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Protein-based hydrogels have great potential to be used as bioinks for biofabrication-driven tissue regeneration strategies due to their innate bioactivity. Nevertheless, their use as bioinks in conventional 3D bioprinting is impaired due to their intrinsic low viscosity. Using embedding bioprinting, a liquid bioink is printed within a support that physically holds the patterned filament. Inspired by the recognized microencapsulation technique complex coacervation, crystal self-healing embedding bioprinting (CLADDING) is introduced based on a highly transparent crystal supporting bath. The suitability of distinct classes of gelatins is evaluated (i.e., molecular weight distribution, isoelectric point, and ionic content), as well as the formation of gelatin-gum arabic microparticles as a function of pH, temperature, solvent, and mass ratios. Characterizing and controlling this parametric window resulted in high yields of support bath with ideal self-healing properties for interaction with protein-based bioinks. This support bath achieved transparency, which boosted light permeation within the bath. Bioprinted constructs fully composed of platelet lysates encapsulating a co-culture of human mesenchymal stromal cells and endothelial cells are obtained, demonstrating a high-dense cellular network with excellent cell viability and stability over a month. CLADDING broadens the spectrum of photocrosslinkable materials with extremely low viscosity that can now be bioprinted with sensitive cells without any additional support.
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Olive pomace is an agro-industrial waste product generated from the olive oil industry and constituted by bioactive compounds with potential applications in several industrial sectors. The purpose of this work was to evaluate the effects of electron beam (e-beam) radiation on olive pomace, specifically on phenolic compounds (by HPLC-DAD-ESI/MS) and the bioactive properties (antioxidant, antiproliferative, and antimicrobial activities) of crude olive pomace (COP) and extracted olive pomace (EOP) extracts. The amount of total flavonoid content and the reducing power of COP extracts were higher than those obtained for EOP extracts. The results suggested that e-beam radiation at 6 kGy increased both total phenolic and total flavonoid contents as well as the reducing power of COP extracts, due to the higher extractability (>2.5-fold) of phenolic compounds from these samples, while decreasing the scavenging activity of extracts. The extracts of both olive pomaces showed antibacterial potential, and COP extracts at 400 µg/mL also presented antiproliferative activity against A549, Caco-2, 293T, and RAW264.7 cell lines, with both properties preserved with the e-beam treatment. All in all, e-beam radiation at 6 kGy appears to be a promising technology to valorize the pollutant wastes of the olive oil industry through enhancing phenolic extractability and bioactive properties, and, furthermore, to contribute to the environmental and economical sustainability of the olive oil industry.
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Over the last decade, researchers have developed a variety of new analytical and clinical diagnostic devices. These devices are predominantly based on microfluidic technologies, where biological samples can be processed and manipulated for the collection and detection of important biomolecules. Polydimethylsiloxane (PDMS) is the most commonly used material in the fabrication of these microfluidic devices. However, it has a hydrophobic nature (contact angle with water of 110°), leading to poor wetting behavior and issues related to the mixing of fluids, difficulties in obtaining uniform coatings, and reduced efficiency in processes such as plasma separation and molecule detection (protein adsorption). This work aimed to consider the fabrication aspects of PDMS microfluidic devices for biological applications, such as surface modification methods. Therefore, we studied and characterized two methods for obtaining hydrophilic PDMS surfaces: surface modification by bulk mixture and the surface immersion method. To modify the PDMS surface properties, three different surfactants were used in both methods (Pluronic® F127, polyethylene glycol (PEG), and polyethylene oxide (PEO)) at different percentages. Water contact angle (WCA) measurements were performed to evaluate the surface wettability. Additionally, capillary flow studies were performed with microchannel molds, which were produced using stereolithography combined with PDMS double casting and replica molding procedures. A PDMS microfluidic device for blood plasma separation was also fabricated by soft lithography with PDMS modified by PEO surfactant at 2.5% (v/v), which proved to be the best method for making the PDMS hydrophilic, as the WCA was lower than 50° for several days without compromising the PDMS's optical properties. Thus, this study indicates that PDMS surface modification shows great potential for enhancing blood plasma separation efficiency in microfluidic devices, as it facilitates fluid flow, reduces cell aggregations and the trapping of air bubbles, and achieves higher levels of sample purity.
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Porous titanium scaffolds fabricated by powder bed fusion additive manufacturing techniques have been widely adopted for orthopedic and bone tissue engineering applications. Despite the many advantages of this approach, topological defects inherited from the fabrication process are well understood to negatively affect mechanical properties and pose a high risk if dislodged after implantation. Consequently, there is a need for further post-process surface cleaning. Traditional techniques such as grinding or polishing are not suited to lattice structures, due to lack of a line of sight to internal features. Chemical etching is a promising alternative; however, it remains unclear if changes to surface properties associated with such protocols will influence how cells respond to the material surface. In this study, we explored the response of bone marrow derived mesenchymal stem/stromal cells (MSCs) to Ti-6Al-4V whose surface was exposed to different durations of chemical etching. Cell morphology was influenced by local topological features inherited from the SLM fabrication process. On the as-built surface, topological nonhomogeneities such as partially adhered powder drove a stretched anisotropic cellular morphology, with large areas of the cell suspended across the nonhomogeneous powder interface. As the etching process was continued, surface defects were gradually removed, and cell morphology appeared more isotropic and was suggestive of MSC differentiation along an osteoblastic-lineage. This was accompanied by more extensive mineralization, indicative of progression along an osteogenic pathway. These findings point to the benefit of post-process chemical etching of additively manufactured Ti-6Al-4V biomaterials targeting orthopedic applications.
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Aleaciones , Materiales Biocompatibles , Rayos Láser , Células Madre Mesenquimatosas , Titanio , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Titanio/química , Aleaciones/química , Aleaciones/farmacología , Materiales Biocompatibles/química , Calcificación Fisiológica/efectos de los fármacos , Animales , Diferenciación Celular/efectos de los fármacos , Humanos , Propiedades de Superficie , Ensayo de MaterialesRESUMEN
Introduction: Pulmonary artery aneurysm (PAA) is a rare abnormality of pulmonary vasculature. It can be idiopathic or secondary to various pathologies, frequently with multiple factors leading to its formation. We report the case of a man with concomitant sarcoidosis and PAA. Case description: A 75-year-old male with a diagnosis of pulmonary sarcoidosis was referred to the Cardiology department due to heart failure with reduced left ventricular ejection fraction (LVEF). The transthoracic echocardiogram revealed mildly reduced LVEF, aortic root and pulmonary artery (PA) dilatation, and no signs of pulmonary hypertension (PH). Cardiac magnetic resonance imaging was performed, revealing mild left ventricular dilation, LVEF of 40%, main PA dilation (43 mm) and a pattern of late gadolinium enhancement suggestive of cardiac sarcoidosis. At follow-up, a thoracic computed tomography (CT) angiography scan revealed ascending aorta ectasia and giant main PA aneurysm (60 mm). A right heart catheterisation was performed, and a mean PA pressure of 34 mmHg was obtained. Given the clinical context, the patient was considered to have PH due to lung disease and left heart disease, and PAA was possible due to vascular granulomatous involvement by sarcoidosis. Conclusion: PAA is a rare finding and mostly occurs in the setting of PH. Sarcoidosis is a granulomatous disease that mostly affects the lungs, but the sarcoid involvement of great vessels has been described. In this clinical case, the probable cause for the PA fragility leading to aneurysm formation remains sarcoid vascular infiltration, regarding the discrepancy between the PA dimensions and mildly elevated PA pressure. LEARNING POINTS: Pulmonary artery aneurysm is a rare abnormality of pulmonary vasculature that can be idiopathic or a consequence of pulmonary hypertension, congenital heart disease, infection, vasculitis or collagenopathies.Due to the low incidence of this disease, there are no guidelines for its diagnosis, management or follow-up, and treatment is based on the underlying aetiology, aneurysm dimensions and occurrence of symptoms.Sarcoidosis is a multisystem disorder of unknown aetiology characterised by non-caseating granulomas that mostly involve the lungs, but can also affect skin, eyes, and lymph nodes. Sarcoid involvement of great vessels has been rarely described.
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Nonmelanoma skin cancer (NMSC) is the most common cancer worldwide, among which 80% is basal cell carcinoma (BCC). Current therapies' low efficacy, side effects, and high recurrence highlight the need for alternative treatments. In this work, a partially reduced nanographene oxide (p-rGOn) developed in our laboratory was used. It has been achieved through a controlled reduction of nanographene oxide via UV-C irradiation that yields small nanometric particles (below 200 nm) that preserve the original water stability while acquiring high light-to-heat conversion efficiency. The latter is explained by a loss of carbon-oxygen single bonds (C-O) and the re-establishment of sp2 carbon bonds. p-rGOn was incorporated into a Carbopol hydrogel together with the anticancer drug 5-fluorouracil (5-FU) to evaluate a possible combined PTT and chemotherapeutic effect. Carbopol/p-rGOn/5-FU hydrogels were considered noncytotoxic toward normal skin cells (HFF-1). However, when A-431 skin cancer cells were exposed to NIR irradiation for 30 min in the presence of Carbopol/p-rGOn/5-FU hydrogels, almost complete eradication was achieved after 72 h, with a 90% reduction in cell number and 80% cell death of the remaining cells after a single treatment. NIR irradiation was performed with a light-emitting diode (LED) system, developed in our laboratory, which allows adjustment of applied light doses to achieve a safe and selective treatment, instead of the standard laser systems that are associated with damages in the healthy tissues in the tumor surroundings. Those are the first graphene-based materials containing pharmaceutical formulations developed for BCC phototherapy.
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Grafito , Fotoquimioterapia , Neoplasias Cutáneas , Humanos , Grafito/química , Fluorouracilo/farmacología , Composición de Medicamentos , Línea Celular Tumoral , Fototerapia , Neoplasias Cutáneas/tratamiento farmacológico , Carbono , Óxidos , Hidrogeles/farmacología , Hidrogeles/químicaRESUMEN
OBJECTIVES: This study aims to evaluate if low levels of serum maternal pregnancy associated plasma protein-A (PAPP-A) during the first trimester are related to increased umbilical artery pulsatility index (UA PI) later in pregnancy, in cases of estimated fetal weight between the 3rd and 10th percentiles, in order to establish PAPP-A as a predictor of this particular cases of fetal growth restriction (FGR). METHODS: An observational, retrospective cohort study, conducted at a tertiary University Hospital located in Oporto, Portugal. Pregnant women who did the first trimester combined screening, between May 2013 and June 2020 and gave birth in the same hospital, with an estimated fetal weight (EFW) between the 3rd and 10th percentiles were included. The primary outcome is the difference in increased UA PI prevalence between two groups: PAPP-A<0.45 MoM and PAPP-A≥0.45 MoM. As secondary outcomes were evaluated differences in neonatal weight, gestational age at delivery, cesarean delivery, neonatal intensive care unit hospitalization, 5-min Apgar score below 7 and live birth rate between the same two groups. RESULTS: We included 664 pregnancies: 110 cases of PAPP-A<0.45 MoM and 554 cases with PAPP-A≥0.45 MoM. Increased UA PI prevalence, which was the primary outcome of this study, was significantly different between the two groups (p=0.005), as the PAPP-A<0.45 MoM group presents a higher prevalence (12.7â¯%) when compared to the PAPP-A≥0.45 MoM group (5.4â¯%). The secondary outcome cesarean delivery rate was significantly different between the groups (p=0.014), as the PAPP-A<0.45 MoM group presents a higher prevalence (42.7â¯%) than the PAPP-A≥0.45 MoM group (30.1â¯%). No other secondary outcomes showed differences between the two groups. CONCLUSIONS: There is an association of low serum maternal PAPP-A (<0.45 MoM) during the first trimester and increased UA PI (>95th percentile) later in pregnancy, in cases of EFW between the 3rd and 10th percentiles. However, this association is not strong enough alone for low PAPP-A to be a reliable predictor of increased UA PI in this population.
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Peso Fetal , Proteína Plasmática A Asociada al Embarazo , Recién Nacido , Embarazo , Humanos , Femenino , Arterias Umbilicales/diagnóstico por imagen , Estudios Retrospectivos , Ultrasonografía Prenatal , Retardo del Crecimiento Fetal/diagnóstico , Edad GestacionalRESUMEN
Developing biocompatible, non-fouling and biodegradable hydrogels for blood-contacting devices remains a demanding challenge. Such materials should promote natural healing, prevent clotting, and undergo controlled degradation. This study evaluates the biocompatibility and biodegradation of degradable poly(2-hydroxyethyl methacrylate) (d-pHEMA) hydrogels with or without reinforcement with oxidized few-layer graphene (d-pHEMA/M5ox) in a long term implantation in rats, assessing non-desired side-effects (irritation, chronic toxicity, immune response). Subcutaneous implantation over 6 months revealed degradation of both hydrogels, despite slower for d-pHEMA/M5ox, with degradation products found in intracellular vesicles. No inflammation nor infection at implantation areas were observed, and no histopathological findings were detected in parenchymal organs. Immunohistochemistry confirmed d-pHEMA and d-pHEMA/M5ox highly anti-adhesiveness. Gene expression of macrophages markers revealed presence of both M1 and M2 macrophages at all timepoints. M1/M2 profile after 6 months reveals an anti-inflammatory environment, suggesting no chronic inflammation, as also demonstrated by cytokines (IL-α, TNF-α and IL-10) analysis. Overall, modification of pHEMA towards a degradable material was successfully achieved without evoking a loss of its inherent properties, specially its anti-adhesiveness and biocompatibility. Therefore, these hydrogels hold potential as blank-slate for further modifications that promote cellular adhesion/proliferation for tissue engineering applications, namely for designing blood contacting devices with different load bearing requirements. STATEMENT OF SIGNIFICANCE: Biocompatibility, tunable biodegradation kinetics, and suitable immune response with lack of chronic toxicity and irritation, are key features in degradable blood contact devices that demand long-term exposure. We herein evaluate the 6-month in vivo performance of a degradable and hemocompatible anti-adhesive hydrogel based in pHEMA, and its mechanically reinforced formulation with few-layer graphene oxide. This subcutaneous implantation in a rat model, shows gradual degradation with progressive changes in material morphology, and no evidence of local inflammation in surrounding tissue, neither signs of inflammation or adverse reactions in systemic organs, suggesting biocompatibility of degradation products. Such hydrogels exhibit great potential as a blank slate for tissue engineering applications, including for blood contact, where cues for specific cells can be incorporated.
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Grafito , Ratas , Animales , Grafito/farmacología , Polihidroxietil Metacrilato/química , Hidrogeles/farmacología , Hidrogeles/química , Ingeniería de Tejidos , Inflamación , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/químicaRESUMEN
Meniscus injuries are a common problem in orthopedic medicine and are associated with a significantly increased risk of developing osteoarthritis. While developments have been made in the field of meniscus regeneration, the engineering of cell-laden constructs that mimic the complex structure, composition and biomechanics of the native tissue remains a significant challenge. This can be linked to the use of cells that are not phenotypically representative of the different zones of the meniscus, and an inability to direct the spatial organization of engineered meniscal tissues. In this study we investigated the potential of zone-specific meniscus progenitor cells (MPCs) to generate functional meniscal tissue following their deposition into melt electrowritten (MEW) scaffolds. We first confirmed that fibronectin selected MPCs from the inner and outer regions of the meniscus maintain their differentiation capacity with prolonged monolayer expansion, opening their use within advanced biofabrication strategies. By depositing MPCs within MEW scaffolds with elongated pore shapes, which functioned as physical boundaries to direct cell growth and extracellular matrix production, we were able to bioprint anisotropic fibrocartilaginous tissues with preferentially aligned collagen networks. Furthermore, by using MPCs isolated from the inner (iMPCs) and outer (oMPCs) zone of the meniscus, we were able to bioprint phenotypically distinct constructs mimicking aspects of the native tissue. An iterative MEW process was then implemented to print scaffolds with a similar wedged-shaped profile to that of the native meniscus, into which we deposited iMPCs and oMPCs in a spatially controlled manner. This process allowed us to engineer sulfated glycosaminoglycan and collagen rich constructs mimicking the geometry of the meniscus, with MPCs generating a more fibrocartilage-like tissue compared to the mesenchymal stromal/stem cells. Taken together, these results demonstrate how the convergence of emerging biofabrication platforms with tissue-specific progenitor cells can enable the engineering of complex tissues such as the meniscus.
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Bioimpresión , Menisco , Bioimpresión/métodos , Células Madre , Ingeniería de Tejidos/métodos , Colágeno , Andamios del Tejido/químicaRESUMEN
This brief report presents the findings of an epidemiological investigation into a large-scale outbreak of norovirus gastroenteritis that occurred in a hotel in Algarve, Portugal, in August 2022. A total of 244 cases were reported, primarily affecting Portuguese families, with the parents aged 40-50 years and the children aged 0-19 years. Reported symptoms included vomiting, nausea, abdominal pain, and diarrhoea. Norovirus genotype GI.3 [P3] was detected in stool samples from eight probable cases, while food samples tested negative for norovirus and common pathogenic bacteria. The investigation data collected suggest that the source of the outbreak was likely in the hotel's common areas, with subsequent person-to-person transmission in other areas. The final report emphasizes the importance of improving outbreak prevention and control measures, including the development of a foodborne outbreak investigation protocol, the establishment of an outbreak response team, and the enhancement of regional laboratory capacity.
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Norovirus , Niño , Humanos , Norovirus/genética , Brotes de Enfermedades , Diarrea , Portugal/epidemiología , VómitosRESUMEN
OBJECTIVES: To compare positive airway pressure (PAP) adherence between patients with or without excessive daytime sleepiness (EDS) in mild, moderate and severe obstructive sleep apnea (OSA). METHODS: Patients ≥18 years diagnosed with OSA in 2018 and 2019, without previous history of PAP usage and with adherence registration in the first medical consultation after treatment initiation, were included. EDS was defined as a score of ≥10 on the Epworth Scale. Patients were divided into two groups according to the adherence to PAP: "Adherent" if using the device for ≥4 h for ≥70% of the nights and "Nonadherent" otherwise. Simple and multiple logistic regression models for adherence were determined. RESULTS: 321 patients were included, most male (64.2%), with mean age 56.56 years. Most patients had severe OSA (n = 159; 49.5%), and median AHI was 29.3/h [16.8; 47.5]. Being older or having a severe OSA resulted in an increased adherence (OR = 1.020, CI95% = [1.002; 1.039] and OR = 2.299, CI95% = [1.273; 4.191], respectively). In patients without EDS a statistically significant difference was found in adherence between those with severe OSA and both mild and moderate OSA categories (OR = 0.285, p = 0.023 and OR = 0.387, p = 0.026, respectively), with patients with severe OSA being adherent. There was no statistical difference in adherence between patients with or without EDS (OR 1.083; p = 0.876), nor in the different degrees of severity in those with EDS. CONCLUSION: In our study there were no differences in PAP therapy adherence between patients with or without excessive daytime sleepiness. Older age and higher OSA severity resulted in higher adherence rates.
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Trastornos de Somnolencia Excesiva , Apnea Obstructiva del Sueño , Humanos , Masculino , Persona de Mediana Edad , Trastornos de Somnolencia Excesiva/terapia , Trastornos de Somnolencia Excesiva/diagnóstico , Polisomnografía , Cumplimiento y Adherencia al Tratamiento , Cooperación del PacienteRESUMEN
Triboelectric nanogenerators (TENGs) are associated with several drawbacks that limit their application in the biomedical field, including toxicity, thrombogenicity, and poor performance in the presence of fluids. By proposing the use of a hemo/biocompatible hydrogel, poly(2-hydroxyethyl methacrylate) (pHEMA), this study bypasses these barriers. In contact-separation mode, using polytetrafluoroethylene (PTFE) as a reference, pHEMA generates an output of 100.0 V, under an open circuit, 4.7 µA, and 0.68 W/m2 for an internal resistance of 10 MΩ. Our findings unveil that graphene oxide (GO) can be used to tune pHEMA's triboelectric properties in a concentration-dependent manner. At the lowest measured concentration (0.2% GO), the generated outputs increase to 194.5 V, 5.3 µA, and 1.28 W/m2 due to the observed increase in pHEMA's surface roughness, which expands the contact area. Triboelectric performance starts to decrease as GO concentration increases, plateauing at 11% volumetric, where the output is 51 V, 1.76 µA, and 0.17 W/m2 less than pHEMA's. Increases in internal resistance, from 14 ΩM to greater than 470 ΩM, ζ-potential, from -7.3 to -0.4 mV, and open-circuit characteristic charge decay periods, from 90 to 120 ms, are all observed in conjunction with this phenomenon, which points to GO function as an electron trapping site in pHEMA's matrix. All of the composites can charge a 10 µF capacitor in 200 s, producing a voltage between 0.25 and 3.5 V and allowing the operation of at least 20 LEDs. The triboelectric output was largely steady throughout the 3.33 h durability test. Voltage decreases by 38% due to contact-separation frequency, whereas current increases by 77%. In terms of pressure, it appears to have little effect on voltage but boosts current output by 42%. Finally, pHEMA and pHEMA/GO extracts were cytocompatible toward fibroblasts. According to these results, pHEMA has a significant potential to function as a biomaterial to create bio/hemocompatible TENGs and GO to precisely control its triboelectric outputs.
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Electrónica Médica , Hidrogeles , Electrones , Polihidroxietil MetacrilatoRESUMEN
A low blood glucose level (less than 55 mg/dL) associated with autonomic and neuroglycopenic signs and symptoms that resolve after glucose administration establishes Whipple's triad, indicating the presence of a hypoglycemic disorder. Insulinoma remains the most common cause of endogenous hyperinsulinemia. We present the case of a 73-year-old male who was brought to the emergency department after losing consciousness. On initial assessment, severe hypoglycemia was identified and treated. No abnormalities were detected on the physical examination, initial blood tests, abdominal ultrasound and computed tomography (CT) thorax, and abdomen and pelvis. The patient had another episode of symptomatic hypoglycemia, and the blood tests performed were compatible with endogenous hyperinsulinism. The patient was started on diazoxide to prevent further hypoglycemia episodes. Magnetic resonance imaging (MRI) showed a nodular area in the cephalic region of the pancreas, and the patient was discharged with diazoxide and flash glucose monitoring. In the follow-up appointment, he presented with signs and symptoms of congestive heart failure. Endoscopic ultrasound was requested, but the patient was at high risk for complications while undergoing the procedure under anesthesia due to congestive heart failure. A 68Gallium-DOTA-NOC positron emission tomography and computed tomography (PET-CT) was requested and confirmed the presence of a nodular area in the cephalic region of the pancreas. He was referred to general surgery for definitive treatment. Insulinoma is still a challenging medical condition. Therefore, management by a multidisciplinary team is essential. This case highlights the impact that side effects of medication used to treat this condition can have. Diazoxide was initiated to stop severe recurrent hypoglycemia; however, the patient developed congestive heart failure and was unable to undergo an endoscopic ultrasound to localize the lesion, resulting in a delay in diagnosis and definitive treatment. Diazoxide is a potent hyperglycemic drug but it can also cause fluid retention, nausea, hypertrichosis, neutropenia, and thrombocytopenia.
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Degradable biomaterials for blood-contacting devices (BCDs) are associated with weak mechanical properties, high molecular weight of the degradation products and poor hemocompatibility. Herein, the inert and biocompatible FDA approved poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel was turned into a degradable material by incorporation of different amounts of a hydrolytically labile crosslinking agent, pentaerythritol tetrakis(3-mercaptopropionate). In situ addition of 1wt.% of oxidized graphene-based materials (GBMs) with different lateral sizes/thicknesses (single-layer graphene oxide and oxidized forms of few-layer graphene materials) was performed to enhance the mechanical properties of hydrogels. An ultimate tensile strength increasing up to 0.2 MPa (293% higher than degradable pHEMA) was obtained using oxidized few-layer graphene with 5 µm lateral size. Moreover, the incorporation of GBMs has demonstrated to simultaneously tune the degradation time, which ranged from 2 to 4 months. Notably, these features were achieved keeping not only the intrinsic properties of inert pHEMA regarding water uptake, wettability and cytocompatibility (short and long term), but also the non-fouling behavior towards human cells, platelets and bacteria. This new pHEMA hydrogel with degradation and biomechanical performance tuned by GBMs, can therefore be envisioned for different applications in tissue engineering, particularly for BCDs where non-fouling character is essential. STATEMENT OF SIGNIFICANCE: Suitable mechanical properties, low molecular weight of the degradation products and hemocompatibility are key features in degradable blood contacting devices (BCDs), and pave the way for significant improvement in the field. In here, a hydrogel with outstanding anti-adhesiveness (pHEMA) provides hemocompatibility, the presence of a degradable crosslinker provides degradability, and incorporation of graphene oxide reestablishes its strength, allowing tuning of both degradation and mechanical properties. Notably, these hydrogels simultaneously provide suitable water uptake, wettability, cytocompatibility (short and long term), no acute inflammatory response, and non-fouling behavior towards endothelial cells, platelets and bacteria. Such results highlight the potential of these hydrogels to be envisioned for applications in tissue engineered BCDs, namely as small diameter vascular grafts.
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Grafito , Hidrogeles , Humanos , Hidrogeles/farmacología , Polihidroxietil Metacrilato , Grafito/farmacología , Células Endoteliales , Materiales Biocompatibles/farmacología , AguaRESUMEN
In silico models of biological systems are usually very complex and rely on a large number of parameters describing physical and biological properties that require validation. As such, parameter space exploration is an essential component of computational model development to fully characterize and validate simulation results. Experimental data may also be used to constrain parameter space (or enable model calibration) to enhance the biological relevance of model parameters. One widely used computational platform in the mathematical biology community is PhysiCell, which provides a standardized approach to agent-based models of biological phenomena at different time and spatial scales. Nonetheless, one limitation of PhysiCell is the lack of a generalized approach for parameter space exploration and calibration that can be run without high-performance computing access. Here, we present PhysiCOOL, an open-source Python library tailored to create standardized calibration and optimization routines for PhysiCell models.
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Cancer cells metabolize glucose through metabolic pathways that differ from those used by healthy and differentiated cells. In particular, tumours have been shown to consume more glucose than their healthy counterparts and to use anaerobic metabolic pathways, even under aerobic conditions. Nevertheless, scientists have still not been able to explain why cancer cells evolved to present an altered metabolism and what evolutionary advantage this might provide them. Experimental and computational models have been increasingly used in recent years to understand some of these biological questions. Multicellular tumour spheroids are effective experimental models as they replicate the initial stages of avascular solid tumour growth. Furthermore, these experiments generate data which can be used to calibrate and validate computational studies that aim to simulate tumour growth. Hybrid models are of particular relevance in this field of research because they model cells as individual agents while also incorporating continuum representations of the substances present in the surrounding microenvironment that may participate in intracellular metabolic networks as concentration or density distributions. Henceforth, in this review, we explore the potential of computational modelling to reveal the role of metabolic reprogramming in tumour growth.
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Biliary ascariasis is rare in non-endemic areas. This infection is associated with severe complications of the biliary tract, which can become a medical emergency. Treatment with oral anthelmintics is often effective, but, in some cases, surgery is required. We describe an unusual case of ultrasound diagnosis of biliary ascariasis in the gallbladder in a patient who, besides residing in a low-prevalence area of the infection, did not present with biliary tract manifestations. We intend to raise awareness of this clinical entity in non-endemic areas, where this diagnosis is not usually considered. A brief review of the subject is also presented.
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The meniscus is characterised by an anisotropic collagen fibre network which is integral to its biomechanical functionality. The engineering of structurally organized meniscal grafts that mimic the anisotropy of the native tissue remains a significant challenge. In this study, inkjet bioprinting was used to deposit a cell-laden bioink into additively manufactured scaffolds of differing architectures to engineer fibrocartilage grafts with user defined collagen architectures. Polymeric scaffolds consisting of guiding fibre networks with varying aspect ratios (1:1; 1:4; 1:16) were produced using either fused deposition modelling (FDM) or melt electrowriting (MEW), resulting in scaffolds with different internal architectures and fibre diameters. Scaffold architecture was found to influence the spatial organization of the collagen network laid down by the jetted cells, with higher aspect ratios (1:4 and 1:16) supporting the formation of structurally anisotropic tissues. The MEW scaffolds supported the development of a fibrocartilaginous tissue with compressive mechanical properties similar to that of native meniscus, while the anisotropic tensile properties of these constructs could be tuned by altering the fibre network aspect ratio. This MEW framework was then used to generate scaffolds with spatially distinct fibre patterns, which in turn supported the development of heterogenous tissues consisting of isotropic and anisotropic collagen networks. Such bioprinted tissues could potentially form the basis of new treatment options for damaged and diseased meniscal tissue. STATEMENT OF SIGNIFICANCE: This study describes a multiple tool biofabrication strategy which enables the engineering of spatially organized fibrocartilage tissues. The architecture of MEW scaffolds can be tailored to not only modulate the directionality of the collagen fibres laid down by cells, but also to tune the anisotropic tensile mechanical properties of the resulting constructs, thereby enabling the engineering of biomimetic meniscal-like tissues. Furthermore, the inherent flexibility of MEW enables the development of zonally defined and potentially patient-specific implants.
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Bioimpresión , Menisco , Humanos , Andamios del Tejido , Ingeniería de Tejidos/métodos , Bioimpresión/métodos , Anisotropía , ColágenoRESUMEN
Mycobacterium marinum is a non-tuberculous mycobacteria present in natural and non-chlorinated bodies of water. It is a known fish pathogen but can also cause human disease. It usually causes cutaneous lesions but in rare cases may originate more invasive diseases with the involvement of deep structures. We describe three cases of patients with cutaneous infection by M. marinum evaluated in a tertiary care center, two with confirmed infection and one with a presumptive diagnosis based on clinical and epidemiological features. A brief bibliographic review of M. marinum infections is then presented to support the theme. We aim to alert one to the difficulties in establishing the correct diagnosis of this infection, emphasize the importance of a high degree of suspicion for its identification, and review the therapeutic management options.