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1.
Biotechnol Adv ; 73: 108378, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38754797

RESUMO

The bioprocessing industry is undergoing a significant transformation in its approach to quality assurance, shifting from the traditional Quality by Testing (QbT) to Quality by Design (QbD). QbD, a systematic approach to quality in process development, integrates quality into process design and control, guided by regulatory frameworks. This paradigm shift enables increased operational efficiencies, reduced market time, and ensures product consistency. The implementation of QbD is framed around key elements such as defining the Quality Target Product Profile (QTPPs), identifying Critical Quality Attributes (CQAs), developing Design Spaces (DS), establishing Control Strategies (CS), and maintaining continual improvement. The present critical analysis delves into the intricacies of each element, emphasizing their role in ensuring consistent product quality and regulatory compliance. The integration of Industry 4.0 and 5.0 technologies, including Artificial Intelligence (AI), Machine Learning (ML), Internet of Things (IoT), and Digital Twins (DTs), is significantly transforming the bioprocessing industry. These innovations enable real-time data analysis, predictive modelling, and process optimization, which are crucial elements in QbD implementation. Among these, the concept of DTs is notable for its ability to facilitate bi-directional data communication and enable real-time adjustments and therefore optimize processes. DTs, however, face implementation challenges such as system integration, data security, and hardware-software compatibility. These challenges are being addressed through advancements in AI, Virtual Reality/ Augmented Reality (VR/AR), and improved communication technologies. Central to the functioning of DTs is the development and application of various models of differing types - mechanistic, empirical, and hybrid. These models serve as the intellectual backbone of DTs, providing a framework for interpreting and predicting the behaviour of their physical counterparts. The choice and development of these models are vital for the accuracy and efficacy of DTs, enabling them to mirror and predict the real-time dynamics of bioprocessing systems. Complementing these models, advancements in data collection technologies, such as free-floating wireless sensors and spectroscopic sensors, enhance the monitoring and control capabilities of DTs, providing a more comprehensive and nuanced understanding of the bioprocessing environment. This review offers a critical analysis of the prevailing trends in model-based bioprocessing development within the sector.


Assuntos
Inteligência Artificial , Biotecnologia , Biotecnologia/métodos , Internet das Coisas , Aprendizado de Máquina , Controle de Qualidade
2.
Bioact Mater ; 34: 311-325, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38274293

RESUMO

More effective approaches are needed in the treatment of blood cancers, in particular acute myeloid leukemia (AML), that are able to eliminate resistant leukemia stem cells (LSCs) at the bone marrow (BM), after a chemotherapy session, and then enhance hematopoietic stem cell (HSC) engraftment for the re-establishment of the HSC compartment. Here, we investigate whether light-activatable nanoparticles (NPs) encapsulating all-trans-retinoic acid (RA+NPs) could solve both problems. Our in vitro results show that mouse AML cells transfected with RA+NPs differentiate towards antitumoral M1 macrophages through RIG.1 and OASL gene expression. Our in vivo results further show that mouse AML cells transfected with RA+NPs home at the BM after transplantation in an AML mouse model. The photo-disassembly of the NPs within the grafted cells by a blue laser enables their differentiation towards a macrophage lineage. This macrophage activation seems to have systemic anti-leukemic effect within the BM, with a significant reduction of leukemic cells in all BM compartments, of animals treated with RA+NPs, when compared with animals treated with empty NPs. In a separate group of experiments, we show for the first time that normal HSCs transfected with RA+NPs show superior engraftment at the BM niche than cells without treatment or treated with empty NPs. This is the first time that the activity of RA is tested in terms of long-term hematopoietic reconstitution after transplant using an in situ activation approach without any exogenous priming or genetic conditioning of the transplanted cells. Overall, the approach documented here has the potential to improve consolidation therapy in AML since it allows a dual intervention in the BM niche: to tackle resistant leukemia and improve HSC engraftment at the same time.

3.
Braz J Microbiol ; 54(3): 1533-1545, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37610567

RESUMO

N-Acetyl-glucosaminidases (GlcNAcases) are exoenzymes found in a wide range of living organisms, which have gained great attention in the treatment of disorders related to diabetes, Alzheimer's, Tay-Sachs', and Sandhoff's diseases; the control of phytopathogens; and the synthesis of bioactive GlcNAc-containing products. Aiming at future industrial applications, in this study, GlcNAcase production by marine Aeromonas caviae CHZ306 was enhanced first in shake flasks in terms of medium composition and then in bench-scale stirred-tank bioreactor in terms of physicochemical conditions. Stoichiometric balance between the bioavailability of carbon and nitrogen in the formulated culture medium, as well as the use of additional carbon and nitrogen sources, played a central role in improving the bioprocess, considerably increasing the enzyme productivity. The optimal cultivation medium was composed of colloidal α-chitin, corn steep liquor, peptone A, and mineral salts, in a 5.2 C:N ratio. Optimization of pH, temperature, colloidal α-chitin concentration, and kLa conditions further increased GlcNAcase productivity. Under optimized conditions in bioreactor (i.e., 34 °C, pH 8 and kLa 55.2 h-1), GlcNAcase activity achieved 173.4 U.L-1 after 12 h of cultivation, and productivity no less than 14.45 U.L-1.h-1 corresponding to a 370-fold enhancement compared to basal conditions.


Assuntos
Aeromonas caviae , Aeromonas caviae/genética , Reatores Biológicos , Carbono , Quitina , Hexosaminidases , Nitrogênio
5.
Adv Sci (Weinh) ; 10(5): e2205475, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36529964

RESUMO

Messenger RNA (mRNA)-based therapies offer enhanced control over the production of therapeutic proteins for many diseases. Their clinical implementation warrants formulations capable of delivering them safely and effectively to target sites. Owing to their chemical versatility, polymeric nanoparticles can be designed by combinatorial synthesis of different ionizable, cationic, and aromatic moieties to modulate cell targeting, using inexpensive formulation steps. Herein, 152 formulations are evaluated by high-throughput screening using a reporter fibroblast model sensitive to functional delivery of mRNA encoding Cre recombinase. Using in vitro and in vivo models, a polymeric nanoformulation based on the combination of 3 specific monomers is identified to transfect fibroblasts much more effectively than other cell types populating the skin, with superior performance than lipid-based transfection agents in the delivery of Cas9 mRNA and guide RNA. This tropism can be explained by receptor-mediated endocytosis, involving CD26 and FAP, which are overexpressed in profibrotic fibroblasts. Structure-activity analysis reveals that efficient mRNA delivery required the combination of high buffering capacity and low mRNA binding affinity for rapid release upon endosomal escape. These results highlight the use of high-throughput screening to rapidly identify chemical features towards the design of highly efficient mRNA delivery systems targeting fibrotic diseases.


Assuntos
Técnicas de Transferência de Genes , Nanopartículas , RNA Mensageiro/genética , Transfecção , Polímeros , Fibroblastos
6.
Rev. med (São Paulo) ; 101(3): e-183634, 2022.
Artigo em Inglês, Português | LILACS-Express | LILACS | ID: biblio-1392295

RESUMO

Apesar do uso de plantas medicinais para tratamento de problemas de saúde ser tradicionalmente aceito, esta prática da medicina popular ainda encontra resistência por profissionais da saúde, sobretudo sob a alegação da falta de comprovação de seus efeitos. Durante o surto de Covid-19, houve aumento significativo do estresse, sintomas ansiosos e insônia e o uso de plantas medicinais e fitoterápicos surge como uma alternativa terapêutica. O objetivo deste estudo foi realizar uma revisão da literatura sobre a eficácia de plantas medicinais como terapia alternativa e/ou complementar para transtornos de ansiedade e insônia. As plantas investigadas foram selecionadas a partir do Formulário de Fitoterápicos e Memento Fitoterápico da Farmacopeia Brasileira, sendo utilizados como descritores o nome científico da planta e os termos "anxiety" e "insomnia" com recorte temporal de 2015 a 2020. 230 resultados foram encontrados, 42 selecionados (27 em humanos e 15 em animais). Foi possível demonstrar efeitos ansiolíticos para as plantas capim santo (Cymbopogon citratus), lavanda (Lavandula officinalis), melissa (Melissa officinalis), maracujá (Passiflora incarnata)e valeriana (Valeriana officinalis) e sedativos para melissa, maracujá e valeriana. A kava-kava (Piper methysticum) demonstrou apenas efeito sedativo e a camomila (Matricaria chamomilla) apresentou eficácia clínica ansiolítica. Portanto, a potencial aplicação clínica dessas plantas é indicada para tratamento dos sintomas de ansiedade e insônia, ajudando a reduzir os sintomas psicológicos decorrentes da pandemia de Covid-19. Contudo, vale ressaltar a necessidade da padronização dos procedimentos metodológicos e avanço da fitoterapia na prática médica. [au]


Although the use of medicinal plants to treat health problems is traditionally accepted, this practice of popular medicine still finds resistance from health professionals, especially under the allegation of lack of scientific proof of its effects. During the outbreak of COVID-19, there was a significant increase in stress, anxiety, and insomnia symptoms, and the use of plants and herbal medicines emerged as a possible therapeutic alternative. The objective of this study was to conduct a literature review about the effectiveness of medicinal plants as an alternative and/or complementary therapy for anxiety and insomnia disorders. The main medicinal plants were selected from the Phytotherapeutic Formulary and Phytotherapeutic Memento of the Brazilian Pharmacopoeia, using the 'scientific name' and terms 'anxiety' and 'insomnia' as descriptors between 2015-2020. 230 results were found and 42 studies were selected (27 in humans and 15 in animals). Anxiolytic effects have been demonstrated to Cymbopogon citratus, Lavandula officinalis, Melissa officinalis, Passiflora incarnata, and Valeriana officinalis and sedatives effects to M. officinalis, P. incarnata, and V. officinalis. Piper methysticum revealed only a sedative effect and Matricaria chamomilla showed anxiolytic clinical efficacy. Then, the potential clinical application of these plants in the treatment of anxiety and insomnia symptoms is indicated, helping to reduce the psychological symptoms resulting from the Covid-19 pandemic. However, it is worth emphasizing the need to standardize methodological procedures and advance phytotherapy in medical practice. [au]

7.
APL Bioeng ; 5(3): 031511, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34476328

RESUMO

The use of pharmacologically active compounds to manage and treat diseases is of utmost relevance in clinical practice. It is well recognized that spatial-temporal control over the delivery of these biomolecules will greatly impact their pharmacokinetic profile and ultimately their therapeutic effect. Nanoparticles (NPs) prepared from different materials have been tested successfully in the clinic for the delivery of several biomolecules including non-coding RNAs (siRNA and miRNA) and mRNAs. Indeed, the recent success of mRNA vaccines is in part due to progress in the delivery systems (NP based) that have been developed for many years. In most cases, the identification of the best formulation was done by testing a small number of novel formulations or by modification of pre-existing ones. Unfortunately, this is a low throughput and time-consuming process that hinders the identification of formulations with the highest potential. Alternatively, high-throughput combinatorial design of NP libraries may allow the rapid identification of formulations with the required release and cell/tissue targeting profile for a given application. Combinatorial approaches offer several advantages over conventional methods since they allow the incorporation of multiple components with varied chemical properties into materials, such as polymers or lipid-like materials, that will subsequently form NPs by self-assembly or chemical conjugation processes. The current review highlights the impact of high-throughput in the development of more efficient drug delivery systems with enhanced targeting and release kinetics. It also describes the current challenges in this research area as well as future directions.

8.
Nanoscale Horiz ; 6(3): 245-259, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33576750

RESUMO

The vascular bioactivity/safety of nanomaterials is typically evaluated by animal testing, which is of low throughput and does not account for biological differences between animals and humans such as ageing, metabolism and disease profiles. The development of personalized human in vitro platforms to evaluate the interaction of nanomaterials with the vascular system would be important for both therapeutic and regenerative medicine. A library of 30 nanoparticle (NP) formulations, in use in imaging, antimicrobial and pharmaceutical applications, was evaluated in a reporter zebrafish model of vasculogenesis and then tested in personalized humanized models composed of human-induced pluripotent stem cell (hiPSC)-derived endothelial cells (ECs) with "young" and "aged" phenotypes in 3 vascular network formats: 2D (in polystyrene dish), 3D (in Matrigel) and in a blood vessel on a chip. As a proof of concept, vascular toxicity was used as the main readout. The results show that the toxicity profile of NPs to hiPSC-ECs was dependent on the "age" of the endothelial cells and vascular network format. hiPSC-ECs were less susceptible to the cytotoxicity effect of NPs when cultured in flow than in static conditions, the protective effect being mediated, at least in part, by glycocalyx. Overall, the results presented here highlight the relevance of in vitro hiPSC-derived vascular systems to screen vascular nanomaterial interactions.


Assuntos
Vasos Sanguíneos/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Nanopartículas/toxicidade , Adolescente , Animais , Células Endoteliais/efeitos dos fármacos , Feminino , Humanos , Dispositivos Lab-On-A-Chip , Masculino , Testes de Toxicidade/instrumentação , Testes de Toxicidade/métodos , Peixe-Zebra
9.
Methods ; 190: 13-25, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33359052

RESUMO

RNA-based therapies are highly selective and powerful regulators of biological functions. Non-viral vectors such as nanoparticles (NPs) are very promising formulations for the delivery of RNA-based therapies but their cell targeting, cell internalization and endolysomal escape capacity is rather limited. Here, we present a methodology that combines high-throughput synthesis of light-triggerable NPs and a high-content imaging screening to identify NPs capable of efficiently delivering different type of RNAs. The NPs were generated using polymers synthesized by Michael type addition reactions and they were designed to: (i) efficiently complex coding (mRNAs) and non-coding (miRNAs and/or lncRNAs) RNA molecules, (ii) allow rapid cell uptake and cytoplasmic release of RNA molecules and (iii) target different cell types based on their composition. Furthermore, light-responsive domains were attached to the polymers by distinctive methods to provide diverse disassembly strategies. The most efficient formulations were identified using cell-based assays and high-content imaging analysis. This strategy allows precise delivery of RNA-based therapies and provides an effective design approach to address critical issues in non-viral gene delivery.


Assuntos
Ensaios de Triagem em Larga Escala , Sistemas de Liberação de Medicamentos , Técnicas de Transferência de Genes , MicroRNAs , Nanopartículas , Polímeros , RNA Longo não Codificante
10.
Nanoscale ; 12(18): 9935-9942, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32352454

RESUMO

The control of vascular remodeling mediated by transcription factor HIF-1α is critical in the treatment of several diseases including cancer, retinopathies, chronic wounds, and ischemic heart disease, among others. Gene silencing using a small interfering RNA (siRNA) is a promising therapeutic strategy to regulate HIF-1α; however, the delivery systems developed so far have limited endothelial targeting and efficiency. Herein, we have synthesized a light-triggerable polymeric nanoparticle (NP) library composed of 110 formulations which showed variable morphology, charge and disassembly rates after UV exposure. More than 35% of the formulations of the library were more efficient in gene knockdown than the siRNA delivered by a commercial transfection agent (lipofectamine RNAiMAX). The most efficient siRNA delivery formulations were tested against different cell types to identify one with preferential targeting to endothelial cells. Using a two-step methodology, we have identified a formulation that shows exquisite targeting to endothelial cells and is able to deliver more efficiently the siRNA that modulates HIF-1α than commercial transfection agents. Overall, the strategy reported here increases the specificity for tissue regulation and the efficiency for the intracellular delivery of siRNAs.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Raios Ultravioleta , Acrilamidas/química , Proliferação de Células , Química Farmacêutica , Diaminas/química , Portadores de Fármacos/química , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Prolina Dioxigenases do Fator Induzível por Hipóxia/antagonistas & inibidores , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Nanopartículas/química , Polímeros/química , Estabilidade Proteica , Interferência de RNA , RNA Interferente Pequeno/química , RNA Interferente Pequeno/metabolismo , Transfecção/métodos
11.
Angew Chem Int Ed Engl ; 59(5): 1985-1991, 2020 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-31729147

RESUMO

RNA-based therapies offer a wide range of therapeutic interventions including the treatment of skin diseases; however, the strategies to efficiently deliver these biomolecules are still limited due to obstacles related to the cellular uptake and cytoplasmic delivery. Herein, we report the synthesis of a triggerable polymeric nanoparticle (NP) library composed of 160 formulations, presenting physico-chemical diversity and differential responsiveness to light. Six formulations were more efficient (up to 500 %) than commercially available lipofectamine in gene-knockdown activity. These formulations showed differential internalization by skin cells and the endosomal escape was rapid (minutes range). The NPs were effective in the release of siRNA and miRNA. Acute skin wounds treated with the top hit NP complexed with miRNA-150-5p healed faster than wounds treated with scrambled miRNA. Light-activatable NPs offer a new strategy to topically deliver non-coding RNAs.


Assuntos
Células HeLa/química , Nanopartículas/química , RNA/química , Humanos
12.
J Nanobiotechnology ; 17(1): 97, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31526377

RESUMO

BACKGROUND: Externally triggered drug delivery systems hold considerable promise for improving the treatment of many diseases, in particular, diseases where the spatial-temporal release of the drug is critical to maximize their biological effect whilst minimizing undesirable, off-target, side effects. RESULTS: Herein, we developed a light-triggerable formulation that takes advantage of host-guest chemistry to complex drugs functionalized with a guest molecule and release it after exposure to near infrared (NIR) light due to the disruption of the non-covalent host-guest interactions. The system is composed by a gold nanorod (AuNR), which generates plasmonic heat after exposure to NIR, a thin layer of hyaluronic acid immobilized to the AuNR upon functionalization with a macrocycle, cucurbit[6]uril (CB[6]), and a drug functionalized with a guest molecule that interacts with the macrocycle. For proof of concept, we have used this formulation for the intracellular release of a derivative of retinoic acid (RA), a molecule known to play a key role in tissue development and homeostasis as well as during cancer treatment. We showed that the formulation was able to conjugate approximately 65 µg of RA derivative per mg of CB[6] @AuNR and released it within a few minutes after exposure to a NIR laser. Importantly, the bioactivity of RA released from the formulation was demonstrated in a reporter cell line expressing luciferase under the control of the RA receptor. CONCLUSIONS: This NIR light-triggered supramolecular-based modular platform holds great promise for theranostic applications.


Assuntos
Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos/métodos , Bibliotecas de Moléculas Pequenas/química , Linhagem Celular Tumoral , Células Cultivadas , Liberação Controlada de Fármacos/efeitos dos fármacos , Ouro/química , Humanos , Ácido Hialurônico/química , Raios Infravermelhos , Nanotubos/química , Bibliotecas de Moléculas Pequenas/administração & dosagem , Tretinoína/química
13.
Exp Parasitol ; 205: 107714, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31279927

RESUMO

The objective of the present study was to evaluate the clinical signs, electrocardiographic signs and evolution of histopathological lesions in the heart of sheep experimentally infected by Trypanosoma vivax during the acute and chronic phases of infection as well as to investigate the presence of parasitic DNA in the heart using polymerase chain reaction (PCR). Twenty-two male sheep were divided into the following four groups: G1, which consisted of six sheep infected by T. vivax that were evaluated until 20 days post-infection (dpi; acute phase); G2, which consisted of six sheep infected by T. vivax that were evaluated until 90 dpi (chronic phase); and G3 and G4 groups, which each consisted of five uninfected sheep. At the end of the experimental period, electrocardiographic evaluations and necroscopic examinations were performed. Fragments of the heart were collected and stained by Hematoxylin-Eosin and Masson's trichrome, and the fragments were also evaluated by PCR for T. vivax. G2 animals presented clinical signs suggestive of heart failure and electrocardiogram alterations characterized by prolonged P, T and QRS complex durations as well as by a cardiac electrical axis shift to the left and increased heart rate. In these animals, mononuclear multifocal myocarditis and interstitial fibrosis were also observed. PCR revealed positivity for T. vivax in two G1 animals and in all G2 animals. Thus, these findings suggested that T. vivax is responsible for the occurrence of cardiac lesions, which are related to heart failure, electrocardiographic alterations and mortality of the infected animals.


Assuntos
DNA de Protozoário/isolamento & purificação , Insuficiência Cardíaca/veterinária , Coração/parasitologia , Doenças dos Ovinos/parasitologia , Trypanosoma vivax/patogenicidade , Tripanossomíase Africana/veterinária , Doença Aguda , Animais , Anticorpos Antiprotozoários/sangue , Doença Crônica/veterinária , Eletrocardiografia/veterinária , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/parasitologia , Imunoglobulina G/sangue , Masculino , Miocárdio/patologia , Parasitemia/veterinária , Pericardite/parasitologia , Pericardite/patologia , Pericardite/veterinária , Reação em Cadeia da Polimerase/veterinária , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/mortalidade , Doenças dos Ovinos/patologia , Trypanosoma vivax/genética , Trypanosoma vivax/imunologia , Trypanosoma vivax/isolamento & purificação , Tripanossomíase Africana/complicações , Tripanossomíase Africana/mortalidade , Tripanossomíase Africana/patologia
14.
Bioconjug Chem ; 29(5): 1485-1489, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29652487

RESUMO

We report the synthesis and characterization of phototriggerable polymeric nanoparticles (NPs) for the intracellular delivery of small molecules and proteins to modulate cell activity. For that purpose, several photocleavable linkers have been prepared providing diverse functional groups as anchoring points for biomolecules.


Assuntos
Preparações de Ação Retardada/química , Nanopartículas/química , Preparações Farmacêuticas/administração & dosagem , Fotólise , Polímeros/química , Proteínas/administração & dosagem , Animais , Reagentes de Ligações Cruzadas/química , Humanos , Muramidase/administração & dosagem , Raios Ultravioleta
15.
Artigo em Inglês | MEDLINE | ID: mdl-30687702

RESUMO

L-Asparaginase (ASNase) is a vital component of the first line treatment of acute lymphoblastic leukemia (ALL), an aggressive type of blood cancer expected to afflict over 53,000 people worldwide by 2020. More recently, ASNase has also been shown to have potential for preventing metastasis from solid tumors. The ASNase treatment is, however, characterized by a plethora of potential side effects, ranging from immune reactions to severe toxicity. Consequently, in accordance with Quality-by-Design (QbD) principles, ingenious new products tailored to minimize adverse reactions while increasing patient survival have been devised. In the following pages, the reader is invited for a brief discussion on the most recent developments in this field. Firstly, the review presents an outline of the recent improvements on the manufacturing and formulation processes, which can severely influence important aspects of the product quality profile, such as contamination, aggregation and enzymatic activity. Following, the most recent advances in protein engineering applied to the development of biobetter ASNases (i.e., with reduced glutaminase activity, proteolysis resistant and less immunogenic) using techniques such as site-directed mutagenesis, molecular dynamics, PEGylation, PASylation and bioconjugation are discussed. Afterwards, the attention is shifted toward nanomedicine including technologies such as encapsulation and immobilization, which aim at improving ASNase pharmacokinetics. Besides discussing the results of the most innovative and representative academic research, the review provides an overview of the products already available on the market or in the latest stages of development. With this, the review is intended to provide a solid background for the current product development and underpin the discussions on the target quality profile of future ASNase-based pharmaceuticals.

16.
Phys Chem Chem Phys ; 19(21): 13640-13649, 2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28530732

RESUMO

The formation of inclusion complexes between lucigenin (N,N'-dimethyl-9,9'-biacridinium dinitrate) and p-sulfonatocalix[n]arenes (SCn; n = 6, 8) was investigated by fluorescence and NMR spectroscopy. Both SC6 and SC8 were found to form 1 : 1 and 1 : 2 host-guest complexes with lucigenin showing up to 109 M-1 binding affinities. Strong quenching of the lucigenin fluorescence upon complexation was observed. Fluorescence regeneration after competitive binding with other potential guests present in solution was used as an indicator displacement assay to characterize the binding mechanism and affinity of alkaline metal ions (Li+, Na+, K+ and Cs+) with SC6 and SC8. The results demonstrate the formation of 1 : 1 and 1 : 2 calixarene : metal complexes with association constants on the order of 103 M-1 and heteroternary calixarene : lucigenin : metal complexes that predominate at metal cation concentrations above the millimolar range. Owing to the ubiquitous presence of metal cations in SCn solutions as counterions (typically Na+), the detailed description of the complexation of these species is crucial to understand and quantify the host-guest binding properties of these receptors. This work demonstrates that both the thermodynamic stability and the stoichiometric nature of the complexes is dependent on the metal ion concentration and, consequently, on the calixarene concentration.

17.
Org Biomol Chem ; 15(4): 911-919, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-28045174

RESUMO

The selective binding behavior of a trimethylammonium-derived pillar[5]arene towards different guests in aqueous media and under neutral conditions is reported. Although it is known that this macrocycle has the capability to form complexes with guests, we anticipate that the intrinsic pillar shape of the macrocycle with two positively charged rims should allow a diversity of binding modes. The three guests were selected based on their charge and size. The inclusion binding modes and the affinity of the macrocycle to form host-guest complexes were determined by ITC and NMR techniques. We reveal the ability of a cationic water soluble pillar[5]arene to effectively complex two guest molecules, one in each rim, evidencing the diversity of binding modes. Two different structures for 1 : 1 and three for 1 : 2 complexes are reported showing the pillararene ability for internal/external binding.


Assuntos
Benzenossulfonatos/química , Naftalenossulfonatos/química , Compostos de Amônio Quaternário/química , Sítios de Ligação , Calixarenos , Estrutura Molecular
18.
J Chromatogr A ; 1456: 123-36, 2016 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-27328885

RESUMO

Different multi-column options to perform continuous chromatographic separations of ternary mixtures have been proposed in order to overcome limitations of batch chromatography. One attractive option is given by simulated moving bed chromatography (SMB) with 8 zones, a process that offers uninterrupted production, and, potentially, improved economy. As in other established ternary separation processes, the separation sequence is crucial for the performance of the process. This problem is addressed here by computing and comparing optimal performances of the two possibilities assuming linear adsorption isotherms. The conclusions are presented in a decision tree which can be used to guide the selection of system configuration and operation.


Assuntos
Cromatografia/instrumentação , Adsorção , Algoritmos , Cromatografia/economia , Cromatografia/métodos , Simulação por Computador , Árvores de Decisões , Destilação , Eficiência , Modelos Econômicos , Reprodutibilidade dos Testes , Termodinâmica
19.
Exp Parasitol ; 167: 17-24, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27130703

RESUMO

The present study aimed to evaluate the effects of Trypanosoma vivax infection on the shape of the lactation curve and the milk quality of dairy goats experimentally infected with T. vivax. In total, twenty Saanen goats, aged 26-30 months and the same number of calving (two calvings), were divided into two experimental groups: an infected group, consisting of ten goats intravenously infected with 0.5 ml of blood containing approximately 1.25 × 10(5) trypomastigotes of T. vivax and ten uninfected animals as the control group. Clinical tests and hematocrit, parasitemia, and serum biochemistry evaluations were performed on all of the goats. Milk production was measured daily for 152 days by hand milking the goats and weighing the milk. Every seven days, physiochemical analyses were performed to evaluate the milk. Wood's nonlinear model was used to analyze the lactation curve parameters. The infected goats had high levels of parasitemia and hyperthermia, significantly reduced hematocrit, serum total protein, albumin, and glucose levels and increased cholesterol and urea concentrations. Wood's model indicated that the milk production of goats in the infected group declined sharply over a short period of time and produced a flattened yield curve and significant difference (P < 0.05) in the rate of increase of peak milk production, rate of decrease of milk production after the peak, day of peak milk production, and maximum peak milk production compared with that of the control group. Trypanosomiasis also affected the persistency of lactation, which was significantly reduced in goats in the infected group. In addition, the physico-chemical properties of the milk, including the fat content, defatted dry extracts (DDE) and protein content, decreased significantly (P < 0.05) in the goats in the infected group compared with those in the control group. The T. vivax-infected goats showed reduction in milk production, persistence of lactation, and fat levels, the defatted dry extract (DDE) content, and protein, changing the quality of milk.


Assuntos
Doenças das Cabras/fisiopatologia , Transtornos da Lactação/veterinária , Leite/normas , Trypanosoma vivax , Tripanossomíase Africana/veterinária , Ração Animal , Animais , Análise Química do Sangue/veterinária , Proteínas Sanguíneas/metabolismo , Temperatura Corporal , Colesterol/sangue , Ingestão de Alimentos , Feminino , Doenças das Cabras/parasitologia , Cabras , Hematócrito/veterinária , Transtornos da Lactação/parasitologia , Leite/química , Parasitemia/veterinária , Distribuição Aleatória , Tripanossomíase Africana/fisiopatologia , Ureia/sangue
20.
Chemistry ; 20(38): 12123-32, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25110897

RESUMO

The complexation of an anionic guest by a cationic water-soluble pillararene is reported. Isothermal titration calorimetry (ITC), (1)H NMR, (1)H and (19)F DOSY, and STD NMR experiments were performed to characterize the complex formed under aqueous neutral conditions. The results of ITC and (1)H NMR analyses showed the inclusion of the guest inside the cavity of the pillar[5]arene, with the binding constant and thermodynamic parameters influenced by the counter ion of the macrocycle. NMR diffusion experiments showed that although a fraction of the counter ions are expelled from the host cavity by exchange with the guest, a complex with both counter ions and the guest inside the pillararene is formed. The results also showed that at higher concentrations of guest in solution, in addition to the inclusion of one guest molecule in the cavity, the pillararene can also form an external complex with a second guest molecule.


Assuntos
Compostos de Amônio Quaternário/química , Água/química , Calixarenos , Troca Iônica , Modelos Moleculares
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