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Hypoxia and high concentration of glutathione (GSH) in tumor seriously hinder the role of reactive oxygen species (ROS) and oxygen-dependence strategy in tumor treatment. In this work, a self-generating oxygen and self-consuming GSH hyaluronic acid (HA)-coated porphyrin nanoplatform (TAPPP@CaO2/Pt(IV)/HA) is established for enhancing photodynamic/ion/chemo targeting synergistic therapy of tumor. During the efforts of ROS production by nanosystems, a GSH consuming strategy is implemented for augmenting ROS-induced oxidative damage for synergetic cancer therapy. CaO2 in the nanosystems is decomposed into O2 and H2O2 in an acidic environment, which alleviates hypoxia and enhances the photodynamic therapy (PDT) effect. Calcium overload causes mitochondria dysfunction and induces apoptosis. Pt (IV) reacts with GSH to produce Pt (II) for chemotherapy and reduce the concentration of GSH, protecting ROS from scavenging for augmenting ROS-induced oxidative damage. In vitro and in vivo results demonstrated the self-generating oxygen and self-consuming GSH strategy can enhance ROS-dependent PDT coupled with ion/chemo synergistic therapy. The proposed strategy not only solves the long-term problem that hypoxia limits therapeutic effect of PDT, but also ameliorates the highly reducing environment of tumors. Thus the preparation of TAPPP@CaO2/Pt(IV)/HA provided a novel strategy for the effective combined therapy of cancers.
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The use of dermal substitutes with subsequent skin graft application constitutes an alternative treatment option in situations that limit the use of other conventional approaches.
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The incidence of infectious diseases has risen in recent years, leading to a significant surge in the demand for medical molecular detection. High-throughput molecular detection platforms play a crucial role in facilitating rapid and efficient molecular detection. Among the various techniques employed in high-throughput molecular detection, microliquid transfer stands out as one of the most frequently utilized methods. However, ensuring the accuracy of liquid transfer poses a challenge due to variations in the physical and chemical properties of different samples and reagents. In this study, a pipetting complementation model was developed specifically for the serum, paraffin oil, and throat swabs. The aim was to enhance the transfer accuracy of diverse liquids in the context of high-throughput molecular detection, ultimately ensuring detection reliability and stability. The experimental findings revealed notable improvements in pipetting accuracy after compensating for the three liquids. In particular, the pipetting error rates decreased by 52.5, 96, and 71.4% for serum, paraffin oil, and throat swabs, respectively. These results underscore the model's effectiveness in providing reliable support for the precise transfer of liquids on the high-throughput molecular detection platform.
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Óleos , Parafina , Reprodutibilidade dos TestesRESUMO
Learning-based policy optimization methods have shown great potential for building general-purpose control systems. However, existing methods still struggle to achieve complex task objectives while ensuring policy safety during learning and execution phases for black-box systems. To address these challenges, we develop data-driven safe policy optimization (D 2 SPO), a novel reinforcement learning (RL)-based policy improvement method that jointly learns a control barrier function (CBF) for system safety and a linear temporal logic (LTL) guided RL algorithm for complex task objectives. Unlike many existing works that assume known system dynamics, by carefully constructing the data sets and redesigning the loss functions of D 2 SPO, a provably safe CBF is learned for black-box dynamical systems, which continuously evolves for improved system safety as RL interacts with the environment. To deal with complex task objectives, we take advantage of the capability of LTL in representing the task progress and develop LTL-guided RL policy for efficient completion of various tasks with LTL objectives. Extensive numerical and experimental studies demonstrate that D 2 SPO outperforms most state-of-the-art (SOTA) baselines and can achieve over 95% safety rate and nearly 100% task completion rates. The experiment video is available at https://youtu.be/2RgaH-zcmkY.
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AIMS: To explore novel microbial endoglucanases with unique properties derived from extreme environments by using metagenomics approach. METHODS AND RESULTS: A Tibetan soil metagenomic library was applied for screening cellulase-active clones by function-based metagenomics. The candidate genes in the active clones were identified through bioinformatic analyses and heterologously expressed using an Escherichia coli system. The recombinant endoglucanases were purified and characterized using enzyme assays to determine their bioactivities, stabilities, substrate specificities, and other enzymatic properties. A novel endoglucanase gene Zfeg1907 was identified, which consisted of a glycoside hydrolase family 44 (GH44) catalytic domain along with a polycystic kidney disease (PKD) domain and a fibronectin type â ¢ (Fn3) domain at the C terminal. Recombinant enzyme ZFEG1907 and its truncated mutant ZFEG1907t (ΔPKDΔFn3) were successfully expressed and purified. The two recombinants exhibited catalytic activities toward carboxymethyl cellulose, konjac glucomannan (KGM), and lichenan. Both enzymes had an optimal temperature of 50°C and an optimal pH value of 5.0. The catalytic activities of both recombinant enzymes were promoted by adding Zn2+ and Ca2+ at the final concentration of 10 mM. The Km value of ZFEG1907 was lower, while the kcat/Km value of ZFEG1907 was higher than those of of ZFEG1907t when using carboxymethyl cellulose, KGM, and lichenan as substrates. Structure prediction of two recombinants revealed that PKD-Fn3 domains consisted of a flexible linker and formed a ß-sandwich structure. CONCLUSIONS: A novel endoglucanase ZFEG1907 contained a GH44 catalytic domain and a PKD-Fn3 domain was characterized. The PKD-Fn3 domains were not indispensable for the activity but contributed to the enzyme binding of the polysaccharide substrates as a carbohydrate-binding module (CBM).
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Carboximetilcelulose Sódica , Celulase , Celulase/genética , Metagenômica , Tibet , Escherichia coli/genética , Glicosídeo HidrolasesRESUMO
Cellulases are widely used in industry, and the usage in bioconversion of biofuels makes cellulases more valuable. In this study, two tandem genes that encoded cellulases ZF994-1 and ZF994-2, respectively, were identified on a cosmid from a soil metagenomic library. Phylogenetic analysis indicated that ZF994-1 and ZF994-2 belonged to glycoside hydrolase family 12 (GH12), and GH3, respectively. Based on the substrate specificity analysis, the recombinant ZF994-1 exhibited weak endoglucanase activity, moderate ß-1,3-glucanase and ß-1,4-mannanase activities, and strong ß-glucosidase activity, while the recombinant ZF994-2 exhibited moderate endoglucanase activity and strong ß-glucosidase activity. More than 45% ß-glucosidase activity of the recombinant ZF994-1 retained in the buffer containing 3 M glucose, indicating the good tolerance against glucose. The recombinant ZF994-2 showed high activity in the presence of metal ions and organic reagents, exhibiting potential industrial applications.
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Celulase , Celulases , Celulases/genética , Celulases/metabolismo , Celulase/genética , Celulase/metabolismo , Metagenômica , Filogenia , Glucose , Especificidade por SubstratoRESUMO
In this paper, the adoption of SO2 emission tax rates higher than the legal minimum standard is regarded as a noteworthy policy reform in China (quasi-natural experiment), and a spatial Difference-in-Differences (Spatial-DID) model is constructed to test the direct effects (local effects) and indirect effects (spatial spillover effects) of SO2 emission tax policy reform on PM2.5 concentrations in the atmosphere of 285 China's cities. The estimation and calculation results of the Spatial-DID model show that the SO2 emission tax policy reform can significantly reduce local PM2.5 concentration and significantly promote PM2.5 concentration in surrounding areas. The results of heterogeneity analysis show that the SO2 emission tax policy reform can produce a relatively more beneficial spatial spillover effect in eastern cities and higher administrative level cities, while the pollutants emission rights trading and the reform of NOx emission tax rates can produce beneficial spatial spillover effects when cooperating with the reform of SO2 emission tax rates. The results of the mediation effect analysis show that the higher SO2 emission tax rate can aggravate the surrounding PM2.5 pollution by promoting the aggregation level of industrial production factors and the industrial SO2 emission intensity in the surrounding areas, which can support the existence of the pollution heaven effect.
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Bacterial aromatic polyketides are usually biosynthesized by the type II polyketide synthase (PKS-II) system. Advances in deoxyribonucleic acid (DNA) sequencing, informatics, and biotechnologies have broadened opportunities for the discovery of aromatic polyketides. Meanwhile, metagenomics is a biotechnology that has been considered as a promising approach for the discovery of novel natural products from uncultured bacteria. Here, we cloned a type II polyketide biosynthetic gene cluster (BGC) from the soil metagenome, and the heterologous expression of this gene cluster in Streptomyces coelicolor M1146 resulted in the production of three anthraquinones, two of which (coelulatins 2 and 3) had special hydroxymethyl and methyloxymethyl modifications at C2 of the polyketide scaffold. Gene deletion and in vitro biochemical characterization indicated that the HemN-like radical S-adenosyl-L-methionine (SAM) enzyme CoeI exhibits methylation and is involved in C2 modification.
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A type II polyketide synthase biosynthetic gene cluster (amd) containing three P450 genes was identified from a soil metagenomic library, and novel benz[h]isoquinoline-desferrioxamine B conjugated compound amodesmycins were isolated from Streptomyces albus J1074 harboring the amd gene cluster. Genetic evidence showed that the benz[h]isoquinoline part and desferrioxamine B part in amodesmycins were derived from the amd gene cluster and S. albus J1074, respectively, while P450 enzymes played critical roles in the conjunction of these two parts.
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Policetídeos , Streptomyces griseus , Sideróforos , Desferroxamina , Família MultigênicaRESUMO
As bacterial natural products have been proved to be the most important source of many therapeutic medicines, the need to discover novel natural products becomes extremely urgent. Despite the fact that the majority of bacterial species are yet to be cultured in a laboratory setting, and that most of the bacterial natural product biosynthetic genes are silent, "metagenomics technology" offers a solution to help clone natural product biosynthetic genes from environmental samples, and genetic engineering enables the silent biosynthetic genes to be activated. In this work, a type II polyketide biosynthetic gene cluster was identified from a soil metagenomic library and was activated by over-expression of a SARP regulator gene in the gene cluster in Streptomyces hosts. A new tetracenomycin type compound tetracenomycin Y was identified from the fermentation broth. This study shows that metagenomics and genetic engineering could be combined to provide access to new natural metabolites.
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Produtos Biológicos , DNA Ambiental , Policetídeos , Streptomyces , Produtos Biológicos/metabolismo , Família Multigênica , Naftacenos , Policetídeos/metabolismo , Solo , Streptomyces/genética , Streptomyces/metabolismoRESUMO
The development of chemo/photothermal nanotherapeutic systems with excellent photothermal performance, stable drug loading, tumor targeting and strong membrane penetration still remains a challenge. To address this problem, herein a rod-like nanocomposite system (AuNR@FA-PR/PEG) forming from folic acid (FA) terminated carboxylated cyclodextrin (CD) pseudopolyrotaxane (FA-PR) and polyethylene glycol (PEG) modifying gold nanorods (AuNR) was reported. Cisplatin (CDDP) was loaded in AuNR@FA-PR/PEG via coordination bonds to prepare a rod-like pH-responsive nanosystem (AuNR@FA-PR/PEG/CDDP) with chemotherapy/photothermal therapy. The rod-like morphology of AuNR@FA-PR/PEG was characterized by transmission electron microscope. In vitro drug release experiments showed the pH-responsive of AuNR@FA-PR/PEG/CDDP. In vivo real-time imaging assays proved AuNR@FA-PR/PEG/CDDP could rapidly enrich in the tumor area and stay for a long time because of folate targeting and their rod-like morphology. In vivo photothermal imaging assays showed AuNR@FA-PR/PEG/CDDP excellent photothermal performance, the average temperature of tumor region could reach 63.5 °C after 10 min irradiation. In vitro and in vivo experiments also demonstrated that the combined therapy of chemotherapy and photothermal therapy had an outstandingly synergistic effect and improved the therapeutic efficacy comparing with chemotherapy and photothermal therapy alone. Therefore, the prepared rod-like AuNR@FA-PR/PEG/CDDP will provide a new strategy for the effective treatment of cancer.
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Hipertermia Induzida , Nanocompostos , Neoplasias , Linhagem Celular Tumoral , Cisplatino/farmacologia , Doxorrubicina/química , Ácido Fólico/química , Humanos , Concentração de Íons de Hidrogênio , Nanocompostos/uso terapêutico , Neoplasias/tratamento farmacológico , Fototerapia/métodos , Terapia Fototérmica , Polietilenoglicóis/químicaRESUMO
Mesoporous polydopamine (MPDA) and MPDA-based nanosystems have been widely used in the field of photothermal therapy (PTT) and drug delivery. However, synthesis of the corresponding nanoplatforms for efficient PTT and controlled drug release simultaneously in the second near infrared (NIR-II) region remains a great challenge. Herein, a NIR-II and pH dual-responsive HMPDA@Cu2-xSe cascade catalytic nanoplatform was constructed by assembling hollow mesoporous polydopamine (HMPDA) with ultra-small Cu2-xSe, which could compensate the inadequate NIR-II-induced PTT effect of HMPDA and enhance the efficacy of chemodynamic therapy (CDT) simultaneously under NIR-II laser irradiation. Meanwhile, doxorubicin (DOX) and glucose oxidase (GOx) were encapsulated into the synthesized HMPDA@Cu2-xSe using the photothermal-induced phase change material (PCM) tetradecyl (1-TD) as a gatekeeper to achieve the controlled release of the cargo. Under 1064 nm laser, the generated heat could cause 1-TD melting, resulting in the release of large amounts of DOX and GOx. The released GOx could further catalyze glucose to H2O2 and gluconic acid, which in turn promoted the effects of PTT/CDT and the release of drugs. In vitro and in vivo experiments showed that the synthesized HMPDA@Cu2-xSe-DOX-GOx@PCM (HMPC-D/G@PCM) nanosystem exhibited a significant tumor cell inhibition effect by combining different treatment modes. Thus, this smart nanoplatform with multiple stimuli-activated cascade reactions provided a new idea for designing effective multi-modal combination therapy for tumors.
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Peróxido de Hidrogênio , Nanopartículas , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Nanopartículas/uso terapêutico , Nanotecnologia , Preparações Farmacêuticas , Fototerapia/métodosRESUMO
AIMS: The aim of this study was to evaluate the diversity and potential for horizontal transfer of amikacin resistance genes from the human gut. METHODS AND RESULTS: A library of human faecal microbiota was constructed and subjected to functional screening for amikacin resistance. In total, five amikacin resistance genes that conferred relatively high amikacin resistance, with minimum inhibitory concentrations (MICs) ranging from 64 to >512, were identified from the library, including a novel aminoglycoside acetyltransferase gene and a 16S rRNA methyltransferase (MTase) gene, labelled aac (6')-Iao and rmtI, respectively. AAC(6')-Iao showed the highest identity of 48% to AAC(6')-Ian from a clinical isolate Serratia marcescens, whereas RmtI shared the closest amino acid identity of 32% with ArmA from Klebsiella pneumonia. The MICs of these five subclones to six commonly used aminoglycosides were determined. Susceptibility analysis indicated that RmtI was associated with high resistance phenotype to 4,6-disubstituted 2-DOS aminoglycosides, whereas AAC(6')-Iao conferred resistance to amikacin and kanamycin. In addition, kinetic parameters of AAC(6')-Iao were determined, suggesting a strong catalytic effect on amikacin and kanamycin. CONCLUSIONS: Antibiotic resistance genes with low identity to known sequences can be uncovered by functional metagenomics. In addition, the diversity and prevalence of amikacin resistance genes merit further investigation in extended habitats, especially the 16S rRNA MTase gene that might have been underestimated in previous cognition. SIGNIFICANCE AND IMPACT OF STUDY: Two novel amikacin resistance genes were identified in this study, including a 16S rRNA methyltransferase gene rmtI and an aminoglycoside acetyltransferase gene aac(6')-Iao. This work would contribute to the in-depth study of the diversity and horizontal transfer potential of amikacin resistance genes in the microbiome of the human gut.
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Amicacina , Microbioma Gastrointestinal , Amicacina/farmacologia , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Microbioma Gastrointestinal/genética , Humanos , Canamicina , Metiltransferases/genética , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genéticaRESUMO
The life-threatening adverse effects of doxorubicin (Dox) caused by its cardiotoxic properties limit its clinical application. DDX3X has been shown to participate in a variety of physiological processes, and it acts as a regulator of Wnt/ß-catenin signaling. However, the role of DDX3X in Dox-induced cardiotoxicity (DIC) remains unclear. In this study, we found that DDX3X expression was significantly decreased in H9c2 cardiomyocytes treated with Dox. Ddx3x knockdown and RK-33 (DDX3X ATPase activity inhibitor) pretreatment exacerbated cardiomyocyte apoptosis and mitochondrial dysfunction induced by Dox treatment. In contrast, Ddx3x overexpression ameliorated the DIC response. Moreover, Wnt/ß-catenin signaling in cardiomyocytes treated with Dox was suppressed, but this suppression was reversed by Ddx3x overexpression. Overall, this study demonstrated that DDX3X plays a protective role in DIC by activating Wnt/ß-catenin signaling.
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Cardiotoxicidade , RNA Helicases DEAD-box , Doxorrubicina , Via de Sinalização Wnt , Animais , Apoptose , Cardiotoxicidade/etiologia , Cardiotoxicidade/metabolismo , Linhagem Celular , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/farmacologia , Doxorrubicina/toxicidade , Miócitos Cardíacos/metabolismo , Ratos , beta Catenina/metabolismoRESUMO
Drug-resistant bacterial infections exhibit a major threat to public health. Thus, exploring a novel antibacterial with efficient inhibition is urgently needed. Herein, this paper describes three types of MSNs (MSNs-FC2-R1, MSNs-FC2-R0.75, MSNs-FC2-R0.5) with controllable pore size (4-6 nm) and particle size (30-90 nm) that were successfully prepared. The MSNs were loaded with tetracycline hydrochloride (TCH) for effective inhibition of Escherichia coli (ATCC25922) and TCH-resistant Escherichia coli (MQ776). Results showed that the loading capacity of TCH in three types of MSNs was as high as over 500 mg/g, and the cumulative release was less than 33% in 60 h. The inhibitory rate of MSNs-FC2-R0.5 loaded with TCH against E. coli and drug-resistant E. coli reached 99.9% and 92.9% at the concentration of MIC, respectively, compared with the other two types of MSNs or free TCH. Modified MSNs in our study showed a great application for long-term bacterial growth inhibition.
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Antibacterianos/administração & dosagem , Portadores de Fármacos/química , Escherichia coli/efeitos dos fármacos , Nanopartículas/química , Dióxido de Silício/química , Tetraciclina/administração & dosagem , Sistemas de Liberação de Medicamentos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Tamanho da Partícula , Porosidade , Análise EspectralRESUMO
BACKGROUND: Acute graft-versus-host disease (aGVHD) is a complication of allogeneic hematopoietic stem cell transplantation. Ras-related protein 1A (RAP1A) has been recently identified as a novel oncoprotein in several human malignancies. However, its specific role in aGVHD remains unclear. OBJECTIVE: To study the role of RAP1A in the pathogenesis of aGVHD. MATERIAL AND METHODS: Study participants included six patients with grade 2-4 aGVHD, 13 patients with grade 1 aGVHD, 11 patients without aGVHD, and 12 healthy people. The expression level of RAP1A in whole cells was detected by western blot and qRT-PCR. The proportions of CD4+CD25+FoxP3+ Treg cells (T regulatory cells) and the expression of RAP1A in Treg cells in peripheral blood mononuclear cells (PBMCs) were detected by flow cytometry and the levels of related cytokines in the serum was detected by cytometric bead array. RESULTS: We found the level of RAP1A was higher in patients than in healthy individuals. A negative correlation was noted between RAP1A and the number of Treg cells. In addition, the level of IL-10 in patients with grade 2-4 aGVHD was significantly lower than that in healthy donors, however, the level of TNF-É in patients with grade 2-4 aGVHD was higher. Furthermore, we found a negative correlation between levels of IL-10 and RAP1A, and a positive correlation between TNF-É and RAP1A. CONCLUSION: The expression of RAP1A in patients with aGVHD was significantly increased, and shows potential as a target for the prevention and treatment of aGVHD.
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Transplante de Células-Tronco de Sangue do Cordão Umbilical , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Interleucina-10/metabolismo , Leucócitos Mononucleares/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Proteínas rap1 de Ligação ao GTP/metabolismoRESUMO
Phototherapies, including photothermal therapy (PTT) and photodynamic therapy (PDT) have been potential noninvasive therapeutic modality with high efficiency, however, there still exist some intrinsic limitations that impede their clinical applications. Herein, taking the advantages of the synergistic effect and high reactivity of manganese dioxide (MnO2) nanosheets and glucose oxidase (GOx), multifunctional MPDA@MnO2-MB-GOx nanoamplifier was constructed for enhanced PTT, PDT, and starvation therapy. In tumor microenvironment (TME), MnO2 nanosheets on the surface of mesoporous polydopamine (MPDA) could react with endogenous hydrogen peroxide (H2O2) and generate oxygen (O2) to relieve tumor hypoxia, thus enhancing the efficacy of PDT and GOx catalysis. Glucose consumption under the catalysis of GOx will enhance the acidity of TME and increase intracellular H2O2 concentration, which in turn promotes the production of O2 by MnO2 nanosheets, thus forming efficient cascade reaction and maximizing the efficacy of the functional agents. Furthermore, the heat generated by MPDA under the irradiation of 808 nm laser can accelerate chemical reactions, thus further enhancing synergistic therapeutic efficacy. In vitro/vivo results emphasize that enhanced cancer cell death and tumor inhibition are gained by modulating unfavorable TME with the functional nanosystem, which highlights the promise of the synthesized MPDA@MnO2-MB-GOx nanomaterial to overcome the limitations of phototherapy.
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Peróxido de Hidrogênio , Compostos de Manganês , Humanos , Hipóxia , Óxidos , FototerapiaRESUMO
A cosmid clone cZFYN1413 with CMCase activity was identified from a soil metagenomic library. The sequence analysis of a subclone of cZFYN1413 revealed an endo-ß-1,4-glucanase gene ZFYN1413 belonging to glycoside hydrolase family 6 and a transmembrane region in the N-terminal of ZFYN1413. Expression of ZFYN1413 in Escherichia coli BL21 (DE3) resulted in ZFYN1413-87, which was a truncated protein cleaved in transmembrane region of ZFYN1413. ZFYN1413-87 was expressed and its enzyme properties were studied. ZFYN1413-87 possessed strong endo-ß-1,4-glucanase activity, and 52% of the activity could be retained after the protein was treated in buffer of pH 3.0 for 2 h. The study provided a special example of endo-ß-1,4-glucanase in GH6 family.
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Biblioteca Gênica , Glicosídeo Hidrolases/genética , Metagenômica , Solo , Glicosídeo Hidrolases/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
In order to reduce the toxicity and side effects of anti-tumor drugs and improve their therapeutic effect against cancer, photodynamic and chemical combination therapy has been exploited. However, the complicated preparation and metabolic toxicity of photosensitizer-loaded materials remain major obstacles for bioapplications. In this study, we designed and prepared a specific photosensitizer self-transporting drug-delivery system. First, 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphine (TAPP) was modified using specific molecules of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) with a certain antitumor effect, to prepare a specific fluorescent amphiphilic system (TAPP-TPGS). Then, the drug-loaded fluorescence nanomicelle (TAPP-TPGS/PTX) was formed via self-assembly using the amphiphilic system and the anticancer drug paclitaxel (PTX). The carrier material could be used as a drug tracer and cancer therapy reagent to synergistically trace the chemotherapy drug and treat cancers. The biocompatibility and the enhanced antitumor effect of TAPP-TPGS/PTX were confirmed by in vitro and in vivo experiments. To detect the synergistic anticancer effect enhanced by TPGS, TAPP-mPEG synthesized with a similar method as TAPP-TPGS was used for a comparative analysis. The results showed that the excellent synergistic anticancer effect of the TAPP-TPGS/PTX was enhanced due to the introduction of TPGS. Thus, the specific porphyrin self-transporting nanomicelle is a very promising carrier material for applications in biomedicine.
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Antineoplásicos/farmacologia , Corantes Fluorescentes/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Humanos , Micelas , Estrutura Molecular , Imagem Óptica , Tamanho da Partícula , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Porfirinas/síntese química , Porfirinas/química , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais CultivadasRESUMO
Microbes, especially the uncultured microbes, have been considered as an important resource for discovery of novel cellulases. In this study, a novel bifunctional cellulase/hemicellulase (ZFYN184) was identified by functional screening of a soil metagenomic library. Sequence analysis indicated that ZFYN184 shared at best 39% identity with glycoside hydrolase family 44 (GH44) proteins and contained a glutamic acid residue at 235 acting as the catalytic proton donor in hydrolysis of polysaccharides. The recombinant ZFYN184 was expressed in Escherichia coli BL21 (DE3), and the biochemical profiles of the enzyme, including optimum pH and temperature, pH and thermal stabilities, tolerance to various additives, and substrate specificity, were determined. ZFYN184 possessed strong endo-ß-1,4-glucanase and endo-1,4-ß-mannanase activities, as well as weak xylanase activity, while all these hydrolytic activities were derived from a single catalytic domain in this GH44 enzyme. KEY POINTS: ⢠Discovery a novel bifunctional glycosyl hydrolase from uncultured microorganism. ⢠ZFYN184 contains a single catalytic domain belonged to GH44.