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1.
Am J Cancer Res ; 14(5): 1957-1980, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38859839

RESUMO

Cancer disease is the second leading cause of death worldwide. In 2023, about 2 million new cancer cases and 609,820 cancer deaths are projected to occur in the United States. The driving forces of cancer progression and metastasis are widely varied and comprise multifactorial events. Although there is significant success in treating cancer, patients still present with tumors at advanced stages. Therefore, the discovery of novel oncologic pathways has been widely developed. Tumor cells communicate with each other through small extracellular vesicles (sEVs), which contribute to tumor-stromal interaction and promote tumor growth and metastasis. sEV-specific inhibitors are being investigated as a next-generation cancer therapy. A literature search was conducted to discuss different options for targeting sEV pathways in cancer cells. However, there are some challenges that need to be addressed in targeting sEVs: i) specificity and toxicity of sEV inhibitor, ii) targeted delivery of sEV inhibitors, iii) combination of sEV inhibitors with current standard chemotherapy to improve patients' clinical outcomes, and iv) data reproducibility and applicability at distinct levels of the disease. Despite these challenges, sEV inhibitors have immense potential for effectively treating cancer patients.

2.
Ther Deliv ; 14(1): 17-29, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36919692

RESUMO

Aim: Major challenges to islet transplantation in Type 1 diabetes include host-inflammation, which results in failure to maintain survival and functions of transplanted islets. Therefore, this study investigated the applications of encapsulating the bile acid ursodeoxycholic acid (UDCA) with transplanted islets within improved nano-gel systems for Type 1 diabetes treatment. Materials & methods: Islets were harvested from healthy mice, encapsulated using UDCA-nano gel and transplanted into the diabetic mice, while the control group was transplanted encapsulated islets without UDCA. The two groups' survival plot, blood glucose, and inflammation and bile acid profiles were analyzed. Results & conclusion: UDCA-nano gel enhanced survival, glycemia and normalized bile acids' profile, which suggests improved islets functions and potential adjunct treatment for insulin therapy.


In this study, we explore the delivery of insulin producing cells that may benefit those with Type 1 diabetes. Cells were delivered to mice in a protective matrix. The matrix contained unique components, such as bile acids, that allowed for sustained reduction in glucose levels. This process may represent a novel diabetes treatment that could be an alternative to traditional insulin therapies.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Transplante das Ilhotas Pancreáticas , Camundongos , Animais , Ácidos e Sais Biliares/uso terapêutico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/cirurgia , Diabetes Mellitus Experimental/tratamento farmacológico , Insulina/uso terapêutico , Transplante das Ilhotas Pancreáticas/métodos , Glicemia
3.
Biotechnol Lett ; 45(2): 175-189, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36482052

RESUMO

Carrageenan is one of the most common carbohydrates utilised in the entrapment industry to immobilise cells and enzymes. However, it lacks functionality. Carrageenan has been grafted to produce fructose by covalently immobilising glucose isomerase (GI). Fructose is one of the most widely used sweeteners in beverages, food production, and the pharmaceutical business. Up to 91.1 U g-1 gel beads are immobilised by the grafted beads. Immobilized GI has a Vmax of 13.8 times that of the free enzyme. pH of immobilized GI was improved from 6.5-7 to 6-7.5 that means more stability in wide pH range. Also, optimum temperature was improved and become 65-75 °C while it was at 70 °C for free enzyme. The immovability and tolerance of the gel beads immobilised with GI over 15 consecutive cycles were demonstrated in a reusability test, with 88 percent of the enzyme's original activity retained, compared to 60 percent by other authors. These findings are encouraging for high-fructose corn syrup producers.


Assuntos
Enzimas Imobilizadas , Frutose , Enzimas Imobilizadas/metabolismo , Estabilidade Enzimática , Cápsulas , Carragenina , Temperatura , Indústria Alimentícia , Concentração de Íons de Hidrogênio , Cinética
4.
Aging Med (Milton) ; 4(3): 214-220, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34553119

RESUMO

Nicotinamide adenine dinucleotide (NAD) is a coenzyme found in every human cell and regulates a number of systems across multiple cellular compartments and tissue types via an endogenous and exogenous influence. NAD levels are demonstrated to decline with age and therefore measures to counteract the waning of NAD have been devised. A number of NAD precursor candidates such as nicotinamide riboside (NR), nicotinamide mononucleotide (NMN), the reduced form of nicotinamide mononucleotide (NMNH), nicotinic acid (NA) nicotinamide (NAM), and dihydronicotinamide riboside (DNR) increase NAD levels in vitro and in vivo. This discussion will focus on the precursors NR, NMN, NMNH, and DNR in the upregulation of NAD. There are many publications on NAD precursors as it has become popular for human consumption in recent years due to its vital importance to the general consumer. However, there is no consensus between researchers and this was the aim of this review, to determine and discuss their areas of agreement versus disagreement, to highlight the gaps in research, and to give recommendations for future work. Bioavailability and potency of NR, NMNH, NMN, and DNR is also examined on the light of the most recent literature.

5.
Future Sci OA ; 7(3): FSO660, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33552541

RESUMO

There are approximately 1 billion prediabetic people worldwide, and the global cost for diabetes mellitus (DM) is estimated to be $825 billion. In regard to Type 1 DM, transplanting a whole pancreas or its islets has gained the attention of researchers in the last few decades. Recent studies showed that islet transplantation (ILT) containing insulin-producing ß cells is the most notable advancement cure for Type 1 DM. However, this procedure has been hindered by shortage and lack of sufficient islet donors and the need for long-term immunosuppression of any potential graft rejection. The strategy of encapsulation may avoid the rejection of stem-cell-derived allogeneic islets or xenogeneic islets. This review article describes various biotechnology features in encapsulation-of-islet-cell therapy for humans, including the use of bile acids.

6.
PLoS One ; 14(4): e0214984, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947243

RESUMO

Type 2 diabetes (T2D) is characterised by ß-cell damage and hyperglycaemia. The lipophilic drug, probucol, has shown significant ß-cell protective and potential antidiabetic effects, which were enhanced by hydrophilic bile acid incorporation using taurocholic acid and chenodeoxycholic acid. However, probucol has severe cardiotoxicity and a variable absorption profile, which limit its potential applications in T2D. Accordingly, this study aimed to design multiple formulations to optimise probucol oral delivery in T2D and test their effects on probucol absorption and accumulation in the heart. Adult male mice were given a high fat diet (HFD), and a week later, injected with a single dose of alloxan to accelerate T2D development, and once diabetes confirmed, divided into three groups (six to seven mice each). The groups were gavaged a daily dose of probucol powder, probucol microcapsules, or probucol-bile acid microcapsules for three months, and euthanized; and blood, tissues, and feces collected for blood glucose and probucol concentration analyses. Probucol concentrations in plasma were similar among all the groups. Groups given probucol microcapsules and probucol-bile acid microcapsules showed significant reduction in probucol accumulation in the heart compared with the group given probucol powder (p<0.05). Probucol microencapsulation with or without bile acids reduced its accumulation in heart tissues, without changing plasma concentrations, which may be beneficial in reducing its cardiotoxicity and optimise its potential applications in T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Probucol , Administração Oral , Animais , Cápsulas , Cardiotoxicidade/sangue , Cardiotoxicidade/prevenção & controle , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Miocárdio/metabolismo , Probucol/farmacocinética , Probucol/farmacologia
7.
Biochem Mol Biol Educ ; 46(2): 121-129, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29219232

RESUMO

In Australian Universities, based on a study from 1992 to 2014, the Feedback item has been consistently poorly rated by students. In addition, Biochemistry is a complex STEM subject which many students find difficult and was considered the hardest subject according to a recent study by Antigua medical school in the United States. In this work, a new and interactive teaching method, FastFeedback Questions (FFQs), has been devised. FFQs are a rapid formative feedback method that involves embedding carefully crafted focus questions alongside PowerPoint slides (outside the slide field). The PPT is then projected as usual, but not in slide show mode, so the areas outside the main slide window are visible to the students. Prior to the lecture students receive a version without the answers. During the face-to-face lecture, the lecturer goes through the answers in an interactive way by requesting that students answer the FFQs, which can be verified immediately from the PPT slide. The focus questions not only increase students' understanding of the slides, they also model good answers. FFQs were delivered to the students of third year clinical biochemistry at Curtin University. Number of students in this study, n = 311. The final exam marks support the use of FFQs as there is an overall improvement of the student average grade by ≈10% from ≈63% in 2010-2014 (no FFQs) to ≈72.6% in 2015-2017 (FFQs). FFQs have also gained the accolade of the students as their feedback was on average ≈97% compared to ≈80.5% for the Faculty and University. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(2):121-129, 2018.


Assuntos
Bioquímica/educação , Avaliação Educacional , Feedback Formativo , Estudantes/psicologia , Inquéritos e Questionários , Ensino/normas , Humanos , Aprendizagem , Universidades
8.
3 Biotech ; 6(1): 14, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28330084

RESUMO

Naringinase induced from the fermented broth of marine-derived fungus Aspergillus niger was immobilized into grafted gel beads, to obtain biocatalytically active beads. The support for enzyme immobilization was characterized by ART-FTIR and TGA techniques. TGA revealed a significant improvement in the grafted gel's thermal stability from 200 to 300 °C. Optimization of the enzyme loading capacity increased gradually by 28-fold from 32 U/g gel to 899 U/g gel beads, retaining 99 % of the enzyme immobilization efficiency and 88 % of the immobilization yield. The immobilization process highly improved the enzyme's thermal stability from 50 to 70 °C, which is favored in food industries, and reusability test retained 100 % of the immobilized enzyme activity after 20 cycles. These results are very useful on the marketing and industrial levels.

9.
3 Biotech ; 6(1): 29, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28330097

RESUMO

A novel extreme halophilic exochitinase enzyme was produced by honey isolate Aspergillus awamori EM66. The enzyme was immobilized successfully on k-carrageenan-alginate gel carrier (CA) with 93 % immobilization yield. The immobilization process significantly improved the enzyme specific activity 2.6-fold compared to the free form. The significant factors influencing the immobilization process such as enzyme protein concentration and loading time were studied. Distinguishable characteristics of optimum pH and temperature, stability at different temperatures and NaCl tolerance for free and immobilized enzyme were studied. The immobilization process improved optimum temperature from 35 to 45 °C. The immobilized enzyme retained 76.70 % of its activity after 2 h at 75 °C compared to complete loss of activity for the free enzyme. The reusability test proved the durability of the CA gel beads for 28 cycles without losing its activity.

10.
Biomed Res Int ; 2014: 817985, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25013804

RESUMO

"Lactose intolerance" is a medical problem for almost 70% of the world population. Milk and dairy products contain 5-10% w/v lactose. Hydrolysis of lactose by immobilized lactase is an industrial solution. In this work, we succeeded to increase the lactase loading capacity to more than 3-fold to 36.3 U/g gel using epoxy activated hydrogels compared to 11 U/g gel using aldehyde activated carrageenan. The hydrogel's mode of interaction was proven by FTIR, DSC, and TGA. The high activity of the epoxy group was regarded to its ability to attach to the enzyme's -SH, -NH, and -OH groups, whereas the aldehyde group could only bind to the enzyme's -NH2 group. The optimum conditions for immobilization such as epoxy chain length and enzyme concentration have been studied. Furthermore, the optimum enzyme conditions were also deliberated and showed better stability for the immobilized enzyme and the Michaelis constants, K m and V max, were doubled. Results revealed also that both free and immobilized enzymes reached their maximum rate of lactose conversion after 2 h, albeit, the aldehyde activated hydrogel could only reach 63% of the free enzyme. In brief, the epoxy activated hydrogels are more efficient in immobilizing more enzymes than the aldehyde activated hydrogel.


Assuntos
Enzimas Imobilizadas/administração & dosagem , Hidrogéis/administração & dosagem , Lactase/administração & dosagem , Intolerância à Lactose/tratamento farmacológico , Animais , Carragenina/química , Quitosana/administração & dosagem , Quitosana/química , Enzimas Imobilizadas/química , Compostos de Epóxi/química , Hidrogéis/química , Lactase/química , Intolerância à Lactose/metabolismo , Intolerância à Lactose/patologia , Leite/efeitos adversos , beta-Galactosidase/isolamento & purificação
11.
Biomed Res Int ; 2014: 418097, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25028651

RESUMO

Three gel disks formulations prepared using chitosan (Chito) or polyethylenimine (PEI) followed by glutaraldehyde were prepared for biocatalysis and biomedical applications. The carriers have been used to immobilize lactase covalently and it was evaluated in terms of enzyme loading capacity and enzyme kinetics (km and Vmax). The Km of the Chito formulation was almost half that of the PEI formulations, which is favored in industries. On the other hand, the gel disks were evaluated in terms of their swelling kinetics and the gels' morphology using SEM. The mechanism of the three gels' swelling was also studied and it was found to be non-Fickian, where the mechanism of transport depends on both the diffusion and polymer relaxation, which are controlling the overall rate of water uptake. The Chito formulation was 2-5 folds and PEI formulations were 33-62 folds in terms of the swelling rate constant and the diffusion rate, respectively. These results were highly supported by the SEM. This study will help scientists to design the right polymer network for enzymes immobilization as well as control the surface area and the swelling power of the polymers for different applications such as drug delivery systems and tissue engineering.


Assuntos
Carragenina/química , Quitosana/química , Enzimas Imobilizadas/química , Polietilenoimina/química , Catálise , Géis/química
12.
ScientificWorldJournal ; 2014: 571682, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24672334

RESUMO

ß-Galactosidase (ß-gal) was immobilized by covalent binding on novel κ-carrageenan gel beads activated by two-step method; the gel beads were soaked in polyethyleneimine followed by glutaraldehyde. 2(2) full-factorial central composite experiment designs were employed to optimize the conditions for the maximum enzyme loading efficiency. 11.443 U of enzyme/g gel beads was achieved by soaking 40 units of enzyme with the gel beads for eight hours. Immobilization process increased the pH from 4.5 to 5.5 and operational temperature from 50 to 55 °C compared to the free enzyme. The apparent K(m) after immobilization was 61.6 mM compared to 22.9 mM for free enzyme. Maximum velocity Vmax was 131.2 µ mol · min(-1) while it was 177.1 µ mol · min(-1) for free enzyme. The full conversion experiment showed that the immobilized enzyme form is active as that of the free enzyme as both of them reached their maximum 100% relative hydrolysis at 4 h. The reusability test proved the durability of the κ-carrageenan beads loaded with ß -galactosidase for 20 cycles with retention of 60% of the immobilized enzyme activity to be more convenient for industrial uses.


Assuntos
Carragenina/química , Enzimas Imobilizadas/química , beta-Galactosidase/química , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Géis , Glutaral/química , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Microesferas , Polietilenoimina/química , beta-Galactosidase/metabolismo
13.
Chem Commun (Camb) ; 50(5): 590-2, 2014 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-24275772

RESUMO

Protamine hydrochloride adsorbed onto citrated superparamagnetic iron oxide nanoparticles represents an efficient tool for capturing and concentration of hepatitis-C virus from plasma samples, improving the sensitivity of downstream analysis by nucleic acid testing.


Assuntos
Hepacivirus/química , Nanopartículas de Magnetita/química , Protaminas/química , Adsorção , Dextranos/química , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Humanos , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Trombina/química , Trombina/metabolismo
14.
Carbohydr Polym ; 93(2): 740-6, 2013 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-23499118

RESUMO

A sequential optimization strategy, based on statistical experimental designs, was employed to enhance the production of invertase by Lactobacillus brevis Mm-6 isolated from breast milk. First, a 2-level Plackett-Burman design was applied to screen the bioprocess parameters that significantly influence the invertase production. The second optimization step was performed using fractional factorial design in order to optimize the amounts of variables have the highest positive significant effect on the invertase production. A maximal enzyme activity of 1399U/ml was more than five folds the activity obtained using the basal medium. Invertase was immobilized onto grafted alginate beads to improve the enzyme's stability. Immobilization process increased the operational temperature from 30 to 60°C compared to the free enzyme. The reusability test proved the durability of the grafted alginate beads for 15 cycles with retention of 100% of the immobilized enzyme activity to be more convenient for industrial uses.


Assuntos
Alginatos/metabolismo , Proteínas de Bactérias/isolamento & purificação , Ensaios Enzimáticos/métodos , Levilactobacillus brevis/enzimologia , beta-Frutofuranosidase/isolamento & purificação , Proteínas de Bactérias/metabolismo , Meios de Cultura/metabolismo , Ativação Enzimática , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Feminino , Ácido Glucurônico/metabolismo , Ácidos Hexurônicos/metabolismo , Humanos , Levilactobacillus brevis/isolamento & purificação , Leite Humano/microbiologia , Sacarose/metabolismo , Temperatura , beta-Frutofuranosidase/metabolismo
15.
Can J Physiol Pharmacol ; 90(4): 415-23, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22432737

RESUMO

This study was conducted to evaluate the modulatory effect of aqueous extract of Curcuma longa (L.) against γ-irradiation (GR), which induces biochemical disorders in male rats. The sublethal dose of GR was determined in primary hepatocytes. Also, the effect of C. longa extract was examined for its activity against GR. In rats, C. longa extract was administered daily (200 mg/kg body mass) for 21 days before, and 7 days after GR exposure (6.5 Gy). The lipid profile and antioxidant status, as well as levels of transaminases, interleukin-6 (IL-6), and tumour necrosis factor α (TNFα) were assessed. The results showed that in hepatocytes, the aqueous extract exhibited radioprotective activity against exposure to GR. Exposure of untreated rats to GR resulted in transaminase disorders, lipid abnormalities, elevation of lipid peroxidation, trace element alterations, release of IL-6 and TNF, and decrease in glutathione and protein level of superoxide dismutase-1 (SOD-1) and peroxiredoxin-1 (PRDX-1). However, treatment of rats with this extract before and after GR exposure improved antioxidant status and minimized the radiation-induced increase in inflammatory cytokines. Changes occurred in the tissue levels of trace elements, and the protein levels of SOD-1 and PRDX-1 were also modulated by C. longa extract. Overall, C. longa exerted a beneficial radioprotective effect against radiation-induced oxidative stress in male rats by alleviating pathological disorders and modulating antioxidant enzymes.


Assuntos
Curcuma/química , Raios gama/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Protetores contra Radiação/farmacologia , Irradiação Corporal Total/efeitos adversos , Animais , Glutationa/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Interleucina-6/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/patologia , Masculino , Peroxirredoxinas/metabolismo , Cultura Primária de Células , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1 , Oligoelementos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Irradiação Corporal Total/métodos
16.
Appl Biochem Biotechnol ; 159(2): 426-37, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19082762

RESUMO

Lactose has been hydrolyzed using covalently immobilized beta-galactosidase on thermally stable carrageenan coated with chitosan (hydrogel). The hydrogel's mode of interaction was proven by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and Schiff's base formation. The DSC thermogram proved the formation of a strong polyelectrolyte complex between carrageenan and chitosan followed by glutaraldehyde as they formed one single peak. The modification of carrageenan improved the gel's thermal stability in solutions from 35 degrees C to 95 degrees C. The hydrogel has been proven to be efficient for beta-galactosidase immobilization where 11 U/g wet gel was immobilized with 50% enzyme loading capacity. Activity and stability of free and immobilized beta-galactosidase towards pH and temperature showed marked shifts in their optimum pH from 4.5-5 to 5-5.5 and temperature from 50 degrees C to 45-55 degrees C after immobilization, which reveals higher catalytic activity and reasonable stability at wider pHs and temperatures. The apparent K(m) of the immobilized enzyme increased from 13.2 to 125 mM, whereas the V(max) increased from 3.2 to 6.6 micromol/min compared to the free enzyme, respectively. The free and immobilized enzymes showed lactose conversion of 87% and 70% at 7 h, respectively. The operational stability showed 97% retention of the enzyme activity after 15 uses, which demonstrates that the covalently immobilized enzyme is unlikely to leach. The new carrier could be suitable for immobilization of other industrial enzymes.


Assuntos
Biopolímeros/química , Lactose/química , beta-Galactosidase/química , Ativação Enzimática , Estabilidade Enzimática , Enzimas Imobilizadas/química , Temperatura Alta , Hidrólise , Especificidade por Substrato
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