Despite the immense need for effective treatment of spinal cord injury (SCI), no successful repair strategy has yet been clinically implemented. Multifunctional biomaterials, based on porcine adipose tissue-derived extracellular matrix (adECM) and reduced graphene oxide (rGO), were recently shown to stimulate in vitro neural stem cell growth and differentiation. Nevertheless, their functional performance in clinically more relevant in vivo conditions remains largely unknown. Before clinical application of these adECM-rGO nanocomposites can be considered, a rigorous assessment of the cytotoxicity and biocompatibility of these biomaterials is required. For instance, xenogeneic adECM scaffolds could still harbour potential immunogenicity following decellularization. In addition, the toxicity of rGO has been studied before, yet often in experimental settings that do not bear relevance to regenerative medicine. Therefore, the present study aimed to assess both the in vitro as well as in vivo safety of adECM and adECM-rGO scaffolds. First, pulmonary, renal and hepato-cytotoxicity as well as macrophage polarization studies showed that scaffolds were benign invitro. Then, a laminectomy was performed at the 10th thoracic vertebra, and scaffolds were implanted directly contacting the spinal cord. For a total duration of 6 weeks, animal welfare was not negatively affected. Histological analysis demonstrated the degradation of adECM scaffolds and subsequent tissue remodeling. Graphene-based scaffolds showed a very limited fibrous encapsulation, while rGO sheets were engulfed by foreign body giant cells. Furthermore, all scaffolds were infiltrated by macrophages, which were largely polarized towards a pro-regenerative phenotype. Lastly, organ-specific histopathology and biochemical analysis of blood did not reveal any adverse effects. In summary, both adECM and adECM-rGO implants were biocompatible upon laminectomy while establishing a pro-regenerative microenvironment, which justifies further research on their therapeutic potential for treatment of SCI.
ViralFlow v1.0 is a computational workflow developed for viral genomic surveillance. Several key changes turned ViralFlow into a general-purpose reference-based genome assembler for all viruses with an available reference genome. New virus-agnostic modules were implemented to further study nucleotide and amino acid mutations. ViralFlow v1.0 runs on a broad range of computational infrastructures, from laptop computers to high-performance computing (HPC) environments, and generates standard and well-formatted outputs suited for both public health reporting and scientific problem-solving. ViralFlow v1.0 is available at: https://viralflow.github.io/index-en.html.
OBJECTIVES: Dental behaviour support (DBS) describes all specific techniques practiced to support patients in their experience of professional oral healthcare. DBS is roughly synonymous with behaviour management, which is an outdated concept. There is no agreed terminology to specify the techniques used to support patients who receive dental care. This lack of specificity may lead to imprecision in describing, understanding, teaching, evaluating and implementing behaviour support techniques in dentistry. Therefore, this e-Delphi study aimed to develop a list of agreed labels and descriptions of DBS techniques used in dentistry and sort them according to underlying principles of behaviour. METHODS: Following a registered protocol, a modified e-Delphi study was applied over two rounds with a final consensus meeting. The threshold of consensus was set a priori at 75%. Agreed techniques were then categorized by four coders, according to behavioural learning theory, to sort techniques according to their mechanism of action. RESULTS: The panel (n = 35) agreed on 42 DBS techniques from a total of 63 candidate labels and descriptions. Complete agreement was achieved regarding all labels and descriptions, while agreement was not achieved regarding distinctiveness for 17 techniques. In exploring underlying principles of learning, it became clear that multiple and differing principles may apply depending on the specific context and procedure in which the technique may be applied. DISCUSSION: Experts agreed on what each DBS technique is, what label to use, and their description, but were less likely to agree on what distinguishes one technique from another. All techniques were describable but not comprehensively categorizable according to principles of learning. While objective consistency was not attained, greater clarity and consistency now exists. The resulting list of agreed terminology marks a significant foundation for future efforts towards understanding DBS techniques in research, education and clinical care.
RATIONALE: Epilepsy is a complex condition and seizures are only one part of this disease. The move from pediatric to adult healthcare system proves difficult for many adolescents with epilepsy and their families. The challenges increase when patients have epilepsies associated with intellectual and/or developmental disabilities, autism spectrum disorder, and motor disorders. Knowledge and system gaps may exist between the two systems, adding to the challenges. The main goal of this study is to understand the perception of patients with epilepsy and their families who were preparing to move from pediatric to adult healthcare system or had already moved. METHODS: A survey was distributed to patients/caregivers of patients with epilepsy through patient support groups in North America and in-person through the 2019 Epilepsy Awareness Day at Disneyland. Patients were required to be 12 years or older at the time of the survey and were divided into two groups: those between 12 and 17 years and those 18 years or older. Caregivers answered on behalf of patients who were unable to respond (e.g., intellectual disability). Major components of the survey included demographics, epilepsy details, quality and access to care received in pediatric and adult years, and questions regarding transition and readiness. RESULTS: Responses were received from 58 patients/caregivers of patients with epilepsy from Canada and the United States. In group A (patients between 12 and 17 years), none of the 17-year-old patients were spoken to about transition. Patients (caregivers) with epilepsy and intellectual and/or developmental disabilities (IDD) had less time to discuss important things during the transition/transfer phase than patients with normal intelligence. Finally, there was a statistically significant difference observed in access to specialty care reported in the adult years, compared to the years in the pediatric system. In the group B (patients 18 years and older) a) 35 % still visit their family doctor for epilepsy related treatment despite the majority being on 2 or more antiseizure medications (ASMs); b) 27 % of patients in this group were still being followed by their pediatric neurologist; c) one patient received care only through visits to the emergency department; d) only 4 % felt that they received clear instructions during transfer of care such as knowing the name of the adult healthcare practitioner and/or the name of the care institution they were being transferred to. CONCLUSIONS: This study highlights the lack of appropriate transition to adult healthcare system (AHCS) amongst an unselected group of patients with epilepsy in Canada and United States. An overwhelming majority of patients followed in the community and in academy centers were simply "transferred" to an adult health practitioner, or they remained under the care of pediatricians. Finally, most patients lack access to significant social and medical support after moving to the AHCS.
Autism Spectrum Disorder , Epilepsy , Humans , Child , Adult , Adolescent , Pilot Projects , Autism Spectrum Disorder/complications , Autism Spectrum Disorder/therapy , Epilepsy/therapy , Delivery of Health Care , Neurologists
Electrospinning has been widely employed to fabricate complex extracellular matrix-like microenvironments for tissue engineering due to its ability to replicate structurally biomimetic micro- and nanotopographic cues. Nevertheless, these nanofibrous structures are typically either confined to bidimensional systems or confined to three-dimensional ones that are unable to provide controlled multiscale patterns. Thus, an electrospinning modality was used in this work to fabricate chondrocyte-laden nanofibrous scaffolds with highly customizable three-dimensional (3D) architectures in an automated manner, with the ultimate goal of recreating a suitable 3D scaffold for articular cartilage tissue engineering. Three distinct architectures were designed and fabricated by combining multiple nanofibrous and chondrocyte-laden hydrogel layers and tested in vitro in a compression bioreactor system. Results demonstrated that it was possible to precisely control the placement and alignment of electrospun polycaprolactone and gelatin nanofibers, generating three unique architectures with distinctive macroscale porosity, water absorption capacity, and mechanical properties. The architecture organized in a lattice-like fashion was highly porous with substantial pore interconnectivity, resulting in a high-water absorption capacity but a poor compression modulus and relatively weaker energy dissipation capacity. The donut-like 3D geometry was the densest, with lower swelling, but the highest compression modulus and improved energy dissipation ability. The third architecture combined a lattice and donut-like fibrous arrangement, exhibiting intermediary behavior in terms of porosity, water absorption, compression modulus, and energy dissipation capacity. The properties of the donut-like 3D architecture demonstrated great potential for articular cartilage tissue engineering, as it mimicked key topographic, chemical, and mechanical characteristics of chondrocytes' surrounding environment. In fact, the combination of these architectural features with a dynamically compressive mechanical stimulus triggered the best in vitro results in terms of viability and biosynthetic production.
Chondrocytes , Nanofibers , Tissue Scaffolds/chemistry , Porosity , Nanofibers/chemistry , Water
Graphene oxide (GO) and reduced graphene oxide (rGO) have been widely used in the field of tissue regeneration and various biomedical applications. In order to use these nanomaterials in organisms, it is imperative to possess an understanding of their impact on different cell types. Due to the potential of these nanomaterials to enter the bloodstream, interact with the endothelium and accumulate within diverse tissues, it is highly relevant to probe them when in contact with the cellular components of the vascular system. Endothelial progenitor cells (EPCs), involved in blood vessel formation, have great potential for tissue engineering and offer great advantages to study the possible angiogenic effects of biomaterials. Vascular endothelial growth factor (VEGF) induces angiogenesis and regulates vascular permeability, mainly activating VEGFR2 on endothelial cells. The effects of GO and two types of reduced GO, obtained after vacuum-assisted thermal treatment for 15 min (rGO15) and 30 min (rGO30), on porcine endothelial progenitor cells (EPCs) functionality were assessed by analyzing the nanomaterial intracellular uptake, reactive oxygen species (ROS) production and VEGFR2 expression by EPCs. The results evidence that short annealing (15 and 30 minutes) at 200 °C of GO resulted in the mitigation of both the increased ROS production and decline in VEGFR2 expression of EPCs upon GO exposure. Interestingly, after 72 hours of exposure to rGO30, VEGFR2 was higher than in the control culture, suggesting an early angiogenic potential of rGO30. The present work reveals that discrete variations in the reduction of GO may significantly affect the response of porcine endothelial progenitor cells.
Endothelial Progenitor Cells , Nanostructures , Animals , Swine , Endothelial Progenitor Cells/metabolism , Reactive Oxygen Species/metabolism , Vascular Endothelial Growth Factor A/metabolism , Nanostructures/toxicity
Graphene oxide (GO) properties make it a promising material for graphene-based applications in areas such as biomedicine, agriculture, and the environment. Thus, its production is expected to increase, reaching hundreds of tons every year. One GO final destination is freshwater bodies, possibly affecting the communities of these systems. To clarify the effect that GO may impose in freshwater communities, a fluvial biofilm scraped from submerged river stones was exposed to a range (0.1 to 20 mg/L) of GO concentrations during 96 h. With this approach, we hypothesized that GO can: (1) cause mechanical damage and morphological changes in cell biofilms; (2) interfere with the absorption of light by biofilms; (3) and generate oxidative stress, causing oxidative damage and inducing biochemical and physiological alterations. Our results showed that GO did not inflict mechanical damage. Instead, a positive effect is proposed, linked to the ability of GO to bind cations and increase the micronutrient availability to biofilms. High concentrations of GO increased photosynthetic pigment (chlorophyll a, b, and c, and carotenoids) content as a strategy to capture the available light more effectively as a response to the shading effect. A significant increase in the enzymatic (SOD and GSTs activity) and low molecular weight (lipids and carotenoids) antioxidant response was observed, that efficiently reduced oxidative stress effects, reducing the level of peroxidation, and preserving membrane integrity. Being complex entities, biofilms are more similar to environmental communities and may provide more accurate information to evaluate the impact of GO in aquatic systems.
Graphite , Graphite/pharmacology , Chlorophyll A/pharmacology , Oxides/pharmacology , Rivers , Biofilms , Carotenoids/pharmacology
Neural tissue-related illnesses have a high incidence and prevalence in society. Despite intensive research efforts to enhance the regeneration of neural cells into functional tissue, effective treatments are still unavailable. Here, a novel therapeutic approach based on vertically aligned carbon nanotube forests (VA-CNT forests) and periodic VA-CNT micropillars produced by thermal chemical vapor deposition is explored. In addition, honeycomb-like and flower-like morphologies are created. Initial viability testing reveals that NE-4C neural stem cells seeded on all morphologies survive and proliferate. In addition, free-standing VA-CNT forests and capillary-driven VA-CNT forests are created, with the latter demonstrating enhanced capacity to stimulate neuritogenesis and network formation under minimal differentiation medium conditions. This is attributed to the interaction between surface roughness and 3D-like morphology that mimics the native extracellular matrix, thus enhancing cellular attachment and communication. These findings provide a new avenue for the construction of electroresponsive scaffolds based on CNTs for neural tissue engineering.
Nanotubes, Carbon , Neural Stem Cells , Nanotubes, Carbon/chemistry , Tissue Engineering , Cell Differentiation
BACKGROUND: In recent decades, considerable advances have been made in the treatment of acute ischemic stroke (IS) and its prevention. However, even after treatment, approximately two-thirds of patients with IS have some degree of disability that requires rehabilitation, along with an increased possibility of developing psychiatric disorders, particularly depression. OBJECTIVE: To determine the predictors of post-stroke depression in a 6-month period in patients with IS. METHOD: Ninety-seven patients with IS without previous depression were included in the study. The study protocol was applied during hospitalization and at 30, 90, and 180 days after hospital discharge. A binary logistic regression was then used. Age, sex, marital status, occupation, education, thrombolysis, National Institute of Health Stroke Scale, modified Rankin scale (mRS) score, Barthel index, and Mini-Mental State Examination score were included as independent variables. RESULTS: Of the 97 patients, 24% of patients developed post-stroke depression. In the longitudinal follow-up, an mRS score of > 0 was the lone significant predictor of depression development (odds ratio = 5.38; 95% confidence interval: 1.25-23.12; p < 0.05). CONCLUSION: Our results showed that in patients without previous depression, functional impairment of any degree has a 5-fold greater chance of leading to depression development in the first 6 months post-stroke as compared to that in patients without functional impairment.
PURPOSE: Polypharmacy in cancer patients is a recognized issue and should be an integral part of comprehensive patient assessment and management. Despite this, a systematic review of concomitant drugs or a search for potential drug-drug interactions (DDIs) is not always performed. Here, we present the results of a medication reconciliation model performed by a multidisciplinary team to identify clinically meaningful potential DDIs (defined by the presence of DDI of major severity or contraindication) in cancer patients undergoing oral antineoplastic drugs. METHODS: From June to December 2022, we performed a non-interventional, prospective, cross-sectional, single-center study of adult cancer patients, initiating or undergoing treatment with oral antineoplastic drugs, referred by their oncologists for therapeutic review regarding potential DDIs. DDIs were assessed by a multidisciplinary team of hospital pharmacists and medical oncologists, through research in three different drug databases as well as in the summary of product characteristics. A report detailing all potential DDIs was created for each request and provided to the patient's medical oncologist for further examination. RESULTS: Overall, 142 patients' medications were reviewed. Regardless of the severity or clinical importance, 70.4% of patients had at least one potential DDI. We found 184 combinations of oral anticancer and regular therapy agents with potential DDIs, 55 of whom were considered of major severity by at least one DDI database. As expected, the number of potential DDIs increased with the number of active substances in regular therapy (p < 0.001), but we did not find an increased relation between age and the total number of potential DDIs (p = 0.109). Thirty-nine (27.5%) patients had at least one clinically meaningful DDI identified. After adjustment through multivariable logistic regression, only the female sex (odds ratio (OR) 3.01, p = 0.029), the number of active comorbidities (OR 0.60, p = 0.029), and the presence of proton pump inhibitors in chronic medication (OR 2.99, p = 0.033) remained as predictors of potential meaningful DDI. CONCLUSION: Although drug interactions are a concern in oncology, a systematic DDI review is rarely conducted in medical oncology consultations. The availability of a medication reconciliation service, carried out by a multidisciplinary team with dedicated time for this task, is an added value for safety enhancement in cancer patients.
A spinal cord injury (SCI) can be caused by unforeseen events such as a fall, a vehicle accident, a gunshot, or a malignant illness, which has a significant impact on the quality of life of the patient. Due to the limited regenerative potential of the central nervous system (CNS), SCI is one of the most daunting medical challenges of modern medicine. Great advances have been made in tissue engineering and regenerative medicine, which include the transition from two-dimensional (2D) to three-dimensional (3D) biomaterials. Combinatory treatments that use 3D scaffolds may significantly enhance the repair and regeneration of functional neural tissue. In an effort to mimic the chemical and physical properties of neural tissue, scientists are researching the development of the ideal scaffold made of synthetic and/or natural polymers. Moreover, in order to restore the architecture and function of neural networks, 3D scaffolds with anisotropic properties that replicate the native longitudinal orientation of spinal cord nerve fibres are being designed. In an effort to determine if scaffold anisotropy is a crucial property for neural tissue regeneration, this review focuses on the most current technological developments relevant to anisotropic scaffolds for SCI. Special consideration is given to the architectural characteristics of scaffolds containing axially oriented fibres, channels, and pores. By analysing neural cell behaviour in vitro and tissue integration and functional recovery in animal models of SCI, the therapeutic efficacy is evaluated for its successes and limitations.
Spinal Cord Injuries , Tissue Scaffolds , Animals , Tissue Scaffolds/chemistry , Anisotropy , Quality of Life , Tissue Engineering/methods , Spinal Cord Injuries/surgery
Enthralling evidence of the potential of graphene-based materials for neural tissue engineering is motivating the development of scaffolds using various structures related to graphene such as graphene oxide (GO) or its reduced form. Here, we investigated a strategy based on reduced graphene oxide (rGO) combined with a decellularized extracellular matrix from adipose tissue (adECM), which is still unexplored for neural repair and regeneration. Scaffolds containing up to 50 wt% rGO relative to adECM were prepared by thermally induced phase separation assisted by carbodiimide (EDC) crosslinking. Using partially reduced GO enables fine-tuning of the structural interaction between rGO and adECM. As the concentration of rGO increased, non-covalent bonding gradually prevailed over EDC-induced covalent conjugation with the adECM. Edge-to-edge aggregation of rGO favours adECM to act as a biomolecular physical crosslinker to rGO, leading to the softening of the scaffolds. The unique biochemistry of adECM allows neural stem cells to adhere and grow. Importantly, high rGO concentrations directly control cell fate by inducing the differentiation of both NE-4C cells and embryonic neural progenitor cells into neurons. Furthermore, primary astrocyte fate is also modulated as increasing rGO boosts the expression of reactivity markers while unaltering the expression of scar-forming ones.
Graphite , Tissue Engineering , Graphite/chemistry , Neurons , Extracellular Matrix/chemistry
One of the established tissue engineering strategies relies on the fabrication of appropriate materials architectures (scaffolds) that mimic the extracellular matrix (ECM) and assist the regeneration of living tissues. Fibrous structures produced by electrospinning have been widely used as reliable ECM templates but their two-dimensional structure restricts, in part, cell infiltration and proliferation. A recent technique called thermally-induced self-agglomeration (TISA) allowed to alleviate this drawback by rearranging the 2D electrospun membranes into highly functional 3D porous-fibrous systems. Following this trend, the present research focused on preparing polycaprolactone/chitosan blends by electrospinning, to then convert them into 3D structures by TISA. By adding different amounts of chitosan, it was possible to accurately modulate the physicochemical properties of the obtained 3D nanofibrous scaffolds, leading to highly porous constructs with distinct morphologic and mechanical features. Viability and proliferation studies using adult human chondrocytes also revealed that the biocompatibility of the scaffolds was not impaired after 28 days of cell culture, highlighting their potential to be included into musculoskeletal tissue engineering applications, particularly cartilage repair.
Chitosan , Nanofibers , Adult , Humans , Tissue Engineering/methods , Tissue Scaffolds/chemistry , Nanofibers/chemistry , Porosity , Polyesters/chemistry
Remineralization of tooth enamel can be achieved by applying a complex of casein phosphopeptides and amorphous calcium phosphate (CPP-ACP). However, the efficacy and optimization of this agent in molar−incisor hypomineralization (MIH) lacks evidence. The purpose of this study is to evaluate the efficacy of CPP-ACP tooth mousse in remineralizing MIH-affected enamel in an optimized 28-day protocol using polarized Raman microscopy and scanning electron microscopy. The protocol was applied to two types of MIH opacities, white and yellow, and compared against sound enamel specimens before and after treatment. Data was analyzed using a one-way ANOVA and LSD post hoc multiple comparisons test (p < 0.05) for the Raman analysis. Hypomineralized enamel showed an improvement of its structure after CPP-ACP supplementation. In addition, Raman spectroscopy results showed a decrease in the depolarization ratio of the symmetric stretching band of phosphate (p < 0.05 for both groups). In conclusion, there was an improvement in mineral density and organization of the hypomineralized enamel after treatment with CPP-ACP tooth mousse.
Remineralization of tooth enamel can be partially achieved by the application of a casein phosphopeptides and amorphous phosphate (CPP-ACP) complex. However, evidence to support its effectiveness in Molar-incisor-hypomineralization (MIH)-affected teeth is scarce. The study's aim is to evaluate the efficacy of CPP-ACP mousse in remineralizing MIH-affected enamel using a Vickers microhardness test. Two groups of enamel opacities of hypomineralized permanent teeth, white (group A) and yellow (group B) lesions (n = 14), went through a 28-day treatment protocol with GC Tooth Mousse. Before and after treatment, microhardness was measured in three different areas of each tooth (hypomineralized, transition, and outside the hypomineralized area). Data were analyzed using parametric and non-parametric tests with a significance of p < 0.05. The mean microhardness values increased in the hypomineralized and transition areas in both groups after the treatment protocol (in group A, 105.38 ± 11.70 to 158.26 ± 37.34; 123.04 ± 22.84 to 156.33 ± 35.70; in group B, 108.63 ± 14.66 to 143.06 ± 22.81; 132.55 ± 20.66 to 146.00 ± 12.88) and the differences pre/post-treatment were statistically significant within each group (p < 0.001 for both groups). Between groups, there was a statistically significant difference in the same areas (hypomineralized: p = 0.003; transition: p = 0.008) with a higher improvement in enamel hardness in group A. Topical application of CPP-ACP showed an increase in the physical strength of the hypomineralized and transition areas of MIH-affected enamel, likely due to an increase in mineral content.
The activation of T helper (Th) lymphocytes is necessary for the adaptive immune response as they contribute to the stimulation of B cells (for the secretion of antibodies) and macrophages (for phagocytosis and destruction of pathogens) and are necessary for cytotoxic T-cell activation to kill infected target cells. For these issues, Th lymphocytes must be converted into Th effector cells after their stimulation through their surface receptors TCR/CD3 (by binding to peptide-major histocompatibility complex localized on antigen-presenting cells) and the CD4 co-receptor. After stimulation, Th cells proliferate and differentiate into subpopulations, like Th1, Th2 or Th17, with different functions during the adaptative immune response. Due to the central role of the activation of Th lymphocytes for an accurate adaptative immune response and considering recent preclinical advances in the use of nanomaterials to enhance T-cell therapy, we evaluated in vitro the effects of graphene oxide (GO) and two types of reduced GO (rGO15 and rGO30) nanostructures on the Th2 lymphocyte cell line SR.D10. This cell line offers the possibility of studying their activation threshold by employing soluble antibodies against TCR/CD3 and against CD4, as well as the simultaneous activation of these two receptors. In the present study, the effects of GO, rGO15 and rGO30 on the activation/proliferation rate of these Th2 lymphocytes have been analyzed by studying cell viability, cell cycle phases, intracellular content of reactive oxygen species (ROS) and cytokine secretion. High lymphocyte viability values were obtained after treatment with these nanostructures, as well as increased proliferation in the presence of rGOs. Moreover, rGO15 treatment decreased the intracellular ROS content of Th2 cells in all stimulated conditions. The analysis of these parameters showed that the presence of these GO and rGO nanostructures did not alter the response of Th2 lymphocytes.
Lymphocyte Activation , Nanostructures , Antibodies , CD4 Antigens/metabolism , Cytokines/metabolism , Graphite , Peptides/metabolism , Reactive Oxygen Species/metabolism , Receptors, Antigen, T-Cell/metabolism , T-Lymphocytes, Helper-Inducer , Th1 Cells , Th17 Cells , Th2 Cells
Along with the development of the next generation of biomedical platforms, the inclusion of graphene-based materials (GBMs) into therapeutics for spinal cord injury (SCI) has potential to nourish topmost neuroprotective and neuroregenerative strategies for enhancing neural structural and physiological recovery. In the context of SCI, contemplated as one of the most convoluted challenges of modern medicine, this review first provides an overview of its characteristics and pathophysiological features. Then, the most relevant ongoing clinical trials targeting SCI, including pharmaceutical, robotics/neuromodulation, and scaffolding approaches, are introduced and discussed in sequence with the most important insights brought by GBMs into each particular topic. The current role of these nanomaterials on restoring the spinal cord microenvironment after injury is critically contextualized, while proposing future concepts and desirable outputs for graphene-based technologies aiming to reach clinical significance for SCI.
Graphite , Spinal Cord Injuries , Spinal Cord Regeneration , Graphite/pharmacology , Graphite/therapeutic use , Humans , Pharmaceutical Preparations , Spinal Cord , Spinal Cord Injuries/drug therapy
Climate change events, such as drought, are increasing and soil bacteria can be severely affected. Moreover, the accumulation of emerging pollutants is expected to rapidly increase, and their impact on soil organisms, their interactions, and the services they provide is poorly known. The use of graphene oxide (GO) has been increasing due to its enormous potential for application in several areas and it is expected that concentration in soil will increase in the future, potentially causing disturbances in soil microorganisms not yet identified.Here we show the effects that GO nanosheets can cause on soil bacteria, in particular those that promote plant growth, in control and 10% polyethylene glycol (PEG) conditions. Low concentrations of GO nanosheets did not affect the growth of Rhizobium strain E20-8, but under osmotic stress (PEG) GO decreased bacterial growth even at lower concentrations. GO caused oxidative stress, with antioxidant mechanisms being induced to restrain damage, effectively at lower concentrations, but less effective at higher concentrations, and oxidative damage overcame. Under osmotic stress, alginate and glycine betaine osmoregulated the bacteria. Simultaneous exposure to PEG and GO induced oxidative damage. Plant growth promotion traits (indole acetic acid and siderophores production) were increased by osmotic stress and GO did not disturb these abilities. In the context of climate change, our findings might be relevant as they can form the premises for the implementation of crop production methodologies adapted to the new prevailing conditions, which include the presence of nanoparticles in the soil and more frequent and severe drought.
Rhizobium , Rhizobium/metabolism , Osmotic Pressure , Antioxidants/metabolism , Soil , Plant Roots/metabolism , Bacteria/metabolism , Oxidative Stress
The world population growth and average life expectancy rise have increased the number of people suffering from non-communicable diseases, namely osteoarthritis, a disorder that causes a significant increase in the years lived with disability. Many people who suffer from osteoarthritis undergo replacement surgery. Despite the relatively high success rate, around 10% of patients require revision surgeries, mostly because existing implant technologies lack sensing devices capable of monitoring the bone-implant interface. Among the several monitoring methodologies already proposed as substitutes for traditional imaging methods, cosurface capacitive sensing systems hold the potential to monitor the bone-implant fixation states, a mandatory capability for long-term implant survival. A multifaceted study is offered here, which covers research on the following points: (1) the ability of a cosurface capacitor network to effectively monitor bone loosening in extended peri-implant regions and according to different stimulation frequencies; (2) the ability of these capacitive architectures to provide effective sensing in interfaces with hydroxyapatite-based layers; (3) the ability to control the operation of cosurface capacitive networks using extracorporeal informatic systems. In vitro tests were performed using a web-based network sensor composed of striped and interdigitated capacitive sensors. Hydroxyapatite-based layers have a minor effect on determining the fixation states; the effective operation of a sensor network-based solution communicating through a web server hosted on Raspberry Pi was shown. Previous studies highlight the inability of current bone-implant fixation monitoring methods to significantly reduce the number of revision surgeries, as well as promising results of capacitive sensing systems to monitor micro-scale and macro-scale bone-interface states. In this study, we found that extracorporeal informatic systems enable continuous patient monitoring using cosurface capacitive networks with or without hydroxyapatite-based layers. Findings presented here represent significant advancements toward the design of future multifunctional smart implants.
Durapatite , Osteoarthritis , Bone Transplantation/methods , Humans , Prostheses and Implants , Reoperation/methods
