scholarly journals Hypoxic Physiological Environments in a Gas-Regulated Microfluidic Device

Micromachines ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 16
Author(s):  
Insu Lee ◽  
Jin Woo ◽  
Min Lee ◽  
Tae-Joon Jeon ◽  
Sun Kim
Keyword(s):  
Human Physiology ◽  
Computational Simulation ◽  
Hypoxic Condition ◽  
Oxygen Level ◽  
Critical Factors ◽  
Permeable Membrane ◽  
Hypoxic Environment ◽  
O2 Concentration ◽  
Tissue Models

Hypoxic environment is known as one of the critical factors in various physiological/pathological processes. It is imperative to recapitulate oxygen level in microscale for human physiology/pathology induced by hypoxia. Herein, we propose an oxygen-regulating system that can be applied to in vitro tissue models. We fabricated a microdevice with a gas-permeable membrane, allowing oxygen diffusion without direct contact to cells. We verified the formation of oxygen level less than 2% O2 concentration inside the device through computational simulation and experiments. H9c2 heart myoblasts were exposed to hypoxic condition in the device, and their cell viability were investigated. We anticipate that our system will be integrated with a platform to study hypoxia-induced human physiology and pathology as an efficient oxygen-regulating system.

Inhibition of dihydropyridine-sensitive calcium entry in hypoxic relaxation of airway smooth muscle

1995 ◽  
Vol 268 (2) ◽  
pp. L201-L206 ◽  
Author(s):  
C. Vannier ◽  
T. L. Croxton ◽  
L. S. Farley ◽  
C. A. Hirshman
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Muscle Tone ◽  
Bay K 8644 ◽  
O2 Concentration ◽  
Voltage Dependent ◽  
Progressive Hypoxia ◽  
Carbamyl Choline

Hypoxia dilates airways in vivo and reduces active tension of airway smooth muscle in vitro. To determine whether hypoxia impairs Ca2+ entry through voltage-dependent channels (VDC), we tested the ability of dihydropyridines to modulate hypoxia-induced relaxation of KCl- and carbamyl choline (carbachol)-contracted porcine bronchi. Carbachol- or KCl-contracted bronchial rings were exposed to progressive hypoxia in the presence or absence of 1 microM BAY K 8644 (an L-type-channel agonist). In separate experiments, rings were contracted with carbachol or KCl, treated with nifedipine (a VDC antagonist), and finally exposed to hypoxia. BAY K 8644 prevented hypoxia-induced relaxation in KCl-contracted bronchi. Nifedipine (10(-5) M) totally relaxed KCl- contracted bronchi. Carbachol-contracted bronchi were only partially relaxed by nifedipine but were completely relaxed when the O2 concentration of the gas was reduced from 95 to 0%. These data indicate that hypoxia can reduce airway smooth muscle tone by limiting entry of Ca2+ through a dihydropyridine-sensitive pathway, but that other mechanisms also contribute to hypoxia-induced relaxation of carbachol-contracted bronchi.

scholarly journals Cancer Stem Cell Microenvironment Models with Biomaterial Scaffolds In Vitro

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 45
Author(s):  
Ghmkin Hassan ◽  
Said M. Afify ◽  
Shiro Kitano ◽  
Akimasa Seno ◽  
Hiroko Ishii ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Biology ◽  
Advanced Technology ◽  
Cancer Microenvironment ◽  
Critical Factors ◽  
Self Renewal ◽  
Cell Microenvironment ◽  
Biological Phenomena ◽  
Biomaterial Scaffolds

Defined by its potential for self-renewal, differentiation and tumorigenicity, cancer stem cells (CSCs) are considered responsible for drug resistance and relapse. To understand the behavior of CSC, the effects of the microenvironment in each tissue are a matter of great concerns for scientists in cancer biology. However, there are many complicated obstacles in the mimicking the microenvironment of CSCs even with current advanced technology. In this context, novel biomaterials have widely been assessed as in vitro platforms for their ability to mimic cancer microenvironment. These efforts should be successful to identify and characterize various CSCs specific in each type of cancer. Therefore, extracellular matrix scaffolds made of biomaterial will modulate the interactions and facilitate the investigation of CSC associated with biological phenomena simplifying the complexity of the microenvironment. In this review, we summarize latest advances in biomaterial scaffolds, which are exploited to mimic CSC microenvironment, and their chemical and biological requirements with discussion. The discussion includes the possible effects on both cells in tumors and microenvironment to propose what the critical factors are in controlling the CSC microenvironment focusing the future investigation. Our insights on their availability in drug screening will also follow the discussion.

scholarly journals Designing of an Advanced Compression Bioreactor with an Implementation of a Low-Cost Controlling System Connected to a Mobile Application

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 915
Author(s):  
Gözde Dursun ◽  
Muhammad Umer ◽  
Bernd Markert ◽  
Marcus Stoffel
Keyword(s):  
Mobile Application ◽  
Low Cost ◽  
Experimental Information ◽  
Raspberry Pi ◽  
Tissue Constructs ◽  
Cost Controlling ◽  
Controlling System ◽  
And Control ◽  
Tissue Models

(1) Background: Bioreactors mimic the natural environment of cells and tissues by providing a controlled micro-environment. However, their design is often expensive and complex. Herein, we have introduced the development of a low-cost compression bioreactor which enables the application of different mechanical stimulation regimes to in vitro tissue models and provides the information of applied stress and strain in real-time. (2) Methods: The compression bioreactor is designed using a mini-computer called Raspberry Pi, which is programmed to apply compressive deformation at various strains and frequencies, as well as to measure the force applied to the tissue constructs. Besides this, we have developed a mobile application connected to the bioreactor software to monitor, command, and control experiments via mobile devices. (3) Results: Cell viability results indicate that the newly designed compression bioreactor supports cell cultivation in a sterile environment without any contamination. The developed bioreactor software plots the experimental data of dynamic mechanical loading in a long-term manner, as well as stores them for further data processing. Following in vitro uniaxial compression conditioning of 3D in vitro cartilage models, chondrocyte cell migration was altered positively compared to static cultures. (4) Conclusion: The developed compression bioreactor can support the in vitro tissue model cultivation and monitor the experimental information with a low-cost controlling system and via mobile application. The highly customizable mold inside the cultivation chamber is a significant approach to solve the limited customization capability of the traditional bioreactors. Most importantly, the compression bioreactor prevents operator- and system-dependent variability between experiments by enabling a dynamic culture in a large volume for multiple numbers of in vitro tissue constructs.

A co-delivery nanoplatform for Lignan-derived compound and perfluorocarbon tuning IL-25 secretion and oxygen level in tumor microenvironments for meliorative tumor radiotherapy

Nanoscale ◽  
2021 ◽  
Author(s):  
Zhenyu Duan ◽  
Qiang Luo ◽  
Lei Gu ◽  
Xiaoling Li ◽  
Hongyan Zhu ◽  
...  
Keyword(s):  
Therapeutic Efficacy ◽  
Glycolic Acid ◽  
Treatment Technique ◽  
Oxygen Level ◽  
Tumor Microenvironments ◽  
Hypoxic Environment ◽  
Control Tumor ◽  
Tumor Metastases ◽  
Localized Treatment

A hypoxic environment in tumors hampers the therapeutic efficacy of radiotherapy. Moreover, radiotherapy, a localized treatment technique, can barely control tumor metastases. Herein, poly(lactic co-glycolic acid) was used to encapsulate...

scholarly journals The Role of Biomimetic Hypoxia on Cancer Cell Behaviour in 3D Models: A Systematic Review

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1334
Author(s):  
Ye Liu ◽  
Zahra Mohri ◽  
Wissal Alsheikh ◽  
Umber Cheema
Keyword(s):  
Systematic Review ◽  
Cellular Response ◽  
3D Culture ◽  
3D Models ◽  
In Vitro Models ◽  
Research Findings ◽  
Tissue Models

The development of biomimetic, human tissue models is recognized as being an important step for transitioning in vitro research findings to the native in vivo response. Oftentimes, 2D models lack the necessary complexity to truly recapitulate cellular responses. The introduction of physiological features into 3D models informs us of how each component feature alters specific cellular response. We conducted a systematic review of research papers where the focus was the introduction of key biomimetic features into in vitro models of cancer, including 3D culture and hypoxia. We analysed outcomes from these and compiled our findings into distinct groupings to ascertain which biomimetic parameters correlated with specific responses. We found a number of biomimetic features which primed cancer cells to respond in a manner which matched in vivo response.

scholarly journals EFFECT OF POLYMERS ON THE PHYSICOCHEMICAL AND DRUG RELEASE PROPERTIES OF TRANSDERMAL PATCHES OF ATENOLOL

2018 ◽  
Vol 10 (4) ◽  
pp. 68
Author(s):  
Manish Kumar ◽  
Vishal Trivedi ◽  
Ajay Kumar Shukla ◽  
Suresh Kumar Dev
Keyword(s):  
Drug Release ◽  
Hydroxypropyl Methylcellulose ◽  
Research Work ◽  
High Moisture ◽  
Transdermal Drug Delivery System ◽  
Permeable Membrane ◽  
Transdermal Patches ◽  
Egg Membrane ◽  
Hydrophilicity And Hydrophobicity

Objective: The objective of this research work was to develop a transdermal drug delivery system containing atenolol with different ratios of hydrophilic and hydrophobic polymeric combinations, using solvent evaporation technique and to examine the effect of hydrophilicity and hydrophobicity of polymers on the physicochemical and drug release properties of transdermal patches.Methods: Solvent casting method has been used to formulate transdermal patches. Hydroxypropyl methylcellulose (HPMC), Polyvinylpyrrolidone (PVP), Ethylcellulose (EC) in different combination ratios were used as the polymer. Propylene glycol was used as a plasticizer. Permeation enhancers such as span 80 were used to enhance permeation through the skin. In vitro diffusion study was carried out by franz diffusion cell using egg membrane as a semi-permeable membrane for diffusion.Results: Result showed that the thickness of the all batch of patches varied from 0.32 to 0.39 mm with uniformity of thickness in each formulation. Formulations F1 to F3 had high moisture content varied from 2.07±0.09 to 2.56±0.15 and high moisture uptake value varied from 3.21±0.35 to 4.09±0.38, due to a higher concentration of hydrophilic polymers. Drug content of all batches was ranged between 85.92±1.32 to 95.71±1.42. Folding endurance values off all batches were more than 75. Formulation batches F1 to F3 showed higher cumulative drug release varied from 61.34% to 68.11% as compared to formulation batches F4 to F6.Conclusion: Higher proportion of hydrophilic polymer in the formulation of transdermal patches, gives higher percentage drug release from prepared patches. The finding of the study indicates that hydrophilicity and hydrophobicity of polymer effects the physicochemical and drug release properties of transdermal patches and an optimum proportion of hydrophilic and hydrophobic polymer is required for the preparation of effective transdermal patches. 

Biomaterial-based strategies for in vitro neural models

2022 ◽  
Author(s):  
Alp Ozgun ◽  
David Lomboni ◽  
Hallie Arnott ◽  
William A. Staines ◽  
John Woulfe ◽  
...  
Keyword(s):  
Neural Tissue ◽  
Neural Models ◽  
Tissue Models

This review provides a comprehensive compendium of commonly used biomaterials as well as the different fabrication techniques employed for the design of 3D neural tissue models.

Biophysical stimulation for in vitro engineering of functional cardiac tissues

2017 ◽  
Vol 131 (13) ◽  
pp. 1393-1404 ◽  
Author(s):  
Anastasia Korolj ◽  
Erika Yan Wang ◽  
Robert A. Civitarese ◽  
Milica Radisic
Keyword(s):  
Cardiac Tissue ◽  
Culture Media ◽  
Culture Conditions ◽  
Lineage Specification ◽  
Cardiac Tissues ◽  
Cardiac Lineage ◽  
And Function ◽  
Tissue Models

Engineering functional cardiac tissues remains an ongoing significant challenge due to the complexity of the native environment. However, our growing understanding of key parameters of the in vivo cardiac microenvironment and our ability to replicate those parameters in vitro are resulting in the development of increasingly sophisticated models of engineered cardiac tissues (ECT). This review examines some of the most relevant parameters that may be applied in culture leading to higher fidelity cardiac tissue models. These include the biochemical composition of culture media and cardiac lineage specification, co-culture conditions, electrical and mechanical stimulation, and the application of hydrogels, various biomaterials, and scaffolds. The review will also summarize some of the recent functional human tissue models that have been developed for in vivo and in vitro applications. Ultimately, the creation of sophisticated ECT that replicate native structure and function will be instrumental in advancing cell-based therapeutics and in providing advanced models for drug discovery and testing.

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