Figueroa-Pizano María Dolores, Campa-Mada Alma Consuelo, Canett-Romero Rafael, Paz-Samaniego Rita, Martínez-López Ana Luisa, Carvajal-Millan Elizabeth
Several studies have described the health benefits of arabinoxylan as prebiotics; however, other authors have related them with an anti-nutrient effect as arabinoxylan increases the viscosity of the alimentary bolus. In this work, the impact of arabinoxylan and crosslinked arabinoxylan on blood serum lipids and glucose levels of Wistar rats was investigated. Arabinoxylan was extracted from maize bran, presented a Fourier Transform Infra-Red spectrum typical for this polysaccharide, and a molecular weight of 250 kDa. Arabinoxylan solution at 4% (w/v) formed covalent gels induced by laccase. Male Wistar rats were fed a standard diet supplemented with 5% (w/w) lyophilized arabinoxylan or crosslinked arabinoxylan. Blood glucose levels were determined, collecting a drop of blood from the tail vein of rats at 0, 2, and 10 h after food consumption. Total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol were also determined. Postprandial blood glucose of the treatment groups was maintained at the same level as the control group. The serum lipid profile levels also remained close to the control group, excepting total cholesterol and LDL-cholesterol, which were higher in crosslinked arabinoxylan treatment but in the range reported for this murine model. The obtained results revealed that consumption of arabinoxylan and crosslinked arabinoxylan at moderated levels does not interfere with the absorption of these nutrients.
{"title":"Influence of arabinoxylan and crosslinked arabinoxylan consumption on blood serum lipids and glucose levels of Wistar rats","authors":"Figueroa-Pizano María Dolores, Campa-Mada Alma Consuelo, Canett-Romero Rafael, Paz-Samaniego Rita, Martínez-López Ana Luisa, Carvajal-Millan Elizabeth","doi":"10.3934/bioeng.2021018","DOIUrl":"https://doi.org/10.3934/bioeng.2021018","url":null,"abstract":"Several studies have described the health benefits of arabinoxylan as prebiotics; however, other authors have related them with an anti-nutrient effect as arabinoxylan increases the viscosity of the alimentary bolus. In this work, the impact of arabinoxylan and crosslinked arabinoxylan on blood serum lipids and glucose levels of Wistar rats was investigated. Arabinoxylan was extracted from maize bran, presented a Fourier Transform Infra-Red spectrum typical for this polysaccharide, and a molecular weight of 250 kDa. Arabinoxylan solution at 4% (w/v) formed covalent gels induced by laccase. Male Wistar rats were fed a standard diet supplemented with 5% (w/w) lyophilized arabinoxylan or crosslinked arabinoxylan. Blood glucose levels were determined, collecting a drop of blood from the tail vein of rats at 0, 2, and 10 h after food consumption. Total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol were also determined. Postprandial blood glucose of the treatment groups was maintained at the same level as the control group. The serum lipid profile levels also remained close to the control group, excepting total cholesterol and LDL-cholesterol, which were higher in crosslinked arabinoxylan treatment but in the range reported for this murine model. The obtained results revealed that consumption of arabinoxylan and crosslinked arabinoxylan at moderated levels does not interfere with the absorption of these nutrients.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"78 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83929307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Oshinubi, Augustina C. Amakor, O. J. Peter, Mustapha Rachdi, J. Demongeot
This article focuses on the application of deep learning and spectral analysis to epidemiology time series data, which has recently piqued the interest of some researchers. The COVID-19 virus is still mutating, particularly the delta and omicron variants, which are known for their high level of contagiousness, but policymakers and governments are resolute in combating the pandemic's spread through a recent massive vaccination campaign of their population. We used extreme machine learning (ELM), multilayer perceptron (MLP), long short-term neural network (LSTM), gated recurrent unit (GRU), convolution neural network (CNN) and deep neural network (DNN) methods on time series data from the start of the pandemic in France, Russia, Turkey, India, United states of America (USA), Brazil and United Kingdom (UK) until September 3, 2021 to predict the daily new cases and daily deaths at different waves of the pandemic in countries considered while using root mean square error (RMSE) and relative root mean square error (rRMSE) to measure the performance of these methods. We used the spectral analysis method to convert time (days) to frequency in order to analyze the peaks of frequency and periodicity of the time series data. We also forecasted the future pandemic evolution by using ELM, MLP, and spectral analysis. Moreover, MLP achieved best performance for both daily new cases and deaths based on the evaluation metrics used. Furthermore, we discovered that errors for daily deaths are much lower than those for daily new cases. While the performance of models varies, prediction and forecasting during the period of vaccination and recent cases confirm the pandemic's prevalence level in the countries under consideration. Finally, some of the peaks observed in the time series data correspond with the proven pattern of weekly peaks that is unique to the COVID-19 time series data.
{"title":"Approach to COVID-19 time series data using deep learning and spectral analysis methods","authors":"K. Oshinubi, Augustina C. Amakor, O. J. Peter, Mustapha Rachdi, J. Demongeot","doi":"10.3934/bioeng.2022001","DOIUrl":"https://doi.org/10.3934/bioeng.2022001","url":null,"abstract":"This article focuses on the application of deep learning and spectral analysis to epidemiology time series data, which has recently piqued the interest of some researchers. The COVID-19 virus is still mutating, particularly the delta and omicron variants, which are known for their high level of contagiousness, but policymakers and governments are resolute in combating the pandemic's spread through a recent massive vaccination campaign of their population. We used extreme machine learning (ELM), multilayer perceptron (MLP), long short-term neural network (LSTM), gated recurrent unit (GRU), convolution neural network (CNN) and deep neural network (DNN) methods on time series data from the start of the pandemic in France, Russia, Turkey, India, United states of America (USA), Brazil and United Kingdom (UK) until September 3, 2021 to predict the daily new cases and daily deaths at different waves of the pandemic in countries considered while using root mean square error (RMSE) and relative root mean square error (rRMSE) to measure the performance of these methods. We used the spectral analysis method to convert time (days) to frequency in order to analyze the peaks of frequency and periodicity of the time series data. We also forecasted the future pandemic evolution by using ELM, MLP, and spectral analysis. Moreover, MLP achieved best performance for both daily new cases and deaths based on the evaluation metrics used. Furthermore, we discovered that errors for daily deaths are much lower than those for daily new cases. While the performance of models varies, prediction and forecasting during the period of vaccination and recent cases confirm the pandemic's prevalence level in the countries under consideration. Finally, some of the peaks observed in the time series data correspond with the proven pattern of weekly peaks that is unique to the COVID-19 time series data.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"83 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79360740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nucleases currently used in genome engineering induce hydrolysis of DNA phosphate backbone in a sequence-specific manner. The RNA guided nucleases describe today are recognizing a sequence with two distinct molecular interactions: first, like a restriction endonuclease, by direct interaction between the protein and the DNA; and second, by hybridization of the guide RNA with the target DNA sequence. Here we report an in vitro assay to assess the cleavage specificity and the selectivity of the nucleases. The assay is designed using a plasmid encompassing the DNA target site degenerated at positions determined on structural feature. The results demonstrate that the Cpf1 RNA guided nuclease is highly specific for the target sequence, nevertheless its substrate selectivity is low compare to a restriction endonuclease.
{"title":"In vitro analysis of site specific nuclease selectivity by NGS","authors":"V. Brondani","doi":"10.3934/bioeng.2021020","DOIUrl":"https://doi.org/10.3934/bioeng.2021020","url":null,"abstract":"Nucleases currently used in genome engineering induce hydrolysis of DNA phosphate backbone in a sequence-specific manner. The RNA guided nucleases describe today are recognizing a sequence with two distinct molecular interactions: first, like a restriction endonuclease, by direct interaction between the protein and the DNA; and second, by hybridization of the guide RNA with the target DNA sequence. Here we report an in vitro assay to assess the cleavage specificity and the selectivity of the nucleases. The assay is designed using a plasmid encompassing the DNA target site degenerated at positions determined on structural feature. The results demonstrate that the Cpf1 RNA guided nuclease is highly specific for the target sequence, nevertheless its substrate selectivity is low compare to a restriction endonuclease.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"21 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73383270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cong Toai Truong, K. H. Huynh, V. T. Duong, Huy Hung Nguyen, L. Pham, T. Nguyen
Ventilators are drawn to many researchers during the Covid-19 pandemic because it's essential equipment that's accustomed to treat severe Covid-19 patients. In low-income countries, there's a shortage of pricy respiratory devices resulting in exceeding the provision of taking care of Covid-19's patients in ICU. This paper attempts to design and implement an appropriate respiratory device referred to as a bag valve mask (BVM) ventilator for those who are Covid-19 patients in medical care, those patients have a requirement of safe transport and also palliative care. The BVM ventilator comprises a man-made manual breath unit (AMBU) bag and paddles for squeezing the AMBU bag which is popular in medical aid settings. The BVM ventilator is required to travel airflow through the system to the patient's lung with the specified volume for every breath cycle within a threshold air pressure. Since the AMBU bag is straightforward to be deformed over time, it's difficult to get mathematical modelling for constructing a reliable controller. Therefore, a model-free control (MFC) control approach is utilized successfully to style a controller for our BVM ventilator model with a PEEP valve and a HEPA filter. Some experimental scenarios are administered to gauge the effectiveness of the proposed controller for the BVM ventilator to control the airflow and control air pressure mode.
{"title":"Model-free volume and pressure cycled control of automatic bag valve mask ventilator","authors":"Cong Toai Truong, K. H. Huynh, V. T. Duong, Huy Hung Nguyen, L. Pham, T. Nguyen","doi":"10.3934/bioeng.2021017","DOIUrl":"https://doi.org/10.3934/bioeng.2021017","url":null,"abstract":"Ventilators are drawn to many researchers during the Covid-19 pandemic because it's essential equipment that's accustomed to treat severe Covid-19 patients. In low-income countries, there's a shortage of pricy respiratory devices resulting in exceeding the provision of taking care of Covid-19's patients in ICU. This paper attempts to design and implement an appropriate respiratory device referred to as a bag valve mask (BVM) ventilator for those who are Covid-19 patients in medical care, those patients have a requirement of safe transport and also palliative care. The BVM ventilator comprises a man-made manual breath unit (AMBU) bag and paddles for squeezing the AMBU bag which is popular in medical aid settings. The BVM ventilator is required to travel airflow through the system to the patient's lung with the specified volume for every breath cycle within a threshold air pressure. Since the AMBU bag is straightforward to be deformed over time, it's difficult to get mathematical modelling for constructing a reliable controller. Therefore, a model-free control (MFC) control approach is utilized successfully to style a controller for our BVM ventilator model with a PEEP valve and a HEPA filter. Some experimental scenarios are administered to gauge the effectiveness of the proposed controller for the BVM ventilator to control the airflow and control air pressure mode.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"62 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79521702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mayra A. Mendez-Encinas, D. E. Valencia-Rivera, E. Carvajal‐Millan, H. Astiazarán-García, A. Rascón-Chu, F. Brown‐Bojorquez
Arabinoxylans (AX) are gelling polysaccharides with potential applications as colon-targeted biomaterials. Nevertheless, the fermentation of highly cross-linked AX particles (AXP) by colonic bacteria and the effect of its fermentation supernatants on the proliferation of human colon cancer cells have not been investigated so far. In this study, electrosprayed AXP were fermented by Bifidobacterium longum , Bifidobacterium adolescentis , and Bacteroides ovatus . The effect of AXP fermentation supernatant (AXP-fs) on the inhibition of the human colon cancer cell line Caco-2 proliferation was investigated. AXP presented a mean diameter of 533 µm, a spherical shape, and a cross-linking content (dimers and trimers of ferulic acid) of 1.65 µg/mg polysaccharide. After 48 h of bacteria exposure, AXP were only partly fermented, probably due to polymeric network steric hindrance that limits the access of bacterial enzymes to the polysaccharide target sites. AXP partial fermentation was evidenced by a moderate short-chain fatty acid production (SCFA) (23 mM) and a collapsed and disintegrated microstructure revealed by scanning electron microscopy. AXP-fs exerted slight inhibition of Caco-2 cell proliferation (11%), which could be attributed to the SCFA generated during partly polysaccharide fermentation. These findings indicate that electrosprayed AXP are a slow-fermentable biomaterial presenting slight anti-cancer properties and potential application in colon cancer prevention.
{"title":"Electrosprayed highly cross-linked arabinoxylan particles: effect of partly fermentation on the inhibition of Caco-2 cells proliferation","authors":"Mayra A. Mendez-Encinas, D. E. Valencia-Rivera, E. Carvajal‐Millan, H. Astiazarán-García, A. Rascón-Chu, F. Brown‐Bojorquez","doi":"10.3934/BIOENG.2021006","DOIUrl":"https://doi.org/10.3934/BIOENG.2021006","url":null,"abstract":"Arabinoxylans (AX) are gelling polysaccharides with potential applications as colon-targeted biomaterials. Nevertheless, the fermentation of highly cross-linked AX particles (AXP) by colonic bacteria and the effect of its fermentation supernatants on the proliferation of human colon cancer cells have not been investigated so far. In this study, electrosprayed AXP were fermented by Bifidobacterium longum , Bifidobacterium adolescentis , and Bacteroides ovatus . The effect of AXP fermentation supernatant (AXP-fs) on the inhibition of the human colon cancer cell line Caco-2 proliferation was investigated. AXP presented a mean diameter of 533 µm, a spherical shape, and a cross-linking content (dimers and trimers of ferulic acid) of 1.65 µg/mg polysaccharide. After 48 h of bacteria exposure, AXP were only partly fermented, probably due to polymeric network steric hindrance that limits the access of bacterial enzymes to the polysaccharide target sites. AXP partial fermentation was evidenced by a moderate short-chain fatty acid production (SCFA) (23 mM) and a collapsed and disintegrated microstructure revealed by scanning electron microscopy. AXP-fs exerted slight inhibition of Caco-2 cell proliferation (11%), which could be attributed to the SCFA generated during partly polysaccharide fermentation. These findings indicate that electrosprayed AXP are a slow-fermentable biomaterial presenting slight anti-cancer properties and potential application in colon cancer prevention.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2020-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78031505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Júlia Novaes Matias, G. Campanari, Gabriela Achete de Souza, Vinícius Marinho Lima, R. J. Tofano, C. Detregiachi, S. Barbalho
At the end of last year, a new strain of coronavirus emerged in China, which was called SARS-CoV-2. The virus quickly spread throughout the world, reaching pandemic proportions, and is now considered a worldwide public health emergency. In line with this, several studies aimed to postulate and elucidate possible risk factors involved not only in the genesis of coronavirus disease 2019 (COVID-19) but also in the susceptibility and severity of the condition. Among the most reported elements in patients with a more critical clinical scenario and adverse outcomes is metabolic syndrome (MS), a condition consisting of chronic diseases such as obesity, type 2 diabetes mellitus, dyslipidemia, and systemic arterial hypertension. In this light, this work aims to build a descriptive review of the relationship between the factors inherent to MS and COVID-19, in order to better clarify the mechanisms belonging to this association. Resistance to the action of insulin caused by centripetal obesity is permeated by an environment abundant in pro-inflammatory cytokines, which favors the immune imbalance, leading to the modulation of dysfunctional and inefficient responses. Besides, it is important to mention the overlapping of inflammatory secretory patterns of MS with the cytokine storm of COVID-19, leading to a worse prognosis. SARS-CoV-2 and arterial hypertension share pathways through a common enzyme: ACE2, widely expressed in the respiratory epithelium and belonging to the pressure regulation cascade. However, dyslipidemia promotes higher morbidity and mortality through increased cardiovascular risk due to thrombotic events. In short, MS represents a critical element to be considered through association with COVID-19, since it interferes in greater severity and mortality through several factors.
{"title":"Metabolic syndrome and COVID-19","authors":"Júlia Novaes Matias, G. Campanari, Gabriela Achete de Souza, Vinícius Marinho Lima, R. J. Tofano, C. Detregiachi, S. Barbalho","doi":"10.3934/bioeng.2020021","DOIUrl":"https://doi.org/10.3934/bioeng.2020021","url":null,"abstract":"At the end of last year, a new strain of coronavirus emerged in China, which was called SARS-CoV-2. The virus quickly spread throughout the world, reaching pandemic proportions, and is now considered a worldwide public health emergency. In line with this, several studies aimed to postulate and elucidate possible risk factors involved not only in the genesis of coronavirus disease 2019 (COVID-19) but also in the susceptibility and severity of the condition. Among the most reported elements in patients with a more critical clinical scenario and adverse outcomes is metabolic syndrome (MS), a condition consisting of chronic diseases such as obesity, type 2 diabetes mellitus, dyslipidemia, and systemic arterial hypertension. In this light, this work aims to build a descriptive review of the relationship between the factors inherent to MS and COVID-19, in order to better clarify the mechanisms belonging to this association. Resistance to the action of insulin caused by centripetal obesity is permeated by an environment abundant in pro-inflammatory cytokines, which favors the immune imbalance, leading to the modulation of dysfunctional and inefficient responses. Besides, it is important to mention the overlapping of inflammatory secretory patterns of MS with the cytokine storm of COVID-19, leading to a worse prognosis. SARS-CoV-2 and arterial hypertension share pathways through a common enzyme: ACE2, widely expressed in the respiratory epithelium and belonging to the pressure regulation cascade. However, dyslipidemia promotes higher morbidity and mortality through increased cardiovascular risk due to thrombotic events. In short, MS represents a critical element to be considered through association with COVID-19, since it interferes in greater severity and mortality through several factors.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"57 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2020-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86951917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thi Thuy An Nguyen, Le Thanh Huyen Trinh, Hoang Bao Vy Pham, Tri Vien Le, T. H. Phung, Suk-ha Lee, J. Cheong
Drought stress memory in plant can alter their physiological, biochemical and molecular to a subsequent stress. An experiment was conducted to determine biochemical parameters of soybean seedlings under drought stress memory. 14-days-old soybean seedlings were subjected to three consecutive water deficit phases (D1, D2, D3), each phase recovered by re-watering (R1, R2, R3), and control plant watering daily (R0). Leave of seedlings from these phases were collected and analyzed. Significantly increasing contents of soluble sugar and proline observed at the first drought stress. After the first re-water and continuous stress phases, these indicator contents decreased and maintained at a relatively stable level. Expression level of two memory genes encoded to transcription factor (NAC09 and NAC109) and one gene encoded enzyme Δ1-pyrroline-5-carboxylate synthetase (P5CS1) were increased in the first stress and decreased in third stress. Our results demonstrate that changing of biochemical parameters of soybean seedlings can be seen as the strong indications of “drought stress memory”. This result may serve as a reference platform to study advanced researches at molecular and genetic levels.
{"title":"Evaluation of proline, soluble sugar and ABA content in soybean Glycine max (L.) under drought stress memory","authors":"Thi Thuy An Nguyen, Le Thanh Huyen Trinh, Hoang Bao Vy Pham, Tri Vien Le, T. H. Phung, Suk-ha Lee, J. Cheong","doi":"10.3934/bioeng.2020011","DOIUrl":"https://doi.org/10.3934/bioeng.2020011","url":null,"abstract":"Drought stress memory in plant can alter their physiological, biochemical and molecular to a subsequent stress. An experiment was conducted to determine biochemical parameters of soybean seedlings under drought stress memory. 14-days-old soybean seedlings were subjected to three consecutive water deficit phases (D1, D2, D3), each phase recovered by re-watering (R1, R2, R3), and control plant watering daily (R0). Leave of seedlings from these phases were collected and analyzed. Significantly increasing contents of soluble sugar and proline observed at the first drought stress. After the first re-water and continuous stress phases, these indicator contents decreased and maintained at a relatively stable level. Expression level of two memory genes encoded to transcription factor (NAC09 and NAC109) and one gene encoded enzyme Δ1-pyrroline-5-carboxylate synthetase (P5CS1) were increased in the first stress and decreased in third stress. Our results demonstrate that changing of biochemical parameters of soybean seedlings can be seen as the strong indications of “drought stress memory”. This result may serve as a reference platform to study advanced researches at molecular and genetic levels.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"38 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2020-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74878968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonathan A. Butler, Lauren Osborne, M. E. Mohtadi, K. Whitehead
Antibiotic resistance in bacteria is developing at a faster rate than new antibiotics can be discovered. This study investigated the antimicrobial activity of several carbon-based derivative compounds alone and in combination with clinically relevant antibiotics against key ESKAPE pathogens Enterococcus faecium, Klebsiella pneumoniae and Escherichia coli. Three compounds, graphite, graphene and graphene oxide, in conjunction with ciprofloxacin (CIP), chloramphenicol (CHL) and piperacillin/tazobactam (TZP) were examined using fractional inhibitory concentration (FIC) testing. CIP combined with graphene demonstrated additive antimicrobial activity against E. faecium compared to individual application. Furthermore, CIP supplemented with graphene, graphene oxide or graphite showed additive activity with ∑FIC values of 1.0 against K. pneumoniae, whereas only TZP showed ∑FIC values <1.0 with graphene oxide. For E. coli, the antibiotic activity of CIP was enhanced with graphene, graphene oxide or graphite, whereas only graphite and graphene enhanced the activity of CHL and TZP respectively. Graphite and graphene oxide caused significant antagonism (∑FIC ˃ 4.0) in conjunction with TZP against E. coli. In conclusion, the results demonstrate the potential to supplement clinically relevant antibiotics with carbon-based graphene, graphene oxide derivative or graphite for use as an additive supplement for novel systemic or topical treatment solutions against key priority pathogens.
{"title":"Graphene derivatives potentiate the activity of antibiotics against Enterococcus faecium, Klebsiella pneumoniae and Escherichia coli","authors":"Jonathan A. Butler, Lauren Osborne, M. E. Mohtadi, K. Whitehead","doi":"10.3934/bioeng.2020010","DOIUrl":"https://doi.org/10.3934/bioeng.2020010","url":null,"abstract":"Antibiotic resistance in bacteria is developing at a faster rate than new antibiotics can be discovered. This study investigated the antimicrobial activity of several carbon-based derivative compounds alone and in combination with clinically relevant antibiotics against key ESKAPE pathogens Enterococcus faecium, Klebsiella pneumoniae and Escherichia coli. Three compounds, graphite, graphene and graphene oxide, in conjunction with ciprofloxacin (CIP), chloramphenicol (CHL) and piperacillin/tazobactam (TZP) were examined using fractional inhibitory concentration (FIC) testing. CIP combined with graphene demonstrated additive antimicrobial activity against E. faecium compared to individual application. Furthermore, CIP supplemented with graphene, graphene oxide or graphite showed additive activity with ∑FIC values of 1.0 against K. pneumoniae, whereas only TZP showed ∑FIC values <1.0 with graphene oxide. For E. coli, the antibiotic activity of CIP was enhanced with graphene, graphene oxide or graphite, whereas only graphite and graphene enhanced the activity of CHL and TZP respectively. Graphite and graphene oxide caused significant antagonism (∑FIC ˃ 4.0) in conjunction with TZP against E. coli. In conclusion, the results demonstrate the potential to supplement clinically relevant antibiotics with carbon-based graphene, graphene oxide derivative or graphite for use as an additive supplement for novel systemic or topical treatment solutions against key priority pathogens.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"41 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2020-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75622397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recombinant proteins have an economical value with their utilization in many areas from food industry to pharmaceutical and chemical industry. Therefore, it is of great importance to establish optimum production systems for the proteins of interest. One of the critical steps in protein production is regulation of the gene expression. Promoters are among the key regulatory elements which can directly control the level of recombinant gene expression in a host cell. Thus, a suitable promoter is required for optimum gene expression. Promoter engineering is an innovative approach to find out the best promoter system for the expression of recombinant genes, which influences the overproduction of proteins of interest. In this review, some of the bacterial hosts highly used in recombinant protein production were discussed. Next, the importance of promoters in recombinant gene expression, and promoter engineering for enhanced protein production were described. Utilization of double promoter systems was highlighted as one of the successful techniques in overproduction of recombinant proteins. Increment in the variety and availability of the novel methodologies especially in the synthetic biology is expected to increase the quality and the quantity of recombinant proteins with an economical value.
{"title":"Promoter engineering for the recombinant protein production in prokaryotic systems","authors":"Ozgun F. Duzenli, S. Okay","doi":"10.3934/bioeng.2020007","DOIUrl":"https://doi.org/10.3934/bioeng.2020007","url":null,"abstract":"Recombinant proteins have an economical value with their utilization in many areas from food industry to pharmaceutical and chemical industry. Therefore, it is of great importance to establish optimum production systems for the proteins of interest. One of the critical steps in protein production is regulation of the gene expression. Promoters are among the key regulatory elements which can directly control the level of recombinant gene expression in a host cell. Thus, a suitable promoter is required for optimum gene expression. Promoter engineering is an innovative approach to find out the best promoter system for the expression of recombinant genes, which influences the overproduction of proteins of interest. In this review, some of the bacterial hosts highly used in recombinant protein production were discussed. Next, the importance of promoters in recombinant gene expression, and promoter engineering for enhanced protein production were described. Utilization of double promoter systems was highlighted as one of the successful techniques in overproduction of recombinant proteins. Increment in the variety and availability of the novel methodologies especially in the synthetic biology is expected to increase the quality and the quantity of recombinant proteins with an economical value.","PeriodicalId":45029,"journal":{"name":"AIMS Bioengineering","volume":"15 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2020-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80091823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01Epub Date: 2020-05-29DOI: 10.3934/bioeng.2020009
Stephen W Sawyer, Kairui Zhang, Jason A Horton, Pranav Soman
In this work, we report on a perfusion-based co-culture system that could be used for bone tissue engineering applications. The model system is created using a combination of Primary Human Umbilical Vein Endothelial Cells (HUVECs) and osteoblast-like Saos-2 cells encapsulated within a Gelatin Methacrylate (GelMA)-collagen hydrogel blend contained within 3D printed, perfusable constructs. The constructs contain dual channels, within a custom-built bioreactor, that were perfused with osteogenic media for up to two weeks in order to induce mineral deposition. Mineral deposition in constructs containing only HUVECs, only Saos-2 cells, or a combination thereof was quantified by microCT to determine if the combination of endothelial cells and bone-like cells increased mineral deposition. Histological and fluorescent staining was used to verify mineral deposition and cellular function both along and between the perfused channels. While there was not a quantifiable difference in the amount of mineral deposited in Saos-2 only versus Saos-2 plus HUVEC samples, the location of the deposited mineral differed dramatically between the groups and indicated that the addition of HUVECs within the GelMA matrix allowed Saos-2 cells, in diffusion limited regions of the construct, to deposit bone mineral. This work serves as a model on how to create perfusable bone tissue engineering constructs using a combination of 3D printing and cellular co-cultures.
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