Intracellular Enzyme-Responsive Profluorophore and Prodrug Nanoparticles for Tumor-Specific Imaging and Precise Chemotherapy

Author(s):  
Qing Pei ◽  
Shaojin Lu ◽  
Junli Zhou ◽  
Bowen Jiang ◽  
Chaonan Li ◽  
...  
Keyword(s):  
2018 ◽  
Vol 18 (6) ◽  
pp. 891-902 ◽  
Author(s):  
Srinu Bodige ◽  
Parameshwar Ravula ◽  
Kali Charan Gulipalli ◽  
Srinivas Endoori ◽  
J.N. Narendra Sharath Chandra ◽  
...  

Background: Phosphatidylinositol-3-kinase α (PI3Kα) is a ubiquitous intracellular enzyme, mainly involved in intracellular signaling pathways, promotes cellular growth, proliferation, and differentiation. Therefore, inhibition of PI3K can be a hotspot in molecular targeted therapy for the treatment of cancer. Methods: The present research work involves molecular docking studies performed to screen derivatives of urea and thiourea bearing thieno [3,2-d]-pyrimidines against the active site of PI3K enzyme using MOE.2008.10. The designed structures (6a-f) and (7a-j) were synthesized by the facile synthetic methods and evaluated for their anticancer activity against HT-29 and MCF-7 cell lines and inhibitory activity against PI3Kα enzyme. Results: Among the tested compounds, 4-(4-(2-(3-(pyrimidin-2-yl)thioureido)ethyl)piperazin-1-yl)thieno[3,2- d]pyrimidine-6-carboxamide (7f) showed the highest anticancer activity against HT-29 and MCF-7 cell lines with IC50 values of 2.18 µM and 4.25 µM, respectively. Further, the same compound also exhibited potent PI3Kα inhibitory activity with IC50 value of 1.26 µM. Conclusion: Docking studies supported the initial pharmacophoric hypothesis and suggested a mode of interaction at the active binding site of PI3Kα, demonstrating that the target compounds were potential inhibitory agents for cancer therapy.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Katharina N. Schwaiger ◽  
Monika Cserjan-Puschmann ◽  
Gerald Striedner ◽  
Bernd Nidetzky

Abstract Background Glucosylglycerol (2-O-α-d-glucosyl-sn-glycerol; GG) is a natural osmolyte from bacteria and plants. It has promising applications as cosmetic and food-and-feed ingredient. Due to its natural scarcity, GG must be prepared through dedicated synthesis, and an industrial bioprocess for GG production has been implemented. This process uses sucrose phosphorylase (SucP)-catalyzed glycosylation of glycerol from sucrose, applying the isolated enzyme in immobilized form. A whole cell-based enzyme formulation might constitute an advanced catalyst for GG production. Here, recombinant production in Escherichia coli BL21(DE3) was compared systematically for the SucPs from Leuconostoc mesenteroides (LmSucP) and Bifidobacterium adolescentis (BaSucP) with the purpose of whole cell catalyst development. Results Expression from pQE30 and pET21 plasmids in E. coli BL21(DE3) gave recombinant protein at 40–50% share of total intracellular protein, with the monomeric LmSucP mostly soluble (≥ 80%) and the homodimeric BaSucP more prominently insoluble (~ 40%). The cell lysate specific activity of LmSucP was 2.8-fold (pET21; 70 ± 24 U/mg; N = 5) and 1.4-fold (pQE30; 54 ± 9 U/mg, N = 5) higher than that of BaSucP. Synthesis reactions revealed LmSucP was more regio-selective for glycerol glycosylation (~ 88%; position O2 compared to O1) than BaSucP (~ 66%), thus identifying LmSucP as the enzyme of choice for GG production. Fed-batch bioreactor cultivations at controlled low specific growth rate (µ = 0.05 h−1; 28 °C) for LmSucP production (pET21) yielded ~ 40 g cell dry mass (CDM)/L with an activity of 2.0 × 104 U/g CDM, corresponding to 39 U/mg protein. The same production from the pQE30 plasmid gave a lower yield of 6.5 × 103 U/g CDM, equivalent to 13 U/mg. A single freeze–thaw cycle exposed ~ 70% of the intracellular enzyme activity for GG production (~ 65 g/L, ~ 90% yield from sucrose), without releasing it from the cells during the reaction. Conclusions Compared to BaSucP, LmSucP is preferred for regio-selective GG production. Expression from pET21 and pQE30 plasmids enables high-yield bioreactor production of the enzyme as a whole cell catalyst. The freeze–thaw treated cells represent a highly active, solid formulation of the LmSucP for practical synthesis.


AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jie Tang ◽  
Dan Lei ◽  
Min Wu ◽  
Qiong Hu ◽  
Qing Zhang

Abstract Fenvalerate is a pyrethroid insecticide with rapid action, strong targeting, broad spectrum, and high efficiency. However, continued use of fenvalerate has resulted in its widespread presence as a pollutant in surface streams and soils, causing serious environmental pollution. Pesticide residues in the soil are closely related to food safety, yet little is known regarding the kinetics and metabolic behaviors of fenvalerate. In this study, a fenvalerate-degrading microbial strain, CD-9, isolated from factory sludge, was identified as Citrobacter freundii based on morphological, physio-biochemical, and 16S rRNA sequence analysis. Response surface methodology analysis showed that the optimum conditions for fenvalerate degradation by CD-9 were pH 6.3, substrate concentration 77 mg/L, and inoculum amount 6% (v/v). Under these conditions, approximately 88% of fenvalerate present was degraded within 72 h of culture. Based on high-performance liquid chromatography and gas chromatography-mass spectrometry analysis, ten metabolites were confirmed after the degradation of fenvalerate by strain CD-9. Among them, o-phthalaldehyde is a new metabolite for fenvalerate degradation. Based on the identified metabolites, a possible degradation pathway of fenvalerate by C. freundii CD-9 was proposed. Furthermore, the enzyme localization method was used to study CD-9 bacteria and determine that its degrading enzyme is an intracellular enzyme. The degradation rate of fenvalerate by a crude enzyme solution for over 30 min was 73.87%. These results showed that strain CD-9 may be a suitable organism to eliminate environmental pollution by pyrethroid insecticides and provide a future reference for the preparation of microbial degradation agents and environmental remediation.


Author(s):  
Prathap Talwar ◽  
Triveni Kondareddy ◽  
Pranidha Shree C. A.

Background: Pregnancy induced hypertension (PIH) is a global problem with a 5-15% incidence rate in India and complicating 10-17% of all pregnancies. These are multisystem disorders and lead to a lot of cellular death. LDH is an intracellular enzyme and its level is increased in these women due to cellular death. So, serum LDH levels can be used to assess the extent of cellular death and thereby the severity of disease in this group of women. The objective of the study was to correlate the severity of the disease, maternal and perinatal outcome with Lactic Dehydrogenase (LDH) levels in serum in patients of preeclampsia and eclampsia.Methods: A prospective comparative study was conducted in the department of Obstetrics and Gynecology, JSS Medical Hospital, Mysore.Results: LDH levels were significantly elevated in women with preeclampsia and eclampsia (<0.001). Higher LDH levels had significant correlation with high blood pressure (P <0.10) as well as poor maternal and perinatal outcome.Conclusions: High serum LDH levels correlate well with the severity of the disease and poor outcomes in patients of preeclampsia and eclampsia.


Author(s):  
Nirmala Bhandari ◽  
Anjali Gupta ◽  
Simmi Kharb ◽  
Meenakshi Chauhan

Background: Hypertensive disorder of pregnancy occurs in approximately 6-8% of all pregnancies. The most serious consequences for the mother and the baby are the result of preeclampsia and eclampsia. Lactate Dehydrogenase (LDH) is an intracellular enzyme. Recently LDH has been suggested as potential marker to predict severity of pre-eclampsia. The objective of the present study was to compare the serum lactate dehydrogenase levels in women with preeclampsia and normal pregnant women and to correlate lactate dehydrogenase levels with maternal and perinatal outcome in preeclampsia.Methods: An observational prospective study was conducted on 200 antenatal women attending the labour room emergency. Women with singleton pregnancy and cephalic presentation, from 28 weeks onwards were enrolled in the study. Out of 200, 100 were normal pregnant women and 100 were preeclamptic women. Serum LDH levels were measured in all women and maternal and perinatal outcome was assessed in terms of LDH levels.Results: Higher levels of LDH was observed in pregnant women with preeclampsia (627.38±230.04 IU/l) as compared to normal pregnant women (224.43±116.61 IU/l). The maternal complications were found to be maximum in women with LDH > 800 IU/l.  Abruption was the most common complication. The perinatal mortality and neonatal deaths were found to have significant correlation with high LDH levels.Conclusions: Maternal and perinatal complications were associated with higher LDH levels in preeclampsia patients. Serum LDH levels can be offered to all patients of preeclampsia and can be used to predict the prognosis of preeclampsia.


2021 ◽  
Author(s):  
Nilesh Umakant Deshpande ◽  
Mishika Virmani ◽  
Manickam Jayakannan

We report aggregation induced emission (AIE) driven polysaccharide polymersome as fluorescence resonance energy transfer (FRET) nanoprobes to study their intracellular enzyme-responsive delivery by real-time live-cell confocal microscopy bio-imaging techniques. AIE...


1932 ◽  
Vol 16 (2) ◽  
pp. 233-242 ◽  
Author(s):  
B. G. Wilkes ◽  
Elizabeth T. Palmer

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H+) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exerts its physiological activity changes its pH freely and to the same extent as that of the suspending medium. It is suggested that this may indicate that this intracellular enzyme may perform its work somewhere in the outer region of the cell. 4. In using live cells containing maltase, no evidence of increased sucroclastic activity around pH 6.9, due to the action of Weidenhagen's α-glucosidase (maltase), was found.


1995 ◽  
Vol 79 (4) ◽  
pp. 1271-1277 ◽  
Author(s):  
C. M. De Castro ◽  
M. F. Bureau ◽  
M. A. Nahori ◽  
C. H. Dumarey ◽  
B. B. Vargaftig ◽  
...  

One hour after lipopolysaccharide (LPS) administration (intravenous) in guinea pigs, alveolar macrophages are primed for an ex vivo increased secretion of arachidonic acid metabolites from the cyclooxygenase and the lipoxygenase pathways, with challenge by a second stimulus. At the same time, maximal levels of tumor necrosis factor-alpha (TNF-alpha) are observed in the circulation and in the bronchoalveolar lavage fluid. An extracellular form of phospholipase A2, corresponding probably to the low-molecular-mass type II enzyme, known to accumulate in inflammatory exudates, appears later in the serum of guinea pigs, to reach maximal levels 6 h after the LPS. Unlike the intracellular enzyme, extracellular phospholipase A2 is not increased by LPS in alveolar macrophages or in bronchoalveolar lavage fluids. After 24 h, at the time when neither TNF-alpha nor extracellular phospholipase A2 is present and priming of macrophages is over, maximal neutrophil infiltration is observed in the alveolar space of LPS-treated guinea pigs. Dexamethasone administered repeatedly during 3 days (subcutaneous) before the LPS challenge prevented both early events such as the macrophage priming and the TNF-alpha appearance and later events such as extracellular phospholipase A2 release and neutrophil recruitment.


2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Marcin Grąz ◽  
Kamila Rachwał ◽  
Radosław Zan ◽  
Anna Jarosz-Wilkołazka

Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-exchange chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme exhibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of Km for oxalate and Vmax for the enzyme reaction were 0.015 M and 30 mmol min-1, respectively.


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