischemia-induced reduction in S- 100 protein without modification in the expression of endothelial tight junction molecules. We speculate that MgSO4 treatment confers neuroprotection by restoration of blood brain permeability in hypoxia-ischemia

Pulmonary effects of fentanyl administration in newborn piglets maintained on mechanical ventilation.

<p>A- Mean dynamic compliance, C_dyn, B- mean oxygenation index, OI, (white squares) and mean ventilator efficiency index,VEI, (black squares). Values are expressed as mean±SD. Normal values: OI<10; VEI>0.3; C_dyn: 0.8–1.5 ml/cmH₂O/kg. The letter “B1” indicates the baseline measurement during inhaler anesthesia and letter “B2” indicates the baseline measurement after elimination of inhaler anaesthesia. <i>*p</i> <0.05 vs. baseline 2 level.</p

Demographic characteristics and pharmacokinetic (PK) variables of fentanyl calculated for each piglet by noncompartmental analysis (NCA) of the corresponding plasma concentration time curves.

<p>BLLOQ: below the lower limit of quantification.</p><p>F: Female/ M: Male.</p

Early Cell Death in the Brain of Fetal Preterm Lambs After Hypoxic-Ischemic Injury

The objective of the present study was to evaluate using premature fetal lambs the effect of cerebral hypoxia–ischemia induced by partial occlusion of the umbilical cord on the type of cell death which occurs in different brain regions and to ascertain some of the neural pathways which may underlie the associated pathologies. Lambs were sacrificed either immediately after a 1 h hypoxic–ischemic insult or 3 h later. Brains were fixed by perfusion and blocks of the different brain territories were processed for light microscopy (hematoxylin–eosin, Nissl staining), electron transmission microscopy and quantification of apoptosis by the TUNEL method. Other fixed brains were dissociated and labeled by nonyl acridine orange to determine mitochondrial integrity. Non-fixed brains were also used for membrane asymmetry studies, in which cell suspensions were analyzed by flow cytometry to quantify apoptosis. In both hypoxic–ischemic groups, necrotic-like neurons were observed mainly in the mesencephalon, pons, deep cerebellar nuclei and basal nuclei, whereas apoptotic cells were extensively found both in white and gray matter and were not limited to regions where necrotic neurons were present. The 3 h post-partial cord occlusion group, but not the 0 h group, showed a generalized alteration of cell membrane asymmetry and mitochondrial integrity as revealed by Annexin V/PI flow cytometry and nonyl acridine orange studies, respectively. Our results show that the apoptotic/necrotic patterns of cell death occurring early after hypoxic–ischemic injury are brain-region-specific and have distinct dynamics and suggest that therapeutic strategies aimed at rescuing cells from the effects of hypoxia/ischemia should be aimed at blocking the apoptotic components of brain damage

Evaluation of neurophysiological assessment in newborn piglets treated with fentanyl.

<p>A-Cerebral perfusion-oxygenation using NIRS system. Mean cerebral intravascular oxygenation, CIO, (black squares) and mean fractional tissue oxygen extraction, FTOE, (white squares). B- Brain activity using aEEG system. Normal values: FTOE: 0.3–0.6; CIO: (–10) –10. The letter “B1” indicates the baseline measurement during inhaler anesthesia and letter “B2” indicates the baseline measurement after elimination of inhaler anaesthesia. Mean aEEG background activity (black squares) and mean aEEG amplitude (white squares). *<i>p</i> <0.05 vs. baseline 2 level.</p

Gas exchange and hemodynamic parameters in newborn piglets treated with fentanyl.

<p>Normal values (aprox): pH: 7.3–7.45; Pa_CO2: 35–45 mmHg; MABP: 60–85 mmHg; HR: 155–195 beats/min;CO: 0.4–0.7 l/min; CVP: 3–6 mmHg.</p><p>B1: baseline 1; B2: baseline 2; MABP: mean arterial blood pressure; HR: heart rate; CO: cardiac output; CVP: central venous pressure. Values are expressed as mean±SD. *<i>p</i><0.05 vs. B2.</p