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HER2 amplification is one of the mechanisms that induce drug resistance to anti-EGFR therapy in colorectal cancer. In recent years, data from several randomized clinical trials show that anti-HER2 therapies improved the prognosis of patients with HER2-positive colorectal cancer. These results indicate that HER2 is a promising therapeutic target in advanced colorectal cancer. Despite the anti-HER2 therapies including monoclonal antibodies, tyrosine kinase inhibitors, and antibody-drug conjugates improving the outcomes, less than 30â¯% of the patients achieve objective response and eventually have drug resistance. It is necessary to explore the primary and secondary mechanisms for the resistance to anti-HER2 therapies, which will pave the way to overcome the drug resistance. Several studies have reported the potential mechanisms for the resistance to anti-HER2 therapies. In this review, we present a comprehensive overview of the recent advances in clinical research, mechanisms of treatment resistance, and strategies for reversing resistance in HER2-positive colorectal cancer patients.
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In this article, chiral covalent organic framework core-shell composite CCOF-TpPa-Py@SiO2 was facilely synthesized by induction at room temperature. The CCOF-TpPa-Py@SiO2 core-shell composite was used as a chiral stationary phase for the separation of the racemates by high-performance liquid chromatography, which exhibits good separation performance for chiral compounds including ketones, alcohols, esters, epoxides, carboxylic acids, amides, and amines. The effects of analyte injection mass on the enantioseparation were studied. The reproducibility and stability of the CCOF-TpPa-Py@SiO2 chiral column were explored. The intra-day (n = 5), inter-day (n = 5), and inter-column (n = 3) relative standard deviations for the migration times and resolution of benzoin were 0.32%-0.54%, 0.45%-0.61%, and 1.21%-1.53%, respectively. In addition, the chiral separation ability of the CCOF-TpPa-Py@SiO2 chiral column (column A) was compared with that of the MDI-ß-CD-Modified COF@SiO2 (column B) as well as a commercial chiral column (Chiralpak AD-H). The chiral recognition ability of column A is complementary to that of column B and AD-H column. The resolution mechanism of CCOF-TpPa-Py@SiO2 stationary phase towards chiral analyte was explored. Hence, the synthesis of CCOF-TpPa-Py@SiO2 core-shell composite by induction at room temperature as chiral stationary phases for chromatographic separation has important research potential and application prospects.
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For the first time, the dominant magnetoelectric activity of ZIF-67-derived carbonaceous microparticles embedded with Co nanoparticles and distinctive magnetothermal effect of MIL-88B-derived Fe3O4 nanocubes decorated on carbonaceous microrods, respectively, were explored to be controlled by the structure of the MOF-derived electrically conductive carbonaceous matrix and metal nanoparticles.
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In deserts, sedimentation from frequent dust activities on solar cells poses a substantial technical challenge, reducing efficiency and necessitating advanced cost-inefficient cleaning mechanisms. Herein, a novel sandfish scale-inspired self-healing fluorinated copolymer-based triboelectric layer is directly incorporated on top of the polysilicon solar cell for sustained hybrid energy harvesting. The transparent biomimetic layer, with distinctive saw-tooth microstructured morphology, exhibits ultra-low sand adhesion and high abrasion-resistant properties, inhibits sedimentation deposition on solar cells, and concurrently harvests kinetic energy from wind-driven sand particles through triboelectric nanogenerator (TENG). The film exhibits a low friction coefficient (0.149), minimal sand adhesion force (27 nN), and a small wear area (327 µm2). In addition, over 2 months, a solar cell with the sandfish scale-inspired structure demonstrates only a 16% decline in maximum power output compared to the bare solar cell, which experiences a 60% decline. Further, the sandfish scale-based TENG device's electrical output is fully restored to its original value after a 6-h self-healing cycle and maintains consistent stable outputs. These results highlight the exceptional advantages of employing biomimetic self-healing materials as robust triboelectric layers, showcasing sustained device stability and durability for prolonged use in harsh desert environments, ultimately contributing to a low cost-of-electricity generation paradigm.
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BACKGROUND: Regorafenib (R) and fruquintinib (F) are the standard third-line regimens for colorectal cancer (CRC) according to the National Comprehensive Cancer Network guidelines, but both have limited efficacy. Several phase 2 trials have indicated that R or F combined with immune checkpoint inhibitors can reverse immunosuppression and achieve promising efficacy for microsatellite stable or proficient mismatch repair (MSS/pMMR) CRC. Due to the lack of studies comparing the efficacy between F, R, F plus programmed death-1 (PD-1) inhibitor, and R plus PD-1 inhibitors (RP), it is still unclear whether the combination therapy is more effective than monotherapy. AIM: To provide critical evidence for selecting the appropriate drugs for MSS/pMMR metastatic CRC (mCRC) patients in clinical practice. METHODS: A total of 2639 CRC patients were enrolled from January 2018 to September 2022 in our hospital, and 313 MSS/pMMR mCRC patients were finally included. RESULTS: A total of 313 eligible patients were divided into F (n = 70), R (n = 67), F plus PD-1 inhibitor (FP) (n = 95) and RP (n = 81) groups. The key clinical characteristics were well balanced among the groups. The median progression-free survival (PFS) of the F, R, FP, and RP groups was 3.5 months, 3.6 months, 4.9 months, and 3.0 months, respectively. The median overall survival (OS) was 14.6 months, 15.7 months, 16.7 months, and 14.1 months. The FP regimen had an improved disease control rate (DCR) (P = 0.044) and 6-month PFS (P = 0.014) and exhibited a better trend in PFS (P = 0.057) compared with F, and it was also significantly better in PFS than RP (P = 0.030). RP did not confer a significant survival benefit; instead, the R group had a trend toward greater benefit with OS (P = 0.080) compared with RP. No significant differences were observed between the R and F groups in PFS or OS (P > 0.05). CONCLUSION: FP is superior to F in achieving 6-month PFS and DCR, while RP is not better than R. FP has an improved PFS and 6-month PFS compared with RP, but F and R had similar clinical efficacy. Therefore, FP may be a highly promising strategy in the treatment of MSS/pMMR mCRC.
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A novel CCOF core-shell composite material (S)-DTP-COF@SiO2 was prepared via asymmetric catalytic and in situ growth strategy. The prepared (S)-DTP-COF@SiO2 was utilized as separation medium for HPLC enantioseparation using normal-phase and reversed-phase chromatographic modes, which displays excellent chiral separation performance for alcohols, esters, ketones, and epoxides, etc. Compared with chiral commercial chromatographic columns (Chiralpak AD-H and Chiralcel OD-H columns) and some previously reported chiral CCOF@SiO2 (CC-MP CCTF@SiO2 and MDI-ß-CD-modified COF@SiO2)-packed columns, there are 4, 3, 13, and 15 tested racemic compounds that could not be resolved on the Chiralpak AD-H column, Chiralcel OD-H column, CC-MP CCTF@SiO2 column, and MDI-ß-CD-modified COF@SiO2 column, respectively, which indicates that the resolution effect of (S)-DTP-COF@SiO2-packed column can be complementary to the other ones. The effects of the analyte mass, column temperature, and mobile phase composition on the enantiomeric separation were investigated. The chiral column exhibits good reproducibility after multiple consecutive injections. The RSDs (n = 5) of the peak area and retention time were less than 1.5% for repetitive separation of 2-methoxy-2-phenylethanol and 1-phenyl-1-pentanol. The chiral core-shell composite (S)-DTP-COF@SiO2 exhibited good enantiomeric separation performance, which not only demonstrates its potential as a novel CSP material in HPLC but also expands the range of applications for chiral COFs.
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OBJECTIVES: Toxicants inhibit microbial fermentation and reduce product titres. This work investigated the glycerol production characteristics of Candida glycerinogenes in highly toxic unwashed undetoxified hydrolysate and provided new ideas for high glycerol production from hydrolysates. RESULTS: The unwashed hydrolysate contains higher concentrations of toxicants, such as furfural, acetic acid, phenols and NaCl than the washed alkali-treated bagasse hydrolysate. C. glycerinogenes fermented unwashed undetoxified hydrolysate yielded 36.1 g/L glycerol, 15.8% higher than the washed hydrolysate, suggesting that the toxicants stimulated glycerol synthesis. qRT-PCR analysis showed that toxicants of unwashed undetoxified hydrolysates greatly up-regulated the transcript levels of the genes GPD1, HXT4 and MSN4 et al. Overexpressing the above genes increased glycerol production by 27.9% to 46.1 g/L. And it was further increased by 8.8% to 50.1 g/L in a 5 L bioreactor. CONCLUSIONS: This result proves that toxicants in lignocellulosic hydrolysates can increase the titre of microbial glycerol production.
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Metal organic cages (MOCs), as an emerging discrete supramolecular compounds, have received widespread attention in separation, biomedicine, gas capture, catalysis, and molecular recognition due to their porosity, adjustability and stability. Herein, we present a new chiral MOC FeII4L4 coated capillary column prepared for gas chromatographic (GC) separation of different types of organic compounds, including n-alkanes, n-alcohols, alkylbenzenes, isomers, especially for racemic compounds. There are 20 different kinds of racemates (e.g., alcohols, ethers, epoxides, esters, alkenes, and aldehydes) were well resolved on the FeII4L4 chiral column and a maximum resolution value for 1-phenyl-1-propanol reaches 6.17. The FeII4L4 coated column exhibited high column efficiency (3100 plates m-1 for n-dodecane) and good enantiomeric resolution complementary to that of a commercial ß-DEX 120 column and the previously reported chiral MOC [Fe4L6] (ClO4)8 coated column. The relative standard deviation (RSDs) of the peak area and retention time of glycidol and nitrotoluene were below 1.2 %. This study reveals that chiral MOCs have good application prospects in chromatographic separation.
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NAD is a redox coenzyme and is the center of energy metabolism. In metabolic engineering modifications, an insufficient NAD(H) supply often limits the accumulation of target products. In this study, Candida glycerinogenes was found to be able to supply NAD(H) in large fluxes, up to 7.6 times more than Saccharomyces cerevisiae in aerobic fermentation. Aerobic fermentation in a medium without amino nitrogen sources demonstrated that C. glycerinogenes NAD synthesis was not dependent on NAD precursors in the medium. Inhibition by antisense RNA and the detection of transcript levels indicated that the main NAD supply pathway is the de novo biosynthesis pathway. It was further demonstrated that NAD(H) supply was unaffected by changes in metabolic flow through C. glycerinogenes ΔGPD aerobic fermentation (80 g/L ethanol). In conclusion, the ability of C. glycerinogenes to supply NAD(H) in large fluxes provides a new approach to solving the NAD(H) supply problem in synthetic biology.
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Candida , Fermentación , Ingeniería Metabólica , NAD , NAD/metabolismo , Candida/metabolismo , Candida/genética , Aerobiosis , Ingeniería Metabólica/métodos , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Etanol/metabolismo , ARN sin Sentido/genética , ARN sin Sentido/metabolismoRESUMEN
Lactiplantibacillus plantarum M5 and Goji Berry extract were co-microencapsulated to maintain the activity of cells during gastrointestinal digestion, and the mechanism by which they could maintain high activity was investigated. The results showed that the microcapsules with 3% Goji Berry extract(A-GE-3) had the largest encapsulation efficiency(EE) of 92.41 ± 0.58%. SEM showed that the structure of A-GE-3 microcapsules were smoother and denser. Cell viability in A-GE-3 microcapsules remained at 7.17 log10 CFU/g after gastrointestinal digestion. Meanwhile, during the gastrointestinal digestion with 3% Goji Berry extract, cell membrane damage detected by fluorescent probes propidium iodide(PI) and 1.1-N-phenylnaphthylamine(NPN) was significantly reduced; the contents of arginine, glutamic acid and oleic acid in cell membrane were increased, which helped to maintain the dynamic balance of intracellular pH and regulated cell membrane fluidity in response to gastrointestinal environment. This study demonstrated the potential of Goji Berry extract as a probiotic protector in gastrointestinal digestion.
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Caffeic acid (CA) is a phenolic acid compound widely used in pharmaceutical and food applications. However, the efficient synthesis of CA is usually limited by the resources of individual microbial platforms. Here, a cross-kingdom microbial consortium was developed to synthesize CA from sugarcane bagasse hydrolysate using Escherichia coli and Candida glycerinogenes as chassis. In the upstream E. coli module, shikimate accumulation was improved by intensifying the shikimate synthesis pathway and blocking shikimate metabolism to provide precursors for the downstream CA synthesis module. In the downstream C. glycerinogenes module, conversion of p-coumaric acid to CA was improved by increasing the supply of the cytoplasmic cofactor FAD(H2). Further, overexpression of ABC transporter-related genes promoted efflux of CA and enhanced strain resistance to CA, significantly increasing CA titer from 103.8 mg/L to 346.5 mg/L. Subsequently, optimization of the inoculation ratio of strains SA-Ec4 and CA-Cg27 in this cross-kingdom microbial consortium resulted in an increase in CA titer to 871.9 mg/L, which was 151.6% higher compared to the monoculture strain CA-Cg27. Ultimately, 2311.6 and 1943.2 mg/L of CA were obtained by optimization of the co-culture system in a 5 L bioreactor using mixed sugar and sugarcane bagasse hydrolysate, respectively, with 17.2-fold and 14.6-fold enhancement compared to the starting strain. The cross-kingdom microbial consortium developed in this study provides a reference for the production of other aromatic compounds from inexpensive raw materials.
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Background: Polycythemia vera (PV) is a myeloproliferative neoplasm. Ropeginterferon alfa-2b is a new-generation polyethylene glycol-conjugated proline-interferon. It is approved for the treatment of PV at a starting dose of 100 µg (50 µg for patients receiving hydroxyurea (HU)) and dose titrations up to 500 µg by 50 µg increments. The study was aimed at assessing its efficacy and safety at a higher starting dose and simpler intra-patient dose escalation. Methods: Forty-nine patients with PV having HU intolerance from major hospitals in China were treated biweekly with an initial dose of 250 µg, followed by 350 µg and 500 µg thereafter if tolerated. Complete hematological response (CHR) was assessed every 12 weeks based on the European LeukemiaNet criteria. The primary endpoint was the CHR rate at week 24. The secondary endpoints included CHR rates at weeks 12, 36 and 52, changes of JAK2V617F allelic burden, time to first CHR, and safety assessments. Results: The CHR rates were 61.2%, 69.4% and 71.4% at weeks 24, 36, and 52, respectively. Mean allele burden of the driver mutation JAK2V617F declined from 58.5% at baseline to 30.1% at 52 weeks. Both CHR and JAK2V617F allele burden reduction showed consistent increases over the 52 weeks of the treatment. Twenty-nine patients (63.0%) achieved partial molecular response (PMR) and two achieved complete molecular response (CMR). The time to CHR was rapid and median time was 5.6 months according to central lab results. The CHRs were durable and median CHR duration time was not reached at week 52. Mean spleen index reduced from 55.6 cm2 at baseline to 50.2 cm2 at week 52. Adverse events (AEs) were mostly mild or moderate. Most common AEs were reversible alanine aminotransferase and aspartate aminotransferase increases, which were not associated with significant elevations in bilirubin levels or jaundice. There were no grade 4 or 5 AEs. Grade 3 AEs were reversible and manageable. Only one AE led to discontinuation. No incidence of thromboembolic events was observed. Conclusion: The 250-350-500 µg dosing regimen was well tolerated and effectively induced CHR and MR and managed spleen size increase. Our findings demonstrate that ropeginterferon alfa-2b at this dosing regimen can provide an effective management of PV and support using this dosing regimen as a treatment option.
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BACKGROUND: Carboxypeptidase is an exopeptidase that hydrolyzes amino acids at the C-terminal end of the peptide chain and has a wide range of applications in food. However, in industrial applications, the relatively low catalytic efficiency of carboxypeptidases is one of the main limiting factors for industrialization. RESULTS: The study has enhanced the catalytic efficiency of Bacillus megaterium M32 carboxypeptidase (BmeCPM32) through semi-rational design. Firstly, the specific activity of the optimal mutant, BmeCPM32-M2, obtained through single-site mutagenesis and combinatorial mutagenesis, was 2.2-fold higher than that of the wild type (187.9 versus 417.8 U mg-1), and the catalytic efficiency was 2.9-fold higher (110.14 versus 325.75 s-1 mmol-1). Secondly, compared to the wild type, BmeCPM32-M2 exhibited a 1.8-fold increase in half-life at 60 °C, with no significant changes in its enzymatic properties (optimal pH, optimal temperature). Finally, BmeCPM32-M2 significantly increased the umami intensity of soy protein isolate hydrolysate by 55% and reduced bitterness by 83%, indicating its potential in developing tasty protein components. CONCLUSION: Our research has revealed that the strategy based on protein sequence evolution and computational residue mutation energy led to an improved catalytic efficiency of BmeCPM32. Molecular dynamics simulations have revealed that a smaller substrate binding pocket and increased enzyme-substrate affinity are the reasons for the enhanced catalytic efficiency. Furthermore the number of hydrogen bonds and solvent and surface area may contribute to the improvement of thermostability. Finally, the de-bittering effect of BmeCPM32-M2 in soy protein isolate hydrolysate suggests its potential in developing palatable protein components. © 2024 Society of Chemical Industry.
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Bacillus megaterium , Proteínas Bacterianas , Carboxipeptidasas , Gusto , Proteínas Bacterianas/genética , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Carboxipeptidasas/metabolismo , Carboxipeptidasas/genética , Carboxipeptidasas/química , Bacillus megaterium/enzimología , Bacillus megaterium/genética , Cinética , Humanos , Concentración de Iones de Hidrógeno , Estabilidad de Enzimas , Ingeniería de Proteínas , Biocatálisis , Proteínas de Soja/química , Proteínas de Soja/metabolismo , Proteínas de Soja/genética , Mutagénesis Sitio-Dirigida , Aromatizantes/química , Aromatizantes/metabolismo , CatálisisRESUMEN
BACKGROUND: Anlotinib has demonstrated promising anti-tumor efficacy in various solid tumors. Additionally, there is evidence suggesting that immune therapy can enhance the systemic responses of anlotinib. This study aimed to assess the effectiveness and safety of combining anlotinib with PD-1 inhibitors compared to fluoropyrimidine-based chemotherapy as a second-line treatment option for advanced biliary tract cancers (BTCs). METHODS: A total of 242 patients with BTCs were screened at the First Affiliated Hospital of Zhengzhou University from October 2015 to October 2022. Among them, 78 patients who received either anlotinib plus PD-1 inhibitors (AP) or fluoropyrimidine-based chemotherapy (FB) as second-line treatment were included in the study. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), safety, and predictive tumor biomarkers. RESULTS: Among the 78 patients with BTCs, 39 patients received AP, while 39 patients were administered FB. The ORR in the AP group was 20.5%, compared to 5.1% in the FB group. The DCR was 87.2% in the AP group and 66.7% in the FB group. The AP group demonstrated significantly better ORR and DCR compared to the FB group (p = 0.042, p = 0.032). The median PFS and OS in the AP group were 7.9 months (95% CI: 4.35-11.45) and 13.9 months (95% CI: 5.39-22.41), respectively. In the FB group, the median PFS and OS were 4.1 months (95% CI: 3.17-5.03) and 13.2 months (95% CI: 8.72-17.68), respectively. The AP group exhibited significantly better median PFS than the FB group (p = 0.027). In the subgroup analysis, patients without liver metastasis had a much longer PFS in the AP group compared to the FB group (14.3 vs. 5.5 months, p = 0.016). Similarly, patients with CEA ≤ 5 µg/L also demonstrated a longer PFS in the AP group compared to the FB group (8.7 vs. 3.9 months, p = 0.008). CONCLUSIONS: The combination of anlotinib and PD-1 inhibitors demonstrated a promising clinical effect compared to fluoropyrimidine-based chemotherapy in the second-line treatment of refractory advanced BTCs. Liver metastases and CEA levels may serve as predictive factors for identifying patients who may benefit from AP therapy.
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Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias del Sistema Biliar , Inhibidores de Puntos de Control Inmunológico , Indoles , Quinolinas , Humanos , Masculino , Femenino , Persona de Mediana Edad , Quinolinas/uso terapéutico , Quinolinas/efectos adversos , Quinolinas/administración & dosificación , Neoplasias del Sistema Biliar/tratamiento farmacológico , Neoplasias del Sistema Biliar/patología , Neoplasias del Sistema Biliar/mortalidad , Anciano , Indoles/uso terapéutico , Indoles/administración & dosificación , Indoles/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Adulto , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Supervivencia sin Progresión , Estudios Retrospectivos , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Anciano de 80 o más AñosRESUMEN
Self-incompatibility (SI) is a crucial mechanism that prevents self-fertilization and inbreeding in flowering plants. Citrus exhibits SI regulated by a polymorphic S-locus containing an S-RNase gene and multiple S-locus F-box (SLF) genes. It has been documented that S-RNase functions as the pistil S determinant, but there is no direct evidence that the SLF genes closely linked with S-RNase function as pollen S determinants in Citrus. This study assembled the genomes of two pummelo (Citrus grandis) plants, obtained three novel complete and well-annotated S-haplotypes, and isolated 36 SLF or SLF-like alleles on the S-loci. Phylogenetic analysis of 138 SLFs revealed that the SLF genes were classified into 12 types, including six types with divergent or missing alleles. Furthermore, transformation experiments verified that the conserved S6-SLF7a protein can lead to the transition of SI to self-compatibility by recognizing non-self S8-RNase in 'Mini-Citrus' plants (S7S8 and S8S29, Fortunella hindsii), a model plant for citrus gene function studies. In vitro assays demonstrated interactions between SLFs of different S haplotypes and the Skp1-Cullin1-F-box subunit CgSSK1 protein. This study provides direct evidence that SLF controls the pollen function in Citrus, demonstrating its role in the 'non-self recognition' SI system.
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Citrus , Proteínas F-Box , Filogenia , Proteínas de Plantas , Polen , Ribonucleasas , Autoincompatibilidad en las Plantas con Flores , Citrus/genética , Citrus/fisiología , Citrus/metabolismo , Autoincompatibilidad en las Plantas con Flores/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/genética , Polen/fisiología , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Ribonucleasas/metabolismo , Ribonucleasas/genética , Secuencia de AminoácidosRESUMEN
Piezoelectric biomaterials have demonstrated significant potential in the past few decades to heal damaged tissue and restore cellular functionalities. Herein, we discuss the role of bioelectricity in tissue remodeling and explore ways to mimic such tissue-like properties in synthetic biomaterials. In the past decade, biomedical engineers have adopted emerging functional biomaterials-based tissue engineering approaches using innovative bioelectronic stimulation protocols based on dynamic stimuli to direct cellular activation, proliferation, and differentiation on engineered biomaterial constructs. The primary focus of this review is to discuss the concepts of piezoelectric energy harvesting, piezoelectric materials, and their application in soft (skin and neural) and hard (dental and bone) tissue regeneration. While discussing the prospective applications as an engineered tissue, an important distinction has been made between piezoceramics, piezopolymers, and their composites. The superiority of piezopolymers over piezoceramics to circumvent issues such as stiffness mismatch, biocompatibility, and biodegradability are highlighted. We aim to provide a comprehensive review of the field and identify opportunities for the future to develop clinically relevant and state-of-the-art biomaterials for personalized and remote health care.
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Materiales Biocompatibles , Ingeniería de Tejidos , Ingeniería de Tejidos/métodos , Piel , Cicatrización de Heridas , Ingeniería BiomédicaRESUMEN
Candida glycerinogenes is an industrial yeast with excellent multistress resistance. However, due to the diploid genome and the lack of meiosis and screening markers, its molecular genetic operation is limited. Here, a gene editing system using the toxin-antitoxin pair relBE from the type II toxin-antitoxin system in Escherichia coli as a screening marker was constructed. The RelBE complex can specifically and effectively regulate cell growth and arrest through a conditionally controlled toxin RelE switch, thereby achieving the selection of positive recombinants. The constructed editing system achieved precise gene deletion, replacement, insertion, and gene episomal expression in C. glycerinogenes. Compared with the traditional amino acid deficiency complementation editing system, this editing system produced higher biomass and the gene deletion efficiency was increased by 3.5 times. Using this system, the production of 2-phenylethanol by C. glycerinogenes was increased by 11.5-13.5% through metabolic engineering and tolerance engineering strategies. These results suggest that the stable gene editing system based on toxin-antitoxin pairs can be used for gene editing of C. glycerinogenes to modify metabolic pathways and promote industrial applications. Therefore, the constructed gene editing system is expected to provide a promising strategy for polyploid industrial microorganisms lacking gene manipulation methods.
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Antitoxinas , Toxinas Bacterianas , Alcohol Feniletílico , Pichia , Edición Génica/métodos , Antitoxinas/genética , Toxinas Bacterianas/genética , Escherichia coli/genética , Escherichia coli/metabolismoRESUMEN
Geraniol is an attractive natural monoterpene with significant industrial and commercial value in the fields of pharmaceuticals, condiments, cosmetics, and bioenergy. The biosynthesis of monoterpenes suffers from the availability of key intermediates and enzyme-to-substrate accessibility. Here, we addressed these challenges in Candida glycerinogenes by a plasma membrane-anchoring strategy and achieved sustainable biosynthesis of geraniol using bagasse hydrolysate as substrate. On this basis, a remarkable 2.4-fold improvement in geraniol titer was achieved by combining spatial and temporal modulation strategies. In addition, enhanced geraniol transport and modulation of membrane lipid-associated metabolism effectively promoted the exocytosis of toxic monoterpenes, significantly improved the resistance of the engineered strain to monoterpenes and improved the growth of the strains, resulting in geraniol yield up to 1207.4 mg L-1 at shake flask level. Finally, 1835.2 mg L-1 geraniol was obtained in a 5 L bioreactor using undetoxified bagasse hydrolysate. Overall, our study has provided valuable insights into the plasma membrane engineering of C. glycerinogenes for the sustainable and green production of valuable compounds.
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Monoterpenos , Pichia , Monoterpenos Acíclicos/metabolismo , Ingeniería Metabólica , Monoterpenos/metabolismoRESUMEN
Glycerol is an important platform compound with multidisciplinary applications, and glycerol production using low-cost sugar cane bagasse hydrolysate is promising. Candida glycerinogenes, an industrial yeast strain known for its high glycerol production capability, has been found to thrive in bagasse hydrolysate obtained through a simple treatment without detoxification. The engineered C. glycerinogenes exhibited significant resistance to furfural, acetic acid, and 3,4-dimethylbenzaldehyde within undetoxified hydrolysates. To further enhance glycerol production, genetic modifications were made to Candida glycerinogenes to enhance the utilization of xylose. Fermentation of undetoxified bagasse hydrolysate by CgS45 resulted in a glycerol titer of 40.3 g/L and a yield of 40.4%. This process required only 1 kg of bagasse to produce 93.5 g of glycerol. This is the first report of glycerol production using lignocellulose, which presents a new way for environmentally friendly industrial production of glycerol.
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Candida , Glicerol , Pichia , Candida/metabolismo , Lignina/metabolismo , Fermentación , Saccharomyces cerevisiae/metabolismo , XilosaRESUMEN
Cancer immunotherapy has emerged as a promising strategy in the treatment of colorectal cancer, and relapse after tumor immunotherapy has attracted increasing attention. Cancer stem cells (CSCs), a small subset of tumor cells with self-renewal and differentiation capacities, are resistant to traditional therapies such as radiotherapy and chemotherapy. Recently, CSCs have been proven to be the cells driving tumor relapse after immunotherapy. However, the mutual interactions between CSCs and cancer niche immune cells are largely uncharacterized. In this review, we focus on colorectal CSCs, CSC-immune cell interactions and CSC-based immunotherapy. Colorectal CSCs are characterized by robust expression of surface markers such as CD44, CD133 and Lgr5; hyperactivation of stemness-related signaling pathways, such as the Wnt/ß-catenin, Hippo/Yap1, Jak/Stat and Notch pathways; and disordered epigenetic modifications, including DNA methylation, histone modification, chromatin remodeling, and noncoding RNA action. Moreover, colorectal CSCs express abnormal levels of immune-related genes such as MHC and immune checkpoint molecules and mutually interact with cancer niche cells in multiple tumorigenesis-related processes, including tumor initiation, maintenance, metastasis and drug resistance. To date, many therapies targeting CSCs have been evaluated, including monoclonal antibodies, antibodyâdrug conjugates, bispecific antibodies, tumor vaccines adoptive cell therapy, and small molecule inhibitors. With the development of CSC-/niche-targeting technology, as well as the integration of multidisciplinary studies, novel therapies that eliminate CSCs and reverse their immunosuppressive microenvironment are expected to be developed for the treatment of solid tumors, including colorectal cancer.