Electrical stimulation (ES) has been successfully used to treat bone defects clinically. Recently, both cellular and molecular approaches have demonstrated that ES can change cell behavior such as ...migration, proliferation and differentiation.
In the present study we exposed rat bone marrow- (BM-) and adipose tissue- (AT-) derived mesenchymal stem cells (MSCs) to direct current electrical stimulation (DC ES) and assessed temporal changes in osteogenic differentiation. We applied 100 mV/mm of DC ES for 1 h per day for three, seven and 14 days to cells cultivated in osteogenic differentiation medium and assessed viability and calcium deposition at the different time points. In addition, expression of osteogenic genes, Runx2, Osteopontin, and Col1A2 was assessed in BM- and AT-derived MSCs at the different time points.
Results showed that ES changed osteogenic gene expression patterns in both BM- and AT-MSCs, and these changes differed between the two groups. In BM-MSCs, ES caused a significant increase in mRNA levels of Runx2, Osteopontin and Col1A2 at day 7, while in AT-MSCs, the increase in Runx2 and Osteopontin expression were observed after 14 days of ES.
This study shows that rat bone marrow- and adipose tissue-derived stem cells react differently to electrical stimuli, an observation that could be important for application of electrical stimulation in tissue engineering.
Electrochemical signals play an important role in cell communication and behavior. Electrically charged ions transported across cell membranes maintain an electrochemical imbalance that gives rise to ...bioelectric signaling, called membrane potential or V
. V
plays a key role in numerous inter- and intracellular functions that regulate cell behaviors like proliferation, differentiation and migration, all playing a critical role in embryonic development, healing, and regeneration.
With the goal of analyzing the changes in V
during cell proliferation and differentiation, here we used direct current electrical stimulation (EStim) to promote cell proliferation and differentiation and simultaneously tracked the corresponding changes in V
in adipose derived mesenchymal stem cells (AT-MSC).
We found that EStim caused increased AT-MSC proliferation that corresponded to V
depolarization and increased osteogenic differentiation that corresponded to V
hyperpolarization. Taken together, this shows that V
changes associated with EStim induced cell proliferation and differentiation can be accurately tracked during these important cell functions. Using this tool to monitor V
changes associated with these important cell behaviors we hope to learn more about how these electrochemical cues regulate cell function with the ultimate goal of developing new EStim based treatments capable of controlling healing and regeneration.
Bovine trypsin (EC 3.4.21.4) is an enzyme that is widely used for commercial purposes to digest or process other proteins, including some therapeutic proteins. The biopharmaceutical industry is ...trying to eliminate animal-derived proteins from manufacturing processes due to the possible contamination of these products by human pathogens. Recombinant trypsin has been produced in a number of systems, including cell culture, bacteria and yeast. To date, these expression systems have not produced trypsin on a scale sufficient to fulfill the need of biopharmaceutical manufacturers where kilogram quantities are often required. The present paper describes commercial-level production of trypsin in transgenic maize (Zea mays) and its physical and functional characterization. This protease, the first enzyme to be produced on a large-scale using transgenic plant technology, is functionally equivalent to native bovine pancreatic trypsin. The availability of this reagent should allow for the replacement of animal-derived trypsin in the processing of pharmaceutical proteins.
Electrical stimulation in bone tissue engineering treatments Leppik, Liudmila; Oliveira, Karla Mychellyne Costa; Bhavsar, Mit Balvantray ...
European journal of trauma and emergency surgery (Munich : 2007),
04/2020, Letnik:
46, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Electrical stimulation (EStim) has been shown to promote bone healing and regeneration both in animal experiments and clinical treatments. Therefore, incorporating EStim into promising new bone ...tissue engineering (BTE) therapies is a logical next step. The goal of current BTE research is to develop combinations of cells, scaffolds, and chemical and physical stimuli that optimize treatment outcomes. Recent studies demonstrating EStim’s positive osteogenic effects at the cellular and molecular level provide intriguing clues to the underlying mechanisms by which it promotes bone healing. In this review, we discuss results of recent in vitro and in vivo research focused on using EStim to promote bone healing and regeneration and consider possible strategies for its application to improve outcomes in BTE treatments. Technical aspects of exposing cells and tissues to EStim in in vitro and in vivo model systems are also discussed.
Delivery of subunit vaccines in maize seed Lamphear, Barry J; Streatfield, Stephen J; Jilka, Joseph M ...
Journal of controlled release,
12/2002, Letnik:
85, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The use of recombinant gene technologies by the vaccine industry has revolutionized the way antigens are generated, and has provided safer, more effective means of protecting animals and humans ...against bacterial and viral pathogens. Viral and bacterial antigens for recombinant subunit vaccines have been produced in a variety of organisms. Transgenic plants are now recognized as legitimate sources for these proteins, especially in the developing area of oral vaccines, because antigens have been shown to be correctly processed in plants into forms that elicit immune responses when fed to animals or humans. Antigens expressed in maize (
Zea mays) are particularly attractive since they can be deposited in the natural storage vessel, the corn seed, and can be conveniently delivered to any organism that consumes grain. We have previously demonstrated high level expression of the B-subunit of
Escherichia coli heat-labile enterotoxin and the spike protein of swine transmissible gastroenteritis in corn, and have demonstrated that these antigens delivered in the seed elicit protective immune responses. Here we provide additional data to support the potency, efficacy, and stability of recombinant subunit vaccines delivered in maize seed.
ER24/1 !: The greatest emergency of our time van Ee, Elaine Pei-Jing Xiao-Wei; Barker, Nicolas D. John; Barker, John Howard
European journal of trauma and emergency surgery (Munich : 2007),
12/2023, Letnik:
49, Številka:
6
Journal Article
The synthesis of selected antigens in plants and their oral delivery has great potential for reducing the costs of vaccine production and administration. The application of this technology requires ...antigen concentrations in final plant material to be uniform to ensure consistent dosing. In addition, antigen levels should be such as to allow the volume of each dose, containing a set amount of antigen, to be practical for oral delivery. Here, we demonstrate that the Lt-B protein of enterotoxigenic
E. coli is evenly distributed in defatted corn germ prepared from transgenic grain. Furthermore, the choice of sub-cellular location for Lt-B affects accumulation of the protein in excess of four orders of magnitude.
Summary
The availability of foods low in sugar content yet high in flavour is critically important to millions of individuals conscious of carbohydrate intake for diabetic or dietetic purposes. ...Brazzein is a sweet protein occurring naturally in a tropical plant that is impractical to produce economically on a large scale, thus limiting its availability for food products. We report here the use of a maize expression system for the production of this naturally sweet protein. High expression of brazzein was obtained, with accumulation of up to 4% total soluble protein in maize seed. Purified corn brazzein possessed a sweetness intensity of up to 1200 times that of sucrose on a per weight basis. In addition, application tests demonstrated that brazzein‐containing maize germ flour could be used directly in food applications, providing product sweetness. These results demonstrate that high‐intensity sweet protein engineered into food products can give sweetener attributes useful in the food industry.
Background Electrochemical signals play an important role in cell communication and behavior. Electrically charged ions transported across cell membranes maintain an electrochemical imbalance that ...gives rise to bioelectric signaling, called membrane potential or V.sub.mem . V.sub.mem plays a key role in numerous inter- and intracellular functions that regulate cell behaviors like proliferation, differentiation and migration, all playing a critical role in embryonic development, healing, and regeneration. Methods With the goal of analyzing the changes in V.sub.mem during cell proliferation and differentiation, here we used direct current electrical stimulation (EStim) to promote cell proliferation and differentiation and simultaneously tracked the corresponding changes in V.sub.mem in adipose derived mesenchymal stem cells (AT-MSC). Results We found that EStim caused increased AT-MSC proliferation that corresponded to V.sub.mem depolarization and increased osteogenic differentiation that corresponded to V.sub.mem hyperpolarization. Taken together, this shows that V.sub.mem changes associated with EStim induced cell proliferation and differentiation can be accurately tracked during these important cell functions. Using this tool to monitor V.sub.mem changes associated with these important cell behaviors we hope to learn more about how these electrochemical cues regulate cell function with the ultimate goal of developing new EStim based treatments capable of controlling healing and regeneration.
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