Anticancer Activity of Benzo[a]phenoxazine Compounds Promoting Lysosomal Dysfunction.

Specific cancer therapy remains a problem to be solved. Breast and colorectal cancer are among the cancers with the highest prevalence and mortality rates. Although there are some therapeutic options, there are still few effective agents for those cancers, which constitutes a clinical problem that requires further research efforts. Lysosomes play an important role in cancer cells' survival, and targeting lysosomes has gained increased interest. In recent years, our team has been synthetizing and testing novel benzo[a]phenoxazine derivatives, as they have been shown to possess potent pharmacological activities. Here, we investigated the anticancer activity of three of the most potent derivatives from our library, C9, A36, and A42, on colorectal- and breast-cancer-derived cell lines, and compared this with the effect on non-neoplastic cell lines. We observed that the three compounds were selective for the cancer cells, namely the RKO colorectal cancer cell line and the MCF7 breast cancer cell line. In both models, the compounds reduced cell proliferation, cell survival, and cell migration, accumulated on the lysosome, and induced cell death accompanied by lysosomal membrane permeabilization (LMP), increasing the intracellular pH and ROS accumulation. Our results demonstrated that these compounds specifically target lysosomes from cancer cells, making them promising candidates as LMP inducers for cancer therapy.

Ultrasound-assisted water oxidation: unveiling the role of piezoelectric metal-oxide sonocatalysts for cancer treatment.

Ultrasound radiation has been widely used in biomedical application for both diagnosis and therapy. Metal oxides nanoparticles (NPs), like ZnO or TiO2 NPs, have been widely demonstrated to act as excellent sonocatalysts and significantly enhance cavitation at their surface, making them optimal for sonodynamic cancer therapy. These NPs often possess semiconductive and piezoelectric properties that contribute to the complex phenomena occurring at the water-oxide interface during sonostimulation. Despite the great potential in applied sonocatalysis and water splitting, the complex mechanism that governs the phenomenon is still a research subject. This work investigates the role of piezoelectric ZnO micro- and nano-particles in ultrasound-assisted water oxidation. Three metal oxides presenting fundamental electronic and mechanical differences are evaluated in terms of ultrasound-triggered reactive oxygen species generation in aqueous media: electromechanically inert SiO2 NPs, semiconducting TiO2 NPs, piezoelectric and semiconducting ZnO micro- and nanoparticles with different surface areas and sizes. The presence of silver ions in the aqueous solution was further considered to impart a potential electron scavenging effects and better evaluate the oxygen generation performances of the different structures. Following sonoirradiation, the particles are optically and chemically analyzed to study the effect of sonostimulation at their surface. The production of gaseous molecular oxygen is measured, revealing the potential of piezoelectric particles to generate oxygen under hypoxic conditions typical of some cancer environments. Finally, the best candidates, i.e. ZnO nano and micro particles, were tested on osteosarcoma and glioblastoma cell lines to demonstrate their potential for cancer treatment.

Vascular fingerprint tool to identify patients with testicular cancer treated with cisplatin-based chemotherapy at high risk of early cardiovascular events.

BACKGROUND: Patients with testicular cancer treated with chemotherapy have an increased risk of developing early cardiovascular events. Identification of patients with testicular cancer at a high risk of these events enables the development of preventative strategies. This study validates the vascular fingerprint tool to identify these patients. PATIENTS AND METHODS: We carried out a multicenter prospective study in patients with metastatic testicular cancer [International Germ Cell Cancer Collaborative Group (IGCCCG) good or intermediate risk; retroperitoneal mass <5 cm]. In eligible patients, the vascular fingerprint was assessed before the start of cisplatin-based chemotherapy, which consists of five risk factors, namely, smoking, overweight (body mass index >25 kg/m2), hypertension (blood pressure >140/90 mmHg), dyslipidemia (fasting cholesterol >5.1 mmol/l or low-density lipoprotein-cholesterol >2.5 mmol/l), and diabetes mellitus (fasting glucose ≥7.0 mmol/l). The presence of three or more risk factors was defined as high-risk vascular fingerprints. A log-rank test was carried out with a cardiovascular event within 1 year after the start of chemotherapy as the primary endpoint. RESULTS: A total of 196 patients with metastatic testicular cancer were included; 15 patients (8%) developed a cardiovascular event: 4 (2%) arterial events and 11 (6%) venous thrombotic events. Overall, 189 vascular fingerprint scores were available. Patients with a high-risk vascular fingerprint (62/189) had a higher risk of developing a cardiovascular event (hazard ratio 3.27, 95% confidence interval 1.16-9.18; log-rank: P = 0.017). Histological diagnosis, prognosis group, cumulative chemotherapy dose, and retroperitoneal mass size did not differ between patients with or without a cardiovascular event. All patients with an arterial event had a high-risk vascular fingerprint compared with 5/11 patients with a venous event. Overweight was more prevalent in patients with cardiovascular events (87% versus 59%; P = 0.037). CONCLUSIONS: The vascular fingerprint is a validated tool to identify patients with testicular cancer at a high risk of developing early cardiovascular events. This tool can be used to develop preventative strategies with anticoagulant treatment.

O armário: Fruiting phenology data for 4,462 plant taxa in Portugal (1926-2013).

Species phenology - the timing of key life events - is being altered by ongoing climate changes with yet underappreciated consequences for ecosystem stability. While flowering is generally occurring earlier, we know much less about other key processes such as the time of fruit ripening, largely due to the lack of comprehensive long-term datasets. Here we provide information on the exact date and site where seeds of 4,462 taxa were collected for the Index Seminum (seed exchange catalogue) of the Botanic Garden of the University of Coimbra, between 1926 and 2013. Seeds were collected from spontaneous and cultivated individuals across Portugal, including both native and introduced taxa. The database consists of 127,747 curated records with information on the species, or infraspecific taxa (including authority), and the day and site where seeds were collected. All records are georeferenced and provided with a confidence interval for the collection site. Taxonomy was first curated manually by in-house botanists and then harmonized according to the GBIF backbone taxonomy.

[Management of ear, nose and throat emergencies]. / Management von Hals-Nasen-Ohren-Notfällen.

Emergency situations involving the ears, nose, and throat (ENT) area can pose considerable challenges for clinicians and often require an interdisciplinary approach due to the involvement of different organ systems. To avoid damage to highly relevant sensory and perception organs and life-threatening bleeding or respiratory complications, strategies that are as quick and targeted as possible are necessary. This article aims to provide an overview of ENT emergency management strategies. The entire spectrum from simple conservative to highly complex surgical measures plays a role here, both diagnostically and therapeutically. Aspects such as bleeding, respiratory problems, inflammation, hearing disorders, vertigo, facial palsy and injuries to the head and neck area are discussed. In addition, important topics such as preventive measures and possible complications are also addressed to ensure optimal patient care.

Genomic insights into the expansion of carbapenem-resistant Klebsiella pneumoniae within Portuguese hospitals.

Carbapenem-resistant Klebsiella pneumoniae (CR-KP) are a public health concern, causing infections with a high mortality rate, limited therapeutic options and challenging infection control strategies. In Portugal, the CR-KP rate has increased sharply, but the factors associated with this increase are poorly explored. In order to address this question, phylogenetic and resistome analysis were used to compare the draft genomes of 200 CR-KP isolates collected in 2017-2019 from five hospitals in the Lisbon region, Portugal. Most CR-KP belonged to sequence type (ST) 13 (29%), ST17 (15%), ST348 (13%), ST231 (12%) and ST147 (7%). Carbapenem resistance was conferred mostly by the presence of KPC-3 (74%) or OXA-181 (18%), which were associated with IncF/IncN and IncX plasmids, respectively. Almost all isolates were multi-drug resistant, harbouring resistance determinants to aminoglycosides, beta-lactams, trimethoprim, fosfomycin, quinolones and sulphonamides. In addition, 11% of isolates were resistant to colistin. Colonizing and infecting isolates were highly related, and most colonized patients (89%) reported a previous hospitalization. Moreover, among the 171 events of cross-dissemination identified by core genome multi-locus sequence typing data analysis (fewer than five allelic differences), 41 occurred between different hospitals and 130 occurred within the same hospital. The results suggest that CR-KP dissemination in the Lisbon region results from acquisition of carbapenemases in mobile genetic elements, influx of CR-KP into the hospitals by colonized ambulatory patients, and transmission of CR-KP within and between hospitals. Prudent use of carbapenems, patient screening at hospital entry, and improvement of infection control are needed to decrease the burden of CR-KP infection in Portugal.

Long hydraulic retention time mediates stable volatile fatty acids production against slight pH oscillations.

The effect of operational conditions on the stability of acidogenic fermentation (AF) devoted to volatile fatty acids (VFAs) production still presents numerous gaps to achieve high yields and fully understand the responses of open microbiomes associated to this technology. To cope with that, this investigation was designed to assess the stability of VFAs production via AF of agro-food wastes at high hydraulic retention times (HRTs) (20 and 30 d) and pH oscillations (5.8-6.2). Similar bioconversion efficiencies (∼50 %) were reached regardless of the HRT, revealing that HRT of 20 d can be considered as a threshold from which, no further improvement was achieved. The combination of long HRTs, 25 °C and acid pHs promoted a robust microbiome that resulted in a stable outcome against pH variations, being Clostridiales order identified as key player of AF stability. These conditions mediated a high selectivity in the VFAs production profile, with acetic and butyric acids, prevailing in the VFAs pool (∼80 % of total VFAs) at HRT 20 d. The selection of appropriated conditions was shown to be critical to maximize the hydrolysis and acidogenesis of the substrate and attain a stable effluent against pH oscillations.

Smell loss associated with SARS-CoV-2 is not clinically different from other viruses: a multicenter cohort study.

BACKGROUND: Although the COVID-19 pandemic has increased the prevalence of cases with olfactory loss, other respiratory viruses can also cause this condition. We aimed to compare the prevalence of acute SARS-CoV-2 infection and other respiratory viruses in patients with sudden smell loss, and to assess the impact of SARS-CoV-2 viral load and co-infection on olfactory symptoms. METHODS: Patients with sudden smell loss were recruited in a multicenter prospective cohort study in 15 hospitals in Brazil. Clinical questionnaire, Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory test and nasopharyngeal swab to perform a PCR-based respiratory viral panel were collected at first visit (day 0) and 30 and 60 days after recruitment. RESULTS: 188 of 213 patients presented positive test result for SARS-CoV-2, among which 65 were co-infected with other respiratory viruses (e.g., rhinovirus, enterovirus, and parainfluenza). 25 had negative test results for SARS-CoV-2. Patients in both SARSCoV-2 and non-SARS-CoV-2 groups had objective anosmia (less than 2 points according to the psychophysical olfactory CCCRC) at day 0, with no significant difference between them. Both groups had significant smell scores improvement after 30 and 60 days, with no difference between them. Co-infection with other respiratory viruses, and SARS-CoV-2 viral load did not impact olfactory scores. CONCLUSION: Patients with sudden smell loss associated with SARS-CoV-2 and other respiratory viruses had similar presentation, with most participants initiating with anosmia, and total or near total recovery after 60 days. SARS-CoV-2 viral load and co-infections with other respiratory viruses were not associated with poorer olfactory outcomes.

Acromegalia e hipertensão arterial: casualidade ou causalidade? Insights a partir de relato de caso / Acromegaly and arterial hypertension: causality or causality? Insights from case report

INTRODUÇÃO E/OU FUNDAMENTO: A acromegalia é uma doença endócrina rara causada por adenoma hipofisário secretor de Hormônio do Crescimento (GH), cursando com aumento dos níveis plasmáticos de GH e, consequentemente, do Fator de Crescimento Semelhante à Insulina-1 (IGF-1). Ambos os hormônios exercem importantes atividades regulatórias no sistema cardiovascular (CV) que é o principal responsável pelas complicações clínicas da síndrome. O relato de caso a seguir expõe diversas dessas complicações. MÉTODOS: Relatamos caso de paciente do sexo feminino, 47 anos, branca, tabagista, sem outras comorbidades, que procurou atendimento por cansaço progressivo, associado à dispneia aos esforços e edema de membros inferiores. RESULTADOS: O ecocardiograma transtorácico confirmou dupla lesão mitral grave, com predomínio de estenose, tratada cirurgicamente com implante de prótese mitral biológica. Cinco anos após, a paciente desenvolveu hipertensão arterial (HA) estágio 1, tratada com Hidroclorotiazida. Concomitantemente relatou cefaleia, perda visual bitemporal, separação dos dentes, aumento de extremidades (com necessidade de aumentar numeração dos sapatos) e língua. Com suspeita clínica de acromegalia, foi submetida a investigação que evidenciou elevação de níveis plasmáticos de GH e IGF1 e lesão expansiva intrasselar identificada por ressonância magnética nuclear. Iniciou-se tratamento com Bromocriptina. Nesse período a paciente interrompeu o uso da medicação anti-hipertensiva, mantendo controle adequado da pressão arterial. No entanto, três anos depois, foi constatado novo aumento dos níveis de IGF-1 para 785mcg/L (VR 2,5 segundos, sendo indicado e realizado implante de marcapasso definitivo. CONCLUSÕES: A doença CV é a comorbidade mais frequente e a principal causa de morte relacionada a acromegalia. O caso apresentado reúne e ilustra as principais manifestações CV da acromegalia: doença valvar; hipertrofia ventricular esquerda; bradiarritmias e HA, muito embora não tenha sido possível afastar doença reumática como etiologia da dupla lesão mitral. A prevalência de HA varia de 13 a 60% e contribui significativamente com o excesso de morbimortalidade observado. A alta prevalência de HA na população geral faz com que seja árduo discernir na prática clínica em que medida a HA é secundária a acromegalia, essencial ou mista. O controle pressórico obtido concomitantemente com a redução dos níveis plasmáticos de GH e IGF-1 indica uma associação direta destes hormônios com a HA em função do aumento da resistência insulínica, da reabsorção renal de sódio e da atividade simpática. Por outro lado, a persistência da HA após o controle hormonal obtido com o Octreotide sugere que nessa fase mais tardia, o remodelamento arteriolar tenha levado a instalação de HA primária.

Hipertensão arterial e hipervitaminose D iatrogênica: um relato de caso evocando o aforisma de paracelso / Arterial hypertension and iatrogenic D hypervitaminosis: a case report evoking Paracelsus' aphorism

INTRODUÇÃO E/OU FUNDAMENTO: A suplementação de vitamina D em indivíduos sem déficit aumentou significativamente nos últimos anos. Nos Estados Unidos a taxa de prescrição aumentou 30% ao longo de 10 anos. Contribuem para o fenômeno movimentos de opinião sustentando propriedades terapêuticas não comprovadas e a percepção geral de segurança e inocuidade. MÉTODOS: Relatamos um caso de intoxicação grave por vitamina D secundária a suplementação inadequada, inicialmente diagnosticada pela constatação de picos hipertensivos em paciente previamente normotensa. RESULTADOS: Paciente M.C.N., do sexo feminino, 60 anos, com história pregressa de fibromialgia, osteoartrite e depressão, mantinha acompanhamento com reumatologista e uso regular de trazodona, pregabalina e duloxetina. Após dosagem em consulta de rotina (vitamina D = 39ng/mL), recebeu prescrição de suplementação oral de colecalciferol (5000 UI/dia) por tempo indeterminado. Três semanas depois, a paciente, previamente normotensa, constatou picos hipertensivos e evoluiu com prurido generalizado, dor abdominal, náuseas e vômitos. Investigação inicial revelou hipercalcemia (cálcio total corrigido 13mg/ dL), injúria renal aguda (creatinina 2,3mg/dL) e hipertensão arterial (HA) confirmada em Monitorização Ambulatorial da Pressão Arterial (MAPA) de 24 horas. A tomografia de abdome não evidenciou alterações significativas e os sintomas digestivos foram atribuídos ao quadro metabólico. A dosagem de vitamina D confirmou a hipótese de intoxicação iatrogênica e Hipervitaminose D (vitamina D = incalculável). Após internação hospitalar, hidratação parenteral, suspensão da vitamina D e medidas para hipercalcemia, a paciente apresentou melhora progressiva da função renal e remissão dos sintomas. No entanto, mesmo após a resolução do quadro, a HA persiste até o momento, sendo necessárias para seu controle duas classes de anti-hipertensivos. CONCLUSÕES: Quase 500 anos atrás, o médico suíço Paracelso escreveu que "a diferença entre remédio e veneno está na dose". A incidência de intoxicação por vitamina D vem aumentando globalmente, seja por erro de manipulação, erro de prescrição ou uso suplementar em altas doses. Doses acima de 4000 UI/dia em períodos prolongados ou 10000 UI/ dia em períodos mais curtos foram associadas a elevação suprafisiológica do nível sérico (>150 ng/ml). O grau de intoxicação observado no caso apresentado parece desproporcional ao nível de suplementação e não podemos excluir erro de manipulação ou de uso. A associação entre Hipervitaminose D e HA é mediada tanto pela hipercalcemia como pela injuria renal. No entanto, neste caso a HA se manteve após resolução dos gatilhos iniciais, sugerindo que possam estar implicados outros mecanismos ainda não esclarecidos.

Distinct developmental trajectories of autonomous behaviors and agency in rodents.

Behavioral interactions within the nuclear family may play a pivotal role in the emergence of autonomy and agency in mammals. While the emergence of a behavior may arise over weeks in line with nervous system maturation, individual events occur on sub-second time scales. This makes it uniquely challenging to track development in the lab where observations are made over minutes to hours or in ecological studies which lack individual specificity and sub-second precision. Here we study families of gerbils, a highly social rodent, raised in enlarged home-cage environments over weeks of development, using continuous video recordings to capture tens of millions of time points per family. Focusing on postnatal day 15 (when pups leave the nest) to day 30 (around the time when pups would disperse) we identify distinct developmental trajectories for both autonomous behaviors (exploration, food and water foraging), and social behaviors (huddling, approach, time spent together). Most of these behaviors emerge in concert with clear diurnal and crepuscular patterns and we find sex differences in both autonomous and social behaviors. Our work supports the emergence of distinct autonomous and social behavior phenotypes as the behavioral correlates of critical developmental periods of maturation of the rodent brain and can form the basis of future research on development from both neuroscience and behavioral biology perspectives.

Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project.

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions. PHOTONGATE relies on two core technologies: a biochemical technology (molecular gates), which will confer the specificity and, therefore, the capability to be adaptable to the analyte of interest, and which, combined with porous substrates, will increase the sensitivity, and a photonic technology based on localized surface plasmonic resonance (LSPR) structures that serve as transducers for light interaction. Both technologies are in the micron range, facilitating the integration of multiple sensors within a small area (mm2). The concept will be developed for its application in health diagnosis and food safety sectors. It is thought of as an easy-to-use modular concept, which will consist of the sensing module, mainly of a microfluidics cartridge that will house the photonic sensor, and a platform for fluidic handling, optical interrogation, and signal processing. The platform will include a new optical concept, which is fully European Union Made, avoiding optical fibers and expensive optical components.

Structural modification of naturally occurring phenolics as a strategy for developing cytotoxic molecules towards cancer cells.

Natural products belonging to different chemical classes have been established as a promising source of novel anticancer drugs. Several low-molecular-weight compounds from the classes of monoterpenes, phenylpropanoids, and flavonoids were shown to possess anticancer activities in previous studies. In this work, over 20 semisynthetic derivatives of molecules belonging to these classes, namely thymol, eugenol, and 6-hydroxyflavanone were synthesized and tested for their cytotoxicity against two human cancer cell lines, namely AGS cells (gastric adenocarcinoma) and A549 cells (human lung carcinoma). An initial screening based on viability assessment was performed to identify the most cytotoxic compounds at 100 µM. The results evidenced that two 6-hydroxyflavanone derivatives were the most cytotoxic among the compounds tested, being selected for further studies. These derivatives displayed enhanced toxicity when compared with their natural counterparts. Moreover, the lactate dehydrogenase (LDH) assay showed that the loss of cell viability was not accompanied by a loss of membrane integrity, thus ruling out a necrotic process. Morphological studies with AGS cells demonstrated chromatin condensation compatible with apoptosis, confirmed by the activation of caspase 3/7. Furthermore, a viability assay on a noncancer human embryonic lung fibroblast cell line (MRC-5) confirmed that these two derivatives possess selective anticancer activity.

Observation of the effect of gravity on the motion of antimatter.

Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.

Cellular density and variability in laryngeal and pharyngeal squamous cell carcinoma using confocal laser endomicroscopy.

OBJECTIVE: Confocal laser endomicroscopy (CLE) allows the visualization of epithelium in a thousand-fold magnification. This study analyzes the architectural differences at the cellular level of the mucosa and squamous cell carcinoma (SCC). PATIENTS AND METHODS: A total of 60 CLE sequences recorded in 5 patients with SCC undergoing laryngectomy between October 2020 and February 2021 were analyzed. The corresponding histologic sample derived from H&E staining was assigned to each sequence, capturing CLE images of the tumor and healthy mucosa. In addition, the cellular structure analysis was performed to diagnose SCC by measuring the total number of cells and cell size in 60 sequences in a fixed field of view (FOV) with 240 µm in diameter (45,239 µm2). RESULTS: Out of 3,600 images, 1,620 (45%) showed benign mucosa and 1,980 (55%) SCC. The automated analysis yielded a difference in cell size, with healthy epithelial cells being 171.9±82.0 µm2 smaller than SCC cells, which were 246.3±171.9 µm2 and showed greater variability in size (p=0.037). In addition, due to the probe's fixed FOV, there was a difference in cell count with a total of 188.7±38.3 and 124.8±38.6 cells in images of normal epithelium and SCC (p<0.001), respectively. Regarding cell density as a criterion for the differentiation of benign/malign, using a cut-off value of 145.5 cells/FOV, we obtained sensitivity and specificity of 88.0% and 71.9%, respectively. CONCLUSIONS: SCC reveals marked differences at a cellular level compared to the healthy epithelium. Our results further support the importance of this feature for identifying SCC during CLE imaging.

Phenolic Compounds Contribution to Portuguese Propolis Anti-Melanoma Activity.

Melanoma is the deadliest type of skin cancer, with about 61,000 deaths annually worldwide. Late diagnosis increases mortality rates due to melanoma's capacity to metastasise rapidly and patients' resistance to the available conventional therapies. Consequently, the interest in natural products as a strategy for drug discovery has been emerging. Propolis, a natural product produced by bees, has several biological properties, including anticancer effects. Propolis from Gerês is one of the most studied Portuguese propolis. Our group has previously demonstrated that an ethanol extract of Gerês propolis collected in 2018 (G18.EE) and its fractions (n-hexane, ethyl acetate, and n-butanol) decrease melanoma cell viability. Out of all the fractions, G18.EE-n-BuOH showed the highest potential as a melanoma pharmacological therapy. Thus, in this work, G18.EE-n-BuOH was fractioned into 17 subfractions whose effect was evaluated in A375 BRAF-mutated melanoma cells. The subfractions with the highest cytotoxic activity were analysed by UPLC-DAD-ESI/MSn in an attempt to understand which phenolic compounds could account for the anti-melanoma activity. The compounds identified are typical of the Gerês propolis, and some of them have already been linked with antitumor effectiveness. These results reaffirm that propolis compounds can be a source of new drugs and the isolation of compounds could allow its use in traditional medicine.

Novel Benzo[a]phenoxazinium Chlorides Functionalized with Sulfonamide Groups as NIR Fluorescent Probes for Vacuole, Endoplasmic Reticulum, and Plasma Membrane Staining.

The demand for new fluorophores for different biological target imaging is increasing. Benzo[a]phenoxazine derivatives are fluorochromophores that show promising optical properties for bioimaging, namely fluorescent emission at the NIR of the visible region, where biological samples have minimal fluorescence emission. In this study, six new benzo[a]phenoxazinium chlorides possessing sulfonamide groups at 5-amino-positions were synthesized and their optical and biological properties were tested. Compared with previous probes evaluated using fluorescence microscopy, using different S. cerevisiae strains, these probes, with sulfonamide groups, stained the vacuole membrane and/or the perinuclear membrane of the endoplasmic reticulum with great specificity, with some fluorochromophores capable of even staining the plasma membrane. Thus, the addition of a sulfonamide group to the benzo[a]phenoxazinium core increases their specificity and attributes for the fluorescent labeling of cell applications and fractions, highlighting them as quite valid alternatives to commercially available dyes.

Magnesium incorporation in fibrinogen scaffolds promotes macrophage polarization towards M2 phenotype.

The host inflammatory response to biomaterials conditions their capacity to promote tissue repair, and macrophage polarization shift from M1 to M2 is determinant in this process. Previous work showed that extracts of a combination between fibrinogen and metallic magnesium materials acted synergistically to reduce macrophage inflammatory phenotype. The hypothesis underlying the current work was that the ability of magnesium-modified fibrinogen scaffolds to modulate macrophage phenotype depends on the concentration of magnesium. Thus, Fibrinogen (Fg) scaffolds incorporating precise concentrations of magnesium sulfate (Mg: 0, 10, 25, 50 mM) were developed and characterized. Mg incorporation in Fg scaffolds increased surface charge, while porosity decreased with increasing Mg concentrations, but only Fg scaffolds with 10 mM of Mg (FgMg10) had significantly improved mechanical properties. Human macrophages cultured on FgMg10 scaffolds, showed increased M2 and decreased M1 polarization, when compared to those cultured on scaffolds with 0, 25 and 50 mM of Mg. Macrophage polarization results were independent of the anion used (chloride or sulfate). Macrophage modulation by FgMg10 scaffolds involved reduced NF-κB p65 nuclear translocation, and impacted production of pro-inflammatory mediators (e.g. IFNγ, IL-12, TNF-⍺, IP-10). Importantly, FgMg10 scaffolds implanted in vivo increased the expression of M2 marker CD163, in macrophages from inflammatory exudates, compared to Sham and Fg-implanted animals, increasing the M2:M1 ratio. A cytokine/chemokine array showed that, while both Fg and FgMg10 scaffolds decreased inflammatory mediators, only FgMg10 decreased IL-1ß, IP-10, MIP-2, MDC and MIP-3⍺, compared to Sham-operated animals. This study demonstrated that incorporation of 10mM of Mg modulated inflammation, promoting M2 macrophage polarization in vitro and in vivo. STATEMENT OF SIGNIFICANCE: Developing biomaterials that can modulate inflammation and promote macrophage phenotype switch from M1 to M2 is crucial to promote a regenerative microenvironment. Our previous work showed that extracts of a combination between fibrinogen (Fg) and metallic magnesium (Mg) materials synergistically reduced macrophage pro-inflammatory phenotype. Herein, we tested the hypothesis that macrophage modulation was dependent on Mg concentration. A new family of Fg porous scaffolds incorporating different amounts of Mg (0, 10, 25 and 50 mM) was produced and characterized. We observed that only the combination of Fg scaffolds with 10 mM of Mg (FgMg10) significantly changed the scaffolds mechanical properties and directed macrophages towards a M2 phenotype, reducing the production of inflammatory mediators, both in vitro and in vivo.