Seeding density modulates migration and morphology of rabbit chondrocytes cultured in collagen gels

There is a requirement for a convenient and reliable method for evaluating the growth rate of human keratinocytes cultured on collagen-based substrates. Therefore, three methods of determining cell growth were first used to quantify the growth rate of the well-characterised L929 mouse fibroblast cell line on tissue culture plastic and the results compared. The methods used were the measurement of total cell protein, cell counting using an electronic Coulter counter and a fluorimetric assay employing 5-carboxyfluorescein diacetate (CFDA). The CFDA assay showed the highest correlation with seeding density of the L929 cells, and the lowest standard deviations. It was the most rapid and convenient method for processing large numbers of samples. Only viable cells can deacetylate the non-fluorescent CFDA to carboxyfluorescein, which is fluorescent and accumulates inside the cells. Therefore, the assay specifically quantifies only viable cells. Subsequently, this assay has been successfully applied to the measurement of human keratinocyte growth rate on collagen gels and sponges. We have demonstrated that keratinocytes grow equally well on gels and sponges, and that media containing low calcium concentrations (0.09 mM) favour rapid proliferation of keratinocytes. Our results show that the CFDA assay is an accurate, reliable and convenient method for quantifying cell growth in vitro. It is particularly valuable when growing cells on optically opaque substrata, such as collagen sponges, where growth cannot be monitored daily by microscopy.

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Mimicking osteocytes in vivo using 3D collagen gels: development of a novel tool to study osteocyte biology

Endocrine Abstracts ◽

10.1530/endoabs.31.p5 ◽

2013 ◽

pp. 1-1

Author(s):

Nicole Scully ◽

Sam L Evans ◽

Deborah J Mason ◽

Bronwen A J Evans

Keyword(s):

Collagen Gels ◽

3D Collagen

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Effect of Minoxidil Sulfate on the Growth of Human Anagen Hair Follicles Grown in Collagen Gels, and on the Colony Growth of Human Cultured Outer Root Sheath Cells in vitro.

Nishi Nihon Hifuka ◽

10.2336/nishinihonhifu.54.727 ◽

1992 ◽

Vol 54 (4) ◽

pp. 727-732 ◽

Cited By ~ 1

Author(s):

Naoyuki UCHIDA ◽

Takesi FUJIE ◽

Seiji ARASE ◽

Yosiroh NINOMIYA ◽

Hideki NAKANISI ◽

...

Keyword(s):

Colony Growth ◽

Hair Follicles ◽

Collagen Gels ◽

Outer Root Sheath ◽

Root Sheath ◽

Anagen Hair ◽

Outer Root Sheath Cells ◽

Sheath Cells

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SEEDING DENSITY OF DIFFERENT FISH SPECIES IN POLYCULTURE

VESTNIK OF ASTRAKHAN STATE TECHNICAL UNIVERSITY SERIES FISHING INDUSTRY ◽

10.24143/2073-5529-2017-3-74-79 ◽

2017 ◽

pp. 74-79

Author(s):

Yuriy Borisovich Lvov

Keyword(s):

Fish Species ◽

Silver Carp ◽

Seeding Density ◽

Habitat Conditions ◽

Method Of Calculation ◽

Fish Breeding ◽

Trophic Preferences ◽

Breeding Zone ◽

Practical Progress

The article touches upon the principles, biological basics and practical progress of introduction of specific and age polyculture of fishes. Using the results of the analysis of literary and long-term native data, there has been offered the gradation of 12 fish species from different families by resistance to habitat conditions. Crucian ( Carassius gibelio ) has been chosen as the most sustainable object of cultivation. There has been taken an attempt to calculate the number of seeding different fish species in polyculture taking into account their physiological features is made. Subject to specific physiological features of the studied species, there was carried out recalculation of their natural reproductive performance in different fish-breeding zones, which is traditionally carried out for a carp ( Cyprinus carpio ). In particular, in the second fish-breeding zone with area of 1 hectare it is possible to breed 120 kg of carp, or 150 kg of crucian, or 75 kg of silver carp ( Hypophthalmichthys ). Overall productivity is made up of a share of fishes in polyculture, but taking into account tolerance of species, it can be lower than productivity calculated for carp. The method of calculation and formulas which give the chance to determine seeding density of fish species for breeding in polyculture have been offered. This technique makes it possible to use trophic preferences and consider tolerance of each species to the conditions of breeding areas.

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Modulation of proteoglycan metabolism by aortic smooth muscle cells grown on collagen gels.

Arteriosclerosis An Official Journal of the American Heart Association Inc ◽

10.1161/01.atv.6.6.638 ◽

1986 ◽

Vol 6 (6) ◽

pp. 638-650 ◽

Cited By ~ 25

Author(s):

M W Lark ◽

T N Wight

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cells ◽

Muscle Cells ◽

Collagen Gels ◽

Aortic Smooth Muscle Cells ◽

Aortic Smooth Muscle

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Detecting long-range interactions between migrating cells

Scientific Reports ◽

10.1038/s41598-021-94458-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

C. Metzner ◽

F. Hörsch ◽

C. Mark ◽

T. Czerwinski ◽

A. Winterl ◽

...

Keyword(s):

Nk Cells ◽

Tumor Cells ◽

Long Range ◽

Cooperative Behavior ◽

Simulated Data ◽

Movement Direction ◽

Repulsive Interaction ◽

Collagen Gels ◽

Long Range Interactions ◽

A Cell

AbstractChemotaxis enables cells to systematically approach distant targets that emit a diffusible guiding substance. However, the visual observation of an encounter between a cell and a target does not necessarily indicate the presence of a chemotactic approach mechanism, as even a blindly migrating cell can come across a target by chance. To distinguish between the chemotactic approach and blind migration, we present an objective method that is based on the analysis of time-lapse recorded cell migration trajectories: For each movement step of a cell relative to the position of a potential target, we compute a p value that quantifies the likelihood of the movement direction under the null-hypothesis of blind migration. The resulting distribution of p values, pooled over all recorded cell trajectories, is then compared to an ensemble of reference distributions in which the positions of targets are randomized. First, we validate our method with simulated data, demonstrating that it reliably detects the presence or absence of remote cell-cell interactions. In a second step, we apply the method to data from three-dimensional collagen gels, interspersed with highly migratory natural killer (NK) cells that were derived from two different human donors. We find for one of the donors an attractive interaction between the NK cells, pointing to a cooperative behavior of these immune cells. When adding nearly stationary K562 tumor cells to the system, we find a repulsive interaction between K562 and NK cells for one of the donors. By contrast, we find attractive interactions between NK cells and an IL-15-secreting variant of K562 tumor cells. We therefore speculate that NK cells find wild-type tumor cells only by chance, but are programmed to leave a target quickly after a close encounter. We provide a freely available Python implementation of our p value method that can serve as a general tool for detecting long-range interactions in collective systems of self-driven agents.

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Variable-rate in corn sowing for maximizing grain yield

Scientific Reports ◽

10.1038/s41598-021-92238-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Eder Eujácio da Silva ◽

Fábio Henrique Rojo Baio ◽

Daniel Fernando Kolling ◽

Renato Schneider Júnior ◽

Alex Rogers Aguiar Zanin ◽

...

Keyword(s):

Grain Yield ◽

Vegetative Growth ◽

Maximum Yield ◽

Influential Factors ◽

Plant Population ◽

Seeding Density ◽

Corn Yield ◽

Growth Indices ◽

Experimental Conditions ◽

Soil Attributes

AbstractSowing density is one of the most influential factors affecting corn yield. Here, we tested the hypothesis that, according to soil attributes, maximum corn productivity can be attained by varying the seed population. Specifically, our objectives were to identify the soil attributes that affect grain yield, in order to generate a model to define the optimum sowing rate as a function of the attributes identified, and determine which vegetative growth indices can be used to predict yield most accurately. The experiment was conducted in Chapadão do Céu-GO in 2018 and 2019 at two different locations. Corn was sown as the second crop after the soybean harvest. The hybrids used were AG 8700 PRO3 and FS 401 PW, which have similar characteristics and an average 135-day cropping cycle. Tested sowing rates were 50, 55, 60, and 65 thousand seeds ha−1. Soil attributes evaluated included pH, calcium, magnesium, phosphorus, potassium, organic matter, clay content, cation exchange capacity, and base saturation. Additionally, we measured the correlation between the different vegetative growth indices and yield. Linear correlations were obtained through Pearson’s correlation network, followed by path analysis for the selection of cause and effect variables, which formed the decision trees to estimate yield and seeding density. Magnesium and apparent electrical conductivity (ECa) were the most important soil attributes for determining sowing density. Thus, the plant population should be 56,000 plants ha−1 to attain maximum yield at ECa values > 7.44 mS m−1. In addition, the plant population should be 64,800 plants ha−1 at values < 7.44 mS m−1 when magnesium levels are greater than 0.13 g kg−1, and 57,210 plants ha−1 when magnesium content is lower. Trial validation showed that the decision tree effectively predicted optimum plant population under the local experimental conditions, where yield did not significantly differ among populations.

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Expansion and characterization of bone marrow derived human mesenchymal stromal cells in serum-free conditions

Scientific Reports ◽

10.1038/s41598-021-83088-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Samatha Bhat ◽

Pachaiyappan Viswanathan ◽

Shashank Chandanala ◽

S. Jyothi Prasanna ◽

Raviraja N. Seetharam

Keyword(s):

Bone Marrow ◽

Mesenchymal Stromal Cells ◽

Stromal Cells ◽

Population Doubling ◽

Seeding Density ◽

Population Doubling Time ◽

Differentiation Potential ◽

Serum Free ◽

Safety Issues ◽

Free Media

AbstractBone marrow-derived mesenchymal stromal cells (BM-MSCs) are gaining increasing importance in the field of regenerative medicine. Although therapeutic value of MSCs is now being established through many clinical trials, issues have been raised regarding their expansion as per regulatory guidelines. Fetal bovine serum usage in cell therapy poses difficulties due to its less-defined, highly variable composition and safety issues. Hence, there is a need for transition from serum-based to serum-free media (SFM). Since SFM are cell type-specific, a precise analysis of the properties of MSCs cultured in SFM is required to determine the most suitable one. Six different commercially available low serum/SFM with two different seeding densities were evaluated to explore their ability to support the growth and expansion of BM-MSCs and assess the characteristics of BM-MSCs cultured in these media. Except for one of the SFM, all other media tested supported the growth of BM-MSCs at a low seeding density. No significant differences were observed in the expression of MSC specific markers among the various media tested. In contrary, the population doubling time, cell yield, potency, colony-forming ability, differentiation potential, and immunosuppressive properties of MSCs varied with one another. We show that SFM tested supports the growth and expansion of BM-MSCs even at low seeding density and may serve as possible replacement for animal-derived serum.

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Optimizing interleukin-2 concentration, seeding density and bead-to-cell ratio of T-cell expansion for adoptive immunotherapy

BMC Immunology ◽

10.1186/s12865-021-00435-7 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Sasan Ghaffari ◽

Monireh Torabi-Rahvar ◽

Sajjad Aghayan ◽

Zahra Jabbarpour ◽

Kobra Moradzadeh ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Growth Kinetics ◽

Cell Expansion ◽

Mononuclear Cells ◽

Adoptive Cell Therapy ◽

Interleukin 2 ◽

Seeding Density ◽

Healthy Donors ◽

T Cell Expansion

Abstract Background The successful ex vivo expansion of T-cells in great numbers is the cornerstone of adoptive cell therapy. We aimed to achieve the most optimal T-cell expansion condition by comparing the expansion of T-cells at various seeding densities, IL-2 concentrations, and bead-to-cell ratios. we first expanded the peripheral blood mononuclear cells (PBMCs) of a healthy donor at a range of 20 to 500 IU/mL IL-2 concentrations, 125 × 103 to 1.5 × 106 cell/mL, and 1:10 to 10:1 B:C (Bead-to-cell) ratios and compared the results. We then expanded the PBMC of three healthy donors using the optimized conditions and examined the growth kinetics. On day 28, CD3, CD4, and CD8 expression of the cell populations were analyzed by flow cytometry. Results T-cells of the first donor showed greater expansion results in IL-2 concentrations higher than 50 IU/mL compared to 20 IU/mL (P = 0.02). A seeding density of 250 × 103 cell/mL was superior to higher or lower densities in expanding T-cells (P = 0.025). Also, we witnessed a direct correlation between the B:C ratio and T-cell expansion, in which, in 5:1 and 10:1 B:C ratios T-cell significantly expanded more than lower B:C ratios. The results of PBMC expansions of three healthy donors were similar in growth kinetics. In the optimized condition, 96–98% of the lymphocyte population expressed CD3. While the majority of these cells expressed CD8, the mean expression of CD4 in the donors was 19.3, 16.5, and 20.4%. Conclusions Our methodology demonstrates an optimized culture condition for the production of large quantities of polyclonal T-cells, which could be useful for future clinical and research studies.

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