RESUMEN
MAIN CONCLUSION: ZmCBL8-1 enhances salt stress tolerance in maize by improving the antioxidant system to neutralize ROS homeostasis and inducing Na+/H+ antiporter gene expressions of leaves. Calcineurin B-like proteins (CBLs) as plant-specific calcium sensors have been explored for their roles in the regulation of abiotic stress tolerance. Further, the functional variations in ZmCBL8, encoding a component of the salt overly sensitive pathway, conferred the salt stress tolerance in maize. ZmCBL8-1 is a transcript of ZmCBL8 found in maize, but its function in the salt stress response is still unclear. The present study aimed to characterize the protein ZmCBL8-1 that was determined to be composed of 194 amino acids (aa) with three conserved EF hands responsible for binding Ca2+. However, a 20-aa fragment was found to be missing from its C-terminus relative to another transcript of ZmCBL8. Results indicated that it harbored a dual-lipid modification motif MGCXXS at its N-terminus and was located on the cell membrane. The accumulation of ZmCBL8-1 transcripts was high in the roots but relatively lower in the leaves of maize under normal condition. In contrast, its expression was significantly decreased in the roots, while increased in the leaves under NaCl treatment. The overexpression of ZmCBL8-1 resulted in higher salt stress resistance of transgenic Arabidopsis in a Ca2+-dependent manner relative to that of the wild type (WT). In ZmCBL8-1-overexpressing plants exposed to NaCl, the contents of malondialdehyde and hydrogen peroxide were decreased in comparison with those in the WT, and the expression of key genes involved in the antioxidant defense system and Na+/H+ antiporter were upregulated. These results suggested that ZmCBL8-1 played a positive role in the response of leaves to salt stress by inducing the expression of Na+/H+ antiporter genes and enhancing the antioxidant system to neutralize the accumulation of reactive oxygen species. These observations further indicate that ZmCBL8-1 confers salt stress tolerance, suggesting that transcriptional regulation of the ZmCBL8 gene is important for salt tolerance.
Asunto(s)
Arabidopsis , Estrés Salino , Zea mays , Aminoácidos , Antioxidantes , Antiportadores , Arabidopsis/fisiología , Calcineurina/genética , Cloruro de Sodio/farmacología , Zea mays/genéticaRESUMEN
Responsive nanomaterials hold significant promise in the treatment of bacterial infections by recognizing internal or external stimuli to achieve stimuli-responsive behavior. In this study, we present an enzyme-responsive polyelectrolyte complex micelles (PTPMN) with α-helical cationic polypeptide as a coacervate-core for the treatment of Escherichia coli (E. coli) infection. The complex was constructed through electrostatic interaction between cationic poly(glutamic acid) derivatives and phosphorylation-modified poly(ethylene glycol)-b-poly(tyrosine) (PEG-b-PPTyr) by directly dissolving them in aqueous solution. The cationic polypeptide adopted α-helical structure and demonstrated excellent broad-spectrum antibacterial activity against both Gram-negative and Gram-positive bacteria, with a minimum inhibitory concentration (MIC) as low as 12.5 µg mL-1 against E. coli. By complexing with anionic PEG-b-PPTyr, the obtained complex formed ß-sheet structures and exhibited good biocompatibility and low hemolysis. When incubated in a bacterial environment, the complex cleaved its phosphate groups triggered by phosphatases secreted by bacteria, exposing the highly α-helical conformation and restoring its effective bactericidal ability. In vivo experiments confirmed accelerated healing in E. coli-infected wounds.
Asunto(s)
Antibacterianos , Escherichia coli , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/administración & dosificación , Escherichia coli/efectos de los fármacos , Animales , Pruebas de Sensibilidad Microbiana , Polielectrolitos/química , Polielectrolitos/farmacología , Péptidos/química , Péptidos/farmacología , Conformación Proteica en Hélice alfa , Micelas , Infecciones por Escherichia coli/tratamiento farmacológico , Hemólisis/efectos de los fármacos , Polietilenglicoles/química , Polietilenglicoles/farmacología , Ratones , Ácido Poliglutámico/química , Ácido Poliglutámico/análogos & derivados , Ácido Poliglutámico/farmacología , HumanosRESUMEN
The development of fluorescent molecular imprinting sensors for direct, rapid, and sensitive detection of small organic molecules in aqueous systems has always presented a significant challenge in the field of detection. In this study, we successfully prepared a hydrophilic colloidal molecular imprinted polymer (MIP) with 2,4-dichlorophenoxyacetic acid (2,4-D) using a one-pot approach that incorporated polyglycerol methacrylate (PGMMA-TTC), a hydrophilic macromolecular chain transfer agent, to mediate reversible addition-fragmentation chain transfer precipitation polymerization (RAFTPP). To simplify the polymerization process while achieving ratiometric fluorescence detection, red fluorescent CdTe quantum dots (QDs) and green fluorescent nitrobenzodiazole (NBD) were introduced as fluorophores (with NBD serving as an enhancer to the template and QDs being inert). This strategy effectively eliminated background noise and significantly improved detection accuracy. Uniform-sized MIP microspheres with high surface hydrophilicity and incorporated ratiometric fluorescent labels were successfully synthesized. In aqueous systems, the hydrophilic ratio fluorescent MIP exhibited a linear response range from 0 to 25 µM for the template molecule 2,4-D with a detection limit of 0.13 µM. These results demonstrate that the ratiometric fluorescent MIP possesses excellent recognition characteristics and selectivity towards 2,4-D, thus, making it suitable for selective detection of trace amounts of pesticide 2,4-D in aqueous systems.
RESUMEN
The chemical tolerance of ketoenamine covalent organic frameworks (COFs) is excellent; however, the tight crystal structure and low surface area limit their applications in the field of catalysis. In this work, a porous single-atom iron catalyst (FeSAC) with a core-shell structure and high surface area was synthesized by using Schiff base COF nanospheres as the core and ketoenamine COF nanosheets growth on the surfaces. Surface defects were created using sodium cyanoborohydride etching treatment to increase specific surface area. The dye degradation experiments by peroxymonosulfate (PMS) catalyzed by the FeSAC proved that methylene blue can be degraded with a degradation rate constant of 0.125 min-1 under the conditions of 0.1 g L-1 catalyst dosage and 0.05 g L-1 peroxymonosulfate. The FeSAC/PMS system effectively degrades various pollutants in the pH range of 4-10 with over 80% efficiency for four cycles and can be recovered by soaking in iron salt solution. Free radical quenching experiments confirmed that singlet oxygen and superoxide radicals are the main active species for catalysis.
RESUMEN
To fully and deeply understand the weak interactions in the gaseous structure of the TKX-50 molecule, two conformations I and II of the TKX-50 molecule confirmed in a crystal cell were optimized at the B3LYP/6-311g(d,p) level in the gas state, and the single point energy of the optimized structure was calculated at the M06-2X/ma-TZVPP level. Analyzing methods for weak interactions such as the interaction region indicator (IRI), topological basin analysis, and the extended transition state-natural orbitals for chemical valence (ETS-NOCV) theory with the help of Multiwfn code were employed to reveal the corresponding intramolecular weak interactions. The results showed that there were 5 kinds of intramolecular weak interaction in both conformations. They are two types of H bond, two types of intra-ring weak interaction, and one type of O-N bond within the molecular fragment containing the bis-tetrazole ring. The combined effect of all these weak interactions holds the bis-tetrazole ring of TKX-50 retaining an almost coplanar configuration. Meanwhile, the strength of these weak interactions is significantly different in conformation I and conformation II. The most obvious difference is that conformation II has a significant H transfer between intramolecular fragments due to the mirror rotation of almost 180° of cations (NH3OH)+ perpendicular to the N-O bond axis thereof as compared to the reference conformation I. This conformational difference not only makes the weak interaction between the two conformations very different but also forms a quasi-covalent bond in conformation II with much larger bonding energy than other H bonds, thus resulting in conformation II having lower electron energy and more stable geometry. In addition, the order of breaking various H bonds in the combustion decomposition process of TKX-50 is deduced by comparing various H bonds.
RESUMEN
INTRODUCTION: Chronic wounds are wounds that are not healed or have no healing tendency for more than 1 month due to various factors. In clinical nursing, chronic wounds are often not properly treated, and the treatment efficiency is low. Therefore, it is very important to explore effective methods to deal with chronic wounds. OBJECTIVE: To explore the effect of a self-made negative pressure suction device (NPSD) in the nursing of chronic wounds in the elderly. METHODS: A total of 50 elderly patients with chronic wounds who were hospitalised in our hospital from January 2020 to December 2022 were selected as participants by convenient sampling. According to the random number table method, they were divided into a control group and an observation group, with 25 people in each group. The control group was treated with chloroplast foam dressing, debridement gel and alginate dressing. The observation group was treated with a self-made NPSD on the basis of the control group. The wound healing of the two groups was observed. RESULTS: After the intervention of the self-made NPSD, the granulation tissue coverage rate and wound volume reduction rate of the observation group were significantly increased (p < 0.05), and the positive rate of bacterial infection was significantly decreased (p < 0.05). After 3 months of intervention, the total effective rate of the observation group was significantly higher than that of the control group (χ2 = 3.869, p = 0.0492). CONCLUSION: The self-made NPSD can effectively promote the healing of a chronic wound.
Asunto(s)
Trasplante de Piel , Cicatrización de Heridas , Humanos , Anciano , Succión , Resultado del Tratamiento , Desbridamiento , Trasplante de Piel/métodosRESUMEN
Cadmium (Cd) is a major environmental pollutant and poses a risk of transfer into the food chain through contaminated plants. Mechanisms underlying Cd tolerance and hyperaccumulation in plants are not fully understood. Proteomics-based approaches facilitate an in-depth understanding of plant responses to Cd stress at the systemic level by identifying Cd-inducible differentially abundant proteins (DAPs). In this review, we summarize studies related to proteomic changes associated with Cd-tolerance mechanisms in Cd-tolerant crops and Cd-hyperaccumulating plants, especially the similarities and differences across plant species. The enhanced DAPs identified through proteomic studies can be potential targets for developing Cd-hyperaccumulators to remediate Cd-contaminated environments and Cd-tolerant crops with low Cd content in the edible organs. This is of great significance for ensuring the food security of an exponentially growing global population. Finally, we discuss the methodological drawbacks in current proteomic studies and propose that better protocols and advanced techniques should be utilized to further strengthen the reliability and applicability of future Cd-stress-related studies in plants. This review provides insights into the improvement of phytoremediation efficiency and an in-depth study of the molecular mechanisms of Cd enrichment in plants.
Asunto(s)
Cadmio , Contaminantes del Suelo , Cadmio/metabolismo , Biodegradación Ambiental , Proteómica , Reproducibilidad de los Resultados , Contaminantes del Suelo/metabolismo , Productos Agrícolas/metabolismoRESUMEN
Maize accumulates large amounts of starch in seeds which have been used as food for human and animals. Maize starch is an importantly industrial raw material for bioethanol production. One critical step in bioethanol production is degrading starch to oligosaccharides and glucose by α-amylase and glucoamylase. This step usually requires high temperature and additional equipment, leading to an increased production cost. Currently, there remains a lack of specially designed maize cultivars with optimized starch (amylose and amylopectin) compositions for bioethanol production. We discussed the features of starch granules suitable for efficient enzymatic digestion. Thus far, great advances have been made in molecular characterization of the key proteins involved in starch metabolism in maize seeds. The review explores how these proteins affect starch metabolism pathway, especially in controlling the composition, size and features of starch. We highlight the roles of key enzymes in controlling amylose/amylopectin ratio and granules architecture. Based on current technological process of bioethanol production using maize starch, we propose that several key enzymes can be modified in abundance or activities via genetic engineering to synthesize easily degraded starch granules in maize seeds. The review provides a clue for developing special maize cultivars as raw material in the bioethanol industry.
Asunto(s)
Amilosa , Biocombustibles , Etanol , Almidón , Zea mays , Humanos , Amilopectina/metabolismo , Amilosa/metabolismo , Ingeniería Genética , Semillas/metabolismo , Almidón/biosíntesis , Almidón/genética , Zea mays/genética , Zea mays/metabolismoRESUMEN
The calcium ion (Ca2+), as a well-known second messenger, plays an important role in multiple processes of growth, development, and stress adaptation in plants. As central Ca2+ sensor proteins and a multifunctional kinase family, calcium-dependent protein kinases (CDPKs) are widely present in plants. In maize, the signal transduction processes involved in ZmCDPKs' responses to abiotic stresses have also been well elucidated. In addition to Ca2+ signaling, maize ZmCDPKs are also regulated by a variety of abiotic stresses, and they transmit signals to downstream target molecules, such as transport proteins, transcription factors, molecular chaperones, and other protein kinases, through protein interaction or phosphorylation, etc., thus changing their activity, triggering a series of cascade reactions, and being involved in hormone and reactive oxygen signaling regulation. As such, ZmCDPKs play an indispensable role in regulating maize growth, development, and stress responses. In this review, we summarize the roles of ZmCDPKs as a convergence point of different signaling pathways in regulating maize response to abiotic stress, which will promote an understanding of the molecular mechanisms of ZmCDPKs in maize tolerance to abiotic stress and open new opportunities for agricultural applications.
Asunto(s)
Calcio , Zea mays , Zea mays/genética , Zea mays/metabolismo , Calcio/metabolismo , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Plantas/metabolismo , Transducción de Señal , Estrés Fisiológico , Regulación de la Expresión Génica de las PlantasRESUMEN
Graphene materials offer attractive possibilities in spintronics due to their unique atomic and electronic structures, which is in contrast to their limited applications in the design of sophisticated spintronic devices. This should be attributed to the lack of knowledge about the intrinsic characteristics of graphene materials, especially the diverse correlations between sites within the materials and their roles in spin-signal generation and propagation. This work comprehensively studies the spin couplings between transition metal atoms doped on graphene and reveals their potential application in spintronic device design through the realization of various logic gates. In addition, the effects of the distance between doped metal atoms and the number of carbon layers on the logic gate implementation further verify that the spin-coupling effect can exhibit a certain distance dependence and space propagation. The achievements in this work uncover the potential value of graphene materials and are expected to open up new avenues for exploring their application in the design of sophisticated spintronic devices.
RESUMEN
BACKGROUND: Various environmental factors are capable of oxidative stress to result in limiting plant development and agricultural production. Fullerene-based carbon nanomaterials can enable radical scavenging and positively regulate plant growth. Even so, to date, our knowledge about the mechanism of fullerene-based carbon nanomaterials on plant growth and response to oxidative stress is still unclear. RESULTS: 20 or 50 mg/L quaternary ammonium iminofullerenes (IFQA) rescued the reduction in root lengths and root-hair densities and lengths of Arabidopsis and maize induced by accumulation of endogenous hydrogen peroxide (H2O2) under 3-amino-1,2,4-triazole or exogenous H2O2 treatment, as well as the root active absorption area and root activity under exogenous H2O2 treatment. Meanwhile, the downregulated contents of ascorbate acid (ASA) and glutathione (GSH) and the upregulated contents of dehydroascorbic acid (DHA), oxidized glutathione (GSSG), malondialdehyde (MDA), and H2O2 indicated that the exogenous H2O2 treatment induced oxidative stress of maize. Nonetheless, application of IFQA can increase the ratios of ASA/DHA and GSH/GSSG, as well as the activities of glutathione reductase, and ascorbate peroxidase, and decrease the contents of H2O2 and MDA. Moreover, the root lengths were inhibited by buthionine sulfoximine, a specific inhibitor of GSH biosynthesis, and subsequently rescued after addition of IFQA. The results suggested that IFQA could alleviate exogenous-H2O2-induced oxidative stress on maize by regulating the ASA-GSH cycle. Furthermore, IFQA reduced the excess accumulation of ROS in root hairs, as well as the NADPH oxidase activity under H2O2 treatment. The transcript levels of genes affecting ROS-mediated root-hair development, such as RBOH B, RBOH C, PFT1, and PRX59, were significantly induced by H2O2 treatment and then decreased after addition of IFQA. CONCLUSION: The positive effect of fullerene-based carbon nanomaterials on maize-root-hair growth under the induced oxidative stress was discovered. Application IFQA can ameliorate oxidative stress to promote maize-root growth through decreasing NADPH-oxidase activity, improving the scavenging of ROS by ASA-GSH cycle, and regulating the expressions of genes affecting maize-root-hair development. It will enrich more understanding the actual mechanism of fullerene-based nanoelicitors responsible for plant growth promotion and protection from oxidative stress.
Asunto(s)
Fulerenos , Estrés Oxidativo/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Compuestos de Amonio Cuaternario , Zea mays/efectos de los fármacos , Ácido Ascórbico/metabolismo , Fulerenos/química , Fulerenos/farmacología , Glutatión/metabolismo , Homeostasis/efectos de los fármacos , Peróxido de Hidrógeno/metabolismo , Oxidación-Reducción/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/farmacología , Transducción de Señal/efectos de los fármacosRESUMEN
Dementia is a chronic and multifactor-induced neurodegenerative disorder that occurs frequently in the elderly with weak constitution and insufficient vital energy. However, the relationship between vital energy deficiency and the occurrence and development of dementia is still unclear. In this study, a rat model of dementia with vital energy deficiency was established through intraperitoneal injection with d-galactose and AlCl3 and combined with exhaustive swimming. Changes in the dementia with vital energy deficiency rat model were assessed by examining behaviors, hippocampal histopathological and biochemical parameters, and serum biochemical parameters. Urine metabolomics based on ultra-high-performance liquid chromatography coupled with an orbitrap mass spectrometer was also used to discover endogenous metabolic profile and disease-related biomarkers and investigate the potential mechanism of dementia with vital energy deficiency. Among the 31 potential biomarkers that were identified, nine involved metabolic pathways. The four main types were phenylalanine, tyrosine and tryptophan metabolism, taurine and hypotaurine metabolism, and citrate cycle and pyrimidine metabolism. The pathogenesis of dementia with vital energy deficiency is mainly neurotoxin accumulation and body aging that leads to oxidative stress injury and loss of neuronal protective substances. Vital energy deficiency inhibits the body's energy metabolism and eventually leads to aggravate the dementia.
Asunto(s)
Demencia , Metabolómica , Animales , Biomarcadores/metabolismo , Cromatografía Líquida de Alta Presión , Espectrometría de Masas/métodos , Metaboloma , Metabolómica/métodos , RatasRESUMEN
Post-traumatic stress disorder (PTSD) is prevalent in traumatic events. It is a great hazard of physical and mental health due to their severity and frequency. Traumatic fractures are one of the major causes of PTSD. The incidence of traumatic fractures has been high in recent years, which will directly or indirectly result in PTSD. Our target is to estimate the pooled incidence of PTSD in fracture patients after traumatic events and to explore possible influencing factors by a meta-analysis.The systematic searches in the electronic bibliographic databases of Web of Science, ScienceDirect, Ovid MEDLINE, PubMed, CNKI (China National Knowledge Infrastructure), Wangfang , and Veipu Databases. Not only were heterogeneity and 95% confidence interval (CI) used for comprehensive assessing each pooled, but also was the P value. Subgroup analyses for some sample characteristics were calculated the pooled incidence of PTSD among patients suffered from fractures.In total, 2619 patients suffered from fracture, and were assessed PTSD in the 12 eligible studies. The heterogeneity was not low (I2 = 97.6%, P < 0.001) in the 12 eligible studies. The pooled incidence of PTSD in fracture patients was 29% (95% CI, 20% to 39%) using random-effects model. Subgroup analyses revealed that the pooled incidence of PTSD among patients after traumatic fracture was statistically significant differences according to the study design, the study location, tools to assess the symptoms of PTSD, the mean age and injury mechanism (all P < 0.001). Fracture sites, injury mechanism and pain were the main influencing factors of PTSD in fracture patients.Our results highlight the phenomenon that high incidence of PTSD in patients after fracture and they should be followed up regularly and be provided effective interventions. Future efforts to improve and control the main influencing factors of PTSD for this population still needed.
Asunto(s)
Trastornos por Estrés Postraumático , China , Humanos , Incidencia , Salud Mental , Trastornos por Estrés Postraumático/epidemiología , Trastornos por Estrés Postraumático/psicología , Sobrevivientes/psicologíaRESUMEN
Constructing ingenious microstructures, such as core-shell, laminate, microcapsule and porous microstructures, is an efficient strategy for tuning the combustion behaviors and thermal stability of energetic materials (EMs). Electrohydrodynamic atomization (EHDA), which includes electrospray and electrospinning, is a facile and versatile technique that can be used to process bulk materials into particles, fibers, films and three-dimensional (3D) structures with nanoscale feature sizes. However, the application of EHDA in preparing EMs is still in its initial development. This review summarizes the progress of research on EMs prepared by EHDA over the last decade. The morphology and internal structure of the produced materials can be easily altered by varying the operation and precursor parameters. The prepared EMs composed of zero-dimensional (0D) particles, one-dimensional (1D) fibers and two-dimensional (2D) films possess precise microstructures with large surface areas, uniformly dispersed components and narrow size distributions and show superior energy release rates and combustion performances. We also explore the reasons why the fabrication of 3D EM structures by EHDA is still lacking. Finally, we discuss development challenges that impede this field from moving out of the laboratory and into practical application.
RESUMEN
In plants, 3´,5´-cyclic adenosine monophosphate (cAMP) is an important second messenger with varied functions; however, only a few adenylyl cyclases (ACs) that synthesize cAMP have been identified. Moreover, the biological roles of ACs/cAMP in response to stress remain largely unclear. In this study, we used quantitative proteomics techniques to identify a maize heat-induced putative disease-resistance RPP13-like protein 3 (ZmRPP13-LK3), which has three conserved catalytic AC centres. The AC activity of ZmRPP13-LK3 was confirmed by in vitro enzyme activity analysis, in vivo RNAi experiments, and functional complementation in the E. coli cyaA mutant. ZmRPP13-LK3 is located in the mitochondria. The results of in vitro and in vivo experiments indicated that ZmRPP13-LK3 interacts with ZmABC2, a possible cAMP exporter. Under heat stress, the concentrations of ZmRPP13-LK3 and cAMP in the ABA-deficient mutant vp5 were significantly less than those in the wild-type, and treatment with ABA and an ABA inhibitor affected ZmRPP13-LK3 expression in the wild-type. Application of 8-Br-cAMP, a cAMP analogue, increased heat-induced expression of heat-shock proteins in wild-type plants and alleviated heat-activated oxidative stress. Taken together, our results indicate that ZmRPP13-LK3, a new AC, can catalyse ATP for the production of cAMP and may be involved in ABA-regulated heat resistance.
Asunto(s)
Ácido Abscísico , Adenilil Ciclasas , Adenilil Ciclasas/genética , Escherichia coli , Respuesta al Choque Térmico , Zea mays/genéticaRESUMEN
Global warming poses a serious threat to crops. Calcium-dependent protein kinases (CDPKs)/CPKs play vital roles in plant stress responses, but their exact roles in plant thermotolerance remains elusive. Here, we explored the roles of heat-induced ZmCDPK7 in thermotolerance in maize. ZmCDPK7-overexpressing maize plants displayed higher thermotolerance, photosynthetic rates, and antioxidant enzyme activity but lower H2 O2 and malondialdehyde (MDA) contents than wild-type plants under heat stress. ZmCDPK7-knockdown plants displayed the opposite patterns. ZmCDPK7 is attached to the plasma membrane but can translocate to the cytosol under heat stress. ZmCDPK7 interacts with the small heat shock protein sHSP17.4, phosphorylates sHSP17.4 at Ser-44 and the respiratory burst oxidase homolog RBOHB at Ser-99, and upregulates their expression. Site-directed mutagenesis of sHSP17.4 to generate a Ser-44-Ala substitution reduced ZmCDPK7's enhancement of catalase activity but enhanced ZmCDPK7's suppression of MDA accumulation in heat-stressed maize protoplasts. sHSP17.4, ZmCDPK7, and RBOHB were less strongly upregulated in response to heat stress in the abscisic acid-deficient mutant vp5 versus the wild type. Pretreatment with an RBOH inhibitor suppressed sHSP17.4 and ZmCDPK7 expression. Therefore, abscisic acid-induced ZmCDPK7 functions both upstream and downstream of RBOH and participates in thermotolerance in maize by mediating the phosphorylation of sHSP17.4, which might be essential for its chaperone function.
Asunto(s)
Respuesta al Choque Térmico/fisiología , Proteínas de Plantas/metabolismo , Proteínas Quinasas/metabolismo , Termotolerancia/fisiología , Zea mays/enzimología , Zea mays/fisiología , Ácido Abscísico/farmacología , Antioxidantes/farmacología , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Respuesta al Choque Térmico/efectos de los fármacos , Respuesta al Choque Térmico/genética , Peróxido de Hidrógeno/metabolismo , Mutación/genética , Fosforilación/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Protoplastos/efectos de los fármacos , Protoplastos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Serina/genética , Fracciones Subcelulares/efectos de los fármacos , Fracciones Subcelulares/metabolismo , Termotolerancia/efectos de los fármacos , Termotolerancia/genética , Zea mays/efectos de los fármacos , Zea mays/genéticaRESUMEN
The innate hypoxic microenvironment of most solid tumors has a major influence on tumor growth, invasiveness, and distant metastasis. Here, a hypoxia-activated self-immolative prodrug of paclitaxel (PTX2 -Azo) was synthesized and encapsulated by a peptide copolymer decorated with the photosensitizer chlorin e6 (Ce6) to prepare light-boosted PTX nanoparticle (Ce6/PTX2 -Azo NP). In this nanoparticle, PTX2 -Azo prevents premature drug leakage and realizes specific release in hypoxic tumor microenvironment and the photosensitizer Ce6 not only efficiently generates singlet oxygen under light irradiation but also acts as a positive amplifier to promote the release of PTX. The combination of photodynamic therapy (PDT) and chemotherapy results in excellent antitumor efficacy, demonstrating the great potential for synergistic cancer therapy.
Asunto(s)
Antineoplásicos/farmacología , Paclitaxel/farmacología , Profármacos/farmacología , Hipoxia Tumoral/efectos de los fármacos , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Clorofilidas , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Luz , Ratones , Ratones Desnudos , Estructura Molecular , Nanopartículas/química , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Paclitaxel/síntesis química , Paclitaxel/química , Fotoquimioterapia , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Porfirinas/química , Porfirinas/farmacología , Profármacos/síntesis química , Profármacos/química , Especies Reactivas de Oxígeno/metabolismo , Microambiente Tumoral/efectos de los fármacosRESUMEN
The properties of graphdiyne (GDY), such as energy gap, morphology, and affinity to alkali metals, can be adjusted by including electron-withdrawing/donating groups. The push-pull electron ability and size differences of groups play a key role on the partial property adjusting of GDY derivatives MeGDY, HGDY, and CNGDY. Cyano groups (electron-withdrawing) and methyl groups (electron-donating) decrease the band gap and increase the conductivity of the GDY network. The cyano and methyl groups affects the aggregation of GDY, providing a higher number of micropores and specific surface area. These groups also endow the original GDY additional advantages: the stronger electronegativity of cyano groups increase the affinity of GDY frameworks to lithium atoms, and the larger atomic volume of methyl groups increases the interlayer distance and provides more storage space and diffusion tunnels.
RESUMEN
Starch is the major form of carbohydrate storage in plants and exists as discrete starch granules (SGs). Isolation of high-quality SGs in different plant tissues is a prerequisite for studying the roles of SGs during plant growth, development, and responses to abiotic stress. However, it is difficult to isolate transitory SGs from leaves and storage SGs from pollen grains due to their small sizes and low quantities. Herein, we develop a novel method for isolating SGs by using the aqueous two-phase system (ATS) of ethanol/NaH2 PO4 . The ATS method efficiently separated SGs from contaminants based on their differences in density, solubility, and polarity. Using this method, we first isolated and purified three kinds of SGs from maize seeds, pollen, and leaves. The biochemical, microscopic, and proteomic analyses demonstrated the high purity of the isolated SGs. Proteomic analysis revealed distinct differences in SG-bound proteins between seed SGs and pollen SGs. As a simple, rapid, and low-cost method, the ATS-based method exhibits highly universal and reproducible results for starch-containing tissues in various plant species.
Asunto(s)
Especificidad de Órganos , Plantas/metabolismo , Almidón/metabolismo , Endospermo/metabolismo , Hojas de la Planta/metabolismo , Polen/metabolismo , Polen/ultraestructura , Almidón/ultraestructura , Zea mays/metabolismoRESUMEN
Polymersomes, the structural analogues of liposomes, are hollow structures enclosed by a bilayer membrane made from amphiphilic copolymers. Polymersomes have been proposed to mimic the structure and properties of cellular membranes and viral capsids. Excellent robustness and stability, chemical versatility for tunable membrane properties and surface functionalization make polymersomes attractive candidates for drug delivery, diagnostic imaging, nanoreactor vessels, and artificial organelles. In further biomimetic strategies, stimuli-responsive polymersomes that can recognize various external physical or internal biological environmental stimuli and conduct "on demand" release in dose-, spatial-, and temporal-controlled fashions have been widely developed. This Perspective focuses on recent advances in stimuli-responsive polymersomes and their potential biomedical applications. Representative examples of each stimulus, the advantages and limitations of different strategies, and the future opportunities and challenges are discussed.