scholarly journals Measurement and analysis of sarcomere length in rat cardiomyocytes in situ and in vitro

2010 ◽  
Vol 298 (5) ◽  
pp. H1616-H1625 ◽  
Author(s):  
G. Bub ◽  
P. Camelliti ◽  
C. Bollensdorff ◽  
D. J. Stuckey ◽  
G. Picton ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Sarcomere Length ◽  
Ex Vivo ◽  
Living Cells ◽  
Perfused Heart ◽  
Experimental Conditions ◽  
Rat Cardiomyocytes ◽  
Two Photon

Sarcomere length (SL) is an important determinant and indicator of cardiac mechanical function; however, techniques for measuring SL in living, intact tissue are limited. Here, we present a technique that uses two-photon microscopy to directly image striations of living cells in cardioplegic conditions, both in situ (Langendorff-perfused rat hearts and ventricular tissue slices, stained with the fluorescent marker di-4-ANEPPS) and in vitro (acutely isolated rat ventricular myocytes). Software was developed to extract SL from two-photon fluorescence image sets while accounting for measurement errors associated with motion artifact in raster-scanned images and uncertainty of the cell angle relative to the imaging plane. Monte-Carlo simulations were used to guide analysis of SL measurements by determining error bounds as a function of measurement path length. The mode of the distribution of SL measurements in resting Langendorff-perfused heart is 1.95 μm ( n = 167 measurements from N = 11 hearts) after correction for tissue orientation, which was significantly greater than that in isolated cells (1.71 μm, n = 346, N = 9 isolations) or ventricular slice preparations (1.79 μm, n = 79, N = 3 hearts) under our experimental conditions. Furthermore, we find that edema in arrested Langendorff-perfused heart is associated with a mean SL increase; this occurs as a function of time ex vivo and correlates with tissue volume changes determined by magnetic resonance imaging. Our results highlight that the proposed method can be used to monitor SL in living cells and that different experimental models from the same species may display significantly different SL values under otherwise comparable conditions, which has implications for experiment design, as well as comparison and interpretation of data.

scholarly journals Generation of vascular chimerism within donor organs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahar Cohen ◽  
Shirly Partouche ◽  
Michael Gurevich ◽  
Vladimir Tennak ◽  
Vadym Mezhybovsky ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Patient Specific ◽  
Machine Perfusion ◽  
Organ Perfusion ◽  
Perfusion Process ◽  
Hind Limbs ◽  
Porcine Organs ◽  
Immunological Barrier

AbstractWhole organ perfusion decellularization has been proposed as a promising method to generate non-immunogenic organs from allogeneic and xenogeneic donors. However, the ability to recellularize organ scaffolds with multiple patient-specific cells in a spatially controlled manner remains challenging. Here, we propose that replacing donor endothelial cells alone, while keeping the rest of the organ viable and functional, is more technically feasible, and may offer a significant shortcut in the efforts to engineer transplantable organs. Vascular decellularization was achieved ex vivo, under controlled machine perfusion conditions, in various rat and porcine organs, including the kidneys, liver, lungs, heart, aorta, hind limbs, and pancreas. In addition, vascular decellularization of selected organs was performed in situ, within the donor body, achieving better control over the perfusion process. Human placenta-derived endothelial progenitor cells (EPCs) were used as immunologically-acceptable human cells to repopulate the luminal surface of de-endothelialized aorta (in vitro), kidneys, lungs and hind limbs (ex vivo). This study provides evidence that artificially generating vascular chimerism is feasible and could potentially pave the way for crossing the immunological barrier to xenotransplantation, as well as reducing the immunological burden of allogeneic grafts.

In-vitro, ex-vivo, and in-vivo release evaluation of in situ forming buprenorphine implants using mixture of PLGA copolymers and additives

2018 ◽  
Vol 68 (16) ◽  
pp. 965-977 ◽  
Author(s):  
Hossein Kamali ◽  
Elham Khodaverdi ◽  
Farzin Hadizadeh ◽  
Seyed Ahmad Mohajeri ◽  
Younes Kamali ◽  
...  
Keyword(s):  
Ex Vivo ◽  
In Situ Forming ◽  
In Vivo Release

DEVELOPMENT AND EVALUATION OF NANOPARTICULATE BASED IN-SITU GELLING SYSTEM FOR NASAL DRUG DELIVERY OF AN ANTI-EPILEPTIC DRUG

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (09) ◽  
pp. 83-85
Author(s):  
A Ambavkar ◽  
◽  
N. Desai
Keyword(s):  
Drug Release ◽  
Ex Vivo ◽  
Entrapment Efficiency ◽  
Poloxamer 407 ◽  
Nasal Drug Delivery ◽  
Anti Epileptic Drug ◽  
Nanolipid Carriers ◽  
In Situ Nasal Gel

The objective of the study was to develop and evaluate nanolipid carriers based in situ gel of Carbamazepine, for brain delivery through intranasal route. The non – invasive nasal route can provide rapid delivery of drugs directly to the central nervous system by bypassing the blood brain barrier. The nanolipid carriers of carbamazepine as in situ nasal gel can prolong the drug release for control of repetitive seizures and were prepared by Phase Inversion Temperature technique. The retention of the carriers in the nasal cavity was improved by using Poloxamer 407 as thermoresponsive and Carbopol 974P as mucoadhesive gelling polymers, respectively. The developed gel was evaluated for particle size, polydispersity index, zeta potential, morphology, entrapment efficiency, mucoadhesive and thermoresponsive behaviour, in vitro drug release, ex vivo permeation and nasociliotoxicity. The gel showed sustained release over prolonged periods and was found to be non-toxic to the sheep nasal mucosa.

scholarly journals A fluorescent ESIPT-based benzimidazole platform for the ratiometric two-photon imaging of ONOO−in vitro and ex vivo

2020 ◽  
Vol 11 (28) ◽  
pp. 7329-7334
Author(s):  
Maria L. Odyniec ◽  
Sang-Jun Park ◽  
Jordan E. Gardiner ◽  
Emily C. Webb ◽  
Adam C. Sedgwick ◽  
...  
Keyword(s):  
Cell Imaging ◽  
Ex Vivo ◽  
Two Photon ◽  
Photon Imaging ◽  
Two Photon Imaging

In this work, we have developed an ESIPT benzimidazole-based platform for the two-photon cell imaging of ONOO− and a potential ONOO−-activated theranostic scaffold.

scholarly journals Bidirectional in vivo structural dendritic spine plasticity revealed by two-photon glutamate uncaging in the mouse neocortex

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jun Noguchi ◽  
Akira Nagaoka ◽  
Tatsuya Hayama ◽  
Hasan Ucar ◽  
Sho Yagishita ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Time Course ◽  
Hippocampal Slices ◽  
Low Frequency ◽  
Structural Plasticity ◽  
Experimental Conditions ◽  
Two Photon ◽  
Spine Plasticity

Abstract Most excitatory synapses in the brain form on dendritic spines. Two-photon uncaging of glutamate is widely utilized to characterize the structural plasticity of dendritic spines in brain slice preparations in vitro. In the present study, glutamate uncaging was used to investigate spine plasticity, for the first time, in vivo. A caged glutamate compound was applied to the surface of the mouse visual cortex in vivo, revealing the successful induction of spine enlargement by repetitive two-photon uncaging in a magnesium free solution. Notably, this induction occurred in a smaller fraction of spines in the neocortex in vivo (22%) than in hippocampal slices (95%). Once induced, the time course and mean long-term enlargement amplitudes were similar to those found in hippocampal slices. However, low-frequency (1–2 Hz) glutamate uncaging in the presence of magnesium caused spine shrinkage in a similar fraction (35%) of spines as in hippocampal slices, though spread to neighboring spines occurred less frequently than it did in hippocampal slices. Thus, the structural plasticity may occur similarly in the neocortex in vivo as in hippocampal slices, although it happened less frequently in our experimental conditions.

Preparation of levofloxacin loaded in situ gel for sustained ocular delivery: in vitro and ex vivo evaluations

2019 ◽  
Vol 46 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Pooja Jain ◽  
Chandra Prakash Jaiswal ◽  
Mohd. Aamir Mirza ◽  
Md. Khalid Anwer ◽  
Zeenat Iqbal
Keyword(s):  
Ex Vivo ◽  
Ocular Delivery ◽  
In Situ Gel

scholarly journals Safety Pharmacological Evaluation of the Coffee Component, Caffeoylquinic Acid, and Its Metabolites, Using Ex Vivo and In Vitro Profiling Assays

2019 ◽  
Vol 12 (3) ◽  
pp. 110 ◽  
Author(s):  
Yuto Amano ◽  
Hiroshi Honda ◽  
Yuko Nukada ◽  
Naohiro Ikeda ◽  
Masayuki Yamane ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Hippocampal Slices ◽  
Area Under The Curve ◽  
Pharmacological Effects ◽  
Dose Dependency ◽  
Fundamental Function ◽  
Perfused Heart ◽  
Caffeoylquinic Acid ◽  
Discharge Rates

Although coffee components have gained interest for use as pharmaceuticals, little is known about their safety pharmacological effects. Hence, we aimed to evaluate the safety pharmacological effects of a chlorogenic acid (CGA)-related compound contained in coffee, 5-O-caffeoylquinic acid (5-CQA), and its metabolites, 5-O-feruloylquinic acid (5-FQA), caffeic acid (CA), and ferulic acid (FA). Langendorff perfused heart assay, electrophysiological assay of acute rat hippocampal slices, and in vitro Magnus assay of gastrointestinal tracts were conducted at 1–100 µM. Moreover, in vitro profiling assays against 38 major targets were conducted. In the Langendorff assay, no significant adverse effects were observed. In the electrophysiological assay, although epileptiform discharge rates were increased at 10 µM CA with 4-aminopyridine, and area under the curve (AUC) and number of population spike were increased at 10 µM FA with bicuculline, dose dependency was not confirmed, and no significant changes were observed at 1 µM and by CGAs alone. In the Magnus assay, a slight increase in contraction activity was observed at >1 µM FA in the stomach fundi and 100 µM 5-CQA in the ileum, suggesting enterokinesis promotion. No significant interactions were observed in the in vitro profiling assays. Therefore, CGAs could have a fundamental function as safe pharmaceuticals.

scholarly journals DEVELOPMENT AND EVALUATION OF A POLOXAMER- AND CHITOSAN-BASED IN SITU GEL-FORMING INJECTABLE DEPOT

2020 ◽  
pp. 36-41
Author(s):  
Hema a Nair ◽  
NAZIA BEGUM
Keyword(s):  
Ex Vivo ◽  
Gelation Time ◽  
In Vitro Release ◽  
Aqueous Acetic Acid ◽  
Drug Content ◽  
Low Viscosity ◽  
Model Drug ◽  
Dialysis Bag

Objective: The present study is intended to investigate the applicability of poloxamer- and chitosan-based temperature induced in situ injectable gelling depot for once a week therapy as an intramuscular injection employing olanzapine as a model drug. Methods: The thermosetting gel was prepared by admixture of a solution of poloxamer P127 and a solution of olanzapine and chitosan in aqueous acetic acid. The resultant formulation was characterized for gelation temperature, gelation time, viscosity, syringeability, pH, drug content, and in vitro drug release. The in vitro release of olanzapine from the gelled depot was followed using USP paddle type II apparatus in conjunction with a dialysis bag. The gel was injected ex vivo into chicken muscle and observed by subsequent dissection. Results: The formulation was designed to have a phase transition temperature of 34°C and gelled in <10 s at 37°C. Addition of chitosan imparted favorable rheological properties to the poloxamer gel and resulted in a pseudoplastic mixture with low viscosity in the sol state and higher viscosity post gelation. The preparation had a pH of 5.4, appropriate drug content and readily passed through a 20 gauge needle. The release of olanzapine was unhindered by the dialysis bag. Following an initial bust, a sustained, zero-order release of the remainder of drug was observed up to 9 days. The injectable was found to form a compact depot when evaluated ex vivo. Conclusion: The developed system showed several features which make it a suitable vehicle for sustained intramuscular delivery of drugs.

In vitro and ex vivo characterisation of an in situ gelling formulation for sustained lidocaine release with potential use following knee arthroplasty

2018 ◽  
Vol 8 (3) ◽  
pp. 820-829 ◽  
Author(s):  
Manisha Sharma ◽  
Kaushik Chandramouli ◽  
Louise Curley ◽  
Beau Pontre ◽  
Keryn Reilly ◽  
...  
Keyword(s):  
Knee Arthroplasty ◽  
Ex Vivo ◽  
In Situ Gelling ◽  
Potential Use

scholarly journals Development and Correlation between in vitro Drug Release and in vitro Permeation of Thermally Triggered Mucoadhesive in situ Nasal Gel of Repaglinide PVP K30 Complex

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Kamla Pathak ◽  
Anil Kumar ◽  
Ekta Yadav
Keyword(s):  
Ex Vivo ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Type Ii Diabetes Mellitus ◽  
Poloxamer 407 ◽  
Ex Vivo Permeation ◽  
In Situ Nasal Gel ◽  
Pvp K30

The aim of the investigation was to develop and evaluate thermoreversible in situ nasal gel formulations of repaglinide (REP) and to establish correlation between its in vitro release and ex vivo permeation profiles. The solubility of REP was enhanced by preparing solid dispersions (SDs) with hydrophilic carriers (PVP K30/ PEG 6000/ poloxamer 188) in different weight ratios. REP: PVP K30 (1:5) was selected as the optimized SD as it showed highest enhancement in solubility (405%). The optimized SD was characterized by SEM and DSC and incorporated into a blend of thermoreversible and mucoadhesive polymers (poloxamer 407 and carbopol 934 P) by cold technique to form in situ gels (F1-F6). The prepared in-situ gels were evaluated for various pharmacotechnical features and the formulation F3 exhibited least gelling time of 6.1± 0.20, good mucoadhesive property to ensure sufficient residence time at the site of application and a %CDR of 82.25%. The ex vivo permeation characteristics across goat mucosa can be summarized as CDP of 78.7%, flux = 6.80 mg/cm2/h; permeability coefficient of 2.02 mg/h and zero order kinetics. On correlating the CDR profile of F3 with that of its CDP profile, a R2 value of 0.991 (slope= 0.921) was observed. The value of slope approximating one, suggested that almost entire amount of drug released from F3 was capable of permeating across the nasal mucosa, ex-vivo indicating that in-situ nasal gels of REP for systemic action can be successfully developed for the management non-insulin dependent type-II diabetes mellitus.

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