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Malignant pleural effusion (MPE) has become an increasingly prevalent complication in oncological patients, negatively impacting their quality of life and casting a shadow over their prognosis. Owing to the pathophysiological mechanisms involved and the heterogeneous nature of the underlying disease, this entity is both a diagnostic and therapeutic challenge. Advances in the understanding of MPE have led to a shift in the treatment paradigm towards a more personalized approach. This article provides a comprehensive review and update on the pathophysiology of MPE and describes the diagnostic tools and the latest advances in the treatment of this complex clinical entity.
El derrame pleural maligno (DPM) se ha convertido en una complicación cada vez más prevalente en los pacientes oncológicos, empeorando la calidad de vida y ensombreciendo el pronóstico de los mismos. Debido a los mecanismos fisiopatológicos involucrados y a la naturaleza heterogénea de la enfermedad subyacente, esta entidad representa un desafío diagnóstico y terapéutico. Los avances en la comprensión del DPM han originado un cambio en el paradigma del tratamiento hacia un enfoque más personalizado. Este artículo proporciona una revisión exhaustiva y una actualización sobre la fisiopatología del DPM, y describe las herramientas diagnósticas y los últimos avances en el tratamiento de esta compleja entidad clínica.
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This study aims to deepen knowledge of the biodegradation of plastics, focusing on polypropylene (PP) fabric from surgical masks and polystyrene (PS) by larvae of Zophobas atratus as well as of specialized bacterial consortia from their gut, which were obtained in different enrichment conditions (aerobic, anaerobic, presence or absence of combined nitrogen). Plastics ingested by larvae obtained in Spain did not show any signs of oxidation but only limited depolymerization, preferably from the lowest molecular weight chains. Gut microbiota composition changed as an effect of plastic feeding. Such differences were more evident in bacterial enrichment cultures, where the polymer type influenced the composition more than by culture conditions, with an increase in the presence of nitrogen-fixers in anaerobic conditions. PS and PP degradation by different enrichment cultures was confirmed under aerobic and anaerobic conditions by respirometry tests, with anaerobic conditions favouring a more active plastic degradation. In addition, exposure to selected bacterial consortia in aerobiosis induced limited surface oxidation of PS. This possibly indicates that different biochemical routes are being utilized in the anaerobic gut and in aerobic conditions to degrade the polymer.
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The microbial compositions from concurrent peri-implant and periodontal lesions were compared, since the results reported in the literature on the etiological relationship between these oral pathologies are contradictory. Microbial compositions from nine patients were evaluated using Illumina MiSeq sequencing of 16S rRNA gene amplicons and Principal Components Analysis. Comparisons between the use of curettes or paper points as collection methods and between bacterial composition in both pathologies were performed. Paper points allowed the recovery of a higher number of bacterial genera. A higher bacterial diversity was found in peri-implantitis compared to periodontal samples from the same patient, while a greater number of operational taxonomic units (OTUs) were present in the corresponding periodontal samples. A higher abundance of oral pathogens, such as Porphyromonas or Treponema, was found in peri-implantitis sites. The opposite trend was observed for Aggregatibacter abundance, which was higher in periodontal than in peri-implantitis lesions, suggesting that both oral pathologies could be considered different but related diseases. Although the analysis of a higher number of samples would be needed, the differences regarding the microbial composition provide a basis for further understating the pathogenesis of peri-implant infections.
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AIM: Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the treatment of choice for colorectal cancer (CRC) in inflammatory bowel disease. CRC may also be discovered incidentally at IPAA for other indications. We sought to determine whether incidentally found CRC at IPAA was associated with worse outcomes. METHODS: Our institutional pouch registry (1983-2021) was retrospectively reviewed. Patients with CRC at pathology after IPAA were divided into two groups: a preoperative diagnosis (PreD) group and an incidental diagnosis (InD) group. Their long-term outcomes (overall survival, disease-free survival and pouch survival) were compared. RESULTS: We included 164 patients: 53 (32%) InD and 111 (68%) PreD. There were no differences in cancer staging, differentiation and location. After a median follow-up of 11 (IQR 3-25) years for InD and 9 (IQR 3-20) years for the PreD group, deaths were 14 (26%) in the InD group and 18 (16%) in the PreD group. Pouch failures were five (9%) in the InD group and nine (8%) in the PreD group, of which two (5%) and four (4%) were cancer related. Ten-year overall survival was 94% for InD and 89% for PreD (P = 0.41), disease-free survival was 95% for InD and 90% for PreD (P = 0.685) and pouch survival was 89% for InD and 97% for PreD (P = 0.80). Pouch survival at 10 years was lower in rectal versus colon cancer (87% vs. 97%, P = 0.01). No difference was found in outcomes in handsewn versus stapled anastomoses. CONCLUSION: Inflammatory bowel disease patients with incidentally found CRC during IPAA appear to have similarly excellent oncological and pouch outcomes to patients with a preoperative cancer diagnosis.
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Bolsas Cólicas , Neoplasias Colorretais , Achados Incidentais , Doenças Inflamatórias Intestinais , Proctocolectomia Restauradora , Humanos , Proctocolectomia Restauradora/efeitos adversos , Proctocolectomia Restauradora/métodos , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/patologia , Doenças Inflamatórias Intestinais/cirurgia , Doenças Inflamatórias Intestinais/complicações , Bolsas Cólicas/efeitos adversos , Resultado do Tratamento , Intervalo Livre de Doença , Período Pré-Operatório , Sistema de RegistrosRESUMO
The emergence of convergent Klebsiella pneumoniae strains showing multiresistance, characteristic of nosocomial pathotypes and hypervirulent traits typical of community-acquired isolates, makes them important models for studying K. pneumoniae pathogenesis. Here, we describe the convergent, multidrug-resistant KLEB-33 strain harboring several hypervirulence genes and make its genome available to the scientific community.
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Given the increasing incidence of multidrug-resistant (MDR) Klebsiella pneumoniae infections, it is of great interest to investigate the risk of transmission associated with the prevalence of this pathogen. Some studies have described fresh raw poultry meat as a reservoir of MDR K. pneumoniae, including clinically relevant sequence types (ST) and extended-spectrum ß-lactamase (ESBL) strains, indicating possible consumer exposure. This study compared 47 MDR strains of K. pneumoniae from poultry meat and human clinical isolates to assess similarities, including analysis of antimicrobial resistance profiles and virulence factors involved in infection. In addition, several biofilm culture methods were evaluated for reproducible assessment of biofilm formation in K. pneumoniae strains. Globally, no association between strain origin and STs, hypermucoviscosity, biofilm formation or serum resistance could be found between isolates of food and clinical origin, nor an associated AMR pattern, suggesting overlapping populations. We found that LB supplemented with glucose in microaerobiosis was the best discrimination condition for biofilm formation in the active attachment biofilm cultivation model. The biofilm formation capacity was strongly dependent on culture conditions, with a strain-specific response, but only a minor increase in biofilm levels was recorded in clinical K. pneumoniae populations. Our results suggest that a similar risk of zoonosis transmission from potentially virulent foodborne strains previously observed in E. coli is also present in this high-priority pathogen. This study further confirms that foodborne isolates of K. pneumoniae pose a risk to consumers and therefore this pathogen should be included in the surveillance of foodborne pathogens with high risk of MDR infections and therapeutic failure.
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Escherichia coli , Infecções por Klebsiella , Animais , Humanos , Klebsiella pneumoniae , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Zoonoses , Biofilmes , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , beta-Lactamases , Testes de Sensibilidade MicrobianaRESUMO
INTRODUCTION: The implementation of Information and Communication Technology (ICT) in daily healthcare practice has become standardized. In relation to education within the nursing degree, ICTs make it possible to carry out practical immersion training from the" classroom or from any other place with an Internet connection, as evidenced by circumstances that have occurred in recent years, such as the pandemic caused by COVID-19. OBJECTIVE: Design and assess a didactic simulation program for the training of the nursing process that promotes learning in the nursing care METHODOLOGY: The methodological approach is quantitative and it is a descriptive cross-sectional study. The sampling method used was non-probabilistic by convenience. RESULTS: When observing the comparison of the averages of student satisfaction with respect to the didactic simulator, it is worth mentioning that all the items are above 2.80 on a score in which "0" is the minimum value and "5" the maximum value. The results of the use of the computer tool by the students, we highlight as significant data that all the items present an average equal to or lower than 3.04 out of 7, where "1" corresponds to a lot of use and "7" to little use. CONCLUSION: The implication of ICT in the teaching-learning process among Nursing Degree students, it is considered optimal. when analyzing the answers obtained in the items that refer to a higher ease in the execution of development of Care plans, a fundamental work in Nursing performance.
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BACKGROUND: Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer. In cases of invisible or nonendoscopically resectable dysplasia found at colonoscopy, total proctocolectomy with ileal pouch anal anastomosis can be offered with good long-term outcomes; however, little is known regarding cancer-related outcomes when dysplasia is found incidentally after surgery on final pathology. METHODS: Using our prospectively collected pouch registry, we identified patients who had preoperative colonic dysplasia or dysplasia found only after colectomy. Patients with cancer preoperatively or after colectomy were excluded. Included patients were divided into 3 groups: PRE (+preoperative biopsy, negative final pathology), BOTH (+preoperative biopsy and final pathology), and POST (negative preoperative biopsy, +final pathology). Long-term outcomes in the 3 groups were assessed. RESULTS: In total, 517 patients were included: PREâ =â 125, BOTHâ =â 254, POSTâ =â 137. After a median follow-up of 12 years (IQR 3-21), there were no differences in overall, disease-free, or pouch survival between groups. Cancer/dysplasia developed in 11 patients: 3 (2%) in the PRE, 5 (2%) in the BOTH, and 3 (2%) in the POST group. Only 1 cancer-related death occurred in the entire cohort (PRE group). Disease-free survival at 10 years was 98% for all groups (P = .97). Pouch survival at 10 years was 96% for PRE, 99% for BOTH, and 97% for POST (P = .24). CONCLUSIONS: The incidental finding of dysplasia on final pathology after proctocolectomy was not associated with worsened outcomes compared with preoperatively diagnosed dysplasia.
In this study on 517 patients with inflammatory bowel disease who underwent total colectomy with ileal pouch-anal anastomosis with a finding of dysplasia in their colectomy specimen, outcomes were comparable regardless of known dysplasia vs incidental finding.
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Quorum quenching (QQ) is the inhibition of bacterial communication, i.e., quorum sensing (QS). QS is a key mechanism in regulating biofilm formation and phenotype in complex bacterial communities, such as those found within cariogenic biofilms. Whereas QQ approaches were shown to effectively reduce biomass, knowledge of their impact on the taxonomic composition of oral polymicrobial biofilms remains scarce. Here, we investigate the effect of the QQ lactonase Aii20J on biomass production and taxonomical composition of biofilms. We collected supragingival plaque samples from 10 caries-free and 10 caries-active children and cultured them to generate in vitro biofilms. We describe significant biomass reductions upon Aii20J exposure, as assessed by crystal violet assays. Taxonomical profiling using 16S rRNA gene amplicon sequencing revealed no significant changes in bacterial composition at the genus level. Interestingly, at the species level Aii20J-treatment increased the abundance of Streptococcus cristatus and Streptococcus salivarius. Both S. cristatus and S. salivarius express pH-buffering enzymes (arginine deiminase and urease, respectively) that catalyze ammonia production, thereby potentially raising local pH and counteracting the biofilm's cariogenic potential. Within the limitations of the study, our findings provide evidence of the biofilm-modulating ability of QQ and offer novel insights into alternative strategies to restore homeostasis within dysbiotic ecosystems.
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Education in the XXI century is called to move forward in the right direction and to gain momentum to face diverse challenges and take opportunities offered by the knowledge that is inherent in society. Therefore, it can be postulated that there must be a close relationship between learning, the generation of knowledge, continuous innovation and the use of new technologies. This is a cross-sectional descriptive study conducted among a sample of 242 first year and second year Cadiz University nursing students, using the validated Learning and Study Strategies Inventory questionnaire to assess motivation and the Relationship between Learning Styles and Information and Communication Technologies questionnaire to assess knowledge, use and attitude. The predominant profile type of nursing degree students was women under 21 years old, who were single and exclusively dedicated to their studies. In addition, they showed positive motivation in relation to learning while facing adversity (between 76% and 76.6%). Regarding the level of knowledge, use and attitude towards ICTs, most of the considered items presented high values. For some questions, age was proven to be a sociodemographic variable that influenced both the motivation and attitude of the students. The level of knowledge, use and attitude that students have regarding ICTs are good when we refer to communication technologies, interpersonal relationships or basic programs. However, they are low when considering programs related to education or learning.
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Prognostic scales may help to optimize the use of hospital resources, which may be of prime interest in the context of a fast spreading pandemics. Nonetheless, such tools are underdeveloped in the context of COVID-19. In the present article we asked whether accurate prognostic scales could be developed to optimize the use of hospital resources. We retrospectively studied 467 files of hospitalized patients after COVID-19. The odds ratios for 16 different biomarkers were calculated, those that were significantly associated were screened by a Pearson's correlation, and such index was used to establish the mathematical function for each marker. The scales to predict the need for hospitalization, intensive-care requirement and mortality had enhanced sensitivities (0.91 CI 0.87-0.94; 0.96 CI 0.94-0.98; 0.96 CI 0.94-0.98; all with p < 0.0001) and specificities (0.74 CI 0.62-0.83; 0.92 CI 0.87-0.96 and 0.91 CI 0.86-0.94; all with p < 0.0001). Interestingly, when a different population was assayed, these parameters did not change considerably. These results show a novel approach to establish the mathematical function of a marker in the development of highly sensitive prognostic tools, which in this case, may aid in the optimization of hospital resources. An online version of the three algorithms can be found at: http://benepachuca.no-ip.org/covid/index.php.
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COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Estudos Retrospectivos , Unidades de Terapia Intensiva , Hospitalização , Cuidados Críticos , Biomarcadores , ProbabilidadeRESUMO
Escherichia coli is the main cause of urinary tract infections (UTI). While genomic comparison of specific clones recovered from animals, and human extraintestinal infections show high identity, studies demonstrating the uropathogenicity are lacking. In this study, comparative genomics combined with bladder-cell and biofilm formation assays, were performed for 31 E. coli of different origins: 7 from meat (poultry, beef, and pork); 2 from avian-farm environment; 12 from human uncomplicated UTI, uUTI; and 10 from human complicated UTI, cUTI. These isolates were selected based on their genetic uropathogenic (UPEC) status and phylogenetic background. In silico analysis revealed similar virulence-gene profiles, with flagella, type 1 and curli fimbriae, outer-membrane proteins (agn43, ompT, iha), and iron-uptake (iutA, entA, and fyuA) associated-traits as the most prevalent (>65%). In bladder-cell assays, moderate to strong values of association (83%, 60%, 77.8%) and invasion (0%, 70%, 55.5%) were exhibited by uUTI, cUTI, and animal-derived isolates, respectively. Of interest, uUTI isolates exhibited a significantly lower invasive capacity than cUTI isolates (p < 0.05). All isolates but one produced measurable biofilm. Notably, 1 turkey meat isolate O11:H6-F-ST457, and 2 cUTI isolates of the pandemic lineages O83:H42-F-ST1485-CC648 and O25b:H4-B2-ST131, showed strong association, invasion and biofilm formation. These isolates showed common carriage of type 1 fimbriae and csg operons, toxins (hlyF, tsh), iron uptake systems (iutA, entA, iroN), colicins, protectins (cvaC, iss, kpsM, traT), ompT, and malX. In summary, the similar in vitro behaviour found here for certain E. coli clones of animal origin would further reinforce the role of food-producing animals as a potential source of UPEC. Bladder-cell infection assays, combined with genomics, might be an alternative to in vivo virulence models to assess uropathogenicity.
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Acyl-homoserine lactones (AHLs) are typical quorum-sensing molecules of gram-negative bacteria. Recent evidence suggests that AHLs may also affect gram-positives, although knowledge of these interactions remains scarce. Here, we assessed the effect of AHLs on biofilm formation and transcriptional regulations in the gram-positive Enterococcus faecalis. Five E. faecalis strains were investigated herein. Crystal violet was employed to quantify the biomass formed, and confocal microscopy in combination with SYTO9/PI allowed the visualisation of biofilms' structure. The differential expression of 10 genes involved in quorum-sensing, biofilm formation and stress responses was evaluated using reverse-transcription-qPCR. The AHL exposure significantly increased biofilm production in strain ATCC 29212 and two isolates from infected dental roots, UmID4 and UmID5. In strains ATCC 29212 and UmID7, AHLs up-regulated the quorum-sensing genes (fsrC, cylA), the adhesins ace, efaA and asa1, together with the glycosyltransferase epaQ. In strain UmID7, AHL exposure additionally up-regulated two membrane-stress response genes (σV, groEL) associated with increased stress-tolerance and virulence. Altogether, our results demonstrate that AHLs promote biofilm formation and up-regulate a transcriptional network involved in virulence and stress tolerance in several E. faecalis strains. These data provide yet-unreported insights into E. faecalis biofilm responses to AHLs, a family of molecules long-considered the monopole of gram-negative signalling.
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Introduction: Recent studies have revealed the presence of N-acyl-homoserine lactones (AHLs) quorum sensing (QS) signals in the oral environment. Yet, their role in oral biofilm development remains scarcely investigated. The use of quorum quenching (QQ) strategies targeting AHLs has been described as efficient for the control of pathogenic biofilms. Here, we evaluate the use of a highly active AHL-targeting QQ enzyme, Aii20J, to modulate oral biofilm formation in vitro. Methods: The effect of the QQ enzyme was studied in in vitro multispecies biofilms generated from oral samples taken from healthy donors and patients with periodontal disease. Subgingival samples were used as inocula, aiming to select members of the microbiota of the periodontal pocket niche in the in vitro biofilms. Biofilm formation abilities and microbial composition were studied upon treating the biofilms with the QQ enzyme Aii20J. Results and Discussion: The addition of the enzyme resulted in significant biofilm mass reductions in 30 - 60% of the subgingival-derived biofilms, although standard AHLs could not be found in the supernatants of the cultured biofilms. Changes in biofilm mass were not accompanied by significant alterations of bacterial relative abundance at the genus level. The investigation of 125 oral supragingival metagenomes and a synthetic subgingival metagenome revealed a surprisingly high abundance and broad distribution of homologous of the AHL synthase HdtS and several protein families of AHL receptors, as well as an enormous presence of QQ enzymes, pointing to the existence of an intricate signaling network in oral biofilms that has been so far unreported, and should be further investigated. Together, our findings support the use of Aii20J to modulate polymicrobial biofilm formation without changing the microbiome structure of the biofilm. Results in this study suggest that AHLs or AHL-like molecules affect oral biofilm formation, encouraging the application of QQ strategies for oral health improvement, and reinforcing the importance of personalized approaches to oral biofilm control.
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Doenças Periodontais , Percepção de Quorum , Humanos , Biofilmes , Bactérias/metabolismo , Acil-Butirolactonas/metabolismoRESUMO
Nearly 90% of fungal diversity, one of the most speciose branches in the tree of life, remains undescribed. Lichenized fungi as symbiotic associations are still a challenge for species delimitation, and current species diversity is vastly underestimated. The ongoing democratization of Next-Generation Sequencing is turning the tables. Particularly, reference-based RADseq allows for metagenomic filtering of the symbiont sequence and yields robust phylogenomic trees of closely related species. We implemented reference-based RADseq to disentangle the evolution of neuropogonoid lichens, which inhabit harsh environments and belong to Usnea (Parmeliaceae, Ascomycota), one of the most taxonomically intriguing genera within lichenized fungi. Full taxon coverage of neuropogonoid lichens was sampled for the first time, coupled with phenotype characterizations. More than 20,000 loci of 126 specimens were analyzed through concatenated and coalescent-based methods, including time calibrations. Our analysis addressed the major taxonomic discussions over recent decades. Subsequently, two species are newly described, namely U. aymondiana and U. fibriloides, and three species names are resurrected. The late Miocene and Pliocene-Pleistocene boundary is inferred as the timeframe for neuropogonoid lichen diversification. Ultimately, this study helped fill the gap of fungal diversity by setting a solid backbone phylogeny which raises new questions about which factors may trigger complex evolutionary scenarios.
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Design of advanced contact lenses (CLs) demands materials that are safe and comfortable for the wearers and that preserve the normal eye microbiota, avoiding chronic inflammation and biofilm development. This work aimed to combine the natural antibiofouling phosphorylcholine and the antioxidant and prebiotic resveratrol as integral components of CLs that may have the additional performance of preventing oxidative-stress related eye diseases. Different from previous uses of 2-methacryloyloxyethyl phosphorylcholine (MPC) as coating, we explored the feasibility of adding MPC at high proportions as a comonomer of 2-hydroxyethyl methacrylate (HEMA)-based hydrogels while still allowing for the loading of the hydrophobic resveratrol. Homogeneous distribution of MPC along the hydrogel depth (confirmed by Raman spectroscopy) notably increased solvent uptake and the proportion of free water while it decreased Young's modulus. Relevantly, MPC did not hinder the uptake of resveratrol by CLs (>10 mg/g), which indeed showed network/water partition coefficients of >100. Protocols for CLs sterilization and loading of resveratrol under aseptic conditions were implemented, and the effects of tear proteins on resveratrol release rate were investigated. CLs sustained resveratrol release for more than 24 h in vitro, and sorption of albumin onto the hydrogel, although attenuated by MPC, slowed down the release. The combination of MPC and resveratrol reduced P. aeruginosa and S. aureus growth as tested in a novel hydrogel disk-agar interface biofilm growth setup. The developed CLs showed excellent anti-inflammatory properties and biocompatibility in in ovo and rabbit tests and provided higher and more prolonged levels of resveratrol in tear fluid, which favored resveratrol biodistribution in anterior and posterior eye segments compared to eye drops. Correlations between the release profiles of resveratrol in vitro and in vivo were assessed. Relevantly, the CLs preserved the antioxidant properties of resveratrol during the entire 8 h of wearing. In sum, CLs prepared with high proportion in MPC may help address safety and comfort requirements while having drug releasing capabilities.
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Anti-Infecciosos , Lentes de Contato , Animais , Coelhos , Antioxidantes/farmacologia , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/química , Resveratrol/farmacologia , Fosforilcolina/química , Staphylococcus aureus , Distribuição Tecidual , Hidrogéis/farmacologia , Hidrogéis/química , ÁguaRESUMO
Carvacrol is a natural low-cost compound derived from oregano which presents anti-bacterial properties against both Gram-positive and Gram-negative bacteria. In this work, carvacrol-loaded PLA scaffolds were fabricated by 3D printing as platforms to support bone tissue regeneration while preventing biofilm development. Scaffolds were printed with or without a perimeter (lateral wall) mimicking the cortical structure of bone tissue to further evaluate if the lateral interconnectivity could affect the biological or antimicrobial properties of the scaffolds. Carvacrol incorporation was performed by loading either the PLA filament prior to 3D printing or the already printed PLA scaffold. The loading method determined carvacrol localization in the scaffolds and its release profile. Biphasic profiles were recorded in all cases, but scaffolds loaded post-printed released carvacrol much faster, with 50-80% released in the first day, compared to those containing carvacrol in PLA filament before printing which sustained the release for several weeks. The presence or absence of the perimeter did not affect the release rate, but total amount released. Tissue integration and vascularization of carvacrol-loaded scaffolds were evaluated in a chorioallantoic membrane model (CAM) using a novel quantitative micro-computed tomography (micro-CT) analysis approach. The obtained results confirmed the CAM tissue ingrowth and new vessel formation within the porous structure of the scaffolds after 7 days of incubation, without leading to hemorrhagic or cytotoxic effects. The absence of lateral wall facilitated lateral integration of the scaffolds in the host tissue, although increased the anisotropy of the mechanical properties. Scaffolds loaded with carvacrol post-printing showed antibiofilm activity against Staphylococcus aureus and Pseudomonas aeruginosa as observed in a decrease in CFU counting after biofilm detachment, changes in metabolic heat measured by calorimetry, and increased contact killing efficiency. In summary, this work demonstrated the feasibility of tuning carvacrol release rate and the amount released from PLA scaffolds to achieve antibiofilm protection without altering angiogenesis, which was mostly dependent on the perimeter density of the scaffolds.
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Engenharia Tecidual , Alicerces Teciduais , Alicerces Teciduais/química , Engenharia Tecidual/métodos , Poliésteres/química , Antibacterianos/farmacologia , Microtomografia por Raio-X , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Impressão Tridimensional , BiofilmesRESUMO
Ocular health may strongly benefit from the supply of antioxidant agents that counteract free radicals and reactive oxygen species responsible for long-term eye diseases. Additionally, natural antioxidants like resveratrol can inhibit bacteria growth and restore natural microbiota. However, their use is hindered by limited solubility, fast degradation, and low ocular permeability. This work aimed to overcome these limitations by preparing single and mixed micelles of Pluronic® F127 and casein that serve as resveratrol nanocarriers. Single and mixed (0.1 % casein) micelles (0.0 to -17.0 mV; 2.4 to 32.7 nm) increased 50-fold resveratrol solubility, remained stable for one month at 4 °C, withstood fast dilution, underwent sol-to-gel transitions in the 23.9-27.1 °C range, and exhibited potent antioxidant properties. All formulations successfully passed the HET-CAM assay but showed Pluronic®-casein dose-dependent toxicity in the zebrafish embryo model. Resveratrol-loaded single and mixed micelles (10-15 mM Pluronic® F127) displayed antimicrobial activity against S. aureus and P. aeruginosa. The micelles favored resveratrol accumulation in cornea and sclera, but mixed micelles showed larger lag times and provided lower amount of resveratrol permeated through sclera. In vivo (rabbit) tests confirmed the safety of resveratrol-loaded single micelles and their capability to supply resveratrol to anterior and posterior eye segments.
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Micelas , Poloxâmero , Animais , Coelhos , Poloxâmero/metabolismo , Resveratrol , Caseínas/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Staphylococcus aureus , Peixe-Zebra , Córnea/metabolismo , Sistemas de Liberação de Medicamentos , Portadores de Fármacos/metabolismoRESUMO
Increasing antibiotic resistance and the decline in the pharmaceutical industry's investments have amplified the need for novel treatments for multidrug-resistant bacteria. Quorum sensing (QS) inhibitors reduce pathogens' virulence without selective pressure on bacteria and provide an alternative to conventional antibiotic-based therapies. P. aeruginosa uses complex QS signaling to control virulence and biofilm formation. We aimed to identify inhibitors of P. aeruginosa QS acting on acyl-homoserine lactones (AHL)-mediated circuits. Bioluminescence and qRT-PCR assays were employed to screen a library of 81 small phenolic derivatives to reduce AHL-dependent signaling. We identified GM-50 as the most active compound inhibiting the expression of AHL-regulated genes but devoid of cytotoxic activity in human epithelial cells and biocidal effects on bacteria. GM-50 reduces virulence factors such as rhamnolipids, pyocyanin, elastase secretion, and swarming motility in P. aeruginosa PAO1 laboratory strain. By molecular docking, we provide evidence that GM-50 highly interacts with RhlR. GM-50 significantly improved aztreonam-mediated biofilm disruption. Moreover, GM-50 prevents adhesion of PAO1 and inflammatory damage in the human A549 cell line and protects Galleria mellonella from PAO1-mediated killing. GM-50 significantly reduces virulence factors in 20 P. aeruginosa clinical isolates from patients with respiratory tract infections. In conclusion, GM-50 inhibits AHL-signaling, reduces virulence factors, enhances the anti-biofilm activity of aztreonam, and protects G. mellonella larvae from damage induced by P. aeruginosa. Since GM-50 is active on clinical strains, it represents a starting point for identifying and developing new phenolic derivatives acting as QS-inhibitors in P. aeruginosa infections.