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Advanced Biology Aug 2023Regeneration and functional recovery of the damaged nerve are challenging due to the need for effective therapeutic drugs, biomaterials, and approaches. The poor outcome... (Review)
Review
Regeneration and functional recovery of the damaged nerve are challenging due to the need for effective therapeutic drugs, biomaterials, and approaches. The poor outcome of the treatment of nerve injury stems from the incomplete understanding of axonal biology and interactions between neurons and the surrounding environment, such as glial cells and extracellular matrix. Microfluidic devices, in combination with various injury techniques, have been applied to test biological hypotheses in nerve injury and nerve regeneration. The microfluidic devices provide multiple advantages over the in vitro cell culture on a petri dish and in vivo animal models because a specific part of the neuronal environment can be manipulated using physical and chemical interventions. In addition, single-cell behavior and interactions between neurons and glial cells can be visualized and quantified on microfluidic platforms. In this article, current in vitro nerve injury models on a chip that mimics in vivo axonal injuries and the regeneration process of axons are summarized. The microfluidic-based nerve injury models could enhance the understanding of the physiological and pathophysiological mechanisms of nerve tissues and simultaneously serve as powerful drug and biomaterial screening platforms.
Topics: Animals; Axons; Neurons; Microfluidics; Cell Culture Techniques; Trauma, Nervous System; Lab-On-A-Chip Devices
PubMed: 36709421
DOI: 10.1002/adbi.202200227 -
Langmuir : the ACS Journal of Surfaces... Nov 2023Hydrophilicity is a requisite attribute for the 2D cell culture substrate's surface, facilitating cell adhesion and spreading. Conventional poly(dimethylsiloxane) (PDMS)...
Hydrophilicity is a requisite attribute for the 2D cell culture substrate's surface, facilitating cell adhesion and spreading. Conventional poly(dimethylsiloxane) (PDMS) microfluidic chips necessitate protein coatings to enhance hydrophilicity; however, this approach is afflicted by issues of transient efficacy, interference with cell analysis, and high costs. This paper presents a protein-free microfluidic chip, termed a "microfluidic Petri dish-chip (MPD-chip)", integrating PDMS as the cover and a tissue culture-treated (TC-treated) Petri dish as the substrate. Microstructures are hot-embossed onto the Petri dish substrate using a silicon mold. This meticulous replication process serves to establish stable flow field dynamics within the chip. A simplified method for irreversible bonding, utilizing plasma activation and silylation, is proposed for affixing the PDMS cover onto the microstructured Petri dish substrate. The prepared composite chip exhibits remarkable tightness, boasting a notable bond strength of 2825 kPa. Furthermore, the composite microfluidic chip demonstrates the capability to withstand flow velocities of at least 200 μL/min, effectively meeting the required injection standards for both cell suspension and culture medium. SH-SY5Y and HeLa cells are cultured dynamically in the MPD-chip and control groups. Outcomes encompassing normalized cell density, cell adhesion area, and cell viability metrics unequivocally highlight the superiority of the MPD-chip in facilitating long-term two-dimensional (2D) cell cultures.
Topics: Humans; Microfluidics; Microfluidic Analytical Techniques; HeLa Cells; Neuroblastoma; Cell Culture Techniques; Proteins
PubMed: 37906157
DOI: 10.1021/acs.langmuir.3c01982 -
Biomedicines Apr 2024Stroke is a common neurological disorder, the second leading cause of death, and the third leading cause of disability. Unfortunately, the only approved drug for it is... (Review)
Review
Stroke is a common neurological disorder, the second leading cause of death, and the third leading cause of disability. Unfortunately, the only approved drug for it is tissue plasminogen, but the therapeutic window is limited. In this context, preclinical studies are relevant to better dissect the underlying mechanisms of stroke and for the drug screening of potential therapies. Brain organoids could be relevant in this setting. They are derived from pluripotent stem cells or isolated organ progenitors that differentiate to form an organ-like tissue, exhibiting multiple cell types that self-organize to form a structure not unlike the organ in vivo. Brain organoids mimic many key features of early human brain development at molecular, cellular, structural, and functional levels and have emerged as novel model systems that can be used to investigate human brain diseases including stroke. Brain organoids are a promising and powerful tool for ischemic stroke studies; however, there are a few concerns that need to be addressed, including the lack of vascularization and the many cell types that are typically present in the human brain. The aim of this review is to discuss the potential of brain organoids as a novel model system for studying ischemic stroke, highlighting both the advantages and disadvantages in the use of this technology.
PubMed: 38672231
DOI: 10.3390/biomedicines12040877 -
MicroLife 2023On 9-13 July 2023, the 10th FEMS Congress took place in Hamburg, Germany. As part of this major event in European microbiology, the European Academy of Microbiology...
On 9-13 July 2023, the 10th FEMS Congress took place in Hamburg, Germany. As part of this major event in European microbiology, the European Academy of Microbiology (EAM) organized two full sessions. One of these sessions aimed to highlight the research of four recently elected EAM fellows and saw presentations on bacterial group behaviours and development of resistance to antibiotics, as well as on new RNA viruses including bacteriophages and giant viruses of amoebae. The other session included five frontline environmental microbiologists who showcased real-world examples of how human activities have disrupted the balance in microbial ecosystems, not just to assess the current situation but also to explore fresh approaches for coping with external disturbances. Both sessions were very well attended, and no doubt helped to gain the EAM and its fellows more visibility.
PubMed: 38107236
DOI: 10.1093/femsml/uqad045 -
Plants (Basel, Switzerland) Nov 2023Oats () hold immense economic and nutritional value as a versatile crop. They have long been recognized as an exceptional choice for human consumption and animal feed.... (Review)
Review
Oats () hold immense economic and nutritional value as a versatile crop. They have long been recognized as an exceptional choice for human consumption and animal feed. Oats' unique components, including proteins, starches, and β-glucans, have led to its widespread use in various food products such as bread, noodles, flakes, and milk. The popularity of oat milk as a vegan alternative to dairy milk has soared due to the increasing number of vegetarians/vegans and growing environmental awareness. Oat milk offers a sustainable option with reduced greenhouse gas emissions during its production, rendering it an appropriate choice for individuals who are lactose-intolerant or have dairy allergies. To ensure improved adaptability and enhanced nutrition, the development of new oat varieties is crucial, considering factors like cultivation, climate, and growing conditions. Plant cell culture plays a crucial role in both traditional and contemporary breeding methods. In classical breeding, plant cell culture facilitates the rapid production of double haploid plants, which can be employed to accelerate the breeding process. In modern breeding methods, it enables genetic manipulation and precise genome editing at the cellular level. This review delves into the importance of oats and their diverse applications, highlighting the advantages of plant cell culture in both classical and modern breeding methods. Specifically, it provides an overview of plant tissue culture, encompassing genetic transformation, haploid technology, protoplast technology, and genome editing.
PubMed: 37960138
DOI: 10.3390/plants12213782 -
Environmental Science & Technology Aug 2023Microorganisms colonizing the surfaces of microplastics form a plastisphere in the environment, which captures miscellaneous substances. The plastisphere, owning to its... (Review)
Review
Microorganisms colonizing the surfaces of microplastics form a plastisphere in the environment, which captures miscellaneous substances. The plastisphere, owning to its inherently complex nature, may serve as a "Petri dish" for the development and dissemination of antibiotic resistance genes (ARGs), adding a layer of complexity in tackling the global challenge of both microplastics and ARGs. Increasing studies have drawn insights into the extent to which the proliferation of ARGs occurred in the presence of micro/nanoplastics, thereby increasing antimicrobial resistance (AMR). However, a comprehensive review is still lacking in consideration of the current increasingly scattered research focus and results. This review focuses on the spread of ARGs mediated by microplastics, especially on the challenges and perspectives on determining the contribution of microplastics to AMR. The plastisphere accumulates biotic and abiotic materials on the persistent surfaces, which, in turn, offers a preferred environment for gene exchange within and across the boundary of the plastisphere. Microplastics breaking down to smaller sizes, such as nanoscale, can possibly promote the horizontal gene transfer of ARGs as environmental stressors by inducing the overgeneration of reactive oxygen species. Additionally, we also discussed methods, especially quantitatively comparing ARG profiles among different environmental samples in this emerging field and the challenges that multidimensional parameters are in great necessity to systematically determine the antimicrobial dissemination risk in the plastisphere. Finally, based on the biological sequencing data, we offered a framework to assess the AMR risks of micro/nanoplastics and biocolonizable microparticles that leverage multidimensional AMR-associated messages, including the ARGs' abundance, mobility, and potential acquisition by pathogens.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Microplastics; Plastics; Gene Transfer, Horizontal
PubMed: 37578142
DOI: 10.1021/acs.est.3c01128 -
Experimental & Applied Acarology Oct 2023Tetranychus urticae is an important pest worldwide. The auto-dissemination of spores of entomopathogenic fungi from an infected individual to conspecifics may be...
Tetranychus urticae is an important pest worldwide. The auto-dissemination of spores of entomopathogenic fungi from an infected individual to conspecifics may be important for controlling pests that can build high populations. The current study was carried out to determine the auto-dissemination of the entomopathogenic fungus Cordyceps fumosorosea strain PFs-1 (Priority®) between T. urticae females. The study consisted of four experiments. First, the efficacy of entomopathogenic fungus bioassays was assessed in Petri dishes (experiment 1) and on potted bean plants (experiment 2). In the auto-dissemination trials (experiments 3 and 4, in Petri dishes and on potted plants, respectively), contaminated adult females (1-5) were released among uncontaminated females (10 individuals). All experiments were carried out separately, and observations were made on days 3, 5, and 7. In exp. 1, the control was different from Priority on all observation days. In exp. 2, the average number of surviving individuals in the control was significantly higher than in the Priority treatment. In the auto-dissemination experiments, as the number of contaminated individuals increased, the mortality rate of uncontaminated individuals also increased, in exp. 3 (Petri dishes) on all observation days, and in exp. 4 (potted plants) only on days 5 and 7. The median lethal time (LT50) decreased as the number of individuals contaminated with Priority increased in both Petri dish and pot trials. Consequently, the effectiveness of biological control may increase with the occurrence of indirect contamination from infected to uncontaminated individuals.
Topics: Humans; Female; Animals; Tetranychidae; Pest Control, Biological; Cordyceps; Fabaceae
PubMed: 37787901
DOI: 10.1007/s10493-023-00845-9 -
Environmental Science and Pollution... Nov 2023The possibility of using the non-nitrogen-fixing cyanobacterium (Chroococcus sp.) for the reduction of soil nitrate contamination was tested through Petri dish...
The possibility of using the non-nitrogen-fixing cyanobacterium (Chroococcus sp.) for the reduction of soil nitrate contamination was tested through Petri dish experiments. The application of 0.03, 0.05 and 0.08 mg/cm Chroococcus sp. efficiently removed NO-N from the soil through assimilation of nitrate nutrient and promotion of soil denitrification. At the optimal application dose of 0.05 mg/cm, 44.06%, 36.89% and 36.17% of NO-N were removed at initial NO-N concentrations of 60, 90 and 120 mg/kg, respectively. The polysaccharides released by Chroococcus sp. acted as carbon sources for bacterial denitrification and facilitated the reduction of soil salinity, which significantly (p < 0.05) stimulated the growth of denitrifying bacteria (Hyphomicrobium denitrificans and Hyphomicrobium sp.) as well as significantly (p < 0.05) elevated the activities of nitrate reductase and nitrite reductase by 1.07-1.23 and 1.15-1.22 times, respectively. The application of Chroococcus sp. promoted the dominance of Nocardioides maradonensis in soil microbial community, which resulted in elevated phosphatase activity and increased available phosphorus content. The application of Chroococcus sp. positively regulated the growth of soil bacteria belonging to the genera Chitinophaga, Prevotella and Tumebacillus, which may contribute to increased soil fertility through the production of beneficial enzymes such as invertase, urease and catalase. To date, this is the first study verifying the remediation effect of non-nitrogen-fixing cyanobacteria on nitrate-contaminated soil.
Topics: Nitrates; Cyanobacteria; Nitrate Reductase; Nitrite Reductases; Soil; Denitrification
PubMed: 37870669
DOI: 10.1007/s11356-023-30383-1 -
Sensors (Basel, Switzerland) Oct 2023Colony-Forming Unit (CFU) counting is a complex problem without a universal solution in biomedical and food safety domains. A multitude of sophisticated heuristics and...
Colony-Forming Unit (CFU) counting is a complex problem without a universal solution in biomedical and food safety domains. A multitude of sophisticated heuristics and segmentation-driven approaches have been proposed by researchers. However, U-Net remains the most frequently cited and used deep learning method in these domains. The latter approach provides a segmentation output map and requires an additional counting procedure to calculate unique segmented regions and detect microbial colonies. However, due to pixel-based targets, it tends to generate irrelevant artifacts or errant pixels, leading to inaccurate and mixed post-processing results. In response to these challenges, this paper proposes a novel hybrid counting approach, incorporating a multi-loss U-Net reformulation and a post-processing Petri dish localization algorithm. Firstly, a unique innovation lies in the multi-loss U-Net reformulation. An additional loss term is introduced in the bottleneck U-Net layer, focusing on the delivery of an auxiliary signal that indicates where to look for distinct CFUs. Secondly, the novel localization algorithm automatically incorporates an agar plate and its bezel into the CFU counting techniques. Finally, the proposition is further enhanced by the integration of a fully automated solution, which comprises a specially designed uniform Petri dish illumination system and a counting web application. The latter application directly receives images from the camera, processes them, and sends the segmentation results to the user. This feature provides an opportunity to correct the CFU counts, offering a feedback loop that contributes to the continued development of the deep learning model. Through extensive experimentation, the authors of this paper have found that all probed multi-loss U-Net architectures incorporated into the proposed hybrid approach consistently outperformed their single-loss counterparts, as well as other comparable models such as self-normalized density maps and YOLOv6, by at least 1% to 3% in mean absolute and symmetric mean absolute percentage errors. Further significant improvements were also reported through the means of the novel localization algorithm. This reaffirms the effectiveness of the proposed hybrid solution in addressing contemporary challenges of precise in vitro CFU counting.
PubMed: 37837169
DOI: 10.3390/s23198337