High-throughput production of liver parenchymal microtissues and enrichment of organ-specific functions in gelatin methacrylamide microenvironment.

Liver parenchymal microtissues (LPMTs) are three-dimensional (3D) aggregates of hepatocytes that recapitulate in vivo-like cellular assembly. They are considered as a valuable model to study drug metabolism, disease biology, and serve as ideal building blocks for liver tissue engineering. However, their integration into the mainstream drug screening process has been hindered due to the lack of simple, rapid techniques to produce a large number of uniform microtissues and preserve their structural-functional integrity over the long term. Here, we present a high-throughput methodology to produce LPMTs in a novel, economic, and reusable Hanging-drop Culture Chamber (HdCC). A drop-on-demand bioprinting approach was optimized to generate droplets of HepG2 cell suspension on a polyethylene terephthalate substrate. The substrates carrying droplets were placed inside a novel HdCC and incubated to obtain 1600 LPMTs having a size of 200-300 µm. Tissue size, cell viability, cellular arrangement and polarity, and insulin-mediated glucose uptake by LPMTs were analyzed. The microtissues were viable and exhibited an active response to insulin stimulation. Cells within the microtissue reorganized to form hepatic plate-like structures and expressed apical (Multidrug Resistance Protein 2 [MRP2]) and epithelial (Zonula Occludens 1 [ZO1]) markers. Further to maintain the structural integrity and enhance the functional capabilities, LPMTs were sandwiched within gelatin methacrylamide (GelMA) hydrogel and the liver-specific functions were monitored for 2 weeks. The results showed that the 3D structure of LPMTs in GelMA sandwich was maintained while the albumin secretion, urea synthesis, and cytochrome P450 activity were enhanced compared with LPMTs in suspension. In conclusion, this study presents a novel culture chamber for mass production of microtissues and a method for enhancing organ-specific functions of LPMTs in vitro.

MicroRNA-200c/429 mediated regulation of Zeb1 augments N-Cadherin in mouse cardiac mesenchymal cells.

Cardiac mesenchymal cells (CMCs) are a promising cell type that showed therapeutic potential in heart failure models. The analysis of the underlying mechanisms by which the CMCs improve cardiac function is on track. This study aimed to investigate the expression of N-Cadherin, a transmembrane protein that enhances cell adhesion, and recently gained attention for differentiation and augmentation of stem cell function. The mouse CMCs were isolated and analyzed for the mesenchymal markers using flow cytometry. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis were used to assess the expression of N-Cadherin along with its counteracting molecule E-Cadherin and their regulator Zeb1 in CMCs and dermal fibroblast. The expression level of miR-200c and miR-429 was analyzed using miRNA assays. Transient transfection of miR-200c followed by qRT-PCR, western blot analysis, and immunostaining was done in CMCs to analyze the expression of Zeb1, N-Cadherin, and E-Cadherin. Flow cytometry analysis showed that CMCs possess mesenchymal markers and absence for hematopoietic and immune cell markers. Increased expression of N-Cadherin and Zeb1 in CMCs was observed in CMCs at both RNA and protein levels compared to fibroblast. We found significant downregulation of miR-200c and miR-429 in CMCs. The ectopic expression of miR-200c in CMCs significantly downregulated Zeb1 and N-Cadherin expression. Our findings suggest that the significant downregulation of miR-200c/429 in CMCs maintains the expression of N-Cadherin, which may be important for its functional integrity.

Genome-wide identification of Ran GTPase family genes from wheat (T. aestivum) and their expression profile during developmental stages and abiotic stress conditions.

Maintenance of growth is important for sustaining yield under stress conditions. Hence, identification of genes involved in cell division and growth under abiotic stress is utmost important. Ras-related nuclear protein (Ran) is a small GTPase required for nucleocytoplasmic transport, mitotic progression, and nuclear envelope assembly in plants. In the present study, two Ran GTPase genes TaRAN1 and TaRAN2 were identified though genome-wide analysis in wheat (T. aestivum). Comparative analysis of Ran GTPases from wheat, barley, rice, maize, sorghum, and Arabidopsis revealed similar gene structure within phylogenetic clades and highly conserved protein structure. Expression analysis from expVIP platform showed ubiquitous expression of TaRAN genes across tissues and developmental stages. Under biotic and abiotic stresses, TaRAN1 expression was largely unaltered, while TaRAN2 showed stress specific response. In qRT-PCR analysis, TaRAN1 showed significantly higher expression as compared to TaRAN2 in shoot and root at seedling, vegetative, and reproductive stages. During progressive drought stress, TaRAN1 and TaRAN2 expression increase during early stress and restored to control level expression at higher stress levels in shoot. The steady-state level of transcripts was maintained to that of control in roots under drought stress. Under cold stress, expression of both the TaRAN genes decreased significantly at 3 h and became similar to control at 6 h in shoots, while salt stress significantly reduced the expression of TaRAN genes in shoots. The analysis suggests differential regulation of TaRAN genes under developmental stages and abiotic stresses. Delineating the molecular functions of Ran GTPases will help unravel the mechanism of stress induced growth inhibition in wheat.

3D bioprinting and microscale organization of vascularized tissue constructs using collagen-based bioink.

Bioprinting three-dimensional (3D) tissue equivalents have progressed tremendously over the last decade. 3D bioprinting is currently being employed to develop larger and more physiologic tissues, and it is of particular interest to generate vasculature in biofabricated tissues to aid better perfusion and transport of nutrition. Having an advantage over manual culture systems by bringing together biological scaffold materials and cells in precise 3D spatial orientation, bioprinting could assist in placing endothelial cells in specific spatial locations within a 3D matrix to promote vessel formation at these predefined areas. Hence, in the present study, we investigated the use of bioprinting to generate tissue-level capillary-like networks in biofabricated tissue constructs. First, we developed a bioink using collagen type-1 supplemented with xanthan gum (XG) as a thickening agent. Using a commercial extrusion-based multi-head bioprinter and collagen-XG bioink, the component cells were spatially assembled, wherein the endothelial cells were bioprinted in a lattice pattern and sandwiched between bioprinted fibroblasts layers. 3D bioprinted constructs thus generated were stable, and maintained structural shape and form. Post-print culture of the bioprinted tissues resulted in endothelial sprouting and formation of interconnected capillary-like networks within the lattice pattern and between the fibroblast layers. Bioprinter-assisted spatial placement of endothelial cells resulted in fabrication of patterned prevascularized constructs that enable potential regenerative applications in the future.

Development and validation of heat-responsive candidate gene and miRNA gene based SSR markers to analysis genetic diversity in wheat for heat tolerance breeding.

Being a major staple food crop of the world, wheat provides nutritional food security to the global populations. Heat stress is a major abiotic stress that adversely affects wheat production throughout the world including Indo-Gangatic Plains (IGP) where four wheat growing countries viz., India, Bangladesh, Nepal and Pakistan produce 42% of the total wheat production. Therefore, identification of heat stress responsive molecular markers is imperative to marker assisted breeding programs. Information about trait specific gene based SSRs is available but there is lack of information on SSRs from non-coding regions. In the present study, we developed 177 heat-responsive gene-based SSRs (cg-SSR) and MIR gene-based SSR (miRNA-SSR) markers from wheat genome for assessing genetic diversity analysis of thirty- six contrasting wheat genotypes for heat tolerance. Of the 177 SSR loci, 144 yielded unambiguous and repeatable amplicons, however, thirty-seven were found polymorphic among the 36 wheat genotypes. The polymorphism information content (PIC) of primers used in this study ranged from 0.03-0.73, with a mean of 0.35. Number of alleles produced per primer varied from 2 to 6, with a mean of 2.58. The UPGMA dendrogram analysis grouped all wheat genotypes into four clusters. The markers developed in this study has potential application in the MAS based breeding programs for developing heat tolerant wheat cultivars and genetic diversity analysis of wheat germplasm. Identification of noncoding region based SSRs will be fruitful for identification of trait specific wheat germplasm.

E2f1 deletion attenuates infarct-induced ventricular remodeling without affecting O-GlcNAcylation.

Several post-translational modifications figure prominently in ventricular remodeling. The beta-O-linkage of N-acetylglucosamine (O-GlcNAc) to proteins has emerged as an important signal in the cardiovascular system. Although there are limited insights about the regulation of the biosynthetic pathway that gives rise to the O-GlcNAc post-translational modification, much remains to be elucidated regarding the enzymes, such as O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which regulate the presence/absence of O-GlcNAcylation. Recently, we showed that the transcription factor, E2F1, could negatively regulate OGT and OGA expression in vitro. The present study sought to determine whether E2f1 deletion would improve post-infarct ventricular function by de-repressing expression of OGT and OGA. Male and female mice were subjected to non-reperfused myocardial infarction (MI) and followed for 1 or 4 week. MI significantly increased E2F1 expression. Deletion of E2f1 alone was not sufficient to alter OGT or OGA expression in a naïve setting. Cardiac dysfunction was significantly attenuated at 1-week post-MI in E2f1-ablated mice. During chronic heart failure, E2f1 deletion also attenuated cardiac dysfunction. Despite the improvement in function, OGT and OGA expression was not normalized and protein O-GlcNAcyltion was not changed at 1-week post-MI. OGA expression was significantly upregulated at 4-week post-MI but overall protein O-GlcNAcylation was not changed. As an alternative explanation, we also performed guided transcriptional profiling of predicted targets of E2F1, which indicated potential differences in cardiac metabolism, angiogenesis, and apoptosis. E2f1 ablation increased heart size and preserved remote zone capillary density at 1-week post-MI. During chronic heart failure, cardiomyocytes in the remote zone of E2f1-deleted hearts were larger than wildtype. These data indicate that, overall, E2f1 exerts a deleterious effect on ventricular remodeling. Thus, E2f1 deletion improves ventricular remodeling with limited impact on enzymes regulating O-GlcNAcylation.

Cardiac mesenchymal cells from diabetic mice are ineffective for cell therapy-mediated myocardial repair.

Although cell therapy improves cardiac function after myocardial infarction, highly variable results and limited understanding of the underlying mechanisms preclude its clinical translation. Because many heart failure patients are diabetic, we examined how diabetic conditions affect the characteristics of cardiac mesenchymal cells (CMC) and their ability to promote myocardial repair in mice. To examine how diabetes affects CMC function, we isolated CMCs from non-diabetic C57BL/6J (CMCWT) or diabetic B6.BKS(D)-Leprdb/J (CMCdb/db) mice. When CMCs were grown in 17.5 mM glucose, CMCdb/db cells showed > twofold higher glycolytic activity and a threefold higher expression of Pfkfb3 compared with CMCWT cells; however, culture of CMCdb/db cells in 5.5 mM glucose led to metabolic remodeling characterized by normalization of metabolism, a higher NAD+/NADH ratio, and a sixfold upregulation of Sirt1. These changes were associated with altered extracellular vesicle miRNA content as well as proliferation and cytotoxicity parameters comparable to CMCWT cells. To test whether this metabolic improvement of CMCdb/db cells renders them suitable for cell therapy, we cultured CMCWT or CMCdb/db cells in 5.5 mM glucose and then injected them into infarcted hearts of non-diabetic mice (CMCWT, n = 17; CMCdb/db, n = 13; Veh, n = 14). Hemodynamic measurements performed 35 days after transplantation showed that, despite normalization of their properties in vitro, and unlike CMCWT cells, CMCdb/db cells did not improve load-dependent and -independent parameters of left ventricular function. These results suggest that diabetes adversely affects the reparative capacity of CMCs and that modulating CMC characteristics via culture in lower glucose does not render them efficacious for cell therapy.

Cardiomyocyte Ogt limits ventricular dysfunction in mice following pressure overload without affecting hypertrophy.

The myocardial response to pressure overload involves coordination of multiple transcriptional, posttranscriptional, and metabolic cues. The previous studies show that one such metabolic cue, O-GlcNAc, is elevated in the pressure-overloaded heart, and the increase in O-GlcNAcylation is required for cardiomyocyte hypertrophy in vitro. Yet, it is not clear whether and how O-GlcNAcylation participates in the hypertrophic response in vivo. Here, we addressed this question using patient samples and a preclinical model of heart failure. Protein O-GlcNAcylation levels were increased in myocardial tissue from heart failure patients compared with normal patients. To test the role of OGT in the heart, we subjected cardiomyocyte-specific, inducibly deficient Ogt (i-cmOgt -/-) mice and Ogt competent littermate wild-type (WT) mice to transverse aortic constriction. Deletion of cardiomyocyte Ogt significantly decreased O-GlcNAcylation and exacerbated ventricular dysfunction, without producing widespread changes in metabolic transcripts. Although some changes in hypertrophic and fibrotic signaling were noted, there were no histological differences in hypertrophy or fibrosis. We next determined whether significant differences were present in i-cmOgt -/- cardiomyocytes from surgically naïve mice. Interestingly, markers of cardiomyocyte dedifferentiation were elevated in Ogt-deficient cardiomyocytes. Although no significant differences in cardiac dysfunction were apparent after recombination, it is possible that such changes in dedifferentiation markers could reflect a larger phenotypic shift within the Ogt-deficient cardiomyocytes. We conclude that cardiomyocyte Ogt is not required for cardiomyocyte hypertrophy in vivo; however, loss of Ogt may exert subtle phenotypic differences in cardiomyocytes that sensitize the heart to pressure overload-induced ventricular dysfunction.

E2F1 Transcription Factor Regulates O-linked N-acetylglucosamine (O-GlcNAc) Transferase and O-GlcNAcase Expression.

Protein O-GlcNAcylation, which is controlled by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), has emerged as an important posttranslational modification that may factor in multiple diseases. Until recently, it was assumed that OGT/OGA protein expression was relatively constant. Several groups, including ours, have shown that OGT and/or OGA expression changes in several pathologic contexts, yet the cis and trans elements that regulate the expression of these enzymes remain essentially unexplored. Here, we used a reporter-based assay to analyze minimal promoters and leveraged in silico modeling to nominate several candidate transcription factor binding sites in both Ogt (i.e. the gene for OGT protein) and Mgea5 (i.e. the gene for OGA protein). We noted multiple E2F binding site consensus sequences in both promoters. We performed chromatin immunoprecipitation in both human and mouse cells and found that E2F1 bound to candidate E2F binding sites in both promoters. In HEK293 cells, we overexpressed E2F1, which significantly reduced OGT and MGEA5 expression. Conversely, E2F1-deficient mouse fibroblasts had increased Ogt and Mgea5 expression. Of the known binding partners for E2F1, we queried whether retinoblastoma 1 (Rb1) might be involved. Rb1-deficient mouse embryonic fibroblasts showed increased levels of Ogt and Mgea5 expression, yet overexpression of E2F1 in the Rb1-deficient cells did not alter Ogt and Mgea5 expression, suggesting that Rb1 is required for E2F1-mediated suppression. In conclusion, this work identifies and validates some of the promoter elements for mouse Ogt and Mgea5 genes. Specifically, E2F1 negatively regulates both Ogt and Mgea5 expression in an Rb1 protein-dependent manner.

High glucose induces mitochondrial dysfunction independently of protein O-GlcNAcylation.

Diabetes is characterized by hyperglycaemia and perturbations in intermediary metabolism. In particular, diabetes can augment flux through accessory pathways of glucose metabolism, such as the hexosamine biosynthetic pathway (HBP), which produces the sugar donor for the ß-O-linked-N-acetylglucosamine (O-GlcNAc) post-translational modification of proteins. Diabetes also promotes mitochondrial dysfunction. Nevertheless, the relationships among diabetes, hyperglycaemia, mitochondrial dysfunction and O-GlcNAc modifications remain unclear. In the present study, we tested whether high-glucose-induced increases in O-GlcNAc modifications directly regulate mitochondrial function in isolated cardiomyocytes. Augmentation of O-GlcNAcylation with high glucose (33 mM) was associated with diminished basal and maximal cardiomyocyte respiration, a decreased mitochondrial reserve capacity and lower Complex II-dependent respiration (P<0.05); however, pharmacological or genetic modulation of O-GlcNAc modifications under normal or high glucose conditions showed few significant effects on mitochondrial respiration, suggesting that O-GlcNAc does not play a major role in regulating cardiomyocyte mitochondrial function. Furthermore, an osmotic control recapitulated high-glucose-induced changes to mitochondrial metabolism (P<0.05) without increasing O-GlcNAcylation. Thus, increased O-GlcNAcylation is neither sufficient nor necessary for high-glucose-induced suppression of mitochondrial metabolism in isolated cardiomyocytes.

MicroRNA-539 is up-regulated in failing heart, and suppresses O-GlcNAcase expression.

Derangements in metabolism and related signaling pathways characterize the failing heart. One such signal, O-linked ß-N-acetylglucosamine (O-GlcNAc), is an essential post-translational modification regulated by two enzymes, O-GlcNAc transferase and O-GlcNAcase (OGA), which modulate the function of many nuclear and cytoplasmic proteins. We recently reported reduced OGA expression in the failing heart, which is consistent with the pro-adaptive role of increased O-GlcNAcylation during heart failure; however, molecular mechanisms regulating these enzymes during heart failure remain unknown. Using miRNA microarray analysis, we observed acute and chronic changes in expression of several miRNAs. Here, we focused on miR-539 because it was predicted to target OGA mRNA. Indeed, co-transfection of the OGA-3'UTR containing reporter plasmid and miR-539 overexpression plasmid significantly reduced reporter activity. Overexpression of miR-539 in neonatal rat cardiomyocytes significantly suppressed OGA expression and consequently increased O-GlcNAcylation; conversely, the miR-539 inhibitor rescued OGA protein expression and restored O-GlcNAcylation. In conclusion, this work identifies the first target of miR-539 in the heart and the first miRNA that regulates OGA. Manipulation of miR-539 may represent a novel therapeutic target in the treatment of heart failure and other metabolic diseases.

Application of platelet rich fibrin for management of an electrosurge induced osteonecrosis involving maxillary alveolus.

BACKGROUND: Application of principles of electrocautery for hemostasis dates back to prehistoric times. Its modern implementation in various fields of general and head and neck surgeries have been well documented. However its usage in minor oral surgical procedures has gained popularity only recently. Complications associated with electro-surgery in the dental field are relatively rare and there is insufficient literature on its management. CASE REPORT: We present a case report on management of an electrosurgery induced osteonecrosis involving maxillary alveolus of left premolars. DISCUSSION: Inadvertent contact of the electrosurgery tip on bone can result in necrosis making it necessary to remove the sequestrum and graft the defect. Platelet rich fibrin in combination with bone grafts have been well documented to provide successful periodontal regeneration. CLINICAL IMPLICATIONS: Our aim of presenting this report is to create awareness among the health care providers regarding electrosurgical injuries. To our knowledge, this is the first time platelet rich fibrin has been used in the management of intraoral electrosurgical injury. Combining bone grafts with platelet rich fibrin is a good alternative as it can be done with relative ease and predictable outcome.

Sleep bruxism associated with nocturnal enuresis in a 6-year-old child.

BACKGROUND: Bruxism is the involuntary grinding of teeth that occurs during sleep or wake time. The prevalence of bruxism in children and adolescents is high when compared to the adult population. CLINICAL PRESENTATION: This article presents a case report of sleep bruxism in a 6-year-old child. The interesting finding here was its association with nocturnal enuresis (NE)/bedwetting. CONCLUSION/CLINICAL RELEVANCE: NE could be a predisposing factor for sleep bruxism in children, as it causes emotional stress and has a negative impact on a child's self esteem. Psychological support and techniques for overcoming NE, like a scheduled waking program at night helps children with these problems by alleviating the associated stress. In addition, NE and bruxism are often associated with other sleep disorders, such as obstructive sleep apnea syndrome, and hence, child bruxers require careful medical evaluation to rule out such potential interactions.

Multiple bony overgrowths in the mouth - report of two cases.

Tori and exostoses are benign bony protuberances that arise from bone surfaces in the oral cavity. The etiology of these growths has been implicated as multifactorial, but no consensus has been reached so far. These painless overgrowths seldom present as a complaint in the dental office unless functional or esthetic complications set in, and there is a fear for cancer. Here we discuss two rare cases where bony overgrowths present in the mouth were extensive and multiple.

Thermal burn of palate in an elderly diabetic patient.

BACKGROUND: Burns of the oral mucosa may be caused by thermal, mechanical, chemical, electrical or radiation injury. Clinically, these burns can produce localised or diffuse areas of tissue damage depending on the severity and extent of the insult. Most oral thermal burns produce erosions or ulcers on the palate or tongue. MATERIALS AND METHODS: A case of palatal burn in a 66-year-old diabetic patient caused by drinking hot cereal is presented. The role of diabetes in causing oral mucosal dysesthesia that predisposed the occurrence of this burn is also discussed. CONCLUSION: Insensate palatal burn as a rare complication of diabetes mellitus is reported here. With the disease being more widespread now, its potential oral complications will be seen with increasing frequency.

Genome wide analysis of BREVIS RADIX gene family from wheat (Triticum aestivum): A conserved gene family differentially regulated by hormones and abiotic stresses.

BREVIS RADIX is a plant specific gene family with unique protein-protein interaction domain. It regulates developmental processes viz. root elongation and tiller angle which are pertinent for crop improvement. In the present study, five BRX family genes were identified in wheat genome and clustered into five sub-groups. Phylogenetic and synteny analyses revealed evolutionary conservation among BRX proteins from monocot species. Expression analyses showed abundance of TaBRXL1 transcripts in vegetative and reproductive tissues except flag leaf. TaBRXL2, TaBRXL3 and TaBRXL4 showed differential, tissue specific and lower level expression as compared to TaBRXL1. TaBRXL5-A expressed exclusively in stamens. TaBRXL1 was upregulated under biotic stresses while TaBRXL2 expression was enhanced under abiotic stresses. TaBRXL2 and TaBRXL3 were upregulated by ABA and IAA in roots. In shoot, TaBRXL2 was upregulated by ABA while TaBRXL3 and TaBRXL4 were upregulated by IAA. Expression levels, tissue specificity and response time under different conditions suggest distinct as well as overlapping functions of TaBRX genes. This was also evident from global co-expression network of these genes. Further, TaBRX proteins exhibited homotypic and heterotypic interactions which corroborated with the role of BRX domain in protein-protein interaction. This study provides leads for functional characterization of TaBRX genes.

Genome-wide identification and expression analysis of Hsp70 family genes in Cassava (Manihot esculenta Crantz).

Hsp70 proteins function as molecular chaperones, regulating various cellular processes in plants. In this study, a genome-wide analysis led to the identification of 22 Hsp70 (MeHsp70) genes in cassava. Phylogenetic relationship studies with other Malpighiales genomes (Populus trichocarpa, Ricinus communis and Salix purpurea) classified MeHsp70 proteins into eight groups (Ia, Ib, Ic, Id, Ie, If, IIa and IIb). Promoter analysis of MeHsp70 genes revealed the presence of tissue-specific, light, biotic and abiotic stress-responsive cis-regulatory elements showing their functional importance in cassava. Meta-analysis of publically available RNA-seq transcriptome datasets showed constitutive, tissue-specific, biotic and abiotic stress-specific expression patterns among MeHsp70s in cassava. Among 22 Hsp70, six MeHsp70s viz., MecHsp70-3, MecHsp70-6, MeBiP-1, MeBiP-2, MeBiP-3 and MecpHsp70-2 displayed constitutive expression, while three MecHsp70s were induced under both drought and cold stress conditions. Five MeHsp70s, MecHsp70-7, MecHsp70-11, MecHsp70-12, MecHsp70-13, and MecHsp70-14 were induced under drought stress conditions. We predicted that 19 MeHsp70 genes are under the regulation of 24 miRNAs. This comprehensive genome-wide analysis of the Hsp70 gene family in cassava provided valuable insights into their functional roles and identified various potential Hsp70 genes associated with stress tolerance and adaptation to environmental stimuli. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03760-3.

Nitrogen use efficiency-a key to enhance crop productivity under a changing climate.

Nitrogen (N) is an essential element required for the growth and development of all plants. On a global scale, N is agriculture's most widely used fertilizer nutrient. Studies have shown that crops use only 50% of the applied N effectively, while the rest is lost through various pathways to the surrounding environment. Furthermore, lost N negatively impacts the farmer's return on investment and pollutes the water, soil, and air. Therefore, enhancing nitrogen use efficiency (NUE) is critical in crop improvement programs and agronomic management systems. The major processes responsible for low N use are the volatilization, surface runoff, leaching, and denitrification of N. Improving NUE through agronomic management practices and high-throughput technologies would reduce the need for intensive N application and minimize the negative impact of N on the environment. The harmonization of agronomic, genetic, and biotechnological tools will improve the efficiency of N assimilation in crops and align agricultural systems with global needs to protect environmental functions and resources. Therefore, this review summarizes the literature on nitrogen loss, factors affecting NUE, and agronomic and genetic approaches for improving NUE in various crops and proposes a pathway to bring together agronomic and environmental needs.

Mesenchymal Stem Cell-Derived Extracellular Vesicles in the Management of COVID19-Associated Lung Injury: A Review on Publications, Clinical Trials and Patent Landscape.

The unprecedented COVID-19 pandemic situation forced the scientific community to explore all the possibilities from various fields, and so far we have seen a lot of surprises, eureka moments and disappointments. One of the approaches from the cellular therapists was exploiting the immunomodulatory and regenerative potential of mesenchymal stromal cells (MSCs), more so of MSC-derived extracellular vesicles (EVs)-particularly exosomes, in order to alleviate the cytokine storm and regenerate the damaged lung tissues. Unlike MSCs, the EVs are easier to store, deliver, and are previously shown to be as effective as MSCs, yet less immunogenic. These features attracted the attention of many and thus led to a tremendous increase in publications, clinical trials and patent applications. This review presents the current landscape of the field and highlights some interesting findings on MSC-derived EVs in the context of COVID-19, including in silico, in vitro, in vivo and case reports. The data strongly suggests the potential of MSC-derived EVs as a therapeutic regime for the management of acute lung injury and associated complications in COVID-19 and beyond.

Fabrication of collagen with polyhexamethylene biguanide: A potential scaffold for infected wounds.

Bacterial infection remains a great challenge in wound healing, especially in chronic wounds. Multidrug-resistant organisms are increasing in acute and chronic wound infections, which compromise the chance of therapeutics. Resistance to conventional antibiotics has created an urge to study new approach/system that can effectively control wound infection and enhance healing. Wound cover/dressing must exhibit biocompatibility and effectiveness in reducing bioburden at the wound site. Collagen, a natural biopolymer, possesses advantages over synthetic and other natural materials due to its unique biological properties. It can act as an excellent wound dressing and controlled drug delivery system. Currently, antiseptic agents such as silver, iodine, and polyhexamethylene biguanide (PHMB)-incorporated scaffolds have become widely accepted in chronic wound healing. In this study, PHMB-incorporated collagen scaffold has been prepared and characterized using Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), and differential scanning calorimetry (DSC), which showed retention of collagen nativity and integration of PHMB. The scanning electron microscopy (SEM) analysis revealed the porous structures of scaffolds. The cytotoxicity analysis showed PHMB is nontoxic at the concentration of 0.01% (wt/wt). The agar diffusion test and bacterial adhesion study demonstrated the effectiveness of PHMB-incorporated collagen scaffold against both gram positive and negative strains. This study concludes that PHMB-incorporated collagen scaffold could have the potential for infected wound healing.