scholarly journals How to Choose In Vitro Systems to Predict In Vivo Drug Clearance: A System Pharmacology Perspective

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Wang ◽  
ChienWei Chiang ◽  
Hong Liang ◽  
Hengyi Wu ◽  
Weixing Feng ◽  
...  
Keyword(s):  
Large Scale ◽  
Relevant Information ◽  
Drug Clearance ◽  
In Vitro Metabolism ◽  
System Pharmacology ◽  
Clearance Prediction ◽  
In Vitro Systems ◽  
Baculovirus System

The use of in vitro metabolism data to predict human clearance has become more significant in the current prediction of large scale drug clearance for all the drugs. The relevant information (in vitro metabolism data and in vivo human clearance values) of thirty-five drugs that satisfied the entry criteria of probe drugs was collated from the literature. Then the performance of different in vitro systems includingEscherichia colisystem, yeast system, lymphoblastoid system and baculovirus system is compared after in vitro-in vivo extrapolation. Baculovirus system, which can provide most of the data, has almost equal accuracy as the other systems in predicting clearance. And in most cases, baculovirus system has the smaller CV in scaling factors. Therefore, the baculovirus system can be recognized as the suitable system for the large scale drug clearance prediction.

scholarly journals Human Oligodendrocytes and Myelin In Vitro to Evaluate Developmental Neurotoxicity

2021 ◽  
Vol 22 (15) ◽  
pp. 7929
Author(s):  
Megan Chesnut ◽  
Thomas Hartung ◽  
Helena Hogberg ◽  
David Pamies
Keyword(s):  
Large Scale ◽  
In Vitro Models ◽  
Environmental Chemicals ◽  
Developmental Neurotoxicity ◽  
In Vivo Studies ◽  
Regulatory Guidelines ◽  
In Vitro Systems ◽  
Human Oligodendrocytes

Neurodevelopment is uniquely sensitive to toxic insults and there are concerns that environmental chemicals are contributing to widespread subclinical developmental neurotoxicity (DNT). Increased DNT evaluation is needed due to the lack of such information for most chemicals in common use, but in vivo studies recommended in regulatory guidelines are not practical for the large-scale screening of potential DNT chemicals. It is widely acknowledged that developmental neurotoxicity is a consequence of disruptions to basic processes in neurodevelopment and that testing strategies using human cell-based in vitro systems that mimic these processes could aid in prioritizing chemicals with DNT potential. Myelination is a fundamental process in neurodevelopment that should be included in a DNT testing strategy, but there are very few in vitro models of myelination. Thus, there is a need to establish an in vitro myelination assay for DNT. Here, we summarize the routes of myelin toxicity and the known models to study this particular endpoint.

scholarly journals Relevance of In Vitro Metabolism Models to PET Radiotracer Development: Prediction of In Vivo Clearance in Rats from Microsomal Stability Data

2019 ◽  
Vol 12 (2) ◽  
pp. 57 ◽  
Author(s):  
Daniela Schneider ◽  
Angela Oskamp ◽  
Marcus Holschbach ◽  
Bernd Neumaier ◽  
Andreas Bauer ◽  
...  
Keyword(s):  
Liver Microsomes ◽  
In Vitro Metabolism ◽  
Amount Of Substance ◽  
Positron Emission ◽  
Clearance Prediction ◽  
Pet Radiotracers ◽  
Stability Data ◽  
In Vitro Data

The prediction of in vivo clearance from in vitro metabolism models such as liver microsomes is an established procedure in drug discovery. The potentials and limitations of this approach have been extensively evaluated in the pharmaceutical sector; however, this is not the case for the field of positron emission tomography (PET) radiotracer development. The application of PET radiotracers and classical drugs differs greatly with regard to the amount of substance administered. In typical PET imaging sessions, subnanomolar quantities of the radiotracer are injected, resulting in body concentrations that cannot be readily simulated in analytical assays. This raises concerns regarding the predictability of radiotracer clearance from in vitro data. We assessed the accuracy of clearance prediction for three prototypical PET radiotracers developed for imaging the A1 adenosine receptor (A1AR). Using the half-life (t1/2) approach and physiologically based scaling, in vivo clearance in the rat model was predicted from microsomal stability data. Actual clearance could be accurately predicted with an average fold error (AFE) of 0.78 and a root mean square error (RMSE) of 1.6. The observed slight underprediction (1.3-fold) is in accordance with the prediction accuracy reported for classical drugs. This result indicates that the prediction of radiotracer clearance is possible despite concentration differences of more than three orders of magnitude between in vitro and in vivo conditions. Consequently, in vitro metabolism models represent a valuable tool for PET radiotracer development.

Purification of the Antihemophilic Factor by Gel Filtration on Agarose

1969 ◽  
Vol 22 (03) ◽  
pp. 577-583 ◽  
Author(s):  
M.M.P Paulssen ◽  
A.C.M.G.B Wouterlood ◽  
H.L.M.A Scheffers
Keyword(s):  
Factor Viii ◽  
Plasma Proteins ◽  
Large Scale ◽  
Gel Filtration ◽  
Large Scale Preparation ◽  
Scale Preparation ◽  
Antihemophilic Factor

SummaryFactor VIII can be isolated from plasma proteins, including fibrinogen by chromatography on agarose. The best results were obtained with Sepharose 6B. Large scale preparation is also possible when cryoprecipitate is separated by chromatography. In most fractions containing factor VIII a turbidity is observed which may be due to the presence of chylomicrons.The purified factor VIII was active in vivo as well as in vitro.

Naphthoquinones and derivatives for chemotherapy: perspectives and limitations of their anti-trypanosomatids activities

2020 ◽  
Vol 26 ◽  
Author(s):  
Luíza Dantas-Pereira ◽  
Edézio F. Cunha-Junior ◽  
Valter V. Andrade-Neto ◽  
John F. Bower ◽  
Guilherme A. M. Jardim ◽  
...  
Keyword(s):  
Large Scale ◽  
Neglected Tropical Diseases ◽  
Folk Medicine ◽  
Leishmania Species ◽  
Parasitic Infections ◽  
Mechanistic Analysis ◽  
Leishmania Spp ◽  
Nanomolar Range

: Chagas disease, Sleeping sickness and Leishmaniasis, caused by trypanosomatids Trypanosoma cruzi, Trypanosoma brucei and Leishmania spp., respectively, are considered neglected tropical diseases, and they especially affect impoverished populations in the developing world. The available chemotherapies are very limited and a search for alternatives is still necessary. In folk medicine, natural naphthoquinones have been employed for the treatment of a great variety of illnesses, including parasitic infections. This review is focused on the anti-trypanosomatid activity and mechanistic analysis of naphthoquinones and derivatives. Among all the series of derivatives tested in vitro, naphthoquinone-derived 1,2,3-triazoles were very active on T. cruzi infective forms in blood bank conditions, as well as in amastigotes of Leishmania spp. naphthoquinones containing a CF3 on a phenyl amine ring inhibited T. brucei proliferation in the nanomolar range, and naphthopterocarpanquinones stood out for their activity on a range of Leishmania species. Some of these compounds showed a promising selectivity index (SI) (30 to 1900), supporting further analysis in animal models. Indeed, high toxicity to the host and inactivation by blood components are crucial obstacles to be overcome to use naphthoquinones and/or their derivatives for chemotherapy. Multidisciplinary initiatives embracing medicinal chemistry, bioinformatics, biochemistry, and molecular and cellular biology need to be encouraged to allow the optimization of these compounds. Large scale automated tests are pivotal for the efficiency of the screening step, and subsequent evaluation of both the mechanism of action in vitro and pharmacokinetics in vivo are essential for the development of a novel, specific and safe derivative, minimizing adverse effects.

scholarly journals Lentiviral Vectors for Delivery of Gene-Editing Systems Based on CRISPR/Cas: Current State and Perspectives

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1288
Author(s):  
Wendy Dong ◽  
Boris Kantor
Keyword(s):  
Large Scale ◽  
Lentiviral Vector ◽  
Clinical Applications ◽  
Scale Production ◽  
Base Editing ◽  
Epigenome Editing ◽  
Vector Systems ◽  
Dividing Cells

CRISPR/Cas technology has revolutionized the fields of the genome- and epigenome-editing by supplying unparalleled control over genomic sequences and expression. Lentiviral vector (LV) systems are one of the main delivery vehicles for the CRISPR/Cas systems due to (i) its ability to carry bulky and complex transgenes and (ii) sustain robust and long-term expression in a broad range of dividing and non-dividing cells in vitro and in vivo. It is thus reasonable that substantial effort has been allocated towards the development of the improved and optimized LV systems for effective and accurate gene-to-cell transfer of CRISPR/Cas tools. The main effort on that end has been put towards the improvement and optimization of the vector’s expression, development of integrase-deficient lentiviral vector (IDLV), aiming to minimize the risk of oncogenicity, toxicity, and pathogenicity, and enhancing manufacturing protocols for clinical applications required large-scale production. In this review, we will devote attention to (i) the basic biology of lentiviruses, and (ii) recent advances in the development of safer and more efficient CRISPR/Cas vector systems towards their use in preclinical and clinical applications. In addition, we will discuss in detail the recent progress in the repurposing of CRISPR/Cas systems related to base-editing and prime-editing applications.

scholarly journals Pan-ERBB kinase inhibition augments CDK4/6 inhibitor efficacy in oesophageal squamous cell carcinoma

Gut ◽  
2021 ◽  
pp. gutjnl-2020-323276
Author(s):  
Jin Zhou ◽  
Zhong Wu ◽  
Zhouwei Zhang ◽  
Louisa Goss ◽  
James McFarland ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Large Scale ◽  
Cell Cancer ◽  
Oesophageal Squamous Cell Carcinoma ◽  
Squamous Cancer ◽  
Striking Success

ObjectiveOesophageal squamous cell carcinoma (OSCC), like other squamous carcinomas, harbour highly recurrent cell cycle pathway alterations, especially hyperactivation of the CCND1/CDK4/6 axis, raising the potential for use of existing CDK4/6 inhibitors in these cancers. Although CDK4/6 inhibition has shown striking success when combined with endocrine therapy in oestrogen receptor positive breast cancer, CDK4/6 inhibitor palbociclib monotherapy has not revealed evidence of efficacy to date in OSCC clinical studies. Herein, we sought to elucidate the identification of key dependencies in OSCC as a foundation for the selection of targets whose blockade could be combined with CDK4/6 inhibition.DesignWe combined large-scale genomic dependency and pharmaceutical screening datasets with preclinical cell line models, to identified potential combination therapies in squamous cell cancer.ResultsWe identified sensitivity to inhibitors to the ERBB family of receptor kinases, results clearly extending beyond the previously described minority of tumours with EGFR amplification/dependence, specifically finding a subset of OSCCs with dual dependence on ERBB3 and ERBB2. Subsequently. we demonstrated marked efficacy of combined pan-ERBB and CDK4/6 inhibition in vitro and in vivo. Furthermore, we demonstrated that squamous lineage transcription factor KLF5 facilitated activation of ERBBs in OSCC.ConclusionThese results provide clear rationale for development of combined ERBB and CDK4/6 inhibition in these cancers and raises the potential for KLF5 expression as a candidate biomarker to guide the use of these agents. These data suggested that by combining existing Food and Drug Administration (FDA)-approved agents, we have the capacity to improve therapy for OSCC and other squamous cancer.

scholarly journals A therapeutic vascular conduit to support in vivo cell-secreted therapy

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Edward X. Han ◽  
Hong Qian ◽  
Bo Jiang ◽  
Maria Figetakis ◽  
Natalia Kosyakova ◽  
...  
Keyword(s):  
Vascular Graft ◽  
Large Scale ◽  
Biological Effects ◽  
Therapeutic Protein ◽  
Close Proximity ◽  
Delivery Platform ◽  
Stage Renal Disease ◽  
End Stage

AbstractA significant barrier to implementation of cell-based therapies is providing adequate vascularization to provide oxygen and nutrients. Here we describe an approach for cell transplantation termed the Therapeutic Vascular Conduit (TVC), which uses an acellular vessel as a scaffold for a hydrogel sheath containing cells designed to secrete a therapeutic protein. The TVC can be directly anastomosed as a vascular graft. Modeling supports the concept that the TVC allows oxygenated blood to flow in close proximity to the transplanted cells to prevent hypoxia. As a proof-of-principle study, we used erythropoietin (EPO) as a model therapeutic protein. If implanted as an arteriovenous vascular graft, such a construct could serve a dual role as an EPO delivery platform and hemodialysis access for patients with end-stage renal disease. When implanted into nude rats, TVCs containing EPO-secreting fibroblasts were able to increase serum EPO and hemoglobin levels for up to 4 weeks. However, constitutive EPO expression resulted in macrophage infiltration and luminal obstruction of the TVC, thus limiting longer-term efficacy. Follow-up in vitro studies support the hypothesis that EPO also functions to recruit macrophages. The TVC is a promising approach to cell-based therapeutic delivery that has the potential to overcome the oxygenation barrier to large-scale cellular implantation and could thus be used for a myriad of clinical disorders. However, a complete understanding of the biological effects of the selected therapeutic is absolutely essential.

Protein-templated gold nanoclusters as specific bio-imaging probes for the detection of Hg(ii) ions in in vivo and in vitro systems: discriminating between MDA-MB-231 and MCF10A cells

The Analyst ◽  
2021 ◽  
Author(s):  
Subhajit Chakraborty ◽  
Atanu Nandy ◽  
Subhadip Ghosh ◽  
Nirmal Kumar Das ◽  
Sameena Parveen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Human Serum Albumin ◽  
Gold Nanoclusters ◽  
Selective Detection ◽  
Imaging Probes ◽  
Bio Imaging ◽  
In Vitro Systems ◽  
Mcf10a Cells

Sub-nanomolar selective detection of Hg(ii) ions by protein (Human Serum Albumin, HSA) templated gold nanoclusters (AuNCs), both in in vitro as well as in vivo environments and specific endocytose behaviour towards breast cancer (BC) cell lines.

scholarly journals In vitro multiplication, micromorphological studies and ex vitro rooting of Hybanthus enneaspermus (L.) F. Muell. – a rare medicinal plant

2018 ◽  
Vol 77 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Mahipal S. Shekhawat ◽  
M. Manokari
Keyword(s):  
Medicinal Plant ◽  
Large Scale ◽  
Nodal Segments ◽  
Ms Medium ◽  
Ex Vitro ◽  
Culture Bottle ◽  
Hybanthus Enneaspermus ◽  
Half Strength

AbstractHybanthus enneaspermusis a rare medicinal plant. We defined a protocol for micropropagation,ex vitrorooting of cloned shoots and their acclimatization. Surface-sterilized nodal segments were cultured on Murashige and Skoog (MS) medium with different concentrations of 6-benzylaminopurine (BAP) and kinetin (Kin). Medium supplemented with 1.5 mg L−1BAP was found optimum for shoot induction from the explants and 6.4±0.69 shoots were regenerated from each node with 97% response. Shoots were further proliferated maximally (228±10.3 shoots per culture bottle with 7.5±0.43 cm length) on MS medium augmented with 1.0 mg L−1each of BAP and Kin within 4–5 weeks. The shoots were rootedin vitroon half strength MS medium containing 2.0 mg L−1indole-3 butyric acid (IBA). The cloned shoots were pulse-treated with 300 mg L–1 of IBA and cultured on soilrite® in a greenhouse. About 96% of the IBA-pulsed shoots rootedex vitroin soilrite®, each shoot producing 12.5±0.54 roots with 5.1±0.62 cm length. Theex vitrorooted plantlets showed a better rate of survival (92%) in a field study thanin vitrorooted plantlets (86%). A comparative foliar micromorphological study ofH. enneaspermuswas conducted to understand the micromorphological changes during plant developmental processes fromin vitrotoin vivoconditions in terms of variations in stomata, vein structures and spacing, and trichomes. This is the first report onex vitrorooting inH. enneaspermusand the protocol can be exploited for conservation and large-scale propagation of this rare and medicinally important plant.

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