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INTRODUCTION: The evaluation of upcoming Aortic Coarctation (CoA) in new-borns with prenatal suspicion entails a close echocardiographic monitor until Arterial Duct (AD) closure, in a department with pediatric cardiological and surgical expertise. The significant number of false-positive prenatal diagnoses causes parental stress and healthcare costs. AIM: The aim of this study was to elaborate an echocardiographic prediction model to be employed at birth when PDA is still present, in patients suspected of CoA during fetal life in order to foretell CoA requiring neonatal surgical intervention. METHODS: This retrospective monocentric study included consecutive full-term and late preterm neonates with prenatal suspicion of CoA born from 01 January 2007 to 31 December 2020. Patients were divided into two groups according to the need for aortic surgery (CoA - NoCoA). All patients underwent a comprehensive transthoracic echocardiographic exam in presence of PDA. Multivariable logistic regression was used to create a coarctation probability model (CoMOD) including isthmal (D4), transverse arch (D3) diameters, the distance between a left common carotid artery (LCA) and left subclavian artery (LSA), presence/absence of ventricular septal defect (VSD) and bicuspid aortic valve (BAV). RESULTS: We enrolled 87 neonates (49 male, 56%). 44 patients developed CoA in need of surgical repair. Our index CoMOD showed an AUC = 0.9382, high sensitivity (91%) and specificity (86%) in the prediction of CoA in neonates with prenatal suspicion. We classified neonates with CoMOD > 0 to be at high risk for surgical correction of CoA, with good PPV (86.9%) and NPV (90.9%). CONCLUSIONS: CoMOD > 0 is highly suggestive of the need for CoA corrective surgery in newborns with prenatal suspicion.
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Coartação Aórtica , Permeabilidade do Canal Arterial , Criança , Gravidez , Feminino , Humanos , Masculino , Recém-Nascido , Permeabilidade do Canal Arterial/diagnóstico por imagem , Permeabilidade do Canal Arterial/cirurgia , Coartação Aórtica/diagnóstico por imagem , Coartação Aórtica/cirurgia , Estudos Retrospectivos , Ecocardiografia , Aorta Torácica/diagnóstico por imagemRESUMO
Children with congenital heart disease (CHD) are at increased risk for undernutrition. The aim of our study was to describe the growth parameters of Italian children with CHD compared to healthy children. We performed a cross-sectional study collecting the anthropometric data of pediatric patients with CHD and healthy controls. WHO and Italian z-scores for weight for age (WZ), length/height for age (HZ), weight for height (WHZ) and body mass index (BMIZ) were collected. A total of 657 patients (566 with CHD and 91 healthy controls) were enrolled: 255 had mild CHD, 223 had moderate CHD and 88 had severe CHD. Compared to CHD patients, healthy children were younger (age: 7.5 ± 5.4 vs. 5.6 ± 4.3 years, p = 0.0009), taller/longer (HZ: 0.14 ± 1.41 vs. 0.62 ± 1.20, p < 0.002) and heavier (WZ: -0,07 ± 1.32 vs. 0.31 ± 1.13, p = 0.009) with no significant differences in BMIZ (-0,14 ± 1.24 vs. -0.07 ± 1.13, p = 0.64) and WHZ (0.05 ± 1.47 vs. 0.43 ± 1.07, p = 0.1187). Moderate and severe CHD patients presented lower z-scores at any age, with a more remarkable difference in children younger than 2 years (WZ) and older than 5 years (HZ, WZ and BMIZ). Stunting and underweight were significantly more present in children affected by CHD (p < 0.01). In conclusion, CHD negatively affects the growth of children based on the severity of the disease, even in a high-income country, resulting in a significant percentage of undernutrition in this population.
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Cardiopatias Congênitas , Desnutrição , Humanos , Criança , Lactente , Pré-Escolar , Estudos Retrospectivos , Estudos Transversais , Cardiopatias Congênitas/complicações , Desnutrição/complicações , Desnutrição/epidemiologia , Transtornos do Crescimento/etiologia , Transtornos do Crescimento/complicaçõesRESUMO
There is growing concern about the consumption of synthetic cannabinoids (SCs), one of the largest groups of new psychoactive substances, its consequence on human health (general population and workers), and the continuous placing of new SCs on the market. Although drug-induced alterations in neuronal function remain an essential component for theories of drug addiction, accumulating evidence indicates the important role of activated astrocytes, whose essential and pleiotropic role in brain physiology and pathology is well recognized. The study aims to clarify the mechanisms of neurotoxicity induced by one of the most potent SCs, named MAM-2201 (a naphthoyl-indole derivative), by applying a novel three-dimensional (3D) cell culture model, mimicking the physiological and biochemical properties of brain tissues better than traditional two-dimensional in vitro systems. Specifically, human astrocyte spheroids, generated from the D384 astrocyte cell line, were treated with different MAM-2201 concentrations (1-30 µM) and exposure times (24-48 h). MAM-2201 affected, in a concentration- and time-dependent manner, the cell growth and viability, size and morphological structure, E-cadherin and extracellular matrix, CB1-receptors, glial fibrillary acidic protein, and caspase-3/7 activity. The findings demonstrate MAM-2201-induced cytotoxicity to astrocyte spheroids, and support the use of this human 3D cell-based model as species-specific in vitro tool suitable for the evaluation of neurotoxicity induced by other SCs.
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Astrócitos , Canabinoides , Humanos , Astrócitos/metabolismo , Canabinoides/toxicidade , Canabinoides/química , Naftalenos/toxicidade , Naftalenos/metabolismo , Neurônios/metabolismoRESUMO
Although hypertrophic cardiomyopathy (HCM) is classically considered a disease of the left ventricle, right ventricular (RV) involvement has also been reported, though still not extensively characterized. We present a case of biventricular HCM with significant RV involvement in the absence of a left intraventricular gradient: RV outflow tract gradient due to hypertrophy and near obliteration of the RV cavity. Significant RV hypertrophy may cause reduced RV diastolic filling and/or RV outflow obstruction, with potentially increased incidence of symptoms of heart failure, arrhythmias, and pulmonary thromboembolism. The optimal treatment for these patients is unclear. Our patient underwent complete treatment and elimination of right ventricular obstruction, resulting in improved symptoms and a significant reduction in postoperative gradients. Direct relief of outflow tract obstruction can be achieved with low morbidity and good intermediate- to long-term results. Conventional surgery may provide significant symptomatic improvement and should thus be considered in the setting of HCM with outflow obstruction.
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Background: Non-invasive, bedside diagnostic tools are extremely important for tailo ring the management of respiratory failure patients. The use of electronic noses (ENs) for exhaled breath analysis has the potential to provide useful information for phenotyping different respiratory disorders and improving diagnosis, but their application in respiratory failure patients remains a challenge. We developed a novel measurement apparatus for analysing exhaled breath in such patients. Methods: The breath sampling apparatus uses hospital medical air and oxygen pipeline systems to control the fraction of inspired oxygen and prevent contamination of exhaled gas from ambient Volatile Organic Compounds (VOCs) It is designed to minimise the dead space and respiratory load imposed on patients. Breath odour fingerprints were assessed using a commercial EN with custom MOX sensors. We carried out a feasibility study on 33 SARS-CoV-2 patients (25 with respiratory failure and 8 asymptomatic) and 22 controls to gather data on tolerability and for a preliminary assessment of sensitivity and specificity. The most significant features for the discrimination between breath-odour fingerprints from respiratory failure patients and controls were identified using the Boruta algorithm and then implemented in the development of a support vector machine (SVM) classification model. Results: The novel sampling system was well-tolerated by all patients. The SVM differentiated between respiratory failure patients and controls with an accuracy of 0.81 (area under the ROC curve) and a sensitivity and specificity of 0.920 and 0.682, respectively. The selected features were significantly different in SARS-CoV-2 patients with respiratory failure versus controls and asymptomatic SARS-CoV-2 patients (p < 0.001 and 0.046, respectively). Conclusions: the developed system is suitable for the collection of exhaled breath samples from respiratory failure patients. Our preliminary results suggest that breath-odour fingerprints may be sensitive markers of lung disease severity and aetiology.
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Three-dimensional (3D) culture systems like tumor spheroids represent useful in vitro models for drug screening and more broadly for cancer biology research, but the generation of uniform populations of spheroids remains challenging. The possibility to properly characterize spheroid properties would increase the reliability of these models. To address this issue different analysis were combined: i) a new device and relative analytical method for the accurate, simultaneous, and rapid measurement of mass density, weight, and size of spheroids, ii) confocal imaging, and iii) protein quantification, in a clinically relevant 3D model. The LoVo colon cancer cell line forming spheroids, treated with crizotinib (CZB) an ATP-competitive small-molecule inhibitor of the receptor tyrosine kinases, was employed to study and assess the correlation between biophysical and morphological parameters in both live and fixed cells. The new fluidic-based measurements allowed a robust phenotypical characterization of the spheroids structure, offering insights on the spheroids bulk and an accurate measurement of the tumor density. This analysis helps overcome the technical limits of the imaging that hardly penetrates the thickness of 3D structures. Accordingly, we were able to document that CZB treatment has an impact on mass density, which represents a key marker characterizing cancer cell treatment. Spheroid culture is the ultimate technology in drug discovery and the adoption of such precise measurement of the tumor characteristics can represent a key step forward for the accurate testing of treatment's potential in 3D in vitro models.
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Antineoplásicos/farmacologia , Técnicas de Cultura de Células/métodos , Neoplasias do Colo/patologia , Crizotinibe/farmacologia , Esferoides Celulares/patologia , Sobrevivência Celular , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Humanos , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Células Tumorais CultivadasRESUMO
BACKGROUND: Hypoxia caused by inadequate intracardiac mixing owing to a restrictive foramen ovale is a potentially life-threatening complication in neonates with dextro-transposition of the great arteries. An urgent balloon atrial septostomy is a procedure of choice in such cases, but dependent on the availability of a 24-hour interventional cardiology facility. The prenatal identification of predictors for an urgent balloon atrial septostomy at birth would help in optimizing the management of these neonates, minimizing the risk of hypoxic damage. OBJECTIVE: This study aimed to predict with prenatal echocardiography the need of urgent balloon atrial septostomy in neonates with dextro-transposition of the great arteries. STUDY DESIGN: This was a retrospective cohort study of patients with a prenatal diagnosis of transposition of the great arteries that were delivered in our center between 2010 and 2019, for whom fetal ultrasound echocardiograms obtained at less than 3 weeks before delivery were available. The following parameters were systematically obtained at fetal echocardiography: size and appearance of the foramen ovale, septum primum excursion (foramen ovale flap angle at the maximal excursion), diameters of the atria, and size of the ductus arteriosus. Balloon atrial septostomy was defined as urgent if performed within 12 hours from birth in neonates with restrictive foramen ovale. Neonatal follow-up was obtained through medical records analysis. RESULTS: From November 2007 to April 2019, 160 fetuses with complete transposition of the great arteries were referred to our echocardiography laboratory and 60 of these were included in the analysis; 27 underwent urgent balloon atrial septostomy, 11 elective balloon atrial septostomy, and 22 no balloon atrial septostomy. The size of the foramen ovale was the best predictor of an urgent balloon atrial septostomy. A measurement of >6.5 mm had a sensitivity of 100% and a false positive rate of 45%. CONCLUSION: Fetal echocardiography predicts the need of an urgent balloon atrial septostomy in fetuses with dextro-transposition of the great arteries although with a limited precision. In our experience, a measurement of the foramen ovale within 3 weeks of delivery had the greatest accuracy.
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Forame Oval , Transposição dos Grandes Vasos , Artérias , Feminino , Forame Oval/diagnóstico por imagem , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos , Transposição dos Grandes Vasos/diagnóstico por imagem , Ultrassonografia Pré-NatalRESUMO
Restrictive cardiomyopathy (RCM) is the least frequent phenotype among pediatric heart muscle diseases, representing only 2.5-3% of all cardiomyopathies diagnosed during childhood. Pediatric RCM has a poor prognosis, high incidence of pulmonary hypertension (PH), thromboembolic events, and sudden death, is less amenable to medical or surgical treatment with high mortality rates. In this scenario, heart transplantation remains the only successful therapeutic option. Despite a shared hemodynamic profile, characterized by severe diastolic dysfunction and restrictive ventricular filling, with normal ventricle ejection fraction and wall thickness, RCM recognizes a broad etiological spectrum, consisting of genetic/familial and acquired causes, each of which has a distinct pathophysiology and natural course. Hence, the aim of this review is to cover the causes, clinical presentation, diagnostic evaluation, treatment, and prognosis of pediatric RCM.
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AIM: Postoperative recovery of children with heart disease is encumbered by pulmonary complications like pneumothorax (PNX), pleural effusion (PLE), interstitial oedema and pulmonary consolidation (PC). Recently, lung ultrasound (LUS) has become an important diagnostic tool for evaluation of pulmonary diseases in the paediatric context. LUS is accurate in diagnosing pleural and parenchymal diseases. The aim of this study was to evaluate the accuracy of LUS in the identification of PNX, PLE and PC in a paediatric population of patients with congenital heart disease after heart surgery. METHODS: Fifty-three patients aged 0-17 years who underwent cardiac surgery were evaluated in the postoperative period by chest X-ray (CXR) and LUS at the same time. The methods where compared for recognition of PNX, PLE and PC. RESULTS: LUS showed a good agreement for PNX and a moderate agreement for both PLE and PC. LUS also showed a significantly superior relative sensitivity than CXR for PC and PLE and a significantly inferior relative sensitivity for PNX. CONCLUSION: This study confirms that LUS has a sufficient agreement rate with the current clinical standard (CXR). Non-inferiority in diagnosis together with the easiness of bedside performance makes LUS a very attractive tool for the paediatric cardiac intensive care unit.
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Pneumopatias , Pulmão , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva , Pulmão/diagnóstico por imagem , Radiografia , UltrassonografiaRESUMO
Gathering precise information on mass density, size and weight of cells or cell aggregates, is crucial for applications in many biomedical fields with a specific focus on cancer research. Although few technical solutions have been presented for single-cell analysis, literature does not cover this aspect for 3D models such as spheroids. Since the research interest on such samples is notably rising, here we describe a flow-apparatus, and the associated physical method and operative protocol for the accurate measurements of mass density, size and weight. The technique is based on the detection of the terminal velocity of a free-falling sample into a specifically conceived analysis flow-channel. Moreover, in order to demonstrate the accuracy and precision of the presented flow-device, analyses were initially carried out on standardized polystyrene beads. Finally, to display the application of the proposed system for biological samples, mass density, size and weight of live SW620 tumor spheroids were analyzed. The combined measurements of such parameters can represent a step toward a deeper understanding of 3D culture models.
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To improve pathogenetic studies in cancer development and reliable preclinical testing of anti-cancer treatments, three-dimensional (3D) cultures, including spheroids, have been widely recognized as more physiologically relevant in vitro models of in vivo tumor behavior. Currently, the generation of uniformly sized spheroids is still challenging: different 3D cell culture methods produce heterogeneous populations in dimensions and morphology, that may strongly influence readouts reliability correlated to tumor growth rate or antitumor natural killer (NK) cell-mediated cytotoxicity. In this context, an increasing consensus claims the integration of microfluidic technologies within 3D cell culture, as the physical characterization of tumor spheroids is unavoidably demanded to standardize protocols and assays for in vitro testing. In this paper, we employed a flow-based method specifically conceived to measure weight, size and focused onto mass density values of tumor spheroids. These measurements are combined with confocal and digital imaging of such samples. We tested the spheroids of four colorectal cancer (CRC) cell lines that exhibit statistically relevant differences in their physical characteristics, even though starting from the same cell seeding density. These variations are seemingly cell line-dependent and associated with the number of growing cells and the degree of spheroid compaction as well, supported by different adenosine-triphosphate contents. We also showed that this technology can estimate the NK cell killing efficacy by measuring the weight loss and diameter shrinkage of tumor spheroids, alongside with the commonly used cell viability in vitro test. As the activity of NK cells relies on their infiltration rate, the in vitro sensitivity of CRC spheroids proved to be exposure time- and cell line-dependent with direct correlation to the cell viability reduction. All these functional aspects can be measured by the system and are documented by digital image analysis. In conclusion, this flow-based method potentially paves the way towards standardization of 3D cell cultures and its early adoption in cancer research to test antitumor immune response and set up new immunotherapy strategies.
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Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Citometria de Fluxo/métodos , Células Matadoras Naturais/imunologia , Linfócitos do Interstício Tumoral/imunologia , Esferoides Celulares/patologia , Técnicas de Cultura de Células/métodos , Proliferação de Células , Sobrevivência Celular , Técnica Indireta de Fluorescência para Anticorpo/métodos , Células HT29 , Humanos , Microfluídica/métodosRESUMO
OBJECTIVE: To describe clinical presentation, electrocardiographic, and echocardiographic characteristics of carditis at the time of diagnosis of acute rheumatic fever (ARF) over a 13-year period. STUDY DESIGN: A single-center retrospective chart analysis was conducted involving all consecutive patients diagnosed with ARF between 2003 and 2015. Patient age, sex, clinical characteristics, recent medical history for group A streptococcal pharyngotonsillitis and antibiotic treatment, and laboratory, echocardiographic, and electrocardiographic findings were recorded. RESULTS: Of 98 patients (62 boys, mean age 8.81 ± 3.04 years), 59 (60.2%) reported a positive history of pharyngotonsillitis; 48 (49%) had received antibiotic (mean duration of treatment of 5.9 ± 3.1 days), and, among these, 28 (58.3%) had carditis. Carditis was the second most frequent finding, subclinical in 27% of patients. Mitral regurgitation was present in 49 of 56 patients (87.5%) and aortic regurgitation in 36/56 (64.3%) no stenosis was documented. CONCLUSIONS: ARF is still present in high-income countries and can develop despite primary prophylaxis, especially when given for a short course. Our findings highlight the need for 10 days of antistreptococcal treatment to prevent ARF. Echocardiography is important because 27% of cases with carditis were subclinical.
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Miocardite/diagnóstico , Miocardite/epidemiologia , Febre Reumática/diagnóstico , Adolescente , Antibacterianos/uso terapêutico , Insuficiência da Valva Aórtica/diagnóstico por imagem , Artrite/microbiologia , Bloqueio Atrioventricular/diagnóstico , Sedimentação Sanguínea , Criança , Pré-Escolar , Coreia/microbiologia , Países Desenvolvidos , Ecocardiografia Doppler em Cores , Eletrocardiografia , Eritema/microbiologia , Feminino , Hemoglobinas/análise , Humanos , Itália/epidemiologia , Masculino , Insuficiência da Valva Mitral/diagnóstico por imagem , Faringite/epidemiologia , Estudos Retrospectivos , Febre Reumática/tratamento farmacológico , Febre Reumática/epidemiologia , Estações do Ano , Tonsilite/epidemiologiaRESUMO
Organic bioelectronics have a huge potential to generate interfaces and devices for the study of brain functions and for the therapy of brain pathologies. In this context, increasing efforts are needed to develop technologies for monitoring and stimulation of nonexcitable brain cells, called astrocytes. Astroglial calcium signaling plays, indeed, a pivotal role in the physiology and pathophysiology of the brain. Here, the use of transparent organic cell stimulating and sensing transistor (O-CST) architecture, fabricated with N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13), to elicit and monitor intracellular calcium concentration ([Ca2+ ]i ) in primary rat neocortical astrocytes is demonstrated. The transparency of O-CST allows performing calcium imaging experiments, showing that extracellular electrical stimulation of astrocytes induces a drastic increase in [Ca2+ ]i . Pharmacological studies indicate that transient receptor potential (TRP) superfamily are critical mediators of the [Ca2+ ]i increase. Experimental and computational analyses show that [Ca2+ ]i response is enabled by the O-CST device architecture. Noteworthy, the extracellular field application induces a slight but significant increase in the cell volume. Collectively, it is shown that the O-CST is capable of selectively evoking astrocytes [Ca2+ ]i , paving the way to the development of organic bioelectronic devices as glial interfaces to excite and control physiology of non-neuronal brain cells.
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Astrócitos/metabolismo , Encéfalo/metabolismo , Sinalização do Cálcio , Cálcio/metabolismo , Transistores Eletrônicos , Animais , Astrócitos/citologia , Encéfalo/citologia , Células Cultivadas , Estimulação Elétrica , Ratos , Ratos Sprague-DawleyRESUMO
Carminic acid, a natural hydrophilic dye extensively used in the food and cosmetic industries, is converted in hydrophobic dyes by acetylation or pivaloylation. These derivatives are successfully used as biocolourants for rubber objects. In this paper, spectroscopic properties of the carminic acid derivatives in dimethyl sulfoxide and in polybutylacrylate are studied by means of photoluminescence and time-resolved photoluminescence decays, revealing a hypsochromic effect due to the presence of bulky substituents as the acetyl or pivaloyl groups. Molecular mechanics and density functional theory calculations confirm the disruption of planarity between the sugar ring and the anthraquinoid system determined by the esterification.
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We demonstrate the label-free and selective detection of interleukin-6 (IL-6), a key cell-signaling molecule in biology and medicine, by integrating an OECT with an immuno-affinity regenerated cellulose membrane. The objective of the membrane is to increase the local concentration of IL-6 at the sensing electrode and, thereby, enhance the device response for concentrations falling within the physiological concentration range of cytokines. The OECT gate electrode is functionalized with an oligo(ethylene glycol)-terminated self-assembled alkanethiolate monolayer (SAM) for both the immobilization of anti IL-6 antibodies and the inhibition of non-specific biomolecule binding. The OECT gate/electrolyte interface is exploited for the selective detection of IL-6 through the monitoring of antigen-antibody binding events occurring at the gate electrode.
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Potassium channels and aquaporins expressed by astrocytes are key players in the maintenance of cerebral homeostasis and in brain pathophysiologies. One major challenge in the study of astrocyte membrane channels in vitro, is that their expression pattern does not resemble the one observed in vivo. Nanostructured interfaces represent a significant resource to control the cellular behaviour and functionalities at micro and nanoscale as well as to generate novel and more reliable models to study astrocytes in vitro. However, the potential of nanotechnologies in the manipulation of astrocytes ion channels and aquaporins has never been previously reported. Hydrotalcite-like compounds (HTlc) are layered materials with increasing potential as biocompatible nanoscale interface. Here, we evaluate the effect of the interaction of HTlc nanoparticles films with primary rat neocortical astrocytes. We show that HTlc films are biocompatible and do not promote gliotic reaction, while favouring astrocytes differentiation by induction of F-actin fibre alignment and vinculin polarization. Western Blot, Immunofluorescence and patch-clamp revealed that differentiation was accompanied by molecular and functional up-regulation of both inward rectifying potassium channel Kir 4.1 and aquaporin 4, AQP4. The reported results pave the way to engineering novel in vitro models to study astrocytes in a in vivo like condition.
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Astrócitos/citologia , Materiais Biocompatíveis/química , Nanoestruturas , Actinas/metabolismo , Hidróxido de Alumínio/química , Animais , Aquaporina 4/metabolismo , Astrócitos/metabolismo , Técnicas de Cultura de Células , Sobrevivência Celular , Células Cultivadas , Citoesqueleto/metabolismo , Gliose/metabolismo , Hidróxido de Magnésio/química , Teste de Materiais , Microscopia Confocal , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Técnicas de Patch-Clamp , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Ratos , Vinculina/metabolismoRESUMO
The use of doped silk fibroin (SF) films and substrates from Bombyx mori cocoons for green nanotechnology and biomedical applications has been recently highlighted. Cocoons from coloured strains of B. mori, such as Golden-Yellow, contain high levels of pigments that could have a huge potential for the fabrication of SF based biomaterials targeted to photonics, optoelectronics and neuroregenerative medicine. However, the features of extracted and regenerated SF from cocoons of B. mori Golden-Yellow strain have never been reported. Here we provide a chemophysical characterization of regenerated silk fibroin (RSF) fibers, solution, and films obtained from cocoons of a Golden-Yellow strain of B. mori, by SEM, (1) H-NMR, HPLC, FT-IR, Raman and UV-Vis spectroscopy. We found that the extracted solution and films from B. mori Golden-Yellow fibroin displayed typical Raman spectroscopic and optical features of carotenoids. HPLC-analyses revealed that lutein was the carotenoid contained in the fiber and RSF biopolymer from yellow cocoons. Notably, primary neurons cultured on yellow SF displayed a threefold higher neurite length than those grown of white SF films. The results we report pave the way to expand the potential use of yellow SF in the field of neuroregenerative medicine and provide green chemistry approaches in biomedicine.
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Axônios , Materiais Biocompatíveis , Fibroínas/química , Luteína/química , Neurônios/citologia , Seda/química , Animais , Bombyx , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Poly(n-butylacrylate)@polystyrene nanoparticles behaving as a capsule-based sealing nanoadditive are synthesized through an optimized semicontinuous emulsion polymerization protocol. Solid state time-domain (1)H-NMR and (13)C magic angle spinning (MAS) NMR analysis suggest strong phase separation. Line width of (13)C resonances in cross polarization and single pulse experiment MAS-NMR spectra indicates that the peculiar mobility of each phase is preserved at the nanoscale. Atomic force spectroscopy (AFM) shows the permanence of spherical shape in absence of solvent (i.e., subsequent to strong capillary and surface forces) up to moderate external load, as well as the possibility of plastically deforming the polystyrene shell and ultimately triggering the nanoparticle flow at higher force loads. The breakdown characteristic of the nanoparticle shows for the first time baroplastic behavior on a single particle with precise biphasic core@shell morphology.
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Nanopartículas/química , Poliestirenos/química , Acrilatos/química , Difusão Dinâmica da Luz , Espectroscopia de Ressonância Magnética , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Polimerização , Temperatura de TransiçãoRESUMO
We report the design, synthesis and structure-property investigation of a new perylene diimide material (PDI-Lys) bearing lysine end substituents. Water processed films of PDI-Lys were prepared and their self-assembly, morphology and electrical properties in both inert and air environments were theoretically and experimentally investigated. With the aim of evaluating the potential of PDI-Lys as a biocompatible and functional neural interface for organic bioelectronic applications, its electrochemical impedance as well as the adhesion and viability properties of primary neurons on the PDI-Lys films were studied. By combining theoretical calculations and electrical measurements we show that due to conversion between neutral and zwitterionic anions, the PDI-Lys film conductivity increased significantly upon passing from air to an inert atmosphere, reaching a maximum value of 6.3 S m-1. We also show that the PDI-Lys film allows neural cell adhesion and neuron differentiation and decreases up to 5 times the electrode/solution impedance in comparison to a naked gold electrode. The present study introduces an innovative, water processable conductive film usable in organic electronics and as a putative neural interface.