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1.
Sci Rep ; 12(1): 7213, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35508533

RESUMO

Wound healing is a complex process and rapid healing necessitates a proper micro-environment. Therefore, design and fabrication of an efficacious wound dressing is an impressive innovation in the field of wound healing. The fabricated wound dressing in this scenario was designed using a combination of the appropriate coagulating and anti-bacterial materials like fibrinogen (as coagulating agent), nisin (as anti-bacterial agent), ethylenediaminetetraacetic acid (as anti-bacterial agent), and alginate (as wound healing agent). Biophysical characterization showed that the interaction of fibrinogen and alginate was associated with minor changes in the secondary structure of the protein. Conformational studies showed that the protein was structurally stable at 42 °C, is the maximum temperature of the infected wound. The properties of the hydrogel such as swelling, mechanical resistance, nisin release, antibacterial activity, cytotoxicity, gel porosity, and blood coagulation were assessed. The results showed a slow release for the nisin during 48 h. Antibacterial studies showed an inhibitory effect on the growth of Gram-negative and Gram-positive bacteria. The hydrogel was also capable to absorb a considerable amount of water and provide oxygenation as well as incorporation of the drug into its structure due to its sufficient porosity. Scanning electron microscopy showed pore sizes of about 14-198 µm in the hydrogel. Cell viability studies indicated high biocompatibility of the hydrogel. Blood coagulation test also confirmed the effectiveness of the synthesized hydrogel in accelerating the process of blood clot formation. In vivo studies showed higher rates of wound healing, re-epithelialization, and collagen deposition. According to the findings from in vitro as well as in vivo studies, the designed hydrogel can be considered as a novel attractive wound dressing after further prerequisite assessments.


Assuntos
Hidrogéis , Nisina , Alginatos/química , Alginatos/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Fibrinogênio/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Nisina/farmacologia , Cicatrização
2.
Front Pharmacol ; 13: 793727, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35392564

RESUMO

Background: The aggregation of tau and α-synuclein into fibrillary assemblies in nerve cells is the molecular hallmark of Alzheimer's and Parkinson's diseases, respectively. In our previous studies, we investigated the anti-amyloidogenic effects of three different aroma-producing (volatile) compounds including cinnamaldehyde, phenyl ethyl alcohol, and TEMED on the fibrillation process of HEWL, as a model protein. Our previous results showed that while TEMED was able to completely stop the process of fibril formation, cinnamaldehyde and phenyl ethyl alcohol gave rise to oligomeric/protofibrillar forms and were involved in the entrapment of intermediate species of HEWL. In this study, we investigated the anti-amyloidogenic effect of the same three volatile compounds on recombinantly produced tau and α-synuclein proteins. Methods: The thioflavin T fluorescence assay, circular dichroism, SDS-PAGE/native-PAGE, dynamic light scattering, and atomic force microscopy were used, where necessary, to further our understanding of the inhibitory effects of the three volatile compounds on the fibril formation of tau and α-synuclein proteins and allow for a comparison with previous data obtained for HEWL. Results: Our results revealed that contrary to the results obtained for HEWL (a globular protein), the volatile compound TEMED was no longer able to prevent fibril formation in either of the natively unstructured tau or α-synuclein proteins, and instead, cinnamaldehye and phenyl ethyl alcohol, in particular, had the role of preventing fibril formation of tau or α-synuclein. Conclusion: The results of this study further emphasized the exclusion of HEWL as a model protein for fibrillation studies and highlighted the importance of studying brain-related proteins such as tau or α-synuclein and the need to assess the effects of volatile compounds such as cinnamaldehye and phenyl ethyl alcohol as potential substances in the treatment of neurodegenerative diseases.

3.
J Biol Chem ; 298(3): 101662, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35104501

RESUMO

Alzheimer's disease is characterized by the presence of extraneuronal amyloid plaques composed of amyloid-beta (Aß) fibrillar aggregates in the brains of patients. In mouse models, it has previously been shown that atorvastatin (Ator), a cholesterol-lowering drug, has some reducing effect on the production of cerebral Aß. A meta-analysis on humans showed moderate effects in the short term but no improvement in the Alzheimer's Disease Assessment Scale-Cognitive Subscale behavioral test. Here, we explore a potential direct effect of Ator on Aß42 aggregation. Using NMR-based monomer consumption assays and CD spectroscopy, we observed a promoting effect of Ator in its original form (Ator-calcium) on Aß42 aggregation, as expected because of the presence of calcium ions. The effect was reversed when applying a CaCO3-based calcium ion scavenging method, which was validated by the aforementioned methods as well as thioflavin-T fluorescence assays and transmission electron microscopy. We found that the aggregation was inhibited significantly when the concentration of calcium-free Ator exceeded that of Aß by at least a factor of 2. The 1H-15N heteronuclear single quantum correlation and saturation-transfer difference NMR data suggest that calcium-free Ator exerts its effect through interaction with the 16KLVF19 binding site on the Aß peptide via its aromatic rings as well as hydroxyl and methyl groups. On the other hand, molecular dynamics simulations confirmed that the increasing concentration of Ator is necessary for the inhibition of the conformational transition of Aß from an α-helix-dominant to a ß-sheet-dominant structure.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Atorvastatina , Fragmentos de Peptídeos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Atorvastatina/farmacologia , Cálcio/metabolismo , Humanos , Camundongos , Fragmentos de Peptídeos/metabolismo
4.
J Clin Med ; 11(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35160202

RESUMO

This study attempted to draw the present and future perspective of the COVID-19 vaccine by identifying the most important scientists and their scientific contexts, trends of research topics, and relationships between different entities. METHODS: To achieve this purpose, bibliometric and scientometric techniques were used to analyze 6288 scientific documents contributing to COVID-19 vaccines from the beginning of 2019 to 13 December 2021, indexed in the Web of Science. RESULTS: The United States (US) had the greatest impact by publishing 2104 documents and receiving 32,958 citations. The US and the UK countries had the highest level of scientific collaborations with 192 collaborative studies. The University of Oxford and the Harvard Medical School were the most active institutions, and the University of Oxford and Emory University were the most influential institutions. Pollard AJ and Lambe T had the most publications and the highest citations and h-index. T Lambe, SC Gilbert, M Voysey, and AJ Pollard from the University of Oxford had the highest number of co-authorships. More than 19% of the research was conducted in the field of immunology. The Vaccines journal had the most publications, with 425 articles. The US Department of Health & Human Services granted the most research. In 2019, studies were focused on the topics of COVID-19 virus identification and ways to deal with it; in 2020, studies focused on the topics of COVID-19 and vaccines, whereas in 2021, they focused on the topics of COVID-19 vaccines and their effects, vaccines hesitancy, the role of healthcare workers in COVID-19, as well as discussions about these vaccines in the social media. CONCLUSIONS: Recognition of the most important actors (countries, institutes, researchers, and channels for the release of COVID-19 vaccine studies), research trends, and fields of study on the COVID-19 vaccine can be useful for researchers, countries, and policy makers in the field of science and health to make decisions and better understand these vaccines.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 267(Pt 2): 120538, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34749259

RESUMO

We investigated the potential carrier of milk beta-casein (ß-CN) and its interactions with 5-fluorouracil (5-FU) and iron oxide nanoparticles (Fe3O4 NPs). We used different spectroscopic methods of fluorescence, UV-Visble, circular dichroism (CD), synchronous fluorescence, zeta potential assay, and computational studies to clarify the protein interaction with 5-FU and Fe3O4 NPs. The fluorescence data indicated both Fe3O4 NPs and 5-FU could quench the intrinsic fluorescence of ß-CN. Fluorescence measurements showed that the single interaction of ß-CN with 5-FU or Fe3O4 NPs was static, while reacted ß-CN with both 5-FU and Fe3O4 NPs simultaneously showed a dynamic quenching. Synchronous fluorescence data in both tests revealed that the tryptophan (Trp) residue of ß-CN had a dominant role in quenching and the polarity of its microenvironment more than tyrosine (Tyr) increased in interaction with 5-FU. All the binding sites and thermodynamic parameters were obtained at 25, 37, and 42 °C. The analysis of thermodynamic parameters and Job's plot techniques pointed to that both of these complexes with the 1:1 M ratio were exothermic (ΔH°<0) driven with the van der Waals and H-bonding interactions (in agreement with the docking results). The CD spectra in the region of far-UV and thermal denaturation study indicated minor changes in the secondary structure of ß-CN in the presence of various concentrations of Fe3O4 NPs and 5-FU. Also, from the molecular dynamics (MD) analysis, as a result, the protein structure was stable during 100 ns. The outcomes highlighted that ß-CN protein could form a great bind with 5-FU and Fe3O4 NPs ligands (supporting the zeta potential assay results) by independent binding sites. These results would be helpful insight to construct a potential magnetic nanocarrier ß-CN base for 5-FU drug delivery.


Assuntos
Caseínas , Nanopartículas , Sítios de Ligação , Dicroísmo Circular , Fluoruracila , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Espectrometria de Fluorescência , Termodinâmica
6.
Lasers Surg Med ; 54(2): 202-216, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34363230

RESUMO

BACKGROUND AND OBJECTIVE: Optogenetics has opened new insights into biomedical research with the ability to manipulate and control cellular activity using light in combination with genetically engineered photosensitive proteins. By stimulating with light, this method provides high spatiotemporal and high specificity resolution, which is in contrast to conventional pharmacological or electrical stimulation. Optogenetics was initially introduced to control neural activities but was gradually extended to other biomedical fields. STUDY DESIGN: In this paper, firstly, we summarize the current optogenetic tools stimulated by different light sources, including lasers, light-emitting diodes, and laser diodes. Second, we outline the variety of biomedical applications of optogenetics not only for neuronal circuits but also for various kinds of cells and tissues from cardiomyocytes to ganglion cells. Furthermore, we highlight the potential of this technique for treating neurological disorders, cardiac arrhythmia, visual impairment, hearing loss, and urinary bladder diseases as well as clarify the mechanisms underlying cancer progression and control of stem cell differentiation. CONCLUSION: We sought to summarize the various types of promising applications of optogenetics to treat a broad spectrum of disorders. It is conceivable to expect that optogenetics profits a growing number of patients suffering from a range of different diseases in the near future.


Assuntos
Neoplasias , Optogenética , Humanos , Lasers , Neoplasias/metabolismo , Neurônios/metabolismo , Optogenética/métodos
7.
Artigo em Inglês | MEDLINE | ID: mdl-34894353

RESUMO

Targeted drug therapy against cancer has been introduced as a smart strategy to combat the unwanted side effects due to systemic administration of chemotherapeutics. A human serum albumin (HSA)-based nanocarrier was fabricated with the aim to target reductive media and acidic pH of the tumor tissues. α-Lipoic acid (LA) was applied to increase the number of disulfide bonds in the nanocarrier to target higher glutathione concentrations present in tumor tissues and polyethylene glycol was used to target the acidic pH of tumors. UV illumination, ethanol desolvation, oxygen bubbling, and a mixture of redox buffers were employed to prepare doxorubicin-loaded HSA-LA nanoparticles. The nanocarrier was supposed to release the loaded doxorubicin in reductive and acidic pH media. Fourier-transform infrared spectroscopy and energy dispersive X-ray analysis indicated successful attachment of LA to HSA. The prepared nanoplatform presented improved doxorubicin loading efficiency and content and successfully released the loaded doxorubicin in the expected conditions. Protein corona study indicated that positively charged plasma proteins with molecular weights of nearly 80 kDa are absorbed to the surface of the nanoparticles. Furthermore, it showed desirable UV and storage stability, which implied its robustness and improved shelf life if applied in nanomedicine.

8.
BMC Bioinformatics ; 22(1): 549, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34758751

RESUMO

BACKGROUND: Antimicrobial peptides are promising tools to fight against ever-growing antibiotic resistance. However, despite many advantages, their toxicity to mammalian cells is a critical obstacle in clinical application and needs to be addressed. RESULTS: In this study, by using an up-to-date dataset, a machine learning model has been trained successfully to predict the toxicity of antimicrobial peptides. The comprehensive set of features of both physico-chemical and linguistic-based with local and global essences have undergone feature selection to identify key properties behind toxicity of antimicrobial peptides. After feature selection, the hybrid model showed the best performance with a recall of 0. 876 and a F1 score of 0. 849. CONCLUSIONS: The obtained model can be useful in extracting AMPs with low toxicity from AMP libraries in clinical applications. On the other hand, several properties with local nature including positions of strand forming and hydrophobic residues in final selected features show that these properties are critical definer of peptide properties and should be considered in developing models for activity prediction of peptides. The executable code is available at https://git.io/JRZaT .


Assuntos
Aprendizado de Máquina , Peptídeos , Animais , Resistência Microbiana a Medicamentos , Proteínas Citotóxicas Formadoras de Poros
9.
J Lasers Med Sci ; 12: e32, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34733755

RESUMO

Introduction: Non-clinical cardiovascular drug safety assessment is the main step in the progress of new pharmaceutical products. Cardiac drug safety testing focuses on a delayed rectifier potassium channel block and QT interval prolongation, whereas optogenetics is a powerful technology for modulating the electrophysiological properties of excitable cells. Methods: For this purpose, the blue light-gated ion channel, channelrhodopsin-2 (ChR2), has been introduced into isolated primary neonatal cardiomyocytes via a lentiviral vector. After being subjected to optical stimulation, transmembrane potential and intracellular calcium were assessed. Results: Here, we generated cardiomyocytes expressing ChR2 (light-sensitive protein), that upon optical stimulation, the cardiomyocytes depolarized result from alterations of membrane voltage and intracellular calcium. Conclusion: This cell model was easily adapted to a cell culture system in a laboratory, making this method very attractive for therapeutic research on cardiac optogenetics.

10.
Adv Exp Med Biol ; 1318: 923-936, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33973220

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic has been a significant concern worldwide. The pandemic has demonstrated that public health issues are not merely a health concern but also affect society as a whole. In this chapter, we address the importance of bringing together the world's scientists to find appropriate solutions for controlling and managing the COVID-19 pandemic. Interdisciplinary cooperation, through modern scientific methods, could help to handle the consequences of the pandemic and to avoid the recurrence of future pandemics.


Assuntos
COVID-19 , Pandemias , Humanos , Pandemias/prevenção & controle , Saúde Pública , SARS-CoV-2
11.
Mater Sci Eng C Mater Biol Appl ; 121: 111809, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33579453

RESUMO

Applying multifunctional nanocarriers, comprising specifically traceable and tumor targeting moieties, has significantly increased in cancer theranostics. Herein, a novel targeted, trackable, and pH-responsive drug delivery system was fabricated based on glucosamine (GlcN) conjugated graphene quantum dots (GQDs) loaded by hydrophobic anticancer agent, curcumin (Cur), to evaluate its targeting and cytotoxicity potential against breast cancer cells with overexpression of GlcN receptors. The biocompatible photoluminescent GQDs were synthesized from graphene oxide through the green and facile oxidizing method. The structural and spectral characterizations of the as-prepared GQDs and Cur/GlcN-GQDs were investigated. The GQDs sizes were within 20-30 nm and showed less than ten layers. A pH-sensitive and sustained release behavior was also observed for the Cur loaded nanocarrier with a total release of 37% at pH 5.5 and 17% at pH 7.4 after 150 h. In vitro cellular uptake studies through fluorescence microscopy and flow cytometry exhibited stronger fluorescence for the targeted nanocarrier against MCF-7 cells compared to the non-targeted one, owing to higher cellular internalization via GlcN receptor-mediated endocytosis. Furthermore, the MTT assay results demonstrated the nontoxicity of the bare nanocarrier with the cell viability of above 94% even at concentrations as high as 50 µg·ml-1, while the Cur/GlcN-GQDs exhibited much more cytotoxicity against MCF-7 cells compared to Cur/GQDs. It is reasonable to conclude that this advanced multifunctional nano-assembly offers superior potential for breast cancer cell-targeted delivery.


Assuntos
Antineoplásicos , Neoplasias da Mama , Curcumina , Grafite , Pontos Quânticos , Neoplasias da Mama/tratamento farmacológico , Curcumina/farmacologia , Sistemas de Liberação de Medicamentos , Glucosamina , Humanos , Concentração de Íons de Hidrogênio
12.
J Biomol Struct Dyn ; 39(9): 3256-3262, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32345145

RESUMO

In the present work, we studied the structure-activity relationship and kinetics of thermal inactivation of α-glucosidase A (AglA) in a 50 mM potassium phosphate buffer at pH 6.8 using p-nitrophenyl α-d-glucopyranoside (pNPG) as the synthetic substrate following absorbance at 410 nm by UV-Vis spectrophotometer. The interface structure and residual activity plot were analyzed via biochemical measurements by means of conformational lock theory, as well. The thermal inactivation curves were plotted in temperature interval from 30 to 50 °C. Based on experimental and structural data we suggested intermediates during inactivation before the loss of enzyme activity. Arrhenius plot for thermal inactivation rate constant showed biphasic appearance related to before and after 45°C temperature. The contact areas between two subunits were ruptured and unlocked stepwise during dimer dissociation. Cleavage of these areas induced the dissociation of the subunits along with destruction of the active centers and subsequently the loss of activity. It seems that the contact areas interact with active centers by conformational changes involving secondary structural elements.


Assuntos
alfa-Glucosidases , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Conformação Proteica , Temperatura , alfa-Glucosidases/metabolismo
13.
J Biomol Struct Dyn ; 39(8): 3025-3033, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32274964

RESUMO

The widespread antigenic changes lead to the emergence of a new type of coronavirus (CoV) called as severe acute respiratory syndrome (SARS)-CoV-2 that is immunologically different from the previous circulating species. Angiotensin-converting enzyme-2 (ACE-2) is one of the most important receptors on the cell membrane of the host cells (HCs) which its interaction with spike protein (SP) with a furin-cleavage site results in the SARS-CoV-2 invasion. Hence, in this review, we presented an overview on the interaction of ACE-2 and furin with SP. As several kinds of CoVs, from various genera, have at their S1/S2 binding site a preserved site, we further surveyed the role of furin cleavage site (FCS) on the life cycle of the CoV. Furthermore, we discussed that the small molecular inhibitors can limit the interaction of ACE-2 and furin with SP and can be used as potential therapeutic platforms to combat the spreading CoV epidemic. Finally, some ongoing challenges and future prospects for the development of potential drugs to promote targeting specific activities of the CoV were reviewed. In conclusion, this review may pave the way for providing useful information about different compounds involved in improving the effectiveness of CoV vaccine or drugs with minimum toxicity against human health.Communicated by Ramaswamy H. Sarma.


Assuntos
COVID-19 , Furina , Enzima de Conversão de Angiotensina 2 , Angiotensinas , Humanos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus
14.
Int J Biol Macromol ; 164: 4403-4414, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931826

RESUMO

Horseradish peroxidase (HRP) was immobilized onto a functionalized reduced graphene oxide-SiO2 through the covalent bonding process. By using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR), the formed nanocomposites were characterized. The kinetic parameters including the catalytic constant, kcat, and the catalytic efficiency, kcat/Km, increased 5.5 and 6 times, respectively, after immobilization. The circular dichroism analysis demonstrated that the α-helical content increased from 39% to 46% after immobilization. The immobilization improved the reusability of HRP as 70% of initial activity retained after 10 cycles. Due to the buffering effect, the immobilized HRP was less sensitive to pH changes as compared to the free HRP. At temperature 40 °C and during 90 min, the immobilized HRP retained 90% of the initial activity while 70% of initial activity remained for the free HRP. After 35-day storage, no reduction in the activity was observed for the immobilized HRP. The removal efficiency for phenol concentration (2500 mg/L) obtained 100% and 50% for the immobilized and free HRP, respectively. The results showed that the immobilized HRP promoted the dyes decolorization from 2-fold until 26-fold as compared to the free HRP. The decolorization efficiencies reached 100% for most dyes in the case of immobilized HRP.


Assuntos
Biodegradação Ambiental , Corantes/química , Enzimas Imobilizadas , Peroxidase do Rábano Silvestre/química , Nanocompostos/química , Fenol/química , Dióxido de Silício/química , Catálise , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Estrutura Molecular , Nanocompostos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-Atividade , Termodinâmica
15.
Comput Biol Chem ; 88: 107308, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32650066

RESUMO

One of the hallmarks of Parkinson's disease (PD), a long-term neurodegenerative syndrome, is the accumulation of alpha-synuclein (α-syn) fibrils. Despite numerous studies and efforts, inhibition of α-syn protein aggregation is still a challenge. To overcome this issue, we propose an in silico pharmacophore-based repositioning strategy, to find a pharmaceutical drug that, in addition to their defined role, can be used to prevent aggregation of the α-syn protein. Ligand-based pharmacophore modeling was developed and the best model was selected with validation parameters including 72 % sensitivity, 98 % specificity and goodness score about 0.7. The optimal model has three groups of hydrogen bond donor (HBD), three groups of hydrogen bond acceptor (HBA), and two aromatic rings (AR). The FDA-Approved reports in the ZINC15 database were screened with the pharmacophore model taken from inhibitor compounds. The model identified 22 hits, as promising candidate drugs for Parkinson's therapy. It is noteworthy that among these, 10 drugs have been reported to inhibition of α-syn aggregation or treat/reduce Parkinson's pathogenesis. This model was used to virtual screen ZINC, NCI databases, and natural products from the pomegranate. The results of this screen were filtered for their inability to cross the blood-brain barrier, poor oral bioavailability, etc. Finally, the selected compounds of two ZINC and NCI databases were combined and structurally clustered. Remained compounds were clustered in 28 different clusters, and the 17 compounds were introduced as final candidates.


Assuntos
Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , alfa-Sinucleína/antagonistas & inibidores , Bases de Dados Factuais , Reposicionamento de Medicamentos , Humanos , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/química , Doença de Parkinson/metabolismo , Agregados Proteicos/efeitos dos fármacos , alfa-Sinucleína/metabolismo
16.
Protein J ; 39(4): 328-336, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32671518

RESUMO

New support was fabricated to enhance the enzyme activity of cellulase following immobilization. Functionalized core-shell magnetic gold nanoparticles were prepared and characterized by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cellulase enzyme was immobilized on support via covalent bonding. The successful binding of the enzyme was chemically confirmed by Fourier-transform infrared spectroscopy (FTIR). The binding efficiency was 84% determined by Bradford assay. Filter Paper Activity (FPase) method was used to measure the enzyme activity at different temperatures (35-75 °C) and pH (2-8). The immobilized cellulase maintained 73% of its initial catalytic activity after 9 h and its activity is 0.78 mmol.ml-1. The newly designed nano-system also enhanced the thermal stability of immobilized cellulase in comparison to free cellulase and facilitated its long term storage.


Assuntos
Celulase/química , Enzimas Imobilizadas/química , Proteínas Fúngicas/química , Ouro/química , Nanopartículas de Magnetita/química , Talaromyces/enzimologia , Ácido Aspártico/química , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio
17.
Food Chem ; 330: 127218, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32535315

RESUMO

The objective of this work was to study ß-carotene functionalities (color and antioxidant activity) and practical limitations (aggregate formation, poor solubility and low stability) when included in the aqueous systems containing milk proteins. According to the results, self-association constant of ß-carotene in the presence of casein is 1.7-fold of that calculated for WPI. Casein and WPI were capable of conserving ß-carotene against chemical oxidation up to 15 and 12%, respectively, at 1:5 M ratio of ß-carotene to protein. While, WPI reduced its photodegradation quantum yield from 0.03 to 0.012 compared to 0.017 obtained for casein. A 2.7- and 3.6-fold enhancement in ß-carotene solubility was observed in the presence of 1.5 mg/mL of casein and WPI, respectively. The study of ß-carotene interaction with proteins showed, on the one hand, a negative effect on electron transfer and, on the other hand, improved hydrogen transfer to the radical species in the solution.


Assuntos
Caseínas/química , Proteínas do Soro do Leite/química , beta Caroteno/química , Animais , Emulsões , Oxirredução
18.
J Transl Med ; 18(1): 205, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32430070

RESUMO

The COVID-19 pandemic has become the leading societal concern. The pandemic has shown that the public health concern is not only a medical problem, but also affects society as a whole; so, it has also become the leading scientific concern. We discuss in this treatise the importance of bringing the world's scientists together to find effective solutions for controlling the pandemic. By applying novel research frameworks, interdisciplinary collaboration promises to manage the pandemic's consequences and prevent recurrences of similar pandemics.


Assuntos
Pesquisa Biomédica/organização & administração , Infecções por Coronavirus/epidemiologia , Prestação Integrada de Cuidados de Saúde/organização & administração , Emergências , Necessidades e Demandas de Serviços de Saúde , Pandemias , Pneumonia Viral/epidemiologia , Betacoronavirus/patogenicidade , Pesquisa Biomédica/métodos , COVID-19 , Infecções por Coronavirus/terapia , Infecções por Coronavirus/virologia , Prestação Integrada de Cuidados de Saúde/métodos , História do Século XXI , Humanos , Comunicação Interdisciplinar , Estudos Interdisciplinares , Pneumonia Viral/terapia , Pneumonia Viral/virologia , Saúde Pública/história , Saúde Pública/normas , SARS-CoV-2
19.
Curr Drug Deliv ; 17(5): 375-386, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32294035

RESUMO

The passage of therapeutic molecules across the Blood-Brain Barrier (BBB) is a profound challenge for the management of the Central Nervous System (CNS)-related diseases. The ineffectual nature of traditional treatments for CNS disorders led to the abundant endeavor of researchers for the design the effective approaches in order to bypass BBB during recent decades. Cell-Penetrating Peptides (CPPs) were found to be one of the promising strategies to manage CNS disorders. CPPs are short peptide sequences with translocation capacity across the biomembrane. With special regard to their two key advantages like superior permeability as well as low cytotoxicity, these peptide sequences represent an appropriate solution to promote therapeutic/theranostic delivery into the CNS. This scenario highlights CPPs with specific emphasis on their applicability as a novel theranostic delivery system into the brain.


Assuntos
Barreira Hematoencefálica/metabolismo , Peptídeos Penetradores de Células/administração & dosagem , Doenças do Sistema Nervoso Central/diagnóstico , Doenças do Sistema Nervoso Central/tratamento farmacológico , Animais , Estabilidade de Medicamentos , Humanos , Medicina de Precisão
20.
Talanta ; 212: 120782, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32113545

RESUMO

Development of optical nanobiosensors has emerged as one of the most important bioresearch areas of interest over the past decades especially in the modern innovations in the design and utilization of sensing platforms. The application of nanobiosensors has been accelerated with the introduction of plasmonic NPs, which overcome the most of the limitations in the case of conventional optical nanobiosensors. Since the plasmonic AuNPs-based nanobiosensors provide high potential achievements to develop promising platforms in fully integrated multiplex assays, some well-developed investigations are clearly required to improve the current technologies and integration of multiple signal inputs. Therefore, in this literature, we summarized the performance and achievements of optical nanobiosensors according to plasmonic rules of AuNPs, including SPR, LSPR, SERS and chiroptical phenomena. Also, we investigated the effects of the physicochemical properties of AuNPs such as size, shape, composition, and assembly on the plasmonic signal propagation in AuNPs-based nanobiosensors. Moreover, we presented an overview on the current state of plasmonic AuNPs-based nanobiosensors in the biomedical activities. Besides, this paper looks at the current and future challenges and opportunities of ongoing efforts to achieve the potential applications of AuNPs-based optical plasmonic nanobiosensors in integration with other nanomaterials. Taken together, the main focus of this paper is to provide some applicable information to develop current methodologies in fabrication of potential AuNPs-based nanobiosensors for detection of a wide range of analytes.

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