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1.
PLoS Biol ; 17(2): e3000162, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30811402

RESUMO

Feeding preference is critical for insect adaptation and survival. However, little is known regarding the determination of insect feeding preference, and the genetic basis is poorly understood. As a model lepidopteran insect with economic importance, the domesticated silkworm, Bombyx mori, is a well-known monophagous insect that predominantly feeds on fresh mulberry leaves. This species-specific feeding preference provides an excellent model for investigation of host-plant selection of insects, although the molecular mechanism underlying this phenomenon remains unknown. Here, we describe the gene GR66, which encodes a putative bitter gustatory receptor (GR) that is responsible for the mulberry-specific feeding preference of B. mori. With the aid of a transposon-based, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) system, the GR66 locus was genetically mutated, and homozygous mutant silkworm strains with truncated gustatory receptor 66 (GR66) proteins were established. GR66 mutant larvae acquired new feeding activity, exhibiting the ability to feed on a number of plant species in addition to mulberry leaves, including fresh fruits and grain seeds that are not normally consumed by wild-type (WT) silkworms. Furthermore, a feeding choice assay revealed that the mutant larvae lost their specificity for mulberry. Overall, our findings provide the first genetic and phenotypic evidences that a single bitter GR is a major factor affecting the insect feeding preference.


Assuntos
Bombyx/genética , Comportamento Alimentar/fisiologia , Proteínas de Insetos/genética , Receptores de Superfície Celular/genética , Percepção Gustatória/genética , Animais , Sequência de Bases , Bombyx/crescimento & desenvolvimento , Bombyx/metabolismo , Proteína 9 Associada à CRISPR/genética , Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas , Cromossomos de Insetos/química , Grão Comestível/parasitologia , Frutas/parasitologia , Edição de Genes/métodos , Expressão Gênica , Engenharia Genética/métodos , Loci Gênicos , Células HEK293 , Homozigoto , Humanos , Proteínas de Insetos/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Morus/parasitologia , Folhas de Planta/parasitologia , RNA Guia de Cinetoplastídeos/genética , RNA Guia de Cinetoplastídeos/metabolismo , Receptores de Superfície Celular/metabolismo
2.
Nanotechnology ; 32(37)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34044371

RESUMO

Phosphate-stabilized amorphous calcium carbonate (ACCP) has excellent biocompatibility, bioactivity, and biodegradability, and can be easily synthesized and stored. However, unmodified ACCP, as a controlled drug release carrier, decomposes rapidly in an acidic environment and highly depends on the system's pH value, which can not meet the need for long-term release of active substances, thus limiting its application scope. To realize the specific pH responsiveness of ACCP nanoparticles, we designed and synthesized monodisperse sodium alginate/ACCP (Alginate/ACCP) composite nanoparticles in this paper. After ultrasonic treatment, nanoparticles with an average particle size less than 200 nm could form stable water dispersion that could be dispersed for up to 10 d. Based on the specific pH sensitivity of sodium alginate, the drug-controlled release performance of composite nanoparticles and the therapeutic effect of drug-loaded nanoparticles on A549 cancer cells were studied. The results indicated that under the same pH condition, the curcumin (Cur) release rate of composite nanoparticles gradually decreased with sodium alginate addition. When the dosage of sodium alginate was 1.0 mg ml-1, the cumulative drug release rate of nanoparticles in 40 h was only about 35%. Besides, the drug-loaded nanoparticles showed the excellent killing ability of cancer cells, and the survival rate of cancer cells decreased in a concentration-dependent manner. Therefore, through reasonable optimization design, we can synthesize composite nanoparticles with excellent sustained-release properties to provide a new strategy for cancer cells' long-term treatment.

3.
Proc Natl Acad Sci U S A ; 115(35): 8757-8762, 2018 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-30082397

RESUMO

Spider silk is one of the best natural fibers and has superior mechanical properties. However, the large-scale harvesting of spider silk by rearing spiders is not feasible, due to their territorial and cannibalistic behaviors. The silkworm, Bombyx mori, has been the most well known silk producer for thousands of years and has been considered an ideal bioreactor for producing exogenous proteins, including spider silk. Previous attempts using transposon-mediated transgenic silkworms to produce spider silk could not achieve efficient yields, due to variable promoter activities and endogenous silk fibroin protein expression. Here, we report a massive spider silk production system in B. mori by using transcription activator-like effector nuclease-mediated homology-directed repair to replace the silkworm fibroin heavy chain gene (FibH) with the major ampullate spidroin-1 gene (MaSp1) in the spider Nephila clavipes We successfully replaced the ∼16-kb endogenous FibH gene with a 1.6-kb MaSp1 gene fused with a 1.1-kb partial FibH sequence and achieved up to 35.2% chimeric MaSp1 protein amounts in transformed cocoon shells. The presence of the MaSp1 peptide significantly changed the mechanical characteristics of the silk fiber, especially the extensibility. Our study provides a native promoter-driven, highly efficient system for expressing the heterologous spider silk gene instead of the transposon-based, random insertion of the spider gene into the silkworm genome. Targeted MaSp1 integration into silkworm silk glands provides a paradigm for the large-scale production of spider silk protein with genetically modified silkworms, and this approach will shed light on developing new biomaterials.


Assuntos
Animais Geneticamente Modificados , Bombyx , Fibroínas , Engenharia Genética , Aranhas/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/metabolismo , Bombyx/genética , Bombyx/metabolismo , Fibroínas/biossíntese , Fibroínas/genética
4.
Proc Natl Acad Sci U S A ; 115(35): 8752-8756, 2018 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-30104361

RESUMO

Sex separation methods are critical for genetic sexing systems in commercial insect production and sterile insect techniques. Integration of selectable marker genes into a sex chromosome is particularly useful in insects with a heterogametic sex determination system. Here, we describe targeted gene integration of fluorescent marker expression cassettes into a randomly amplified polymorphic DNA (RAPD) marker region in the W chromosome of the lepidopteran model insect Bombyx mori using transcriptional activator-like effector nuclease (TALEN)-mediated genome editing. This silkworm strain shows ubiquitous female-specific red or green fluorescence from the embryonic to adult stages. Furthermore, we developed a binary, female-specific, embryonic lethality system combining the TALEN and the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology. This system includes one strain with TALEN-mediated, W-specific Cas9 expression driven by the silkworm germ cell-specific nanos (nos) promoter and another strain with U6-derived single-guide RNA (sgRNA) expression targeting transformer 2 (tra2), an essential gene for silkworm embryonic development. Filial 1 (F1) hybrids exhibit complete female-specific lethality during embryonic stages. Our study provides a promising approach for B. mori genetic sexing and sheds light on developing sterile insect techniques in other insect species, especially in lepidopteran pests with WZ/ZZ sex chromosome systems.


Assuntos
Bombyx/genética , Sistemas CRISPR-Cas , Cromossomos de Insetos/genética , Edição de Genes/métodos , Cromossomos Sexuais/genética , Processos de Determinação Sexual , Animais , Feminino , Masculino
5.
Med Sci Monit ; 22: 2006-12, 2016 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-27292522

RESUMO

BACKGROUND There is increasing evidence that adenosine triphosphate (ATP), a well-known neurotransmitter and neuromodulator in the central nervous system, plays an important role as an extracellular chemical messenger in the cochlea. MATERIAL AND METHODS Using a whole-cell recording technique, we studied the effects of ATP on isolated Hensen's cells, which are supporting cells in the cochlea, to determine if they are involved in the transduction of ions with hair cells. RESULTS ATP (0.1-10 µM) reduced the potassium current (IK+) in the majority of the recorded Hensen's cells (21 out of 25 cells). An inward current was also induced by high concentrations of ATP (100 µM to 10 mM), which was reversibly blocked by 100 µM suramin (a purinergic antagonist) and blocked by nifedipine (an L-type calcium channel blocker). After the cochleas were perfused with artificial perilymph solutions containing nifedipine and exposed to noise, the amplitude increase in the compound action potential (CAP) threshold and the reduction in cochlear microphonics was lower than when they were exposed to noise alone. CONCLUSIONS Our results suggest that ATP can block IK+ channels at a low concentration and induce an inward Ca2+ current at high concentrations, which is reversed by purinergic receptors. Nifedipine may have a partially protective effect on noise-induced hearing loss (NIHL).


Assuntos
Trifosfato de Adenosina/farmacologia , Células Ciliadas Auditivas/efeitos dos fármacos , Perda Auditiva Provocada por Ruído/prevenção & controle , Nifedipino/farmacologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/antagonistas & inibidores , Potenciais de Ação/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Cobaias , Células Ciliadas Auditivas/metabolismo , Perda Auditiva Provocada por Ruído/metabolismo , Órgão Espiral , Técnicas de Patch-Clamp/métodos , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Distribuição Aleatória , Transdução de Sinais/fisiologia , Suramina/farmacologia
6.
Proc Natl Acad Sci U S A ; 110(17): 6766-70, 2013 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-23569267

RESUMO

Transgene-based genetic sexing methods are being developed for insects of agricultural and public health importance. Male-only rearing has long been sought in sericulture because males show superior economic characteristics, such as better fitness, lower food consumption, and higher silk yield. Here we report the establishment of a transgene-based genetic sexing system for the silkworm, Bombyx mori. We developed a construct in which a positive feedback loop regulated by sex-specific alternative splicing leads to high-level expression of the tetracycline-repressible transactivator in females only. Transgenic animals show female-specific lethality during embryonic and early larval stages, leading to male-only cocoons. This transgene-based female-specific lethal system not only has wide application in sericulture, but also has great potential in lepidopteran pest control.


Assuntos
Processamento Alternativo/genética , Bombyx/genética , Cruzamento/métodos , Genes Letais/genética , Caracteres Sexuais , Animais , Bombyx/fisiologia , Clonagem Molecular , Primers do DNA/genética , Feminino , Immunoblotting , Masculino , Microscopia de Fluorescência , Controle Biológico de Vetores/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Seda/biossíntese , Tetraciclina/farmacologia , Transativadores/metabolismo
7.
Amino Acids ; 46(11): 2615-25, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25240738

RESUMO

Hydrophobins are a large group of low-molecular weight proteins. These proteins are highly surface-active and can form amphipathic membranes by self-assembling at hydrophobic-hydrophilic interfaces. Based on physical properties and hydropathy profiles, hydrophobins are divided into two classes. Upon the analysis of amino acid sequences and higher structures, some models suggest that the Cys3-Cys4 loop regions in class I and II hydrophobins can exhibit remarkable difference in their alignment and conformation, and have a critical role in the rodlets structure formation. To examine the requirement for the Cys3-Cys4 loop in class I hydrophobins, we used protein fusion technology to obtain a mutant protein HGFI-AR by replacing the amino acids between Cys3 and Cys4 of the class I hydrophobin HGFI from Grifola frondosa with those ones between Cys3 and Cys4 of the class II hydrophobin HFBI from Trichoderma reesei. The gene of the mutant protein HGFI-AR was successfully expressed in Pichia pastoris. Water contact angle (WCA) and X-ray photoelectron spectroscopy (XPS) measurements demonstrated that the purified HGFI-AR could form amphipathic membranes by self-assembling at mica and hydrophobic polystyrene surfaces. This property enabled them to alter the surface wettabilities of polystyrene and mica and change the elemental composition of siliconized glass. In comparison to recombinant class I hydrophobin HGFI (rHGFI), the membranes formed on hydrophobic surfaces by HGFI-AR were not robust enough to resist 1 % hot SDS washing. Atomic force microscopy (AFM) measurements indicated that unlike rHGFI, no rodlet structure was observed on the mutant protein HGFI-AR coated mica surface. In addition, when compared to rHGFI, no secondary structural change was detected by Circular Dichroism (CD) spectroscopy after HGFI-AR self-assembled at the water-air interface. HGFI-AR could not either be deemed responsible for the fluorescence intensity increase of Thioflavin T (THT) and the Congo Red (CR) absorption spectra shift (after the THT(CR)/HGFI-AR mixed aqueous solution was drastically vortexed). Remarkably, replacement of the Cys3-Cys4 loop could impair the rodlet formation of the class I hydrophobin HGFI. So, it could be speculated that the Cys3-Cys4 loop plays an important role in conformation and functionality, when the class I hydrophobin HGFI self-assembles at hydrophobic-hydrophilic interfaces.


Assuntos
Cisteína/química , Proteínas Fúngicas/química , Grifola/química , Sequência de Bases , Dicroísmo Circular , Escherichia coli/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica , Dados de Sequência Molecular , Mutação , Pichia/metabolismo , Poliestirenos/química , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Espectrofotometria , Propriedades de Superfície , Trichoderma , Água/química , Molhabilidade , Raios X
8.
Arch Insect Biochem Physiol ; 85(3): 127-36, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24478036

RESUMO

The PAR-domain protein 1 (PDP1) is essential for locomotor activity of insects. However, its functions in insect growth and development have not been studied extensively, which prompted our hypothesis that PDP1 acts in energy metabolism. Here we report identification of TcPDP1 in the red flour beetle, Tribolium castaneum, and its functional analysis by RNAi. Treating larvae with dsTcPDP1 induced pupae developmental arrestment, accompanied by accelerated fat body degradation. dsTcPDP1 treatments in adults resulted in reduced female fecundity. Disruption of TcPDP1 expression affected the transcription of genes involved in insulin signaling transduction and mechanistic target of rapamycin (mTOR) pathway. These results support our hypothesis that TcPDP1 acts in energy metabolism in T. castaneum.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Metabolismo Energético/fisiologia , Proteínas de Insetos/metabolismo , Insulina/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Tribolium/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Insulina/genética , Larva/genética , Larva/metabolismo , Masculino , Pupa/genética , Pupa/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Tribolium/genética , Tribolium/crescimento & desenvolvimento
9.
Chem Pharm Bull (Tokyo) ; 62(3): 260-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24583780

RESUMO

In this study, the interactions of different groups substituted isoeuxanthone derivatives with calf thymus DNA (ct DNA) were investigated by spectrophotometric methods and viscosity measurements. Results indicated that the xanthone derivatives could intercalate into the DNA base pairs by the plane of xanthone ring and the various substituents may influence the binding affinity with DNA according to the calculated quenching constant values. Furthermore, two tumor cell lines including the human cervical cancer cell line (HeLa) and human hepatocellular liver carcinoma cell line (HepG2) were used to evaluate the cytotoxic activities of xanthone derivatives by acid phosphatase assay. Analyses showed that the oxiranylmethoxy substituted xanthone exhibited more effective cytotoxic activity against the cancer cells than the other substituted xanthones. The effects on the inhibition of tumor cells in vitro agreed with the studies of DNA-binding.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , DNA/química , Xantonas/química , Xantonas/farmacologia , Animais , Antineoplásicos/síntese química , Bovinos , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Células Hep G2 , Humanos , Xantonas/síntese química
10.
Sci Data ; 11(1): 317, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38538602

RESUMO

Zacco platypus is an endemic colorful freshwater minnow that is intensively distributed in East Asia. In this study, two adult female individuals collected from Haihe River basin were used for karyotypic study and genome sequencing, respectively. The karyotype formula of Z. platypus is 2N = 48 = 18 M + 24SM/ST + 6 T. We used PacBio long-read sequencing and Hi-C technology to assemble a chromosome-level genome of Z. platypus. As a result, an 814.87 Mb genome was assembled with the PacBio long reads. Subsequently, 98.64% assembled sequences were anchored into 24 chromosomes based on the Hi-C data. The chromosome-level assembly contained 54 scaffolds with a N50 length of 32.32 Mb. Repeat elements accounted for 52.35% in genome, and 24,779 protein-coding genes were predicted, with 92.11% were functionally annotated with the public databases. BUSCO analysis yielded a completeness score of 96.5%. This high-quality genome assembly provides valuable resources for future functional genomic research, comparative genomics, and evolutionary studies of genus Zacco.


Assuntos
Cyprinidae , Animais , Feminino , Ásia Oriental , Cromossomos/genética , Cyprinidae/genética , Genômica , Anotação de Sequência Molecular , Filogenia
11.
Bioelectrochemistry ; 156: 108599, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37988979

RESUMO

The accurate determination of organophosphorus pesticide residues is of great importance for human disease monitoring and environmental safety. Numerous detection methods exist, among which sensitive monitoring of organophosphorus compounds using electrochemical sensors has gradually become a research hotspot. This paper used acetylcholinesterase (AChE) as an indicator anchored on a zinc oxide-reduced graphene oxide (ZnO-rGO) composite rich in active sites, in which green non-toxic zinc oxide (ZnO) nanomaterials were uniformly distributed on the reduced graphene for rapid detection of organophosphorus. The effects of different ratios of ZnO to reduced graphene on the performance of ZnO-rGO nanocomposites were investigated. The AChE/ZnO-rGO biosensor detects organophosphorus by electrochemical inhibition of acetylcholinesterase in the presence of organophosphorus. The developed electrochemical biosensor has high selectivity and good linearity, and the ZnO-rGO nanocomposite as a matrix for immobilization of acetylcholinesterase and detection of organophosphorus has the potential for highly sensitive pesticide detection.


Assuntos
Técnicas Biossensoriais , Grafite , Praguicidas , Óxido de Zinco , Humanos , Óxido de Zinco/química , Grafite/química , Compostos Organofosforados , Acetilcolinesterase/química , Técnicas Biossensoriais/métodos
12.
J Biomater Sci Polym Ed ; : 1-17, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38953307

RESUMO

In this study, to address the defects of sodium alginate (SA), such as its susceptibility to disintegration, silica was coated on the outer layer of sodium alginate hydrogel beads in order to improve its swelling and slow-release properties. Tetraethyl orthosilicate (TEOS) was used as the hydrolyzed precursor, and the solution of silica precursor was prepared by sol-gel reaction under acidic conditions. Then SA-silica hydrogel beads prepared by ionic crosslinking method were immersed into the SiO2 precursor solution to prepare SA-silica hydrogel beads. The chemical structure and morphology of the hydrogel beads were characterized by XRD, FTIR, and SEM, and the results showed that the surface of SA-silica beads was successfully encapsulated with the outer layer of SiO2, and the surface was smooth and dense. The swelling experiments showed that the swelling performance effectively decreased with the increase of TEOS molar concentration, and the maximum swelling ratio of the hydrogel beads decreased from 41.07 to 14.3, and the time to reach the maximum swelling ratio was prolonged from 4 h to 8 h. The sustained-release experiments showed that the SA-silica hydrogel beads possessed a good pH sensitivity, and the time of sustained-release was significantly prolonged in vitro. Hemolysis and cytotoxicity experiments showed that the SA-silica hydrogel beads were biocompatible when the TEOS molar concentration was lower than 0.375 M. The SA-silica-2 hydrogel beads had good biocompatibility, swelling properties, and slow-release properties at the same time.

13.
Int J Biol Macromol ; 256(Pt 1): 128014, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37951439

RESUMO

In order to cope with the increasingly severe food contamination and safety problems, a powerful sterilization of food packaging material is urgently needed. Chitosan (CS) has potential applications in food packaging due to its good film-forming properties, but its antibacterial activity is not sufficient to meet the needs in practical applications. Silver nanoparticles (AgNPs) have the problem of weak immediate antibacterial activity as a broad-spectrum antibacterial agent. Therefore, in this study, AgNPs@GA@Cur-POTS (AGCP) composite antibacterial system was prepared by combining AgNPs with antibacterial photodynamic therapy using gallic acid (GA) as a reducing agent, curcumin (Cur) as a photosensitizer and perfluorosilane (POTS) for surface modification. The results showed that AGCP could produce a large number of reactive oxygen species under blue light irradiation, killing >90 % of E. coli and S. aureus within 2 h. Subsequently, the composite film of CS loaded with AGCP (CS/AGCP) was prepared by the flow-delay method. The CS/AGCP composite film exhibited excellent barrier properties and antioxidant activity, while its antibacterial rates against E. coli and S. aureus reached 98.44 ± 1.27 % and 99.11 ± 0.24 %, respectively, while the OD630 values of the two groups of bacteria treated with it showed no significant increase in incubation for up to 132 h, exhibiting remarkable and sustained antibacterial effects. Taken together, this work will provide a new strategy for antibacterial food packaging.


Assuntos
Quitosana , Curcumina , Nanopartículas Metálicas , Prata , Curcumina/farmacologia , Staphylococcus aureus , Escherichia coli , Antibacterianos/farmacologia , Embalagem de Alimentos/métodos
14.
Int J Biol Macromol ; 263(Pt 1): 130336, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38387631

RESUMO

This study focused on the preparation, functionality, and application of smart food packaging films based on polyvinyl alcohol (PVA) and anthocyanins (ACNs) -loaded sodium alginate-chitosan quaternary ammonium salt (HACC-SA) nanocomplexes. The average encapsulation rate of anthocyanins-loaded nanocomplexes reached 62.51 %, which improved the hydrophobicity and water vapor barrier of the PVA film. FTIR confirmed that the nanocomplexes were immobilized in the PVA film matrix by hydrogen bonding, which improved the mechanical properties of the film. The SEM and XRD results demonstrated that the HACC-SA-ACNs nanocomplexes were uniformly distributed in the film matrix and the crystallinity of PVA was decreased. The P/HACC-SA-ACNs film showed a significant response to buffers of pH 2-13 and high color stability after 21 days of storage compared to the P/ACNs film. Furthermore, the color of the composite film changed from purple to red as the milk freshness decreased during 72 h of milk freshness monitoring, indicating that the P/HACC-SA-ACNs films were suitable and promising for application as smart packaging materials.


Assuntos
Quitosana , Materiais Inteligentes , Animais , Antocianinas , Leite , Embalagem de Alimentos , Alginatos , Álcool de Polivinil , Compostos de Amônio Quaternário , Concentração de Íons de Hidrogênio
15.
Food Chem ; 451: 139464, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38704990

RESUMO

Silver-metal organic framework (Ag@MOF) has exhibited outstanding antimicrobial activity in antimicrobial applications, and reducing the biotoxicity associated with silver has become a research priority. In this study, Ag@MOF was initially modified with sodium alginate (SA) to form SA-Ag@MOF. The results showed that SA could control the release of Ag+, reducing the release by about 8% at 24 h, and the biotoxicity was significantly reduced. Finally, SA-Ag@MOF was applied as an antimicrobial agent in citric acid-modified PVA film to develop a novel composite antimicrobial film. When added at 2 MIC, the CA3-M2 film can effectively inhibit the growth of E. coli and S. aureus, and the inhibition rate has reached 98%. For white radish packaging applications, CA3-M2 film inhibited the growth of surface microorganisms, while ensuring moisture and tissue hardness to extend shelf-life up to 7 days. Overall, the strategy conceived here can be a theoretical basis for novel antimicrobial packaging.


Assuntos
Alginatos , Ácido Cítrico , Escherichia coli , Embalagem de Alimentos , Estruturas Metalorgânicas , Prata , Staphylococcus aureus , Alginatos/química , Alginatos/farmacologia , Embalagem de Alimentos/instrumentação , Ácido Cítrico/química , Ácido Cítrico/farmacologia , Prata/química , Prata/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana , Raphanus/química , Raphanus/crescimento & desenvolvimento , Raphanus/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química
16.
Arch Insect Biochem Physiol ; 84(1): 27-42, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23922284

RESUMO

The ecdysone receptor (EcR) is the hormonal receptor of ecdysteroids, which regulates insect growth and development. In this study, we cloned and characterized two isoforms of EcR in Monochamus alternates named MaEcR A and MaEcR B. The cDNAs of MaEcR A and MaEcR B have open repeating frames of 1,695 and 1,392 bp, respectively. The deduced proteins have the same C-terminal sequence and varied in N-terminal, and are consistent with reports on other insect species, particularly with the receptor of another coleopteran, Tribolium castaneum. The isoform-specific developmental expression profile of EcR in the epidermis and the midgut were analyzed with quantitative real-time reverse-transcriptase polymerase chain reaction in the pupal stage. RNA interference (RNAi) with common or isoform-specific regions induced developmental stagnation. When treated in the later larval stage, RNAi with either the common sequence or an EcR A specific sequence caused more severe effects and most larvae died prior to adulthood. The EcR B specific sequence caused less severe effects and about half of the treated larvae became adults, but some showed developmental defects. RNAi with both isoforms at early pupal stage attenuated the expression of 20E-regulated genes E74, E75, and HR3. The study demonstrates the role of EcR in the transduction of ecdysteroid response in Monochamus alternatus.


Assuntos
Besouros/genética , Regulação da Expressão Gênica , Proteínas de Insetos/genética , Receptores de Esteroides/genética , Sequência de Aminoácidos , Animais , Clonagem Molecular , Besouros/crescimento & desenvolvimento , Besouros/metabolismo , DNA Complementar/genética , DNA Complementar/metabolismo , Proteínas de Insetos/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/metabolismo , RNA/genética , RNA/metabolismo , Receptores de Esteroides/metabolismo , Alinhamento de Sequência
17.
Int J Biol Macromol ; 253(Pt 2): 126631, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37659500

RESUMO

In this study, a kind of magnetically recyclable adsorbent for dyes was synthesized by grafting diethylenetriamine pentaacetate acid (DTPA) to the composite of Fe3O4 microspheres and crosslinked chitosan (CS). The microstructures, molecular structure, crystal structure, and magnetic hysteresis loops of the chitosan matrix adsorbent before and after grafting was characterized. The results suggested that DTPA was covalent bonded with the composite of Fe3O4 microspheres and chitosan. The modified composite has larger specific surface area and can realize rapid solid-liquid separation. Batch experiments were conducted to optimize the parameters affecting the adsorption of methyl orange (MO). The adsorption process could be better described by pseudo-second-order kinetics model and Langmuir isotherm equation, and its saturated adsorption capacity of the modified adsorbents was 1541.5 mg·g-1 at 25 °C, which was 1.40 times of that the unmodified adsorbent (1104.1 mg·g-1). The obtained values of the thermodynamic parameters indicated that the adsorption was a spontaneous process. The regeneration experiment proved the stability and reproducibility of the adsorbent even after five cycles of adsorption-desorption. The primary adsorption mechanism was electrostatic interaction and hydrogen bonding. The adsorbent could be potentially applied for removing dyes from wastewater in wide pH of range, especially acid wastewater.


Assuntos
Quitosana , Poluentes Químicos da Água , Adsorção , Águas Residuárias , Quitosana/química , Reprodutibilidade dos Testes , Termodinâmica , Corantes/química , Ácido Pentético , Cinética , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio
18.
Int J Biol Macromol ; 226: 184-193, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36493927

RESUMO

In this study, arginineated chitosan (ACS) was used as a soft brain membrane and chelating agent to synthesize ACS-ZnO NPs, and then ACS and ACS-ZnO NPs were added to a polyvinyl alcohol (PVA) matrix as an antimicrobial agent to form films by casting. The formation and structural morphology of ACS and ACS-ZnO NPs were investigated by applying FTIR, 1H NMR, XRD, EDS, SEM, and TEM techniques, and ACS has shown better water solubility. The cytotoxicity experiments of ACS and ACS-ZnO NPs on A549 cells showed that both had good cytocompatibility. The incorporation of ACS and ACS-ZnO NPs improves the composite film's mechanical properties, water barrier, and oxygen barrier and exhibits excellent antibacterial activities against S. aureus and E. coli. More importantly, in addition to extending the shelf life of cherry tomatoes, the composite film is also biodegradable to some degree. Therefore, polyvinyl alcohol films based on ACS and ACS-ZnO NPs added as antimicrobial agents have great potential for food packaging applications.


Assuntos
Quitosana , Óxido de Zinco , Álcool de Polivinil/química , Quitosana/química , Óxido de Zinco/química , Escherichia coli , Staphylococcus aureus , Embalagem de Alimentos , Antibacterianos/farmacologia , Antibacterianos/química , Água
19.
Colloids Surf B Biointerfaces ; 231: 113548, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37729798

RESUMO

Calcium phosphate cement (CPC) has attracted extensive interest from surgeons and materials scientists. However, the collapsibility of calcium phosphate cement limits its clinical application. In this work, a gel network of SA-CA formed by the reaction of citric acid (CA) and sodium alginate (SA) was introduced into the α-TCP/α-CSH composite. Furthermore, a high proportion of α-CSH provided more calcium sources for the system to combine with SA forming a gel network to improve the cohesion property of the composite, which also played a regulating role in the conversion of materials to HA. The morphology, physicochemical properties, and cell compatibility of the composites were studied with SA-CA as curing solution. The results show that SA-CA plays an important role in the compressive strength and collapse resistance of bone cement, and its properties can be regulated by changing the content of CA. When CA is 10 wt%, the mechanical strength is the highest, reaching 12.49 ± 2.03 MPa, which is 265.80% higher than water as the solidifying liquid. In addition, the cell experiments showed that the samples were not toxic to MC3T3 cells. The results of ALP showed that when SA-CA were used as curing solution, the activity of ALP was higher than that of blank sample, indicating that the composite bone cement could be conducive to the differentiation of osteoblasts. In this work, the α-CSH/α-TCP based composite regulated by gel network of SA-CA can provide a promising strategy to improve the cohesion of bone cement.


Assuntos
Sulfato de Cálcio , Fosfatos , Sulfato de Cálcio/química , Cimentos Ósseos/farmacologia , Cimentos Ósseos/química , Ácido Cítrico/farmacologia , Sulfatos , Alginatos/farmacologia , Alginatos/química , Fosfatos de Cálcio/farmacologia , Fosfatos de Cálcio/química , Teste de Materiais
20.
J Biomater Appl ; 37(10): 1801-1812, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37121598

RESUMO

A novel self-hardening α-tricalcium phosphate (α-TCP) bone cement complexed with different content of α-calcium sulfate hemihydrate (α-CSH) and micrometer hydroxyapatite mineralized silk fibroin (HA-SF) using micro/SF as curing liquid has been investigated in this work, which was capable of tunable setting time, degradation, mechanical property and ability to anti-washout. After addition 0 ∼ 25% α-CSH to the α-TCP cement with SFFs as curing liquid, it shortened the setting time of the modified composite to 10 ∼ 30 min. Furthermore, the addition of SFFs improved the compressive strength of the composite from 5.41 MPa to 9.44 MPa. The composites with both Na2HPO4 and SFFs as curing liquid showed good anti-collapse performance. The weight loss ratio of bone cement was -0.18 ∼ 12.08% in 4 weeks when the content of α-CSH in α-TCP/α-CSH was between 0 ∼ 25 wt%. During the degradation of α-CSH, the amorphous α-TCP were deposited as hydroxyapatite to formed a plate-like products on the surface of composite. Compared to the composite with Na2HPO4 solution as the curing liquid, alkaline phosphatase (ALP) activity of the composites using SFFs as curing liquid were maintained at high levels on the 14th day especially when the Ca/P ratio was 1.7. This study provides a theoretical basis for the regeneration of bone defects guided by bone cement materials.


Assuntos
Sulfato de Cálcio , Fibroínas , Sulfato de Cálcio/química , Fibroínas/química , Cimentos Ósseos/química , Fosfatos de Cálcio/química , Durapatita
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