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•Cylindrical scaffolds were designed with CAD and produced using RP.•3D scaffolds were produced with a TCP/AA mixture and functionalized with GO.•GO inclusion led to porous yet stiff ...scaffolds with a controlled swelling profile.•TCP/AA_GO scaffolds promoted calcium deposition and increased the ALP activity.•All scaffolds displayed a biocompatible profile and promoted osteoblast adhesion.
The incidence of fractures and bone-related diseases like osteoporosis has been increasing due to aging of the world’s population. Up to now, grafts and titanium implants have been the principal therapeutic approaches used for bone repair/regeneration. However, these types of treatment have several shortcomings, like limited availability, risk of donor-to-recipient infection and tissue morbidity. To overcome these handicaps, new 3D templates, capable of replicating the features of the native tissue, are currently being developed by researchers from the area of tissue engineering. These 3D constructs are able to provide a temporary matrix on which host cells can adhere, proliferate and differentiate. Herein, 3D cylindrical scaffolds were designed to mimic the natural architecture of hollow bones, and to allow nutrient exchange and bone neovascularization. 3D scaffolds were produced with tricalcium phosphate (TCP)/alginic acid (AA) using a Fab@home 3D printer. Furthermore, graphene oxide (GO) was incorporated into the structure of some scaffolds to further enhance their mechanical properties. The results revealed that the scaffolds incorporating GO displayed greater porosity, without impairing their mechanical properties. These scaffolds also presented a controlled swelling profile, enhanced biomineralization capacity and were able to increase the Alkaline Phosphatase (ALP) activity. Such characteristics make TCP/AA scaffolds functionalized with GO promising 3D constructs for bone tissue engineering applications.
Recent advances on antimicrobial wound dressing: A review Simões, Déborah; Miguel, Sónia P.; Ribeiro, Maximiano P. ...
European journal of pharmaceutics and biopharmaceutics,
June 2018, 2018-Jun, 2018-06-00, 20180601, Letnik:
127
Journal Article
Recenzirano
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Skin and soft tissue infections (SSTIs) have high rates of morbidity and mortality associated. Despite the successful treatment of some SSTIs, those affecting the subcutaneous tissue, ...fascia, or muscle delay the healing process and can lead to life-threatening conditions. Therefore, more effective treatments are required to deal with such pathological situations. Recently, wound dressings loaded with antimicrobial agents emerged as viable options to reduce wound bacterial colonization and infection, in order to improve the healing process. In this review, an overview of the most prominent antibacterial agents incorporated in wound dressings along with their mode of action is provided. Furthermore, the recent advances in the therapeutic approaches used in the clinic and some future perspectives regarding antibacterial wound dressings are also discussed.
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•A novel targeted covalently functionalized nanomaterial was assembled.•The nanostructures showed a high efficiency in Doxorubicin encapsulation.•The nanomaterials produced a ...temperature increase upon NIR laser irradiation.•The nanohybrids displayed a greater uptake by CD44-overexpressing cancer cells.•The nanostructures showed potential for breast cancer chemo-photothermal therapy.
Nanomaterials’ application in cancer therapy has been driven by their ability to encapsulate chemotherapeutic drugs as well as to reach the tumor site. Nevertheless, nanomedicines’ translation has been limited due to their lack of specificity towards cancer cells. Although the nanomaterials’ surface can be coated with targeting ligands, such has been mostly achieved through non-covalent functionalization strategies that are prone to premature detachment. Notwithstanding, cancer cells often establish resistance mechanisms that impair the effect of the loaded drugs. This bottleneck may be addressed by using near-infrared (NIR)-light responsive nanomaterials. The NIR-light triggered hyperthermic effect generated by these nanomaterials can cause irreversible damage to cancer cells or sensitize them to chemotherapeutics’ action. Herein, a novel covalently functionalized targeted NIR-absorbing nanomaterial for cancer chemo-photothermal therapy was developed. For such, dopamine-reduced graphene oxide nanomaterials were covalently bonded with hyaluronic acid, and then loaded with doxorubicin (DOX/HA-DOPA-rGO). The produced nanomaterials showed suitable physicochemical properties, high encapsulation efficiency, and photothermal capacity. The in vitro studies revealed that the nanomaterials are cytocompatible and that display an improved uptake by the CD44-overexpressing breast cancer cells. Importantly, the combination of DOX/HA-DOPA-rGO with NIR light reduced breast cancer cells’ viability to just 23 %, showcasing their potential chemo-photothermal therapy.
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•The bioactive molecules’ delivery into the wound site improves the healing process.•The nanofibers possess attractive properties to act as drug delivery system.•The antimicrobial ...molecules loaded into nanofibers to avoid infections are described.•The bioactive molecules loaded into nanofibers to assist healing process are listed.•The changes induced on nanofibers’ structural/biological properties are overviewed.
Nowadays, despite the intensive research performed in the area of skin tissue engineering, the treatment of skin lesions remains a big challenge for healthcare professionals. In fact, none of the wound dressings currently used in the clinic is capable of re-establishing all the native features of skin. An ideal wound dressing must confer protection to the wound from external microorganisms, chemical, and physical aggressions, as well as promote the healing process by stimulating the cell adhesion, differentiation, and proliferation. In recent years different types of wound dressings (such as films, hydrocolloids, hydrogels, micro/nano fibers) have been developed. Among them, electrospun nanofibrous membranes due to their intrinsic properties like high surface area-to-volume ratio, porosity and structural similarity with the skin extracellular matrix have been regarded as highly promising for wound dressings applications. Additionally, the nanofibers available in these membranes can act as drug delivery systems, which prompted the incorporation of biomolecules within their structure to prevent skin infections as well as improve the healing process. In this review, examples of different bioactive molecules that have been loaded on polymeric nanofibers are presented, highlighting the antibacterial biomolecules (e.g. antibiotics, silver nanoparticles and natural extracts-derived products) and the molecules capable of enhancing the healing process (e.g. growth factors, vitamins, and anti-inflammatory molecules).
The pursuit of effective treatments for metastatic cancer is still one of the most intensive areas of research in the biomedical field. In a not‐so‐distant past, the scientific community has ...witnessed the rise of immunotherapy based on immune checkpoint inhibitors (ICIs). This therapeutic modality intends to abolish immunosuppressive interactions, re‐establishing T cell responses against metastasized cancer cells. Despite the initial enthusiasm, the ICIs were later found to be associated with low clinical therapeutic outcomes and immune‐related side effects. To address these limitations, researchers are exploring the combination of ICIs with nanomaterial‐mediated phototherapies. These nanomaterials can accumulate within the tumor and produce, upon interaction with light, a temperature increase (photothermal therapy) and/or reactive oxygen species (photodynamic therapy), causing damage to cancer cells. Importantly, these photothermal‐photodynamic effects can pave the way for an enhanced ICI‐based immunotherapy by inducing the release of tumor‐associated antigens and danger‐associated molecular patterns, as well as by relieving tumor hypoxia and triggering a pro‐inflammatory response. This progress report analyses the potential of nanomaterial‐mediated photothermal‐photodynamic therapy in combination with ICIs, focusing on their ability to modulate T cell populations leading to an anti‐metastatic abscopal effect and on their capacity to generate immune memory that prevents tumor recurrence.
Nanomaterial‐mediated photothermal‐photodynamic therapy can trigger several effects (e.g., release of tumor‐associated antigens and danger‐associated molecular patterns) that enhance the outcome of cancer immunotherapy. The nanomaterial photo‐triggered effects synergize with the action of immune checkpoint inhibitors (e.g., IDO1 inhibitors, Anti‐PD‐1/PD‐L1, and Anti‐CTLA‐4 antibodies), leading to an anti‐metastatic abscopal effect and creation of immune memory.
A Review of Obstructive Sleep Apnea Detection Approaches Mendonca, Fabio; Mostafa, Sheikh Shanawaz; Ravelo-Garcia, Antonio G. ...
IEEE journal of biomedical and health informatics,
2019-March, 2019-03-00, 2019-3-00, 20190301, Letnik:
23, Številka:
2
Journal Article
Recenzirano
Sleep disorders are a common health condition that can affect numerous aspects of life. Obstructive sleep apnea is one of the most common disorders and is characterized by a reduction or cessation of ...airflow during sleep. In many countries, this disorder is usually diagnosed in sleep laboratories, by polysomnography, which is an expensive procedure involving much effort for the patient. Multiple systems have been proposed to address this situation, including performing the examination and analysis in the patient's home, using sensors to detect physiological signals that are automatically analyzed by algorithms. However, the precision of these devices is usually not enough to provide clinical diagnosis. Therefore, the objective of this review is to analyze already existing algorithms that have not been implemented on hardware but have had their performance verified by at least one experiment that aims to detect obstructive sleep apnea to predict trends. The performance of different algorithms and methods for apnea detection through the use of different sensors (pulse oximetry, electrocardiogram, respiration, sound, and combined approaches) has been evaluated. 84 original research articles published from 2003 to 2017 with the potential to be promising diagnostic tools have been selected to cover multiple solutions. This paper could provide valuable information for those researchers who want to carry out a hardware implementation of potential signal processing algorithms.
Sleep apnea is a sleep related disorder that significantly affects the population. Polysomnography, the gold standard, is expensive, inaccessible, uncomfortable and an expert technician is needed to ...score. Numerous researchers have proposed and implemented automatic scoring processes to address these issues, based on fewer sensors and automatic classification algorithms. Deep learning is gaining higher interest due to database availability, newly developed techniques, the possibility of producing machine created features and higher computing power that allows the algorithms to achieve better performance than the shallow classifiers. Therefore, the sleep apnea research has currently gained significant interest in deep learning. The goal of this work is to analyze the published research in the last decade, providing an answer to the research questions such as how to implement the different deep networks, what kind of pre-processing or feature extraction is needed, and the advantages and disadvantages of different kinds of networks. The employed signals, sensors, databases and implementation challenges were also considered. A systematic search was conducted on five indexing services from 2008-2018. A total of 255 papers were found and 21 were selected by considering the inclusion and exclusion criteria, using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach.
Sleep related disorders can severely disturb the quality of sleep. Among these disorders, obstructive sleep apnea (OSA) is highly prevalent and commonly undiagnosed. Polysomnography is considered to ...be the gold standard exam for OSA diagnosis. Even though this multi-parametric test provides highly accurate results, it is time consuming, labor-intensive, and expensive. A non-invasive and easy to self-assemble home monitoring device was developed to address these issues. The device can perform the OSA diagnosis at the patient's home and a specialized technician is not required to supervise the process. An automatic scoring algorithm was developed to examine the blood oxygen saturation signal for a minute-by-minute OSA assessment. It was performed by analyzing statistical and frequency-based features that were fed to a classifier. Afterward, the ratio of the number of minutes classified as OSA to the time in bed in minutes was compared with a threshold for the global (subject-based) OSA diagnosis. The average accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve for the minute-by-minute assessment were, respectively, 88%, 80%, 91%, and 0.86. The subject-based accuracy was 95%. The performance is in the same range as the best state of the art methods for the models based only on the blood oxygen saturation analysis. Therefore, the developed model has the potential to be employed in clinical analysis.
One of the most common sleep-related disorders is obstructive sleep apnea, characterized by a reduction of airflow while breathing during sleep and cause significant health problems. This disorder is ...mainly diagnosed in sleep labs with polysomnography, involving high costs and stress for the patient. To address this situation multiple systems have been proposed to conduct the examination and analysis in the patient's home, using sensors to detect physiological signals that are examined by algorithms. The objective of this research is to review publications that show the performance of different devices for ambulatory diagnosis of sleep apnea. Commercial systems that were examined by an independent research group and validated research projects were selected. In total 117 articles were analysed, including a total of 50 commercial devices. Each article was evaluated according to diagnostic elements, level of automatisation implemented and the deducted level of evidence and quality rating. Each device was categorized using the SCOPER categorization system, including an additional proposed category, and a final comparison was performed to determine the sensors that provided the best results.
Listeria monocytogenes is a ubiquitous food-borne pathogen, and its presence in food or production facilities highlights the importance of surveillance. Increased understanding of the surface exposed ...antigens on Listeria would provide potential diagnostic and therapeutic targets. In the present work, using mass spectrometry and genetic cloning, we show that fructose-1,6-bisphosphate aldolase (FBA) class II in Listeria species is the antigen target of the previously described mAb-3F8. Western and dot blot assays confirmed that the mAb-3F8 could distinguish all tested Listeria species from close-related bacteria. Localization studies indicated that FBA is present in every fraction of Listeria cells, including supernatant and the cell wall, setting Listeria spp. as one of the few bacteria described to have this protein on their cell surface. Epitope mapping using ORFeome display and a peptide membrane revealed a 14-amino acid peptide as the potential mAb-3F8 epitope. The target epitope in FBA allowed distinguishing Listeria spp. from closely-related bacteria, and was identified as part of the active site in the dimeric enzyme. However, its function in cell surface seems not to be host cell adhesion-related. Western and dot blot assays further demonstrated that mAb-3F8 together with anti-InlA mAb-2D12 could differentiate pathogenic from non-pathogenic Listeria isolated from artificially contaminated cheese. In summary, we report FBA as a novel immunogenic surface target useful for the detection of Listeria genus.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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