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Pleural and tracheal injuries remain significant problems, and an easy to use, effective pleural or tracheal sealant would be a significant advance. The major challenges are requirements for adherence, high strength and elasticity, dynamic durability, appropriate biodegradability, and lack of cell or systemic toxicity. We designed and evaluated two sealant materials comprised respectively of alginate methacrylate and of gelatin methacryloyl, each functionalized by conjugation with dopamine HCl. Both compounds are cross-linked into easily applied as pre-formed hydrogel patches or as in situ hydrogels formed at the wound site utilizing FDA-approved photo-initiators and oxidants. Material testing demonstrates appropriate adhesiveness, tensile strength, burst pressure, and elasticity with no significant cell toxicity in vitro assessments. Air-leak was absent after sealant application to experimentally-induced injuries in ex-vivo rat lung and tracheal models and in ex vivo pig lungs. Sustained repair of experimentally-induced pleural injury was observed for up to one month in vivo rat models and for up to 2 weeks in vivo rat tracheal injury models without obvious air leak or obvious toxicities. The alginate-based sealant worked best in a pre-formed hydrogel patch whereas the gelatin-based sealant worked best in an in situ formed hydrogel at the wound site thus providing two potential approaches. These studies provide a platform for further pre-clinical and potential clinical investigations. Statement of significance Pneumothorax and pleural effusions resulting from trauma and a range of lung diseases and critical illnesses can result in lung collapse that can be immediately life-threatening or result in chronic leaking (bronchopleural fistula) that is currently difficult to manage. This leads to significantly increased morbidity, mortality, hospital stays, health care costs, and other complications. We have developed sealants originating from alginate and gelatin biomaterials, each functionalized by methacryloylation and by dopamine conjugation to have desired mechanical characteristics for use in pleural and tracheal injuries. The sealants are easily applied, non-cytotoxic, and perform well in vitro and in vivo model systems of lung and tracheal injuries. These initial proof of concept investigations provide a platform for further studies.

Chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF), are characterized by regional extracellular matrix (ECM) remodeling which contributes to disease progression. Previous proteomic studies on whole decellularized lungs have provided detailed characterization on the impact of COPD and IPF on total lung ECM composition. However, such studies are unable to determine the differences in ECM composition between individual anatomical regions of the lung. Here, we employ a post-decellularization dissection method to compare the ECM composition of whole decellularized lungs (wECM) and specific anatomical lung regions, including alveolar-enriched ECM (aECM), airway ECM (airECM), and vasculature ECM (vECM), between non-diseased (ND), COPD, and IPF human lungs. We demonstrate, using mass spectrometry, that individual regions possess a unique ECM signature characterized primarily by differences in collagen composition and basement-membrane associated proteins, including ECM glycoproteins. We further demonstrate that both COPD and IPF lead to alterations in lung ECM composition in a region-specific manner, including enrichment of type-III collagen and fibulin in IPF aECM. Taken together, this study provides methodology for future studies, including isolation of region-specific lung biomaterials, as well as a dataset that may be applied for the identification of novel ECM targets for therapeutics.

Despite progress in use of decellularized lung scaffolds in ex vivo lung bioengineering schemes, including use of gels and other materials derived from the scaffolds, the detailed composition and functional role of extracellular matrix (ECM) proteoglycans (PGs) and their glycosaminoglycan (GAG) chains remaining in decellularized lungs, is poorly understood. Using a commonly utilized detergent-based decellularization approach in human autopsy lungs resulted in disproportionate losses of GAGs with depletion of chondroitin sulfate/dermatan sulfate (CS/DS) > heparan sulfate (HS) > hyaluronic acid (HA). Specific changes in disaccharide composition of remaining GAGs were observed with disproportionate loss of NS and NS2S for HS groups and of 4S for CS/DS groups. No significant influence of smoking history, sex, time to autopsy, or age was observed in native vs. decellularized lungs. Notably, surface plasmon resonance demonstrated that GAGs remaining in decellularized lungs were unable to bind key matrix-associated growth factors FGF2, HGF, and TGFβ1. Growth of lung epithelial, pulmonary vascular, and stromal cells cultured on the surface of or embedded within gels derived from decellularized human lungs was differentially and combinatorially enhanced by replenishing specific GAGs and FGF2, HGF, and TGFβ1. In summary, lung decellularization results in loss and/or dysfunction of specific GAGs or side chains significantly affecting matrix-associated growth factor binding and lung cell metabolism. GAG and matrix-associated growth factor replenishment thus needs to be incorporated into schemes for investigations utilizing gels and other materials produced from decellularized human lungs. STATEMENT OF SIGNIFICANCE: Despite progress in use of decellularized lung scaffolds in ex vivo lung bioengineering schemes, including use of gels and other materials derived from the scaffolds, the detailed composition and functional role of extracellular matrix (ECM) proteoglycans (PGs) and their glycosaminoglycan (GAG) chains remaining in decellularized lungs, is poorly understood. In the current studies, we demonstrate that glycosaminoglycans (GAGs) are significantly depleted during decellularization and those that remain are dysfunctional and unable to bind matrix-associated growth factors critical for cell growth and differentiation. Systematically repleting GAGs and matrix-associated growth factors to gels derived from decellularized human lung significantly and differentially affects cell growth. These studies highlight the importance of considering GAGs in decellularized lungs and their derivatives.

Summary: Heart failure (HF) and subarachnoid hemorrhage (SAH) chronically reduce cerebral perfusion, which negatively affects clinical outcome. This work demonstrates a strong relationship between cerebral artery cystic fibrosis transmembrane conductance regulator (CFTR) expression and altered cerebrovascular reactivity in HF and SAH. In HF and SAH, CFTR corrector compounds (C18 or lumacaftor) normalize pathological alterations in cerebral artery CFTR expression, vascular reactivity, and cerebral perfusion, without affecting systemic hemodynamic parameters. This normalization correlates with reduced neuronal injury. Therefore, CFTR therapeutics have emerged as valuable clinical tools to manage cerebrovascular dysfunction, impaired cerebral perfusion, and neuronal injury. Key Words: cognitive impairment, corrector compounds, cystic fibrosis transmembrane conductance regulator (CFTR), myogenic vasoconstriction, sphingosine-1-phosphate, tumor necrosis factor, vascular smooth muscle cells

The University of Vermont Larner College of Medicine, in collaboration with the National Heart, Lung, and Blood Institute (NHLBI), the Alpha-1 Foundation, the American Thoracic Society, the Cystic Fibrosis Foundation, the European Respiratory Society, the International Society for Cell & Gene Therapy, and the Pulmonary Fibrosis Foundation, convened a workshop titled “Stem Cells, Cell Therapies, and Bioengineering in Lung Biology and Diseases” from July 24 through 27, 2017, at the University of Vermont, Burlington, Vermont. The conference objectives were to review and discuss current understanding of the following topics: 1) stem and progenitor cell biology and the role that they play in endogenous repair or as cell therapies after lung injury, 2) the emerging role of extracellular vesicles as potential therapies, 3) ex vivo bioengineering of lung and airway tissue, and 4) progress in induced pluripotent stem cell protocols for deriving lung cell types and applications in disease modeling. All of these topics are research areas in which significant and exciting progress has been made over the past few years. In addition, issues surrounding the ethics and regulation of cell therapies worldwide were discussed, with a special emphasis on combating the growing problem of unproven cell interventions being administered to patients with lung diseases. Finally, future research directions were discussed, and opportunities for both basic and translational research were identified.

Background aimsCell-based therapies of pulmonary diseases with mesenchymal stromal cells (MSCs) are increasingly under experimental investigation. In most of these, MSCs are administered intravenously or by direct intratracheal instillation. A parallel approach is to administer the cells into the lung by endoscopic atomization (spraying). In a previous study, the authors developed a flexible endoscopic atomization device that allows administration of respiratory epithelial cells in the lungs with high survival.MethodsIn this study, the authors evaluated the feasibility of spraying MSCs with two different endoscopic atomization devices (air and pressure atomization). Following atomization, cell viability was evaluated with live/dead staining. Subsequent effects on cytotoxicity, trilineage differentiation and expression of MSC-specific markers as well as on MSC metabolic activity and morphology were analyzed for up to 7 days.ResultsMSC viability immediately after spraying and subsequent metabolic activity for 7 days was not influenced by either of the devices. Slightly higher cytotoxicity rates could be observed for pressure-atomized compared with control and air-atomized MSCs over 7 days. Flow cytometry revealed no changes in characteristic MSC cell surface marker expression, and morphology remained unchanged. Standard differentiation into osteocytes, chondrocytes and adipocytes was inducible after atomization.ConclusionsIn the literature, a minimal survival of 50% was previously defined as the cutoff value for successful cell atomization. This is easily met with both of the authors’ devices, with more than 90% survival. Thus, there is a potential role for atomization in intrapulmonary MSC-based cell therapies, as it is a feasible and easily utilizable approach based on clinically available equipment.

Decompressive craniectomy (DC) is an accepted surgical technique for reducing life-threatening levels of intracranial pressure. Remodelling the cranial vault following DC can constitute a reconstructive challenge and is known to carry significant morbidity. The aim of our study was to evaluate acrylic versus autologous cranioplasty with regard to specific complication rates. A retrospective analysis was conducted of 286 consecutive adult patients who underwent cranioplasty following supratentorial decompressive craniectomy at our institution between January 2003 and June 2013. The patients were followed based on medical records, operative reports, imaging and outpatient contacts in the postoperative course. A total of 221/286 patients in our series received an autologous bone flap. 65/286 cranioplasty procedures were carried out using acrylic (PMMA) implants to cover uni- or bilateral defects. Within the follow-up period a total of 100 operative revisions were performed. 33.3% patients in the autologous bone group and 40.6% of patients in the acrylic group developed complications requiring surgical attention. The main reason for revision was infection with a total of 37 revisions necessary to treat disturbed wound healing. Postoperative sub- and epidural hematomas requiring revision were more frequent in the acrylic group. Resorption of the autologous bone flap requiring operative revision was seen in 8/222 (3.6%) cases. Other complications included loosening of the implant or dislocation. From our data it can be concluded that cranioplasty procedures using autologous bone-flaps and acrylic implants carry signifikant morbidity, but that both are justifiable techniques for cranioplasty in adult patients.

Chronic lung diseases (CLDs), such as chronic obstructive pulmonary disease, interstitial lung disease, and lung cancer, are among the leading causes of morbidity globally and impose major health and financial burdens on patients and society. Effective treatments are scarce, and relevant human model systems to effectively study CLD pathomechanisms and thus discover and validate potential new targets and therapies are needed. Precision-cut lung slices (PCLS) from healthy and diseased human tissue represent one promising tool that can closely recapitulate the complexity of the lung's native environment, and recently, improved methodologies and accessibility to human tissue have led to an increased use of PCLS in CLD research. Here, we discuss approaches that use human PCLS to advance our understanding of CLD development, as well as drug discovery and validation for CLDs. PCLS enable investigators to study complex interactions among different cell types and the extracellular matrix in the native three-dimensional architecture of the lung. PCLS further allow for high-resolution (live) imaging of cellular functions in several dimensions. Importantly, PCLS can be derived from diseased lung tissue upon lung surgery or transplantation, thus allowing the study of CLDs in living human tissue. Moreover, CLDs can be modeled in PCLS derived from normal lung tissue to mimic the onset and progression of CLDs, complementing studies in end-stage diseased tissue. Altogether, PCLS are emerging as a remarkable tool to further bridge the gap between target identification and translation into clinical studies, and thus open novel avenues for future precision medicine approaches.

Mounting evidence indicates that the presence of cardiovascular disease (CVD) and risk factors elevates the incidence of cognitive impairment (CI) and dementia. CVD and associated decline in cardiovascular function can impair cerebral blood flow (CBF) regulation, leading to the disruption of oxygen and nutrient supply in the brain where limited intracellular energy storage capacity critically depends on CBF to sustain proper neuronal functioning. During hypertension and acute as well as chronic CVD, cerebral hypoperfusion and impaired cerebrovascular function are often associated with neurodegeneration and can lead to CI and dementia. Currently, all forms of neurodegeneration associated to CVD lack effective treatments, which highlights the need to better understand specific mechanisms linking cerebrovascular dysfunction and CBF deficits to neurodegeneration. In this review, we discuss vascular targets that have already shown attenuation of neurodegeneration or CI associated to hypertension, heart failure (HF) and stroke by improving cerebrovascular function or CBF deficits.

PURPOSE OF REVIEW: Bioengineering the lung based on its natural extracellular matrix (ECM) offers novel opportunities to overcome the shortage of donors, to reduce chronic allograft rejections, and to improve the median survival rate of transplanted patients. During the last decade, lung tissue engineering has advanced rapidly to combine scaffolds, cells, and biologically active molecules into functional tissues to restore or improve the lung's main function, gas exchange. This review will inspect the current progress in lung bioengineering using decellularized and recellularized lung scaffolds and highlight future challenges in the field.RECENT FINDINGS: Lung decellularization and recellularization protocols have provided researchers with tools to progress toward functional lung tissue engineering. However, there is continuous evolution and refinement particularly for optimization of lung recellularization. These further the possibility of developing a transplantable bioartificial lung.SUMMARY: Bioengineering the lung using recellularized scaffolds could offer a curative option for patients with end-stage organ failure but its accomplishment remains unclear in the short-term. However, the state-of-the-art of techniques described in this review will increase our knowledge of the lung ECM and of chemical and mechanical cues which drive cell repopulation to improve the advances in lung regeneration and lung tissue engineering. (Less)

The development of reliable tissue engineering methods using decellularized cadaveric or donor lungs could potentially provide a new source of lung tissue. The vast majority of current lung decellularization protocols are detergent based and incompletely removed residual detergents may have a deleterious impact on subsequent scaffold recellularization. Detergent removal and quality control measures that rigorously and reliably confirm removal, ideally utilizing nondestructive methods, are thus critical for generating optimal acellular scaffolds suitable for potential clinical translation. Using a modified and optimized version of a methylene blue-based detergent assay, we developed a straightforward, noninvasive method for easily and reliably detecting two of the most commonly utilized anionic detergents, sodium deoxycholate (SDC) and sodium dodecyl sulfate (SDS), in lung decellularization effluents. In parallel studies, we sought to determine the threshold of detergent concentration that was cytotoxic using four different representative human cell types utilized in the study of lung recellularization: human bronchial epithelial cells, human pulmonary vascular endothelial cells (CBF12), human lung fibroblasts, and human mesenchymal stem cells. Notably, different cells have varying thresholds for either SDC or SDS-based detergent-induced cytotoxicity. These studies demonstrate the importance of reliably removing residual detergents and argue that multiple cell lines should be tested in cytocompatibility-based assessments of acellular scaffolds. The detergent detection assay presented here is a useful nondestructive tool for assessing detergent removal in potential decellularization schemes or for use as a potential endpoint in future clinical schemes, generating acellular lungs using anionic detergent-based decellularization protocols.

Chronic obstructive pulmonary disease (COPD) is the 3rd leading cause of death in the US and is primarily triggered in susceptible individuals by chronic cigarette smoke (CS) exposure. Protease/antiprotease imbalances in COPD leads to destruction of lung matrix. Therapies targeting this imbalance have not yet provided a cure. Mass spectrometry (MS) has been used to analyze the proteome of healthy and COPD lungs, but extracellular matrix (ECM) and matrix bound proteins (i.e. matrisome (MAT) are difficult to detect and thus underrepresented. Decellularized lungs (DEC) have enriched MATs. We hypothesized that the proteomic profile of DEC COPD lungs is distinct from healthy and may provide new insight into COPD pathogenesis. DEC lungs from two murine COPD models (elastase, CS) were analyzed by MS using quantitative TMT-labeling and compared to healthy controls. DEC lungs from 12 normal and 4 COPD human lungs were analyzed using 3 samples from distinct regions per lung. Principal component analysis showed that the proteome of elastase model derived DEC lungs was markedly different compared to normal. Although clustering was not observed for DEC lungs from murine CS or human COPD vs controls, the MAT had detectable differences. Notably, human lung samples had high intra-lung similarity, independent of disease status. Proteome changes in DEC lungs from CS mice positively correlated with those seen in human COPD lungs (Pearson correlation r=0.17, p

While recent work demonstrated that enrofloxacin and ciprofloxacin reach the fetoplacental unit without causing obvious lesions in the 9-month-old equine fetus or resulting foal, many practitioners still hesitate to prescribe a fluoroquinolone during pregnancy. Since early gestation is a critical time for fetal skeletal development, if fluoroquinolones are chondrotoxic to the fetus at any point during gestation, this period would be important. The aim of this study was to assess the effects of 2 weeks’ exposure to enrofloxacin on the equine fetus between 46 and 60 days gestation. Twelve pregnancies from nine healthy mares were allocated into two groups: untreated (n = 7), or treatment (7.5 mg/kg enrofloxacin, PO × 14 days, n = 6). Abortion was induced with prostaglandin 24 h after the last enrofloxacin dose, or on the equivalent day of gestation for untreated mares. Four of nine mares were rebred for a second cycle and were assigned to the opposite treatment to serve as their own controls. Fetal fluids from treated mares were analysed for enrofloxacin and ciprofloxacin concentrations. Fetal organs (heart, lungs, spleen, kidney, and liver) and limbs were examined histopathologically. Enrofloxacin and ciprofloxacin diffused to the fetal fluids during early gestation and did not result in detectable abnormalities in the fetus after 14 days of treatment. While current research does not determine long-term foal outcomes, enrofloxacin may be useful for select bacterial infections in pregnant mares.

Allogeneic lung transplant is limited both by the shortage of available donor lungs and by the lack of suitable long-term lung assist devices to bridge patients to lung transplantation. Avian lungs have different structure and mechanics resulting in more efficient gas exchange than mammalian lungs. Decellularized avian lungs, recellularized with human lung cells, could therefore provide a powerful novel gas exchange unit for potential use in pulmonary therapeutics. To initially assess this in both small and large avian lung models, chicken (Gallus gallus domesticus) and emu (Dromaius novaehollandiae) lungs were decellularized using modifications of a detergent-based protocol, previously utilized with mammalian lungs. Light and electron microscopy, vascular and airway resistance, quantitation and gel analyses of residual DNA, and immunohistochemical and mass spectrometric analyses of remaining extracellular matrix (ECM) proteins demonstrated maintenance of lung structure, minimal residual DNA, and retention of major ECM proteins in the decellularized scaffolds. Seeding with human bronchial epithelial cells, human pulmonary vascular endothelial cells, human mesenchymal stromal cells, and human lung fibroblasts demonstrated initial cell attachment on decellularized avian lungs and growth over a 7-day period. These initial studies demonstrate that decellularized avian lungs may be a feasible approach for generating functional lung tissue for clinical therapeutics.

Chronic obstructive pulmonary disease (COPD) is characterised by a progressive loss of lung tissue. Inducing repair processes within the adult diseased lung is of major interest and Wnt/β-catenin signalling represents a promising target for lung repair. However, the translation of novel therapeutic targets from model systems into clinical use remains a major challenge.We generated murine and patient-derived three-dimensional (3D) ex vivo lung tissue cultures (LTCs), which closely mimic the 3D lung microenvironment in vivo. Using two well-known glycogen synthase kinase-3β inhibitors, lithium chloride (LiCl) and CHIR 99021 (CT), we determined Wnt/β-catenin-driven lung repair processes in high spatiotemporal resolution using quantitative PCR, Western blotting, ELISA, (immuno)histological assessment, and four-dimensional confocal live tissue imaging.Viable 3D-LTCs exhibited preserved lung structure and function for up to 5 days. We demonstrate successful Wnt/β-catenin signal activation in murine and patient-derived 3D-LTCs from COPD patients. Wnt/β-catenin signalling led to increased alveolar epithelial cell marker expression, decreased matrix metalloproteinase-12 expression, as well as altered macrophage activity and elastin remodelling. Importantly, induction of surfactant protein C significantly correlated with disease stage (per cent predicted forced expiratory volume in 1 s) in patient-derived 3D-LTCs.Patient-derived 3D-LTCs represent a valuable tool to analyse potential targets and drugs for lung repair. Enhanced Wnt/β-catenin signalling attenuated pathological features of patient-derived COPD 3D-LTCs.

The postnatal development of the female reproductive system in laboratory animals and humans is reviewed. To enable a meaningful species comparison of the developing female reproductive system, common definitions of developmental processes were established with a focus made on aspects that are similar across species. A species comparison of the key endocrine, morphologic, and functional (onset of ovarian cycles and ability to reproduce) features of postnatal development of the female reproductive system is provided for human, nonhuman primate, dog, rat, and also mouse, minipig, and rabbit where possible. Species differences in the timing and control of female sexual maturation are highlighted. Additionally, a species comparison of the type and timing of female reproductive ovarian cycles was compiled. Human development provided the frame of reference, and then other common laboratory species were compared. The comparison has inherent challenges because the processes involved and sequence of events can differ greatly across species. Broad strokes were taken to assign a particular average age to an event and are to be used with caution. Methods of evaluation of postnatal female reproductive development in laboratory animals are discussed. Lastly, control rodent data from one of the author's laboratory on vaginal opening, first estrus, estrous cyclicity, and the histopathology involved with the developing female rat and mouse are presented. The information provided in this review is intended to be a resource for the design and interpretation of juvenile animal toxicity testing and ultimately, the relevance of the data to characterize potential risks for women and girls. Birth Defects Research 110:163-189, 2018. © 2017 Wiley Periodicals, Inc.

The limited available treatment options for patients with chronic lung diseases, such as fibrosis, lead to poor prognosis after diagnosis and short survival rates. An exciting new bioengineering approach utilizes de- and recellularization of lung tissue to potentially overcome donor organ shortage and immune reactions toward the received transplant. The goal of decellularization is to create a scaffold which contains the necessary framework for stability and functionality for regenerating lung tissue while removing immunomodulatory factors by removal of cells. After decellularization, the scaffold could be re-functionalized by repopulation with the patient's own stem/progenitor cells to create a fully functional organ or can be used as ex vivo models of disease. In this chapter the decellularization of lung tissue from multiple species (i.e., rodents, pigs, and humans) as well as disease states such as fibrosis is described. We discuss and describe the various quality control measures which should be used to characterize decellularized scaffolds, methods for protein analysis of the remaining scaffold, and methods for recellularization of scaffolds.

A novel potential approach for lung transplantation could be to utilize xenogeneic decellularized pig lung scaffolds that are recellularized with human lung cells. However, pig tissues express several immunogenic proteins, notably galactosylated cell surface glycoproteins resulting from alpha 1,3 galactosyltransferase (α-gal) activity, that could conceivably prevent effective use. Use of lungs from α-gal knock out (α-gal KO) pigs presents a potential alternative and thus comparative de- and recellularization of wild-type and α-gal KO pig lungs was assessed.Decellularized lungs were compared by histologic, immunohistochemical, and mass spectrometric techniques. Recellularization was assessed following compartmental inoculation of human lung bronchial epithelial cells, human lung fibroblasts, human bone marrow-derived mesenchymal stromal cells (all via airway inoculation), and human pulmonary vascular endothelial cells (CBF) (vascular inoculation).No obvious differences in histologic structure was observed but an approximate 25% difference in retention of residual proteins was determined between decellularized wild-type and α-gal KO pig lungs, including retention of α-galactosylated epitopes in acellular wild-type pig lungs. However, robust initial recellularization and subsequent growth and proliferation was observed for all cell types with no obvious differences between cells seeded into wild-type versus α-gal KO lungs.These proof of concept studies demonstrate that decellularized wild-type and α-gal KO pig lungs can be comparably decellularized and comparably support initial growth of human lung cells, despite some differences in retained proteins. α-Gal KO pig lungs are a suitable platform for further studies of xenogeneic lung regeneration.

Cigarette smoke is the most relevant risk factor for the development of lung cancer and chronic obstructive pulmonary disease. Many of its more than 4500 chemicals are highly reactive, thereby altering protein structure and function. Here, we used subcellular fractionation coupled to label-free quantitative MS to globally assess alterations in the proteome of different compartments of lung epithelial cells upon exposure to cigarette smoke extract. Proteomic profiling of the human alveolar derived cell line A549 revealed the most pronounced changes within the cellular secretome with preferential downregulation of proteins involved in wound healing and extracellular matrix organization. In particular, secretion of secreted protein acidic and rich in cysteine, a matricellular protein that functions in tissue response to injury, was consistently diminished by cigarette smoke extract in various pulmonary epithelial cell lines and primary cells of human and mouse origin as well as in mouse ex vivo lung tissue cultures. Our study reveals a previously unrecognized acute response of lung epithelial cells to cigarette smoke that includes altered secretion of proteins involved in extracellular matrix organization and wound healing. This may contribute to sustained alterations in tissue remodeling as observed in lung cancer and chronic obstructive pulmonary disease.

Chronic lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF) are all characterized by structural changes of the airways and/or lungs that limit airflow and/or gas exchange. Currently, there is no therapy available that adequately targets the structural remodeling of the airways and lungs in these diseases. This underscores the great need for insight into the mechanisms that underpin the development of airway remodeling, fibrosis and emphysema in these diseases, in order to identify suitable drug targets. It is increasingly evident that structural cell cell communication within the lung is central to the development of remodeling, indicating that a more integrative approach should be considered when studying molecular and cellular mechanisms of remodeling. Therefore, there is a great need to study molecular and cellular physiological and pathophysiological mechanisms in as much detail as possible, but with as little as possible loss of the physiological context. Here, we will review the use of models such as cellular co-culture, tissue culture, and lung slice culture, in which cell cell communication and tissue architecture are better preserved or mimicked than in cell culture, and zoom in on the usefulness of molecular and cellular biological tools in these complex model systems to read out or control signaling and gene/protein regulation. (C) 2011 Elsevier Ltd. All rights reserved.

The chemical composition of calcium phosphate (CaP) materials for the regenerative therapy of large bone defects is similar to that of bone. Additionally, calcium phosphates show an excellent biocompatibility. Besides the support of defect healing calcium phosphate implants should be completely degraded within an adequate time period to be replaced by newly formed bone. Although degradation of CaP-implants occurs mainly by dissolution of the material, it is important to characterize the osteoclastic resorption as well, which is involved in native bone remodeling. The degradation of bone substitutes made of calcium phosphate ceramics is influenced by various parameters, such as defect size and localization, the general health situation, and age of the patient, but also material properties are important. Especially, the calcium phosphate composition is crucial for the degradation behavior of a calcium phosphate material. Additionally, at the cellular level the micro- and macroporosity, including interconnecting pores, influences both, the dissolution and the osteoclastic resorption. In our study, three different calcium phosphate materials (hydroxyapatite, tricalcium phosphate, and a biphasic calcium phosphate) and two different geometries (dense 2D samples and porous 3D scaffolds) are compared regarding their dissolution and resorption behavior. The results show, that the dissolution of CaP-ceramics, as examined by the incubation in a degradation solution, depends mainly on the calcium phosphate phase but also on the porosity of the implant. Regarding the resorption, cell proliferation and differentiation of a monocytic cell line as well as the formation of resorption lacunas are analyzed. Cell proliferation is comparable on all phase compositions. Cell differentiation and resorption, however, are influenced by the calcium phosphate phase composition and by the implant porosity as well. By understanding these two mechanisms of degradation, bone substitute materials and, as a result, the bone regeneration of large bone defects using CaP-ceramics can be improved.

BACKGROUND AND PURPOSE: Blood-pool agents are promising in the imaging of small vessels with slow or complex flow. Our aim was to compare blood-pool contrast-enhanced MR angiography (BPCE-MRA) using gadofosveset trisodium (Vasovist) with 3D time-of-flight MRA (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular therapy. MATERIALS AND METHODS: We included 32 patients with a total of 37 coiled aneurysms. MRAs in the early steady-state phase were performed on a 1.5T scanner within 8 days of digital subtraction angiography (DSA). Two radiologists independently analyzed TOF-MRA and BPCE-MRA images. Consensus was reached by review involving a third neuroradiologist. DSA images were interpreted separately by an interventional radiologist. Findings were assigned to 1 of 3 categories: 1) complete occlusion, 2) residual neck, and 3) residual aneurysm. RESULTS: Follow-up DSA demonstrated 13 complete obliterations (class 1), 13 residual necks (class 2), and 11 residual aneurysms (class 3). Weighted κ statistics showed substantial concordance of TOF-MRA and DSA (0.664) as well as BPCE-MRA and DSA (0.724) ratings. Comparison between TOF-MRA and BPCE-MRA found excellent agreement (0.818) with only 6 (16.2%) discrepancies. For detecting residual flow, the difference in accuracy of both MRA techniques (83.8% versus 91.9%) was not significant (McNemar, P = 1.000). BPCE-MRA showed a tendency towards higher sensitivity and specificity (91.7% and 92.3%, respectively) compared with TOF-MRA (87.5% and 76.9%). CONCLUSIONS: In classifying the completeness of endovascular cerebral aneurysm therapy, we found that BPCE-MRA and 3D TOF-MRA showed very good agreement. The use of Vasovist did not lead to a significantly increased accuracy of MRA follow-up.

To evaluate the need for postnatal neurosurgical intervention after fetoscopic patch coverage of spina bifida aperta (SBA).This was a retrospective analysis of a cohort of 71 fetuses which underwent minimally invasive fetoscopic patch coverage of SBA between 21 + 0 and 29 + 1 weeks of gestation. Postnatal neurosurgical procedures were classified into two types: re-coverage of the SBA within the first 3 months following birth, and shunt placement as treatment of associated hydrocephalus within the first year.Location of the SBA was lumbosacral in 59 cases, lumbar in seven, thoracic in three and sacral in two. In total, 20/71 (28%) patients underwent early postnatal neurosurgical intervention by means of re-coverage of the SBA. This was performed because of cerebrospinal fluid leakage in seven (35%), adhesions with functional deterioration in three (15%), incomplete coverage in five (25%) and skin defect in five (25%) cases. Ventriculoperitoneal shunt placement within 1 year was required in 32 (45%) cases and was preceded by ventriculostomy in two. Three (4%) infants needed Chiari decompression surgery in the first 12 months following birth, because of syringomyelia or gait disturbance.Fetoscopic patch coverage of SBA may require postnatal re-coverage in some cases. In most cases, conservative wound treatment shows good results, without requiring neurosurgical intervention. The low 1-year-shunt rate is comparable to data of the Management of Myelomeningocele Study and lower compared with published data of patients with postnatal only coverage of SBA.

Chronic lung diseases are devastating diseases that are increasing in prevalence. Most have no cure and lung transplantation remains the only available therapeutic option. However, the number of suitable donor lungs is inadequate to meet current clinical demands and thus alternative options are desperately needed. There are a number of conceptually viable alternatives for generating functional pulmonary tissue ex vivo, including the use of either biologic or synthetic scaffolds coupled with an appropriate recellularization and ex vivo culture strategy. Biologic lung scaffolds have been generated using several different perfusion-based decellularization techniques. Whole organ decellularization aims to selectively remove cells while maintaining native tissue macro and microarchitecture. Alternatively, synthetic materials, coupled with advanced manufacturing techniques, could be used to generate a completely artificial scaffold with the necessary biologic properties to permit regeneration of functional lung tissue. Either a biologic or synthetic scaffold could then be subsequently recellularized with autologous cells, thus eradicating the immunological complications frequently accompanying organ transplantation. These approaches are a promising alternative to overcoming the chronic shortage of donor organs.