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Herman L, De Smedt SC, Raemdonck K. Pulmonary surfactant as a versatile biomaterial to fight COVID-19. J Control Release 2021; 342:170-188. [PMID: 34813878 PMCID: PMC8605818 DOI: 10.1016/j.jconrel.2021.11.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 02/06/2023]
Abstract
The COVID-19 pandemic has wielded an enormous pressure on global health care systems, economics and politics. Ongoing vaccination campaigns effectively attenuate viral spreading, leading to a reduction of infected individuals, hospitalizations and mortality. Nevertheless, the development of safe and effective vaccines as well as their global deployment is time-consuming and challenging. In addition, such preventive measures have no effect on already infected individuals and can show reduced efficacy against SARS-CoV-2 variants that escape vaccine-induced host immune responses. Therefore, it is crucial to continue the development of specific COVID-19 targeting therapeutics, including small molecular drugs, antibodies and nucleic acids. However, despite clear advantages of local drug delivery to the lung, inhalation therapy of such antivirals remains difficult. This review aims to highlight the potential of pulmonary surfactant (PS) in the treatment of COVID-19. Since SARS-CoV-2 infection can progress to COVID-19-related acute respiratory distress syndrome (CARDS), which is associated with PS deficiency and inflammation, replacement therapy with exogenous surfactant can be considered to counter lung dysfunction. In addition, due to its surface-active properties and membrane-interaction potential, PS can be repurposed to enhance drug spreading along the respiratory epithelium and to promote intracellular drug delivery. By merging these beneficial features, PS can be regarded as a versatile biomaterial to combat respiratory infections, in particular COVID-19.
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Affiliation(s)
- Lore Herman
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
| | - Stefaan C De Smedt
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
| | - Koen Raemdonck
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
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2
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Pioselli B, Salomone F, Mazzola G, Amidani D, Sgarbi E, Amadei F, Murgia X, Catinella S, Villetti G, De Luca D, Carnielli V, Civelli M. Pulmonary surfactant: a unique biomaterial with life-saving therapeutic applications. Curr Med Chem 2021; 29:526-590. [PMID: 34525915 DOI: 10.2174/0929867328666210825110421] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/26/2021] [Accepted: 06/29/2021] [Indexed: 11/22/2022]
Abstract
Pulmonary surfactant is a complex lipoprotein mixture secreted into the alveolar lumen by type 2 pneumocytes, which is composed by tens of different lipids (approximately 90% of its entire mass) and surfactant proteins (approximately 10% of the mass). It is crucially involved in maintaining lung homeostasis by reducing the values of alveolar liquid surface tension close to zero at end-expiration, thereby avoiding the alveolar collapse, and assembling a chemical and physical barrier against inhaled pathogens. A deficient amount of surfactant or its functional inactivation is directly linked to a wide range of lung pathologies, including the neonatal respiratory distress syndrome. This paper reviews the main biophysical concepts of surfactant activity and its inactivation mechanisms, and describes the past, present and future roles of surfactant replacement therapy, focusing on the exogenous surfactant preparations marketed worldwide and new formulations under development. The closing section describes the pulmonary surfactant in the context of drug delivery. Thanks to its peculiar composition, biocompatibility, and alveolar spreading capability, the surfactant may work not only as a shuttle to the branched anatomy of the lung for other drugs but also as a modulator for their release, opening to innovative therapeutic avenues for the treatment of several respiratory diseases.
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Affiliation(s)
| | | | | | | | - Elisa Sgarbi
- Preclinical R&D, Chiesi Farmaceutici, Parma. Italy
| | | | - Xabi Murgia
- Department of Biotechnology, GAIKER Technology Centre, Zamudio. Spain
| | | | | | - Daniele De Luca
- Division of Pediatrics and Neonatal Critical Care, Antoine Béclère Medical Center, APHP, South Paris University Hospitals, Paris, France; Physiopathology and Therapeutic Innovation Unit-U999, South Paris-Saclay University, Paris. France
| | - Virgilio Carnielli
- Division of Neonatology, G Salesi Women and Children's Hospital, Polytechnical University of Marche, Ancona. Italy
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3
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Surfactant-Assisted Distal Pulmonary Distribution of Budesonide Revealed by Mass Spectrometry Imaging. Pharmaceutics 2021; 13:pharmaceutics13060868. [PMID: 34204670 PMCID: PMC8231273 DOI: 10.3390/pharmaceutics13060868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 11/21/2022] Open
Abstract
Direct lung administration of budesonide in combination with surfactant reduces the incidence of bronchopulmonary dysplasia. Although the therapy is currently undergoing clinical development, the lung distribution of budesonide throughout the premature neonatal lung has not yet been investigated. Here, we applied mass spectrometry imaging (MSI) to investigate the surfactant-assisted distal lung distribution of budesonide. Unlabeled budesonide was either delivered using saline as a vehicle (n = 5) or in combination with a standard dose of the porcine surfactant Poractant alfa (n = 5). These lambs were ventilated for one minute, and then the lungs were extracted for MSI analysis. Another group of lambs (n = 5) received the combination of budesonide and Poractant alfa, followed by two hours of mechanical ventilation. MSI enabled the label-free detection and visualization of both budesonide and the essential constituent of Poractant alfa, the porcine surfactant protein C (SP-C). 2D ion intensity images revealed a non-uniform distribution of budesonide with saline, which appeared clustered in clumps. In contrast, the combination therapy showed a more homogeneous distribution of budesonide throughout the sample, with more budesonide distributed towards the lung periphery. We found similar distribution patterns for the SP-C and budesonide in consecutive lung tissue sections, indicating that budesonide was transported across the lungs associated with the exogenous surfactant. After two hours of mechanical ventilation, the budesonide intensity signal in the 2D ion intensity maps dropped dramatically, suggesting a rapid lung clearance and highlighting the relevance of achieving a uniform surfactant-assisted lung distribution of budesonide early after delivery to maximize the anti-inflammatory and maturational effects throughout the lung.
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Schenck D, Goettler S, Fiegel J. Surfactant-induced spreading of nanoparticles is inhibited on mucus mimetic surfaces that model native lung conditions. Phys Biol 2019; 16:065001. [PMID: 31292288 DOI: 10.1088/1478-3975/ab3109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We investigated the ability of surfactant-induced spreading to promote nanoparticle distribution on model mucus hydrogels. The hydrogels were formulated with viscoelastic properties and surface tensions that match those of native lung mucus. Nanoparticle-containing droplets with or without surfactant were deposited on the mucus surface and spreading patterns were monitored by time-course fluorescence imaging. Overall, surfactant-induced spreading of nanoparticles required an appropriate balance between Marangoni forces and viscoelastic subphase resistance. Spreading was enhanced on bare gels by increasing the concentration of surfactant in the droplets or reducing the viscoelastic properties of the subphase. However, with a pre-existing film of pulmonary surfactant on the mucus surface, spreading was dramatically inhibited as the surface tension gradient between the droplets and the surrounding subphase decreased. A complete lack of spreading was observed at surface tensions that matched those in the tracheobronchial region of the lungs, even with full-concentration Infasurf. These studies demonstrate that the magnitude of spreading on lung mucus-like surfaces is limited by native mucosal properties.
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Affiliation(s)
- D Schenck
- Department of Pharmaceutical Sciences and Experimental Therapeutics, The University of Iowa, Iowa City, IA, United States of America
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5
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Baer B, Souza LMP, Pimentel AS, Veldhuizen RA. New insights into exogenous surfactant as a carrier of pulmonary therapeutics. Biochem Pharmacol 2019; 164:64-73. [DOI: 10.1016/j.bcp.2019.03.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 03/26/2019] [Indexed: 01/03/2023]
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Guagliardo R, Pérez-Gil J, De Smedt S, Raemdonck K. Pulmonary surfactant and drug delivery: Focusing on the role of surfactant proteins. J Control Release 2018; 291:116-126. [PMID: 30321577 DOI: 10.1016/j.jconrel.2018.10.012] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 10/06/2018] [Accepted: 10/08/2018] [Indexed: 11/30/2022]
Abstract
Pulmonary surfactant (PS) has been extensively studied because of its primary role in mammalian breathing. The deposition of this surface-active material at the alveolar air-water interface is essential to lower surface tension, thus avoiding alveolar collapse during expiration. In addition, PS is involved in host defense, facilitating the clearance of potentially harmful particulates. PS has a unique composition, including 92% of lipids and 8% of surfactant proteins (SPs) by mass. Although they constitute the minor fraction, SPs to a large extent orchestrate PS-related functions. PS contains four surfactant proteins (SPs) that can be structurally and functionally divided in two groups, i.e. the large hydrophilic SP-A and SP-D and the smaller hydrophobic SP-B and SP-C. The former belong to the family of collectins and are involved in opsonization processes, thus promoting uptake of pathogens and (nano)particles by phagocytic cell types. The latter SPs regulate interfacial surfactant adsorption dynamics, facilitating (phospho)lipid transfer and membrane fusion processes. In the context of pulmonary drug delivery, the exploitation of PS as a carrier to promote drug spreading along the alveolar interface is gaining interest. In addition, recent studies investigated the interaction of PS with drug-loaded nanoparticles (nanomedicines) following pulmonary administration, which strongly influences their biological fate, drug delivery efficiency and toxicological profile. Interestingly, the specific biophysical mode-of-action of the four SPs affect the drug delivery process of nanomedicines both on the extra-and intracellular level, modulating pulmonary distribution, cell targeting and intracellular delivery. This knowledge can be harnessed to exploit SPs for the design of unique and bio-inspired drug delivery strategies.
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Affiliation(s)
- Roberta Guagliardo
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
| | - Jesús Pérez-Gil
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Research Institute Hospital 12 Octubre, Universidad Complutense, José Antonio Novais 2, 28040 Madrid, Spain.
| | - Stefaan De Smedt
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
| | - Koen Raemdonck
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
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Interaction of levofloxacin with lung surfactant at the air-water interface. Colloids Surf B Biointerfaces 2017; 158:689-696. [DOI: 10.1016/j.colsurfb.2017.07.066] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/30/2017] [Accepted: 07/26/2017] [Indexed: 11/22/2022]
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Cimato A, Facorro G, Martínez Sarrasague M. Developing an exogenous pulmonary surfactant-glucocorticoids association: Effect of corticoid concentration on the biophysical properties of the surfactant. Respir Physiol Neurobiol 2017; 247:80-86. [PMID: 28963086 DOI: 10.1016/j.resp.2017.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 09/22/2017] [Indexed: 12/24/2022]
Abstract
Glucocorticoids (GCs) are used to treat lung disease. GCs incorporated in an exogenous pulmonary surfactant (EPS) could be an alternative management to improve drug delivery avoiding side effects. In the development of these pharmaceutical products, it is important to know the maximum amount of GC that can be incorporated and if increasing quantities of GCs alter EPS biophysical properties. Formulations containing EPS and beclomethasone, budesonide or fluticasone were analyzed (PL 10mg/ml; GC 1-2mg/ml). The microstructure was evaluated by electron paramagnetic resonance spectroscopy, GCs incorporated were determined by UV absorption and polarized light microscopy and surfactant activity with pulsating bubble surfactometer. We found that GCs have a ceiling of incorporation of around 10wt%, and that the GC not incorporated remains as crystals in the aqueous phase without altering the biophysical properties of the surfactant. This fact is important, because the greater the proportion of GC that EPS can carry, the better the efficiency of this pulmonary GC system.
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Affiliation(s)
- Alejandra Cimato
- Cátedra de Física, Departamento de Fisicomatemática, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | - Graciela Facorro
- Cátedra de Física, Departamento de Fisicomatemática, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Margarita Martínez Sarrasague
- Cátedra de Física, Departamento de Fisicomatemática, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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9
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Hidalgo A, Salomone F, Fresno N, Orellana G, Cruz A, Perez-Gil J. Efficient Interfacially Driven Vehiculization of Corticosteroids by Pulmonary Surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7929-7939. [PMID: 28738158 DOI: 10.1021/acs.langmuir.7b01177] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Pulmonary surfactant is a crucial system to stabilize the respiratory air-liquid interface. Furthermore, pulmonary surfactant has been proposed as an effective method for targeting drugs to the lungs. However, few studies have examined in detail the mechanisms of incorporation of drugs into surfactant, the impact of the presence of drugs on pulmonary surfactant performance at the interface under physiologically meaningful conditions, or the ability of pulmonary surfactant to use the air-liquid interface to vehiculise drugs to long distances. This study focuses on the ability of pulmonary surfactant to interfacially vehiculize corticosteroids such as beclomethasone dipropionate (BDP) or Budesonide (BUD) as model drugs. The main objectives have been to (a) characterize the incorporation of corticosteroids into natural and synthetic surfactants, (b) evaluate whether the presence of corticosteroids affects surfactant functionality, and (c) determine whether surfactant preparations enable the efficient spreading and distribution of BDP and BUD along the air-liquid interface. We have compared the performance of a purified surfactant from porcine lungs and two clinical surfactants: Poractant alfa, a natural surfactant of animal origin extensively used to treat premature babies, and CHF5633, a new synthetic surfactant preparation currently under clinical trials. Both, natural and clinical surfactants spontaneously incorporated corticosteroids up to at least 10% by mass with respect to phospholipid content. The presence of the drugs did not interfere with their ability to efficiently adsorb into air-liquid interfaces and form surface active films able to reach and sustain very low surface tensions (<2 mN/m) under compression-expansion cycling mimicking breathing dynamics. Furthermore, the combination of clinical surfactant with corticosteroids efficiently promoted the active diffusion of the drug to long distances along the air-liquid interface. This effect could not be mimicked by vehiculisation of corticosteroids in liposomes or in micellar emulsions similar to the formulations currently in use to deliver anti-inflammatory corticosteroids through inhalation.
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Affiliation(s)
- Alberto Hidalgo
- Department of Biochemistry, Faculty of Biology, and Research Institute Hospital "12 de Octubre", Complutense University , Madrid 28040, Spain
| | | | - Nieves Fresno
- Department of Organic Chemistry, Faculty of Chemistry, Complutense University , Madrid 28040, Spain
| | - Guillermo Orellana
- Department of Organic Chemistry, Faculty of Chemistry, Complutense University , Madrid 28040, Spain
| | - Antonio Cruz
- Department of Biochemistry, Faculty of Biology, and Research Institute Hospital "12 de Octubre", Complutense University , Madrid 28040, Spain
| | - Jesus Perez-Gil
- Department of Biochemistry, Faculty of Biology, and Research Institute Hospital "12 de Octubre", Complutense University , Madrid 28040, Spain
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Hidalgo A, Cruz A, Pérez-Gil J. Pulmonary surfactant and nanocarriers: Toxicity versus combined nanomedical applications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1740-1748. [PMID: 28450046 DOI: 10.1016/j.bbamem.2017.04.019] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 01/05/2023]
Abstract
Pulmonary surfactant is a membrane-based lipid-protein system essential for the process of breathing, which coats and stabilizes the whole respiratory surface and possesses exceptional biophysical properties. It constitutes the first barrier against the entry of pathogens and harmful particles in the alveolar region, extended through the lungs, but on the other hand, it can offer novel possibilities as a shuttle for the delivery of drugs and nanocarriers. The advances in nanotechnology are opening the doors to new diagnostic and therapeutic avenues, which are not accessible by means of the current approaches. In this context, the pulmonary route is called to become a powerful way of entry for innovative treatments based on nanotechnology. In this review, the anatomy of the respiratory system and its properties for drug entry are first revisited, as well as some current strategies that use the respiratory route for both local and peripheral action. Then, a brief overview is presented on what pulmonary surfactant is, how it works and why it could be used as a drug delivery vehicle. Finally, the review is closed with a description of the development of nanocarriers in the lung context and their interaction with endogenous and clinical pulmonary surfactants. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
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Affiliation(s)
- Alberto Hidalgo
- Department of Biochemistry, Fac. of Biology, and Research Institut "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Antonio Cruz
- Department of Biochemistry, Fac. of Biology, and Research Institut "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Jesús Pérez-Gil
- Department of Biochemistry, Fac. of Biology, and Research Institut "Hospital 12 de Octubre", Complutense University, Madrid, Spain.
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Hobi N, Giolai M, Olmeda B, Miklavc P, Felder E, Walther P, Dietl P, Frick M, Pérez-Gil J, Haller T. A small key unlocks a heavy door: The essential function of the small hydrophobic proteins SP-B and SP-C to trigger adsorption of pulmonary surfactant lamellar bodies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2124-34. [DOI: 10.1016/j.bbamcr.2016.04.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/15/2016] [Accepted: 04/27/2016] [Indexed: 02/07/2023]
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12
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Hidalgo A, Cruz A, Pérez-Gil J. Barrier or carrier? Pulmonary surfactant and drug delivery. Eur J Pharm Biopharm 2015; 95:117-27. [PMID: 25709061 DOI: 10.1016/j.ejpb.2015.02.014] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 01/28/2015] [Accepted: 02/06/2015] [Indexed: 11/29/2022]
Abstract
To consider the lung as a target for drug delivery and to optimise strategies directed at the pulmonary route, it is essential to consider the role of pulmonary surfactant, a thin lipid-protein film lining the respiratory surface of mammalian lungs. Membrane-based surfactant multilayers are essential for reducing the surface tension at the respiratory air-liquid interface to minimise the work of breathing. Different components of surfactant are also responsible for facilitating the removal of potentially pathological entities such as microorganisms, allergens or environmental pollutants and particles. Upon inhalation, drugs or nanoparticles first contact the surfactant layer, and these interactions critically affect their lifetime and fate in the airways. This review summarises the current knowledge on the possible role and effects of the pulmonary surfactant system in drug delivery strategies. It also summarises the evidence that suggests that pulmonary surfactant is far from being an insuperable barrier and could be used as an efficient shuttle for delivering hydrophobic and hydrophilic compounds deep into the lung and the organism.
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Affiliation(s)
- Alberto Hidalgo
- Dept. of Biochemistry, Fac. of Biology, and Research Institute Hospital 12 Octubre, Universidad Complutense, Madrid, Spain
| | - Antonio Cruz
- Dept. of Biochemistry, Fac. of Biology, and Research Institute Hospital 12 Octubre, Universidad Complutense, Madrid, Spain
| | - Jesús Pérez-Gil
- Dept. of Biochemistry, Fac. of Biology, and Research Institute Hospital 12 Octubre, Universidad Complutense, Madrid, Spain.
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Facco M, Nespeca M, Simonato M, Isak I, Verlato G, Ciambra G, Giorgetti C, Carnielli VP, Cogo PE. In vivo effect of pneumonia on surfactant disaturated-phosphatidylcholine kinetics in newborn infants. PLoS One 2014; 9:e93612. [PMID: 25551219 PMCID: PMC4281094 DOI: 10.1371/journal.pone.0093612] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 03/03/2014] [Indexed: 01/17/2023] Open
Abstract
Background Bacterial pneumonia in newborns often leads to surfactant deficiency or dysfunction, as surfactant is inactivated or its production/turnover impaired. No data are available in vivo in humans on the mechanism of surfactant depletion in neonatal pneumonia. We studied the kinetics of surfactant's major component, disaturated-phosphatidylcholine (DSPC), in neonatal pneumonia, and we compared our findings with those obtained from control newborn lungs. Methods We studied thirty-one term or near-term newborns (gestational age 39.7±1.7 weeks, birth weight 3185±529 g) requiring mechanical ventilation. Fifteen newborns had pneumonia, while 16 newborns were on mechanical ventilation but had no lung disease. Infants received an intratracheal dose of 13C labeled dipalmitoyl-phosphatidylcholine at the study start. We measured the amount and the isotopic enrichment of DSPC-palmitate from serial tracheal aspirates by gas chromatography and gas chromatography-mass spectrometry, respectively, and we calculated the DSPC half-life (HL) and pool size (PS) from the isotopic enrichment curves of surfactant DSPC-palmitate. Results The mean DSPC amount obtained from all tracheal aspirates did not differ between the two groups. DSPC HL was 12.7 (6.5–20.2) h and 25.6 (17.9–60.6) h in infants with pneumonia compared with control infants (p = 0.003). DSPC PS was 14.1 (6.6–30.9) mg/kg in infants with pneumonia and 34.1 (25.6–65.0) mg/kg in controls, p = 0.042. Myeloperoxidase (MPO) activity, as a marker of lung inflammation, was 1322 (531–2821) mU/ml of Epithelial Lining Fluid (ELF) and 371(174–1080) mU/ml ELF in infants with pneumonia and in controls, p = 0.047. In infants with pneumonia, DSPC PS and HL significantly and inversely correlated with mean Oxygenation Index (OI) during the study (DSPC PS vs. OI R = −0.710, p = 0.004 and HL vs. OI R = −0.525, p = 0.044, respectively). Conclusions We demonstrated for the first time in vivo in humans that DSPC HL and PS were markedly impaired in neonatal pneumonia and that they inversely correlated with the degree of respiratory failure.
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Affiliation(s)
- Maddalena Facco
- Department of Women's and Children's Health, University of Padua, Padua, Italy
- * E-mail:
| | - Matteo Nespeca
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Manuela Simonato
- Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Ilena Isak
- Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Giovanna Verlato
- Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Gianluca Ciambra
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Chiara Giorgetti
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Virgilio P. Carnielli
- Neonatal Medicine, Salesi Children's Hospital, Polytechnic University of Marche and University of Ancona, Ancona, Italy
| | - Paola E. Cogo
- Pediatric Cardiac Anesthesia/Intensive Care Unit, Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children's Hospital, Rome, Italy
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14
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Lopez-Rodriguez E, Pérez-Gil J. Structure-function relationships in pulmonary surfactant membranes: from biophysics to therapy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1568-85. [PMID: 24525076 DOI: 10.1016/j.bbamem.2014.01.028] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 01/22/2014] [Accepted: 01/27/2014] [Indexed: 01/01/2023]
Abstract
Pulmonary surfactant is an essential lipid-protein complex to maintain an operative respiratory surface at the mammalian lungs. It reduces surface tension at the alveolar air-liquid interface to stabilise the lungs against physical forces operating along the compression-expansion breathing cycles. At the same time, surfactant integrates elements establishing a primary barrier against the entry of pathogens. Lack or deficiencies of the surfactant system are associated with respiratory pathologies, which treatment often includes supplementation with exogenous materials. The present review summarises current models on the molecular mechanisms of surfactant function, with particular emphasis in its biophysical properties to stabilise the lungs and the molecular alterations connecting impaired surfactant with diseased organs. It also provides a perspective on the current surfactant-based strategies to treat respiratory pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.
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Affiliation(s)
- Elena Lopez-Rodriguez
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Universidad Complutense de Madrid, Madrid, Spain; Institute for Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in End Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany
| | - Jesús Pérez-Gil
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Universidad Complutense de Madrid, Madrid, Spain
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15
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Role of pore-forming toxins in neonatal sepsis. Clin Dev Immunol 2013; 2013:608456. [PMID: 23710203 PMCID: PMC3655490 DOI: 10.1155/2013/608456] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/27/2013] [Indexed: 11/17/2022]
Abstract
Protein toxins are important virulence factors contributing to neonatal sepsis. The major pathogens of neonatal sepsis, group B Streptococci, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus, secrete toxins of different molecular nature, which are key for defining the disease. Amongst these toxins are pore-forming exotoxins that are expressed as soluble monomers prior to engagement of the target cell membrane with subsequent formation of an aqueous membrane pore. Membrane pore formation is not only a means for immediate lysis of the targeted cell but also a general mechanism that contributes to penetration of epithelial barriers and evasion of the immune system, thus creating survival niches for the pathogens. Pore-forming toxins, however, can also contribute to the induction of inflammation and hence to the manifestation of sepsis. Clearly, pore-forming toxins are not the sole factors that drive sepsis progression, but they often act in concert with other bacterial effectors, especially in the initial stages of neonatal sepsis manifestation.
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Abstract
BACKGROUND Pulmonary surfactant is an important part of the host defence against respiratory infections. Bacterial pneumonia in late preterm or term newborn infants often leads to surfactant deficiency or dysfunction, as surfactant is either inactivated or peroxidated. Studies of animal models of pneumonia and clinical case reports suggest that exogenous surfactant might be beneficial to infants with bacterial pneumonia. OBJECTIVES To assess the effect of exogenous surfactant treatment on mortality and pulmonary complications in infants with bacterial pneumonia. SEARCH METHODS We used standard Cochrane Collaboration methodology to conduct our search of databases. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 6); MEDLINE (accessed via Ovid SP June 2011); EMBASE (via Ovid SP 1980 to June 2011); and CINAHL Plus (accessed via EBSCOHost June 2011). SELECTION CRITERIA We limited our search to randomised and quasi-randomised trials of surfactant replacement therapy in infants > 35 weeks gestation with bacterial pneumonia in the first 28 days of life. The primary outcome measures were death, time to resolution of pneumonia, incidence of chronic lung disease, pneumothoraces and pulmonary haemorrhage. DATA COLLECTION AND ANALYSIS We assessed all studies with predefined criteria as to whether they were eligible for inclusion. We extracted data using RevMan 5 (RevMan 2011). We used the standard Cochrane Collaboration methodology for data collection and analysis to assess risk of bias, heterogeneity, treatment effect, missing data and reporting bias where appropriate. MAIN RESULTS We did not identify any studies that met our inclusion criteria. AUTHORS' CONCLUSIONS There is no evidence from randomised controlled trials (RCTs) to support or refute the efficacy of surfactant in near-term and term infants with proven or suspected bacterial pneumonia. RCTs are still required to answer this question.
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Affiliation(s)
- Kenneth Tan
- Monash Newborn, Monash Medical Centre/Monash University, Clayton, Australia.
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17
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Abstract
Pertussis is an acute respiratory disease caused by the bacterium Bordetella pertussis, for which humans are the only known reservoir. During infection, B. pertussis releases several toxins, including pertussis toxin (PT) and adenylate cyclase toxin (ACT), which have both been shown to play roles in promoting bacterial growth during early infection in a mouse model. Furthermore, in vitro and in vivo studies suggest that PT and ACT affect neutrophil chemotaxis and/or function, thereby altering the innate immune response. In this study we depleted animals of neutrophils to investigate whether neutrophils play a protective role during B. pertussis infection in mice. In addition, by infection with toxin-deficient strains, we investigated whether neutrophils are the main targets for PT and/or ACT activity in promoting bacterial growth. Surprisingly, we found no role for neutrophils during B. pertussis infection in naïve mice. However, in previously infected (immune) mice or in mice receiving immune serum, we observed a significant role for neutrophils during infection. Furthermore, in this immune mouse model our evidence indicates that neutrophils appear to be the main target cells for ACT, but not for PT.
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18
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Gauthier TW, Young PA, Gabelaia L, Tang SM, Ping XD, Harris FL, Brown LAS. In utero ethanol exposure impairs defenses against experimental group B streptococcus in the term Guinea pig lung. Alcohol Clin Exp Res 2008; 33:300-6. [PMID: 19032578 DOI: 10.1111/j.1530-0277.2008.00833.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The effects of fetal alcohol exposure on the risks of neonatal lung injury and infection remain under investigation. The resident alveolar macrophage (AM) is the first line of immune defense against pulmonary infections. In utero ethanol (ETOH) exposure deranges the function of both premature and term guinea pig AM. We hypothesized that fetal ETOH exposure would increase the risk of pulmonary infection in vivo. METHODS We developed a novel in vivo model of group B Streptococcus (GBS) pneumonia using our established guinea pig model of fetal ETOH exposure. Timed-pregnant guinea pigs were pair fed +/-ETOH and some were supplemented with the glutathione (GSH) precursor S-adenosyl-methionine (SAM-e). Term pups were given GBS intratracheally while some were pretreated with inhaled GSH prior to the experimental GBS. Neonatal lung and whole blood were evaluated for GBS while isolated AM were evaluated using fluorescent microscopy for GBS phagocytosis. RESULTS Ethanol-exposed pups demonstrated increased lung infection and sepsis while AM phagocytosis of GBS was deficient compared with control. When SAM-e was added to the maternal diet containing ETOH, neonatal lung and systemic infection from GBS was attenuated and AM phagocytosis was improved. Inhaled GSH therapy prior to GBS similarly protected the ETOH-exposed pup from lung and systemic infection. CONCLUSIONS In utero ETOH exposure impaired the neonatal lung's defense against experimental GBS, while maintaining GSH availability protected the ETOH-exposed lung. This study suggested that fetal alcohol exposure deranges the neonatal lung's defense against bacterial infection, and support further investigations into the potential therapeutic role for exogenous GSH to augment neonatal AM function.
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Affiliation(s)
- Theresa W Gauthier
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
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19
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Gordon SB, Kayhty H, Molyneux ME, Haikala R, Nurkka A, Musaya J, Zijlstra EE, Lindell D, French N. Pneumococcal conjugate vaccine is immunogenic in lung fluid of HIV-infected and immunocompetent adults. J Allergy Clin Immunol 2007; 120:208-10. [PMID: 17544493 PMCID: PMC5063094 DOI: 10.1016/j.jaci.2007.03.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 03/26/2007] [Accepted: 03/27/2007] [Indexed: 10/23/2022]
Affiliation(s)
- Stephen B. Gordon
- Malawi-Liverpool-Wellcome Programme for Research in Tropical Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
- School of Tropical Medicine, Liverpool, United Kingdom
| | - Helena Kayhty
- Vaccine Immunology Laboratory, National Public Health Institute, Helsinki, Finland
| | - Malcolm E. Molyneux
- Malawi-Liverpool-Wellcome Programme for Research in Tropical Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
- School of Tropical Medicine, Liverpool, United Kingdom
| | - Raili Haikala
- Vaccine Immunology Laboratory, National Public Health Institute, Helsinki, Finland
| | - Anu Nurkka
- Vaccine Immunology Laboratory, National Public Health Institute, Helsinki, Finland
| | - Janelisa Musaya
- Malawi-Liverpool-Wellcome Programme for Research in Tropical Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Eduard E. Zijlstra
- Department of Medicine, University of Malawi College of Medicine, Blantyre, Malawi
| | - Dennis Lindell
- Department of Pathology, University of Michigan, Ann Arbor, Mich
| | - Neil French
- Malawi-Liverpool-Wellcome Programme for Research in Tropical Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
- Department of Medicine, University of Malawi College of Medicine, Blantyre, Malawi
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20
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Abstract
Although there is no doubt that administration of exogenous surfactant to very preterm babies who have respiratory distress syndrome is safe and efficacious, surfactant inactivation or deficiency plays a role in the pathophysiology of other pulmonary disorders affecting newborn infants. Preliminary data suggest that there may be a role for surfactant administration to babies who have meconium aspiration syndrome, pneumonia, and possibly bronchopulmonary dysplasia. Further investigation is necessary but seems warranted.
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Affiliation(s)
- Thierry Lacaze-Masmonteil
- Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
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21
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Shon SM, Lee BY, Kim CS, Lee SL, Kwon TC. The outcome of surfactant replacement therapy in above nearterm neonates with severe pulmonary disease. KOREAN JOURNAL OF PEDIATRICS 2007. [DOI: 10.3345/kjp.2007.50.12.1200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Su-Min Shon
- Departments of Pediatrics, Keimyung University School of Medicine, Daegu, Korea
| | - Bo-Young Lee
- Departments of Pediatrics, Keimyung University School of Medicine, Daegu, Korea
| | - Chun-Soo Kim
- Departments of Pediatrics, Keimyung University School of Medicine, Daegu, Korea
| | - Sang-Lak Lee
- Departments of Pediatrics, Keimyung University School of Medicine, Daegu, Korea
| | - Tae-Chan Kwon
- Departments of Pediatrics, Keimyung University School of Medicine, Daegu, Korea
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22
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Choi BY, Kim KM, Yoon JS, Lee JS. A case of acute respiratory distress syndrome treated with surfactant and low dose methylprednisolone. KOREAN JOURNAL OF PEDIATRICS 2006. [DOI: 10.3345/kjp.2006.49.4.455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Bo Yeon Choi
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Kyong Mo Kim
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jong Seo Yoon
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Joon Sung Lee
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
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23
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van Kaam A, Lachmann R, van Iwaarden F, Haitsma J, Lachmann B, De Jaegere A, Noorduyn A, Kok J, Herting E. Should We Start Considering Surfactant for Atelectasis? Am J Respir Crit Care Med 2005. [DOI: 10.1164/ajrccm.172.1.953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
| | | | | | | | | | | | | | - Joke Kok
- Emma Children's Hospital AMC, Amsterdam, The Netherlands
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24
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Rauprich P, Walter G, Jarstrand C, Robertson B, Herting E. Influence of modified natural and synthetic surfactant preparations on bacterial killing by polymorphonuclear leucocytes. Immunobiology 2004; 209:609-17. [PMID: 15638129 DOI: 10.1016/j.imbio.2004.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In addition to its biophysical functions, surfactant plays an important role in pulmonary host defense. In this investigation we studied the influence of various commercially available surfactants on the phagocytosis of bacteria that are common pathogens in the neonatal period. Group B streptococci (GBS), Escherichia coli and Staphylococcus aureus were cultured with isolated human polymorphonuclear leucocytes (PMN) and non-specific serum in the presence or absence of different modified natural (Curosurf, Alveofact, Survanta) or totally synthetic, protein-free surfactant preparations (Exosurf, Pumactant). Prior to and after 30 and 60 min of incubation with PMN at different surfactant concentrations (1, 10 or 20 mg/ml), the number of viable bacteria was determined by colony counting. Killing of S. aureus by PMN was not influenced by any of the surfactants. Alveofact and Curosurf had no significant negative impact on phagocytosis. At 20 mg/ml, Curosurf even reduced the number of viable E. coli. Survanta at 10 and 20 mg/ml and Exosurf at all concentrations impaired the killing of non-encapsulated GBS and E. coli. Pumactant at 1-20 mg/ml interfered with the phagocytosis of E. coli. In further experiments we demonstrated that Curosurf did not interfere with the phagocytosis of an encapsulated GBS-strain opsonised by a specific antiserum either. In additional experiments we analysed the influence of the different surfactants on the release of reactive oxygen metabolite by PMN and found that the changes in nitroblue tetrazolium reduction did not necessarily correlate with the findings of the studies on killing. In conclusion, we found that killing by PMN was influenced by the bacterial species and the composition and concentration of the different surfactant preparations. The strongest impairment in phagocytic function of PMN was observed with the protein-free synthetic surfactant Exosurf, a phospholipid preparation that contains the alcohols hexadecanol and tyloxapol as spreading agents.
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Affiliation(s)
- Petra Rauprich
- Department of Pediatrics, University of Göttingen, Germany
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25
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Abstract
Surfactant has led to a significant reduction in neonatal mortality for premature infants with lung immaturity and respiratory distress. However, surfactant therapy has been shown to be effective in the treatment of a number of other neonatal respiratory disorders and the evidence for surfactant use in such circumstances is presented. Meconium aspiration is characterised by severe atelectasis, the influx of neutrophils, edema, and hyaline membranes, with decreased levels of SP-A and SP-B and the large aggregate fraction of lung surfactant, and altered surfactant surface morphology. Meconium contains cholesterol, free fatty acids and bilirubin all of which can interfere with surfactant function in a dose-dependent fashion. Providing larger amounts of surfactant can overcome some of this inhibition. Animal models of meconium aspiration treated with surfactant have improved histology, lung mechanics and gas exchange. Studies in human infants with meconium aspiration have found elevated concentrations of total protein, albumin, and membrane-derived phospholipid in lung lavage fluid, and haemorrhagic pulmonary edema. Clinical studies in such neonates have reported improved gas exchange and clinical outcomes following surfactant treatment. More recently surfactant lavage has been shown to be a potentially efficacious therapy for such infants. The inflammatory exudate containing plasma proteins and cytokines which accompanies neonatal pneumonia may inactivate surfactant. Surfactant treatment given to animals following the tracheal instillation of group B Streptococcal resulted in significantly less bacterial growth and improved lung function. Small clinical experiences have demonstrated the benefit of surfactant to infants with pneumonia/sepsis. Pulmonary haemorrhage, which some consider a complication of surfactant therapy, has also been effectively managed using surfactant instillation. The hemoglobin and red blood cell lipids may act to inhibit natural surfactant and treatment with surfactant has been shown to improve outcome for infants with pulmonary haemorrhage. Animal models of congenital diaphragmatic hernia (CDH) have hypoplastic lungs with evidence of decreased lamellar bodies in their type II pneumocytes and resultant surfactant deficiency, and respond to surfactant replacement with improved gas exchange and lung mechanics. The lungs of human infants with CDH contain less phospholipids and phosphatidylcholine per milligram of DNA than control infants. Case reports have reported a benefit of surfactant for infants with CDH. In the near-term infants with severe respiratory distress, surfactant is one of the therapies along with inhaled nitric oxide and high frequency ventilations, that have resulted in improved outcomes. Surfactant treatment may be of significant benefit in newborn infants with respiratory compromise secondary to a number of insults, and further prospective evidence of its efficacy in such disorders is needed.
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26
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Abstract
OBJECTIVES The recognition that alveolar overdistension rather than peak inspiratory airway pressure is the primary determinant of lung injury has shifted our understanding of the pathogenesis of ventilator-induced side effects. In this review, contemporary ventilatory methods, supportive treatments, and future developments relevant to pediatric critical care are reviewed. DATA SYNTHESIS A strategy combining recruitment maneuvers, low-tidal volume, and higher positive end-expiratory pressure (PEEP) decreases barotrauma and volutrauma. Given that appropriate tidal volumes are critical in determining adequate alveolar ventilation and avoiding lung injury, volume-control ventilation with high PEEP levels has been proposed as the preferable protective ventilatory mode. Pressure-related volume control ventilation and high-frequency oscillatory ventilation (HFOV) have taken on an important role as protective lung strategies. Further data are required in the treatment of children, confirming the preliminary results in specific lung pathologies. Spontaneous breathing supported artificially during inspiration (pressure support ventilation) is widely used to maintain or reactivate spontaneous breathing and to avoid hemodynamic variation. Volume support ventilation reduces the need for manual adaptation to maintain stable tidal and minute volume and can be useful in weaning. Prone positioning and permissive hypercapnia have taken on an important role in the treatment of patients undergoing artificial ventilation. Surfactant and nitric oxide have been proposed in specific lung pathologies to facilitate ventilation and gas exchange and to reduce inspired oxygen concentration. Investigation of lung ventilation using a liquid instead of gas has opened new vistas on several lung pathologies with high mortality rates. RESULTS The conviction emerges that the best ventilatory treatment may be obtained by applying a combination of types of ventilation and supportive treatments as outlined above. Early treatment is important for the overall positive final result. Lung recruitment maneuvers followed by maintaining an open lung favor rapid resolution of pathology and reduce side effects. CONCLUSIONS The methods proposed require confirmation through large controlled clinical trials that can assess the efficacy reported in pilot studies and case reports and define the optimal method(s) to treat individual pathologies in the various pediatric age groups.
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Affiliation(s)
- Giuseppe A Marraro
- Pediatric Intensive Care Unit, Fatebenefratelli and Ophthalmiatric Hospital, Milan, Italy.
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27
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Gan X, Jarstrand C, Herting E, Berggren P, Robertson B. Effect of surfactant and specific antibody on bacterial proliferation and lung function in experimental pneumococcal pneumonia. Int J Infect Dis 2001; 5:9-18. [PMID: 11285153 DOI: 10.1016/s1201-9712(01)90042-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE To investigate the effect of surfactant and specific antibody on bacterial proliferation in experimental pneumococcal pneumonia. METHODS Near-term newborn rabbits received a standard dose (10(7)) of type 3 pneumococci via the airways. Control animals were sacrificed 1 minute later. Other animals were ventilated for 5 hours and treated via the tracheal cannula with surfactant (Curosurf 200 mg/kg), a mixture of surfactant and a polyclonal antipneumococcal antibody, the antibody without surfactant, or saline. RESULTS There was a significant bacterial proliferation in lung tissue in all animals ventilated for 5 hours. Bacterial growth, expressed as log10 colony forming units (CFU) per gram of lung tissue was less prominent in animals treated with a mixture of surfactant and specific antibody than in animals treated with antibody alone (median, 7.51, range, 6.80--7.70 vs. median, 7.92, range, 7.07--8.50; P < 0.05). Dynamic lung-thorax compliance was improved with surfactant or surfactant plus antibody in comparison with saline or antibody alone. CONCLUSIONS The data suggest that the suppressive effect of the antibody on bacterial proliferation becomes evident only when surfactant is administered together with the antibody.
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Affiliation(s)
- X Gan
- Division for Experimental Perinatal Pathology, Department of Woman and Child Health, Karolinska Hospital, Stockholm, Sweden
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28
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Herting E, Gefeller O, Land M, van Sonderen L, Harms K, Robertson B. Surfactant treatment of neonates with respiratory failure and group B streptococcal infection. Members of the Collaborative European Multicenter Study Group. Pediatrics 2000; 106:957-64; discussion 1135. [PMID: 11061760 DOI: 10.1542/peds.106.5.957] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Connatal pneumonia caused by group B streptococcal (GBS) infection may be associated with surfactant dysfunction. We investigated the effects of surfactant treatment in term and preterm neonates with GBS infection and respiratory failure, in comparison with corresponding data from a control population of noninfected infants treated with surfactant for respiratory distress syndrome (RDS). DESIGN/METHODS The study comprised 118 infants with respiratory failure, clinical and/or laboratory signs of acute inflammatory disease, and GBS infection proven by culture results. They were recruited retrospectively from a database of patients treated with surfactant at 28 neonatology units participating in European multicenter trials (1987-1993) and prospectively from the same units in the following years. A nonrandomized control group of 236 noninfected infants was selected from the same database. The primary parameters evaluated were oxygen requirement, ventilator settings, and incidence of complications. RESULTS Median birth weight in the GBS study group was 1468 g (25th-75th percentiles: 1015-2170), and median gestational age was 30 (27-33) weeks. Thirty-one percent of the infants weighed >2000 g. Median age at surfactant treatment was 6 hours. The mean initial surfactant dose was 142 mg/kg (standard deviation: 53). Ninety of the infants were treated with Curosurf (Chiesi Farmaceutici, Parma, Italy), 13 with Survanta (Abboth GmbH, Wiesbaden, Germany), 12 with Alveofact (Dr Karl Thomae GmbH, Biberach, Germany), and 3 with Exosurf (Wellcome GmbH, Burgwedel, Germany). Within 1 hour of surfactant treatment, median fraction of inspiratory oxygen was reduced from .84 (25th-75th percentiles:.63-1.0) to.50 (.35-.80). The incidence of complications in the study group (mortality: 30%; pneumothorax: 16%; intracranial hemorrhage: 42%) was high, compared with infants with RDS. CONCLUSIONS Surfactant therapy improves gas exchange in the majority of patients with GBS pneumonia. The response to surfactant is slower than in infants with RDS, and repeated surfactant doses are often needed. The mortality and morbidity are substantial, considering the relatively high mean birth weight of the treated infants.
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Affiliation(s)
- E Herting
- Department of Pediatrics, University of Göttingen, Göttingen, Germany.
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29
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Gross NT, Jarstrand C, Robertson B. Treatment of experimental Cryptococcus neoformans infection in newborn rabbits by airway instillation of specific antibody and surfactant. Lett Appl Microbiol 2000; 31:218-22. [PMID: 10972732 DOI: 10.1046/j.1365-2672.2000.00790.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cryptococcosis in AIDS patients has a slow response to antifungal chemotherapy, and passive antibody treatment has thus been considered as an adjunct. Polyclonal anticryptococcal IgG dissolved in a suspension of modified natural surfactant was given intratracheally to near-term rabbits. Killing of Cryptococcus neoformans within the lungs was determined by counting the colony forming units (cfu). After 5 h a significant decrease in cfu was observed in rabbits treated with the IgG-surfactant mixture compared with control animals receiving saline. In conjunction with conventional therapy, the combined treatment of IgG-surfactant given by bronchoscopy might be used in high-risk patients to enhance killing of the yeast within the lungs.
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Affiliation(s)
- N T Gross
- Division of Clinical Bacteriology, Department of Immunology, Microbiology, Pathology and Infectious Diseases, Huddinge Hospital, Huddinge, Sweden.
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