scholarly journals Animal simulations facilitate smart drug design through prediction of nanomaterial transport to individual tissue cells

2020 ◽  
Vol 6 (4) ◽  
pp. eaax2642 ◽  
Author(s):  
Edward Price ◽  
Andre J. Gesquiere

Smart drug design for antibody and nanomaterial-based therapies allows optimization of drug efficacy and more efficient early-stage preclinical trials. The ideal drug must display maximum efficacy at target tissue sites, with transport from tissue vasculature to the cellular environment being critical. Biological simulations, when coupled with in vitro approaches, can predict this exposure in a rapid and efficient manner. As a result, it becomes possible to predict drug biodistribution within single cells of live animal tissue without the need for animal studies. Here, we successfully utilized an in vitro assay and a computational fluid dynamic model to translate in vitro cell kinetics (accounting for cell-induced degradation) to whole-body simulations for multiple species as well as nanomaterial types to predict drug distribution into individual tissue cells. We expect this work to assist in refining, reducing, and replacing animal testing, while providing scientists with a new perspective during the drug development process.

1976 ◽  
Vol 15 (05) ◽  
pp. 248-253
Author(s):  
A. K. Basu ◽  
S. K. Guha ◽  
B. N. Tandon ◽  
M. M. Gupta ◽  
M. ML. Rehani

SummaryThe conventional radioisotope scanner has been used as a whole body counter. The background index of the system is 10.9 counts per minute per ml of sodium iodide crystal. The sensitivity and derived sensitivity parameters have been evaluated and found to be suitable for clinical studies. The optimum parameters for a single detector at two positions above the lying subject have been obtained. It has been found that for the case of 131I measurement it is possible to assay a source located at any point in the body with coefficient of variation less than 5%. To add to the versatility, a fixed geometry for in-vitro counting of large samples has been obtained. The retention values obtained by the whole body counter have been found to correlate with those obtained by in-vitro assay of urine and stool after intravenous administration of 51Cr-albumin.


Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1060-1066 ◽  
Author(s):  
M Miura ◽  
CW Jackson ◽  
SA Lyles

Abstract To gain insight into the regulation of megakaryocyte precursors in vivo, we assayed (in vitro) megakaryocyte growth-promoting activity (Meg-GPA) in plasma of rats in which both marrow hypoplasia and thrombocytopenia had been induced by irradiation. Rats received whole body irradiation of 834 rad from a 137Cs source. Plasma was collected at intervals of hours to days, up through day 21 postirradiation, and was tested, at a concentration of 30%, for Meg-GPA on bone marrow cells cultured in 1.1% methylcellulose with 5 X 10(-5) M 2-mercaptoethanol. With normal rat plasma, no megakaryocyte colonies (defined as greater than or equal to 4 megakaryocytes) were seen and only a few single megakaryocytes and clusters (defined as 2 or 3 megakaryocytes) were formed. Two peaks of plasma Meg-GPA were observed after irradiation. The first appeared at 12 hr, before any decrease in marrow megakaryocyte concentration or platelet count. The second occurred on days 10–14 after irradiation, after the nadir in megakaryocyte concentration and while platelet counts were at their lowest levels. A dose-response study of plasma concentration and megakaryocyte growth, using plasma collected 11 days postirradiation, demonstrated that patterns of megakaryocyte growth were related to plasma concentration; formation of single megakaryocytes was optimal over a range of 20%-30% plasma concentration, while cluster and colony formation were optimal at a plasma concentration of 30%. All forms of megakaryocyte growth were decreased with 40% plasma. There was a linear relationship between the number of bone marrow cells plated and growth of single cells, clusters, and colonies using a concentration of 30% plasma collected 11 days after irradiation. We conclude that irradiation causes time- related increases in circulating megakaryocyte growth-promoting activity. We suggest that the irradiated rat is a good model for studying the relationships between Meg-GPA and megakaryocyte and platelet concentration in vivo.


Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1060-1066 ◽  
Author(s):  
M Miura ◽  
CW Jackson ◽  
SA Lyles

To gain insight into the regulation of megakaryocyte precursors in vivo, we assayed (in vitro) megakaryocyte growth-promoting activity (Meg-GPA) in plasma of rats in which both marrow hypoplasia and thrombocytopenia had been induced by irradiation. Rats received whole body irradiation of 834 rad from a 137Cs source. Plasma was collected at intervals of hours to days, up through day 21 postirradiation, and was tested, at a concentration of 30%, for Meg-GPA on bone marrow cells cultured in 1.1% methylcellulose with 5 X 10(-5) M 2-mercaptoethanol. With normal rat plasma, no megakaryocyte colonies (defined as greater than or equal to 4 megakaryocytes) were seen and only a few single megakaryocytes and clusters (defined as 2 or 3 megakaryocytes) were formed. Two peaks of plasma Meg-GPA were observed after irradiation. The first appeared at 12 hr, before any decrease in marrow megakaryocyte concentration or platelet count. The second occurred on days 10–14 after irradiation, after the nadir in megakaryocyte concentration and while platelet counts were at their lowest levels. A dose-response study of plasma concentration and megakaryocyte growth, using plasma collected 11 days postirradiation, demonstrated that patterns of megakaryocyte growth were related to plasma concentration; formation of single megakaryocytes was optimal over a range of 20%-30% plasma concentration, while cluster and colony formation were optimal at a plasma concentration of 30%. All forms of megakaryocyte growth were decreased with 40% plasma. There was a linear relationship between the number of bone marrow cells plated and growth of single cells, clusters, and colonies using a concentration of 30% plasma collected 11 days after irradiation. We conclude that irradiation causes time- related increases in circulating megakaryocyte growth-promoting activity. We suggest that the irradiated rat is a good model for studying the relationships between Meg-GPA and megakaryocyte and platelet concentration in vivo.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Edward Price ◽  
Andre J. Gesquiere

Abstract In vitro assays and simulation technologies are powerful methodologies that can inform scientists of nanomaterial (NM) distribution and fate in humans or pre-clinical species. For small molecules, less animal data is often needed because there are a multitude of in vitro screening tools and simulation-based approaches to quantify uptake and deliver data that makes extrapolation to in vivo studies feasible. Small molecule simulations work because these materials often diffuse quickly and partition after reaching equilibrium shortly after dosing, but this cannot be applied to NMs. NMs interact with cells through energy dependent pathways, often taking hours or days to become fully internalized within the cellular environment. In vitro screening tools must capture these phenomena so that cell simulations built on mechanism-based models can deliver relationships between exposure dose and mechanistic biology, that is biology representative of fundamental processes involved in NM transport by cells (e.g. membrane adsorption and subsequent internalization). Here, we developed, validated, and applied the FORECAST method, a combination of a calibrated fluorescence assay (CF) with an artificial intelligence-based cell simulation to quantify rates descriptive of the time-dependent mechanistic biological interactions between NMs and individual cells. This work is expected to provide a means of extrapolation to pre-clinical or human biodistribution with cellular level resolution for NMs starting only from in vitro data.


2002 ◽  
Vol 41 (03) ◽  
pp. 129-134 ◽  
Author(s):  
A. Wolski ◽  
E. Palombo-Kinne ◽  
F. Wolf ◽  
F. Emmrich ◽  
W. Becker ◽  
...  

Summary Aim: The cellular joint infiltrate in rheumatoid arthritis patients is rich in CD4-positive T-helper lymphocytes and macrophages, rendering anti-CD4 monoclonal antibodies (mAbs) suitable for specific immunoscintigraphy of human/ experimental arthritis. Following intravenous injection, however, mAbs are present both in the free form and bound to CD4-positive, circulating monocytes and T-cells. Thus, the present study aimed at analyzing the relative contribution of the free and the cell-bound component to the imaging of inflamed joints in experimental adjuvant arthritis (AA). Methods: AA rat peritoneal macrophages or lymph node T-cells were incubated in vitro with saturating amounts of 99mTc-anti-CD4 mAb (W3/25) and injected i.v. into rats with AA. Results: In vitro release of 99mTc-anti-CD4 mAb from the cells was limited (on average 1.57%/h for macrophages and 0.84%/h for T-cells). Following i.v. injection, whole body/joint scans and tissue measurements showed only negligible accumulation of radioactivity in inflamed ankle joints (tissue: 0.22 and 0.34% of the injected activity, respectively), whereas the radioactivity was concentrated in liver (tissue: 79% and 71%, respectively), kidney, and urinary bladder. Unlike macrophages, however, anti-CD4 mAb-coated T-cells significantly accumulated in lymphoid organs, the inflamed synovial membrane of the ankle joints, as well as in elbow and knee joints. Conclusion: While the overall contribution of cell-bound mAbs to the imaging of arthritic joints with anti-CD4 mAbs is minimal, differential accumulation of macrophages and T-cells in lymphoid organs and the inflamed synovial membrane indicates preferential migration patterns of these 2 cell populations in arthritic rats. Although only validated for 99mTc-anti-CD4 mAbs, extrapolation of the results to other anticellular mAbs with similar affinity for their antigen may be possible.


1968 ◽  
Vol 20 (03/04) ◽  
pp. 384-396 ◽  
Author(s):  
G Zbinden ◽  
S Tomlin

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.


1973 ◽  
Vol 30 (01) ◽  
pp. 114-122
Author(s):  
C.R.M Prentice ◽  
K.M Rogers ◽  
G.P McNicol

SummaryThe pharmacological effect of a new preparation of urokinase (Leo) has been studied, both in vitro and in six patients suffering from thrombo-embolic disorders. It was a non-toxic, effective fibrinolytic agent if given in sufficient dosage. A regimen consisting of an initial dose of 7,200 ploug units per kg body weight, followed by hourly maintenance therapy with 3,600 ploug units per kg intravenously, gave satisfactory evidence of whole body fibrinolytic activity. The preparation had minor but insignificant thromboplastic activity both when assayed in the laboratory and when given to patients.


1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S279-S294 ◽  
Author(s):  
Paul Robel

ABSTRACT Of the information available on steroid hormone metabolism in responsive tissues, only that relating hormone metabolism to physiological activity is reviewed, i. e. metabolite activity in isolated in vitro systems, binding of metabolites to target tissue receptors, specific steroid hormone metabolizing enzymes and relationship of hormone metabolism to target organ physiological state. Further, evidence is presented in the androgen field, demonstrating 5α-reduced metabolites, formed inside the target cells, as active compounds. This has led to a consideration of testosterone as a »prehormone«. The possibility that similar events take place in tissues responding to progesterone is discussed. Finally, the role of hormone metabolism in the regulation of hormone availability and/or renewal in target cells is discussed. In this context, reference is made to the potential role of plasma binding proteins and cytosol receptors.


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