Hydrophobicity of hybrid polyhydroxyurethane (HPHU), via sol/gel curing of a PHU made from diglycerol dicarbonate (DGC) and a poly(propylene glycol) (PPG)-based diamine, is increased by reacting the ...carbonate-terminated PHU with diamines based on poly(dimethylsiloxane) (PDMS) and the fatty acid-derived Priamine 1074. The modified PHUs were end-capped with silane moisture-curing agents, and swelling of the HPHUs was studied in water and other solvents over 1 week. These films exhibited a drop in the water swelling index (4%) compared to the original poly(DGC-PPG) HPHUs (75%). The PDMS-modified HPHU has a dominant PDMS phase, due to its comparatively longer chain length relative to the PHU, thereby increasing water repellency. Besides an increase in hydrophobicity, the Priamine 1074-modified HPHU revealed a higher storage modulus that is at least 12 times higher than that of the original films. Consequently, Priamine 1074 is regarded as a promising biobased reactive additive when formulating hydrophobic PHU resins.
The terpolymerization of bio-based diglycerol dicarbonate (DGC) and Priamine 1074 is conducted with aminopropyl terminated polydimethylsiloxane (M n = 1000 g/mol, PDMS) or 1,10-diaminodecane (DAD). ...Depending on DGC contents and PDMS/Priamine 1074 ratios, the resulting amorphous thermoplastic polyhydroxyurethanes (TPHUs) present random or block copolymer-like segmented structures. These TPHUs exhibit nanophase separation of small interdomain spacing (3–3.5 nm) mainly caused by DGC. As for DAD, it introduces crystallinity (8%) and chain ordering into the TPHU structure as observed from X-ray measurements. Some PDMS-based TPHUs are blended with PLA, and the blends are found to be partially miscible as they exhibit two T g’s, and their estimated relative energy differences (RED), calculated from Hoftyzer–Van Krevelen’s group contribution method, are nearly unity. Based on the type of hydrogen bonding interactions and the extent of immiscibility (RED) of each of the blends, the TPHUs find potential applications as toughening agents and/or plasticizers for PLA.
This study focuses on the synthesis of bio‐based and hydrolytically degradable photocurable thermosets made from hydroxyurethane acrylates (HUA). The hydroxyurethanes (HUs) are prepared from the ...reaction between ethylene carbonate and a bio‐based diamine, Priamine 1074. Subsequently, the HU initiates the ring opening polymerization of ε‐caprolactone (CL), resulting in telechelic groups of 5 CL units at both ends of the HU. The resulting HU‐CL5 is finally acrylated to prepare the degradable HUA (HU‐CL5‐A) with transformations confirmed following each step via proton nuclear magnetic resonance (1H‐NMR) and Fourier‐transform infrared (FTIR) spectroscopies. HU‐CL5‐A is photocured with 4‐acryloylmorpholine (ACMO) as a photosensitive reactive diluent. The photocurable thermosets exhibit slight water swelling (swelling index of 46%), as Priamine 1074 and ACMO are hydrophobic and hydrophilic, respectively, leading to the slow and partial degradation of the films in water at 85°C for 14 days. The cleavage of the CL units from the film networks is proven via 1H‐NMR and FTIR, which demonstrates the main objective of this study in synthesizing photocurable and degradable HUA resins.
This study is the first to successfully incorporate degradable ε‐caprolactone moieties in the structure of hydroxyurethane acrylates. The base hydroxyurethane is prepared from a bio‐sourced fatty acid diamine through a non‐toxic isocyanate free route. The final acrylates are cured using UV light, and the resulting films degrade via the hydrolysis of the ester groups found in the ε‐caprolactone units.
A new set of polyhydroxyurethanes (PHUs) is synthesized from bio‐based sorbitol bicarbonate (SBC) and mannitol bicarbonate (MBC). The synthesized dicarbonates are polymerized with two long chain ...diamines, telelechelic amine terminated poly(propylene glycol) (PPG), and poly(dimethylsiloxane) (PDMS). Despite the high melting points of SBC and MBC, PHU prepolymers are prepared in bulk at moderate temperatures of 60–100 °C. The structural and thermal properties of the resulting PHUs are qualitatively and quantitatively characterized in order to evaluate them as potential sealants and adhesives, and they are end‐capped with moisture curing agents and left to cure at ambient conditions (22 °C and 20–30% humidity) with the curing processes monitored rheologically. The chemical stability of the novel partially sustainable hybrid PHUs (HPHUs) in pure water is investigated to check the viability of applying them outdoors. Only SBC or MBC‐PDMS HPHUs are found to be hydrophobic with water contact angles of 105° and 109°, respectively, but they are brittle. Small and wide‐angle X‐ray scattering of these water‐resistant films show that they are potentially composed of three different phases due to microphase separation: the PDMS matrix, a hard segments phase, and a third phase mixing the PDMS diamine end‐segments and some dissolved hard segments.
New partially sustainable hybrid polyhydroxyurethanes (HPHUs) are synthesized from d‐sorbitol and d‐mannitol, sugars obtained from glucose processing. They are engineered to be ultimately modified by silane end‐cappers to afford HPHUs through moisture curing, meaning that these new partially bio‐based materials become solid when interacting with air moisture after spreading them on a given surface.
Polyhedral oligomeric silsesquioxane (POSS) is added to poly(hydroxyurethane) (PHU) prepolymers to create hybrid PHUs (HPHUs) with enhanced mechanical and thermal properties. These hybrid materials ...were then further functionalized with 3‐Isocyanatopropyl(trimethoxy) silane (IPTMS) via the pendent hydroxyl bonds within the backbone of the polymers to obtain a final cured film comparable to conventional polyurethanes (PU), using less isocyanate‐functional material. The incorporation of POSS into PHU prepolymers to obtain HPHUs was supported by gel permeation chromatography, fourier tranform infrared spectroscopy (FTIR) and nuclear magnetic resonance analysis. Furthermore, the thermal degradation of the HPHUs was significantly improved with increasing POSS concentration compared to their PHU counterparts as the degradation temperatures at 50% weight loss increased from 263°C for the PHU to 341°C for the HPHU. Gel content tests in tetrahydrofuran (THF), water, and toluene were performed and gel contents of 87%–99% in THF were observed for the cured films. Water swelling, and contact angle tests confirmed that the POSS‐modified films exhibited hydrophobic behavior. Finally, mechanical properties of the cured films were investigated. The Young's modulus and tensile strength were improved with increasing POSS concentration (from 2.0 to 3.1 MPa and from 0.82 to 1.32 MPa, respectively) and elongations at break up to 41.6% were observed. When compared to a conventional PU sealant, the HPHU achieved a tensile strength that was two‐fold greater and a comparable elongation at break (increasing from 24.8% to as high as 41.6%).
Polyhedral oligomeric silsesquioxane (POSS) are added to poly(hydroxyurethane) prepolymers to create hybrid polymers with enhanced mechanical and thermal properties. These hybrid materials were then further functionalized with 3‐Isocyanatopropyl(trimethoxy) silane via the pendent hydroxyl bonds within the backbone of the polymers to obtain a final cured film comparable to conventional polyurethanes.
Complications from malaria parasite infections still cost the lives of close to half a million people every year. The most severe is cerebral malaria (CM). Employing murine models of CM, autopsy ...results,
experiments, neuroimaging and microscopic techniques, decades of research activity have investigated the development of CM immunopathology in the hope of identifying steps that could be therapeutically targeted. Yet important questions remain. This review summarizes recent findings, primarily mechanistic insights on the essential cellular and molecular players involved gained within the murine experimental cerebral malaria model. It also highlights recent developments in (a) cell-cell communication events mediated through extracellular vesicles (EVs), (b) mounting evidence for innate immune memory, leading to "trained" increased or tolerised responses, and (c) modulation of immune cell function through metabolism, that could shed light on why some patients develop this life-threatening condition whilst many do not.
To investigate the role of the protein C system, endothelial protein C receptor (EPCR) and thrombomodulin (TM) in the pathogenesis of malaria-associated acute respiratory distress syndrome (ARDS) in ...relation to hemozoin and proinflammatory cytokines-induced type II pneumocyte injury and -aggravated pulmonary resolution. A total of 29 left-over lung specimens that were obtained from patients who died from severe falciparum malaria were examined. Histopathological, immunohistochemical and electron microscopic analyses revealed that ARDS coexisted with pulmonary edema and systemic bleeding; the severity was dependent on the level of hemozoin deposition in the lung and internal alveolar hemorrhaging. The loss of EPCR and TM was primarily identified in ARDS patients and was related to the level of hemozoin, parasitized red blood cell (PRBC) and white blood cell accumulation in the lung. Moreover, an in vitro analysis demonstrated that interleukin-13 and -31 and hemozoin induced pneumocytic cell injury and apoptosis, as assessed by EB/AO staining, electron microscopy and the up-regulation of CARD-9 mRNA (caspase recruitment domain-9 messenger-ribonucleic acid). The dysregulation of EPCR and TM in the lung, especially in those with increased levels of hemozoin, may play an important role in the pathogenesis of malaria-associated ARDS through an apoptotic pathway.
This review focusses on the significance of fluorescent, phosphorescent labelling and tracking of extracellular vesicles (EVs) for unravelling their biology, pathophysiology, and potential diagnostic ...and therapeutic uses. Various labeling strategies, such as lipid membrane, surface protein, luminal, nucleic acid, radionuclide, quantum dot labels, and metal complex-based stains, are evaluated for visualizing and characterizing EVs. Direct labelling with fluorescent lipophilic dyes is simple but generally lacks specificity, while surface protein labelling offers selectivity but may affect EV-cell interactions. Luminal and nucleic acid labelling strategies have their own advantages and challenges. Each labelling approach has strengths and weaknesses, which require a suitable probe and technique based on research goals, but new tetranuclear polypyridylruthenium(
ii
) complexes as phosphorescent probes have strong phosphorescence, selective staining, and stability. Future research should prioritize the design of novel fluorescent probes and labelling platforms that can significantly enhance the efficiency, accuracy, and specificity of EV labeling, while preserving their composition and functionality. It is crucial to reduce false positive signals and explore the potential of multimodal imaging techniques to gain comprehensive insights into EVs.
This review focusses on the significance of fluorescent, phosphorescent labelling and tracking of extracellular vesicles (EVs) for unravelling their biology, pathophysiology, and potential diagnostic and therapeutic uses.
Bevacizumab is a treatment option in patients with metastatic breast cancer. Congestive heart failure (CHF) has been reported, although the overall incidence and relative risk (RR) of this ...complication remains unclear. We performed an up-to-date, comprehensive meta-analysis to determine the risk of serious CHF in patients with breast cancer receiving bevacizumab.
The databases of Medline were searched for articles from 1966 to March 2010. Abstracts presented at the American Society of Clinical Oncology and the San Antonio Breast Cancer Symposium meetings were also searched for relevant clinical trials. Eligible studies include randomized trials with bevacizumab in patients with breast cancer. Adequate reporting of safety profile data was required for inclusion. Statistical analyses were conducted to calculate the summary incidence, RR, and 95% CIs by using random-effects models.
A total of 3,784 patients were included. Overall incidence results for high-grade CHF in bevacizumab- and placebo-treated patients were 1.6% (95% CI, 1.0% to 2.6%) and 0.4% (95% CI, 0.2% to 1.0%), respectively. The RR of CHF in bevacizumab-treated patients was 4.74 (95% CI, 1.66 to 11.18; P = .001) compared with placebo-treated ones. In subgroup analyses, there were no significant differences in CHF incidence or risk between patients treated with low-dose (2.5 mg/kg) versus high-dose (5 mg/kg) bevacizumab or among patients treated with different chemotherapy regimens. No evidence of publication bias was observed.
This is the first comprehensive report to show that bevacizumab is associated with an increased risk of significant heart failure in patients with breast cancer.
On 6 December 2013, two laboratory-confirmed cases of chikungunya without a travel history were reported on the French part of the Caribbean island of Saint Martin, indicating the start of the first ...documented outbreak of chikungunya in the Americas. Since this report, the virus spread to several Caribbean islands and French Guiana, and between 6 December 2013 and 27 March 2014 more than 17,000 suspected and confirmed cases have been reported. Further spread and establishment of the disease in the Americas is likely, given the high number of people travelling between the affected and non-affected areas and the widespread occurrence of efficient vectors. Also, the likelihood of the introduction of the virus into Europe from the Americas and subsequent transmission should be considered especially in the context of the next mosquito season in Europe. Clinicians should be aware that, besides dengue, chikungunya should be carefully considered among travellers currently returning from the Caribbean region.
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