39 research outputs found

    Characterization and Modeling of Nitric Oxide Release in Aqueous Solutions

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    Nanotherapeutics to Modulate the Compromised Micro-Environment for Lung Cancers and Chronic Obstructive Pulmonary Disease

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    The use of nanomaterials to modulate the tumor microenvironment has great potential to advance outcomes in patients with lung cancer. Nanomaterials can be used to prolong the delivery time of therapeutics enabling their specific targeting to tumors while minimizing and potentially eliminating cytotoxic effects. Using nanomaterials to deliver small-molecule inhibitors for oncogene targeted therapy and cancer immunotherapy while concurrently enabling regeneration of the extracellular matrix could enhance our therapeutic reach and improve outcomes for patients with non-small cell lung cancer (NSCLC) and chronic obstructive pulmonary disease (COPD). The objective of this review is to highlight the role nanomedicines play in improving and reversing adverse outcomes in the tumor microenvironment for advancing treatments for targeting both diseases

    Alterations in phenotype and gene expression of adult human aneurysmal smooth muscle cells by exogenous nitric oxide

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    International audienceAbdominal aortic aneurysms (AAA) are characterized by matrix remodeling, elastin degradation, absence of nitric oxide (NO) signaling, and inflammation, influencing smooth muscle cell (SMC) phenotype and gene expression. Little is known about the biomolecular release and intrinsic biomechanics of human AAA-SMCs. NO delivery could be an attractive therapeutic strategy to restore lost functionality of AAA-SMCs by inhibiting inflammation and cell stiffening. We aim to establish the differences in phenotype and gene expression of adult human AAA-SMCs from healthy SMCs. Based on our previous study which showed benefits of optimal NO dosage delivered via S-Nitrosoglutathione (GSNO) to healthy aortic SMCs, we tested whether such benefits would occur in AAA-SMCs. The mRNA expression of three genes involved in matrix degradation (ACE, ADAMTS5 and ADAMTS8) was significantly downregulated in AAA-SMCs. Total protein and glycosaminoglycans synthesis were higher in AAA-SMCs than healthy-SMCs (p < 0.05 for AAA-vs. healthy-SMC cultures) and was enhanced by GSNO and 3D cultures (p < 0.05 for 3D vs. 2D cultures; p < 0.05 for GSNO vs. non-GSNO cases). Elastin gene expression, synthesis and deposition, desmosine crosslinker levels, and lysyl oxidase (LOX) functional activity were lower, while cell proliferation, iNOS, LOX and fibrillin-1 gene expressions were higher in AAA-SMCs (p < 0.05 between respective cases), with differential benefits from GSNO exposure. GSNO and 3D cultures reduced MMPs −2, −9, and increased TIMP-1 release in AAA-SMC cultures (p < 0.05 for GSNO vs. non-GSNO cultures). AAA-SMCs were inherently stiffer and had smoother surface than healthy SMCs (p < 0.01 in both cases), but GSNO reduced stiffness (~25%; p < 0.01) and increased roughness (p < 0.05) of both cell types. In conclusion, exogenously-delivered NO offers an attractive strategy by providing therapeutic benefits to AAA-SMCs

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Lysyl Oxidase Enhances Elastin Synthesis and Matrix Formation by Vascular Smooth Muscle Cells

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    Lysyl oxidase (LOX) is a copper-dependent enzyme that initiates covalent crosslinking of elastin precursors by oxidizing peptidyl lysine to aminoadipic semi-aldehydes. Previous studies have shown LOX deficiency to affect crosslinking of elastin and collagen in vivo, resulting in disorganized connective tissue formation. In this study, we investigated the utility of exogenously supplemented LOX peptides (50-100 μ l/well) to elastin synthesis, crosslinking efficiency and matrix deposition in adult rat aortic smooth muscle cell (RASMC) cultures. Additionally, we also examined the role of LOX peptides on SMC proliferation and matrix metalloproteinase (MMP) synthesis in these cultures. Highly purified bovine aorta LOX peptide was found to increase matrix elastin synthesis by 40-80% to that in control cultures in a dose-dependent manner, while the crosslinking efficiency significantly (as measured by the ratio of matrix elastin protein to the total elastin protein synthesized) improved to 45-55% of total elastin synthesized under these conditions. However, LOX peptides affected neither SMC proliferation relative to controls, nor elastin precursor (tropoelastin) synthesis, nor the total elastin synthesis on a per-cell basis. In general, LOX peptides also did not affect MMP-2 and MMP-9 activities relative to control cultures, except for MMP-9 activity suppression at a higher LOX dose, suggesting that these LOX peptide cues could be safely used to enhance tropoelastin crosslinking into matrix structures and elastin matrix yield, within tissue-engineered constructs, a major challenge in the field. Copyright © 2009 John Wiley & Sons, Ltd

    Benefits of Concurrent Delivery of Hyaluronan and IGF-1 Cues to Regeneration of Crosslinked Elastin Matrices by Adult Rat Vascular Cells

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    Elastin, a major component of vascular matrices, critically determines vascular mechanics and maintains the quiescence of smooth muscle cells (SMCs). Attempts to regenerate elastin in elastincompromised blood vessels using tissue-engineering approaches is limited by the unavailability of elastogenic cues to upregulate poor elastin output and matrix assembly by adult vascular cells. We previously showed that hyaluronan (HA) elastogenically stimulates aortic SMCs, although these effects are highly specific to HA fragment size. The elastogenic response of SMCs can also be modulated with growth factors such as insulin-like growth factor (IGF-1). Here, we evaluate the benefits of concurrent delivery of HA fragments (0.76-2000 kDa) and IGF-1 (500 ng/ml) to elastin synthesis, organization and crosslinking. The study outcomes show that, relative to supplement-free cultures, IGF-1 and long-chain HA/large HA fragments, but not HA oligomers, together induce multifold increases in the synthesis of elastin precursors, structural elastin matrix yields and crosslink densities within cell layers, and encourage elastic fibre formation. These outcomes are not all obtained when either of the cues is provided separately. IGF-1 and large HA fragments (\u3e20 kDa) also together inhibit cell proliferation, a concern in elastin-compromised vessels, where SMC hyperproliferation is common. The results will benefit efforts to provide exogenous or scaffold-based elastogenic cues (IGF-1 + HMW HA/large HA fragments) to enable robust and faithful regeneration of elastin matrix structures in vivo or in vitro. The present outcomes may be used to restore elastin matrix homeostasis in de-elasticized vessels and tissue-engineered constructs that may be grafted as a substitute. Copyright © 2008 John Wiley & Sons, Ltd

    Induced Elastin Regeneration by Chronically Activated Smooth Muscle Cells for Targeted Aneurysm Repair

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    Elastin breakdown in vascular aneurysms is mediated by cytokines such as tumor necrosis factor α (TNF-α, which induces vascular smooth muscle cell (SMC) activation and regulates their deposition of matrix. We previously demonstrated that exogenous supplementation with TGF-β1 (1 ng ml-1) and hyaluronan oligomers (0.786 kDa, 0.2 μg ml-1) cues the upregulation of elastin matrix synthesis by healthy cultured SMCs. Here, we determine whether these cues likewise enhance elastin matrix synthesis and assembly by TNF-α-stimulated SMCs, while restoring their healthy phenotype. Adult rat aortic SMCs were treated with TNF-α alone or together with TGF-β1/hyaluronan oligomeric cues and the release of inflammatory markers were monitored during over a 21 day culture. Biochemical analysis was used to quantify cell proliferation, matrix protein synthesis and cross-linking efficiency, while immunofluorescence and electron microscopy were used to analyze the elastin matrix quality. It was observed that SMC activation with TNF-α (10 ng ml-1) induced matrix calcification and promoted production of elastolytic MMP-2 and MMP-9. However, these effects were attenuated by the addition of TGF-β1 and HA oligomer cues to TNF-α-stimulated cultures, which also enhanced tropoelastin and collagen production, improved elastin matrix yield and cross-linking, promoted elastin fiber formation and suppressed elastase activity, although the release of MMP-2 and MMP-9 was not affected. Overall, the results suggest that TGF-β1 and HA oligomers are potentially useful in suppressing SMC activation and inducing regenerative elastin repair within aneurysms. © 2009 Acta Materialia Inc

    Copper Nanoparticle Cues for Biomimetic Cellular Assembly of Crosslinked Elastin Fibers

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    Elastin, a structural protein distributed in the extracellular matrix of vascular tissues, is critical to maintaining the elastic stability and mechanical properties of blood vessels, as well as regulating cell-signaling pathways involved in vascular injury response and morphogenesis. Pathological degradation of vascular elastin or its malformation within native vessels and the poor ability to tissue-engineer elastin-rich vascular replacements due to innately poor elastin synthesis by adult vascular cells can compromise vascular homeostasis, and must thus be addressed. Our recent studies attest to the utility of hyaluronan (HA) oligomers for elastin synthesis and organization by adult vascular smooth muscle cells (SMCs), though the elastin matrix yields in these cases were quite low relative to total elastin produced. Thus, in this study, we investigated the utility of copper (Cu2+) ions to enhance cellular elastin deposition, crosslinking and maturation into structural fibers. Copper nanoparticles (CuNPs; 80-100 nm) in the dose range of 1-100 ng ml-1 were tested for Cu2+ ion release, and based on mathematical modeling of their release profiles, CuNPs (1, 10, and 400 ng ml-1) were chosen for supplementation to adult SMC cultures. The 400 ng ml-1 dose of CuNPs cumulatively delivered Cu2+ doses in the range of 0.1 M, over the 21 day culture period. It was observed that while exogenous CuNP supplements do not up-regulate tropoelastin production by vascular SMCs, they promoted formation of crosslinked elastin matrices. The deposition of crosslinked matrix elastin was further improved by the additional presence of HA oligomers in these cultures. Immunofluorescence imaging and structural analysis of the isolated elastin matrices indicate that amorphous elastin clumps were formed within non-additive control cultures, while aggregating elastin fibrils were observed within SMC cultures treated with CuNPs (1-10 ng ml-1) alone or together with HA oligomers. The presence of 400 ng ml-1 of CuNPs concurrent with HA oligomers furthered aggregation of these elastin fibrils into mature fibers with diameters ranging from 200 to 500 nm. Ultrastructural analysis of elastin matrix within cultures treated with HA oligomers and 400 ng ml-1 of CuNPs suggest that elastin matrix deposition as stimulated by Cu2+ ions proceeds via a fibrillin-mediated assembly process, with enhanced crosslinking occurring via stimulation of lysyl oxidase. Overall, the data suggest that CuNPs and HA oligomers are highly useful for regenerating crosslinked, fibrillar elastin matrices by adult vascular SMCs. These results have immense utility in tissue-engineering vascular replacements. © 2008 Acta Materialia Inc

    Theory of combined AM and high-harmonic FM mode locked laser

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    Closed form solutions for a simultaneously AM and high-harmonic FM mode locked laser system is presented. Analytical expressions for the pulsewidth and pulsewidth-bandwidth products are derived in terms of the system parameters. The analysis predicts production of 17 ps duration pulses in a Nd:YAG laser mode locked with AM and FM modulators driven at 80 MHz and 1.76 GHz for 1 W modulator input power. The predicted values of the pulsewidth-bandwidth product lie between the values corresponding to the pure AM and FM mode locking values
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