scholarly journals A Novel in vitro Model Delineating Hair Cell Regeneration and Neural Reinnervation in Adult Mouse Cochlea

2022 ◽  
Vol 14 ◽  
Author(s):  
Wenyan Li ◽  
Yizhou Quan ◽  
Mingqian Huang ◽  
Wei Wei ◽  
Yilai Shu ◽  
...  
Keyword(s):  
Inner Ear ◽  
Adult Mouse ◽  
Damage Model ◽  
Sensory Epithelium ◽  
Explant Culture ◽  
The Body ◽  
Hair Cell Regeneration ◽  
Vitro Model ◽  
Almost All

The study of an adult mammalian auditory system, such as regeneration, has been hampered by the lack of an in vitro system in which hypotheses can be tested efficiently. This is primarily due to the fact that the adult inner ear is encased in the toughest bone of the body, whereas its removal leads to the death of the sensory epithelium in culture. We hypothesized that we could take advantage of the integral cochlear structure to maintain the overall inner ear architecture and improve sensory epithelium survival in culture. We showed that by culturing adult mouse cochlea with the (surrounding) bone intact, the supporting cells (SCs) survived and almost all hair cells (HCs) degenerated. To evaluate the utility of the explant culture system, we demonstrated that the overexpression of Atoh1, an HC fate-determining factor, is sufficient to induce transdifferentiation of adult SCs to HC-like cells (HCLCs). Transdifferentiation-derived HCLCs resemble developmentally young HCs and are able to attract adult ganglion neurites. Furthermore, using a damage model, we showed that degenerated adult ganglions respond to regenerated HCLCs by directional neurite outgrowth that leads to HCLC-neuron contacts, strongly supporting the intrinsic properties of the HCLCs in establishing HCLC-neuron connections. The adult whole cochlear explant culture is suitable for diverse studies of the adult inner ear including regeneration, HC-neuron pathways, and inner ear drug screening.

Size Does Matter: Generation of Intrinsic Network Rhythms in Thick Mouse Hippocampal Slices

2005 ◽  
Vol 93 (4) ◽  
pp. 2302-2317 ◽  
Author(s):  
Chiping Wu ◽  
Wah Ping Luk ◽  
Jesse Gillis ◽  
Frances Skinner ◽  
Liang Zhang
Keyword(s):  
In Vitro Model ◽  
Adult Mouse ◽  
Hippocampal Slices ◽  
Network Connectivity ◽  
Slice Preparation ◽  
Fundamental Properties ◽  
Mouse Hippocampus ◽  
Hippocampal Network ◽  
Vitro Model

Rodent hippocampal slices of ≤0.5 mm thickness have been widely used as a convenient in vitro model since the 1970s. However, spontaneous population rhythmic activities do not consistently occur in this preparation due to limited network connectivity. To overcome this limitation, we develop a novel slice preparation of 1 mm thickness from adult mouse hippocampus by separating dentate gyrus from CA3/CA1 areas but preserving dentate–CA3-CA1 connectivity. While superfused in vitro at 32 or 37°C, the thick slice exhibits robust spontaneous network rhythms of 1–4 Hz that originate from the CA3 area. Via assessing tissue O2, K+, pH, synaptic, and single-cell activities of superfused thick slices, we verify that these spontaneous rhythms are not a consequence of hypoxia and nonspecific experimental artifacts. We suggest that the thick slice contains a unitary circuitry sufficient to generate intrinsic hippocampal network rhythms and this preparation is suitable for exploring the fundamental properties and plasticity of a functionally defined hippocampal “lamella” in vitro.

scholarly journals Ventricular Slices of Adult Mouse Hearts - a new Multicellular In Vitro Model for Electrophysiological Studies

2006 ◽  
Vol 18 (1-3) ◽  
pp. 1-8 ◽  
Author(s):  
Marcel Halbach ◽  
Frank Pillekamp ◽  
Konrad Brockmeier ◽  
Jürgen Hescheler ◽  
Jochen Müller-Ehmsen ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Adult Mouse ◽  
Electrophysiological Studies ◽  
Vitro Model

Effect of sodium fluorescein on neurite outgrowth from the retinal explant culture: an in vitro model for retinal toxicity

1983 ◽  
Vol 11 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Satoru Kato ◽  
Sachiko Madachi-Yamamoto ◽  
Yokichi Hayashi ◽  
Naomasa Miki ◽  
Koroku Negishi
Keyword(s):  
Neurite Outgrowth ◽  
In Vitro Model ◽  
Explant Culture ◽  
Retinal Toxicity ◽  
Sodium Fluorescein ◽  
Vitro Model

scholarly journals Nanemulsions of foodstuffs and their nutritiological and valleological characteristics

2021 ◽  
Vol 25 (3) ◽  
pp. 389-393
Author(s):  
O. P. Maidebura ◽  
V. V. Hnatyuk ◽  
A. S. Romaniv
Keyword(s):  
Scientific Progress ◽  
High Energy ◽  
The Body ◽  
Biologically Active ◽  
Bioactive Substances ◽  
Thiazolyl Blue Tetrazolium Bromide ◽  
Active Supplement ◽  
Vitro Model ◽  
Franz Diffusion Cells

Annotation. The use of nanotechnology in the medical, food, pharmaceutical, biotechnology industries today is an important scientific progress and valuable human heritage. Nanoemulsion technology is an ideal method for the manufacture of encapsulating systems for functional compounds, as it prevents their biotechnological biodegradation and improves their functional availability in the cells of the body. The aim of the article is a scientific-theoretical and practical review of the nutritional and valeological properties of nanoemulsions, their use for encapsulation of various nutraceuticals, namely fat-soluble vitamin D. The in vitro experiment was performed using Franz diffusion cells to study the release of bioactive compounds from nanocarriers. The cytotoxicity of nanoemulsions was investigated by analyzing the proliferation of thiazolyl blue tetrazolium bromide (TTB) cells and nasal epithelial cells as an “in vitro” model. The article provides to characterize the nutritional and valeological properties of nanoemulsions and to experimentally investigate hydrogels based on nanoemulsions as biocarriers of vitaminized compounds. During the study, low- and high-energy nanoemulsions were created, which were used for encapsulation of vitamin D3 and biologically active supplement - curcumin. Loaded nanoemulsions are added to homopolymer and copolymer hydrogels based on polysaccharides and their combinations. Both nanoemulsions and hydrogels are structurally characterized to evaluate the effect of the composition on the emulsification process by their properties. The cytotoxic effect of nanoemulsions "in vitro" on the epithelium of nasal cells, which had a positive therapeutic effect, was studied. In the future, further exploration and research will investigate the use of nanoemulsions as biocarriers for other vitamins and bioactive substances.

scholarly journals Estimation of the Chelating Ability of an Extract from Aronia melanocarpa L. Berries and Its Main Polyphenolic Ingredients Towards Ions of Zinc and Copper

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1507 ◽  
Author(s):  
Sylwia Borowska ◽  
Michał Tomczyk ◽  
Jakub W. Strawa ◽  
Małgorzata M. Brzóska
Keyword(s):  
Gastrointestinal Tract ◽  
In Vitro Model ◽  
The Body ◽  
Adequate Intake ◽  
Full Stomach ◽  
Aronia Melanocarpa ◽  
Chelating Ability ◽  
Vitro Model ◽  
Derivatives Of

Previously, we have revealed that prolonged administration of a polyphenol-rich 0.1% extract from the berries of Aronia melanocarpa L. (chokeberries) alone and under chronic exposure to cadmium influences the body status of zinc (Zn) and copper (Cu). The aim of this study was to evaluate, in an in vitro model, the chelating properties of the extract (0.05% and 0.1%) and its main polyphenolic ingredients (cyanidin 3-O-β-galactoside, chlorogenic acid, neochlorogenic acid, (+)-catechin, (−)-epicatechin, quercetin, and kaempferol) regarding divalent ions of Zn (Zn2+) and Cu (Cu2+) at pH reflecting physiological conditions at the gastrointestinal tract such as 2 (empty stomach), 5.5 (full stomach), and 8 (duodenum). The study has revealed that the extract from Aronia berries, as well as cyanidin 3-O-β-galactoside and quercetin, can bind Zn2+ and Cu2+, but only at pH 5.5. Moreover, kaempferol was able to chelate Zn2+ at pH 5.5; however, this ability was weaker than those of cyanidin 3-O-β-galactoside and quercetin. The ability of the chokeberry extract to chelate Zn2+ and Cu2+ may be explained, at least partially, by the presence of polyphenols such as anthocyanin derivatives of cyanidin and quercetin. The findings seem to suggest that Aronia products, used as supplements of a diet, should be consumed before meals, and particular attention should be paid to adequate intake of Zn and Cu under prolonged consumption of these products to avoid deficiency of both bioelements in the body due to their complexation by chokeberry ingredients in the lumen of the gastrointestinal tract.

scholarly journals An in vitro model system to study gene therapy in the human inner ear

Gene Therapy ◽  
2007 ◽  
Vol 14 (15) ◽  
pp. 1121-1131 ◽  
Author(s):  
B W Kesser ◽  
G T Hashisaki ◽  
K Fletcher ◽  
H Eppard ◽  
J R Holt
Keyword(s):  
Gene Therapy ◽  
Inner Ear ◽  
In Vitro Model ◽  
Model System ◽  
In Vitro Model System ◽  
Vitro Model ◽  
Human Inner Ear

scholarly journals Bioactivity of vitamin E

2006 ◽  
Vol 19 (2) ◽  
pp. 174-186 ◽  
Author(s):  
Regina Brigelius-Flohé
Keyword(s):  
Vitamin E ◽  
Molecular Basis ◽  
Antioxidant Properties ◽  
The Body ◽  
The Novel ◽  
Transfer Protein ◽  
Almost All ◽  
Selection Of

More than 80 years after the discovery of the essentiality of vitamin E for mammals, the molecular basis of its action is still an enigma. From the eight different forms of vitamin E, only α-tocopherol is retained in the body. This is in part due to the specific selection of RRR-α-tocopherol by the α-tocopherol transfer protein and in part by its low rate of degradation and elimination compared with the other vitamers. Since the tocopherols have comparable antioxidant properties and some tocotrienols are even more effective in scavenging radicals, the antioxidant capacity cannot be the explanation for its essentiality, at least not the only one. In the last decade, a high number of so-called novel functions of almost all forms of vitamin E have been described, including regulation of cellular signalling and gene expression. α-Tocopherol appears to be most involved in gene regulation, whereas γ-tocopherol appears to be highly effective in preventing cancer-related processes. Tocotrienols appear to be effective in amelioration of neurodegeneration. Most of the novel functions of individual forms of vitamin E have been demonstrated in vitro only and require in vivo confirmation. The distinct bioactivities of the various vitamers are discussed, considering their metabolism and the potential functions of metabolites.

scholarly journals Epithelial permeability and the transepithelial migration of human neutrophils.

1983 ◽  
Vol 96 (5) ◽  
pp. 1241-1247 ◽  
Author(s):  
L C Milks ◽  
M J Brontoli ◽  
E B Cramer
Keyword(s):  
In Vitro Model ◽  
The Body ◽  
Human Neutrophils ◽  
Epithelial Permeability ◽  
Cell Contacts ◽  
Epithelial Monolayers ◽  
Tissue Factors ◽  
Vitro Model ◽  
Close Contacts

Although polymorphonuclear leukocytes (PMN's) can migrate through every epithelium in the body regardless of its permeability, very little is known about the effect of epithelial permeability on PMN migration and the effect of emigrating PMN's on the permeability of the epithelium. In an in vitro model system of transepithelial migration, human PMN's were stimulated by 0.1 micrometer fMet-Leu-Phe to traverse confluent, polarized canine kidney epithelial monolayers of varying permeabilities. Epithelial permeability was determined by both conductance measurement and horseradish peroxidase (HRP) tracer studies. As epithelial permeability increased, the number of PMN invasion sites as well as the number of PMN's that traversed the monolayer increased. The effect of PMN migration on epithelial permeability was examined using the ultrastructural tracers HRP and lanthanum nitrate. PMN's traversing the monolayer made close cell-to-cell contacts with other invading PMNs and with adjacent epithelial cells. These close contacts appeared to prevent leakage of tracer across invasion sites. Following PMN emigration, epithelial junctional membranes reapproximated and were impermeable to the tracers. These results indicated that, in the absence of serum and connective tissue factors, (a) the number of PMN invasion sites and the number of PMN's that traversed an epithelium were a function of the conductance of the epithelium and (b) PMN's in the process of transepithelial migration maintained close cell-cell contacts and prevented the leakage of particles (greater than 5 nm in diameter) across the invasion site.

Critical Evaluation of an in Vitro Model for Evaluation of Platelet Reactivity of Biomaterials

1987 ◽  
Vol 110 ◽  
Author(s):  
Raymond Connolly ◽  
Norman Shoenfeld ◽  
Karen Ramberg ◽  
Allan D. Callow
Keyword(s):  
In Vitro Model ◽  
Platelet Reactivity ◽  
Platelet Rich Plasma ◽  
Critical Evaluation ◽  
The Body ◽  
Test Material ◽  
In Vitro Test ◽  
Vitro Model

AbstractAn in vitro model for measuring platelet reactivity to a variety of biomaterial candidates for vascular grafts is described. A model consisting of a standard area of test material exposed to freshly labeled In platelets in plasma was evaluated. The platelets were isolated from ACD anticoagulated blood and resuspended in ACD plasma. It has been previously demonstrated that platelets so treated circulate in the body and will deposit on biomaterials exposed to the blood in vivo. The in vitro test consisted of an incubation of the platelets and materials at 37°C for one hour. At the end of the incubation, the platelet rich plasma was removed and the materials washed and removed for gamma counting. Platelet reactivity was normalized as a percentage of the counts on the material to counts in an aliquot of the platelet-plasma incubation media. The maximum uptake of platelets occurred within one hour. Platelets from three species, human, baboon, and dog were tested. Platelet uptake by Dacron and PTFE were in the range of 30–40% and 1–5% respectively. This is in accord with the known reactivity of these two vascular graft materials in vivo.A second series of studies were conducted with physically and pharmacologically inactivated platelets and inert particles. Those studies suggest that the initial results do not represent a biologic event but may reflect the porosity of the materials. This emphasizes the necessity of adequately defining an in vitro model against known in vivo activity.

scholarly journals Control of the Transdermal Delivery Process of Active Substances of the Phytocomplex during Phonophoresis in Model Experiments

2019 ◽  
Vol 7 (13) ◽  
pp. 2079-2083
Author(s):  
Liudmila Ivanovna Babaskina ◽  
Tatiana Mikhailovna Litvinova ◽  
Dmitrii Vladimirovich Babaskin ◽  
Olga Valerevna Krylova
Keyword(s):  
Dimethyl Sulfoxide ◽  
Transdermal Delivery ◽  
In Vitro Model ◽  
The Body ◽  
Model Experiments ◽  
Vitro Model ◽  
Franz Diffusion Cells ◽  
Kinetics Of ◽  
Active Substances

BACKGROUND: The scientific substantiation for the selection of therapeutically significant dosage of phytocomplex in the dosage form for phonophoresis, control over the delivery of active substances into the body, and what affects this process require the study of the kinetics of phytocomplex flavonoids delivery during phonophoresis. AIM: The aim was to study the possibilities of controlling the process of transdermal delivery of phytocomplex active substances (flavonoids) during phonophoresis in vitro model experiments. METHODS: Working compositions with different concentrations of phytocomplex for phonophoresis were used. The content of flavonoids in the compositions was determined using the spectrophotometric method and was calculated equivalent to quercetin, the flavonoid prevailing in the phytocomplex. The study of the kinetics of flavonoids delivery from working compositions was carried out using Franz diffusion cells and Carbosyl-P membranes. The authors determined the main parameters of the process and established the dependence of the delivery rate of flavonoids on their initial concentration in the working composition. The authors studied the effect of dimethyl sulfoxide and the base-forming substances of the working composition on the kinetics of phytocomplex flavonoid delivery during phonophoresis. RESULTS: The authors recorded an increase in the rate of delivery of the active substances from working compositions containing dimethyl sulfoxide into the model medium by almost 1.5-2 times during the first ten minutes of the experiment (approximate duration of the phonophoresis procedure). The authors proposed technological techniques for improvement of the phonophoresis method for the phytocomplex. The possibilities of control over the process of transdermal delivery of the phytocomplex active ingredients during phonophoresis in vitro model experiments were shown. CONCLUSION: The obtained results provide information for further pharmacological studies of the nature and mechanism of the effect of phytocomplex flavonoids during phonophoresis in the rehabilitation of patients with osteoarthrosis.

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