Coaxial Electrospinning Biopolymer With Living Cells

ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology ◽

10.1115/nemb2010-13282 ◽

2010 ◽

Cited By ~ 1

Author(s):

Qudus Hamid ◽

Wei Sun

Keyword(s):

Growth Factors ◽

Structural Integrity ◽

Cold Water ◽

Living Cells ◽

Coaxial Electrospinning ◽

Tissue Constructs ◽

Poly Ethylene ◽

Differentiation And Proliferation

Tissue engineering and regenerative medicine aim to produce tissue constructs in vitro which can subsequently be implanted in vivo to repair damaged or diseased tissues in a clinically relevant time scale. Coaxial electrospinning techniques are capable of producing 3D scaffolds with living cells, growth factors, and or time release drugs embedded within nano fibers. The fabrication of such electrospun mats requires a novel coaxial delivery system which provides encapsulation, protection and hydration of living cells. The electrospun fibers will form a mat adaptive to its collector that facilitates cell adhesion, differentiation, and proliferation. The embedded living cells may be employed to perform vital tasks such as secretion of matrix components and growth factors. These electrospun mats would improve viability of tissue engineered constructs, and may be made into biomedical devices. Cold water fish skin gelatin (high polarity natural polymer) is used to encapsulate cells while Poly(ethylene oxide) (PEO) serves as the electrospinning filler in the biosuspension. Glutaraldehyde (GTA) solution is used to preserve the 3D environment and structural integrity of the electrospun mats.

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Low angle x-ray diffraction studies of chromatin structure in vivo and in isolated nuclei and metaphase chromosomes

The Journal of Cell Biology ◽

10.1083/jcb.96.4.1120 ◽

1983 ◽

Vol 96 (4) ◽

pp. 1120-1131 ◽

Cited By ~ 74

Author(s):

JP Langmore ◽

Paulson JR

Keyword(s):

Structural Integrity ◽

Divalent Cations ◽

Living Cells ◽

X Rays ◽

Metaphase Chromosomes ◽

Thin Sections ◽

Isolated Nuclei ◽

X Ray

Diffraction of x-rays from living cells, isolated nuclei, and metaphase chromosomes gives rise to several major low angle reflections characteristic of a highly conserved pattern of nucleosome packing within the chromatin fibers. We answer three questions about the x-ray data: Which reflections are characteristic of chromosomes in vivo? How can these reflections be preserved in vitro? What chromosome structures give rise to the reflections? Our consistent observation of diffraction peaks at 11.0, 6.0, 3.8, 2.7 and 2.1 nm from a variety of living cells, isolated nuclei, and metaphase chromosomes establishes these periodicities as characteristic of eukaryotic chromosomes in vivo. In addition, a 30-40- nm peak is observed from all somatic cells that have substantial amounts of condensed chromatin, and a weak 18-nm reflection is observed from nucleated erythrocytes. These observations provide a standard for judging the structural integrity of isolated nuclei, chromosomes, and chromatin, and thus resolve long standing controversy about the "tru" nature of chromosome diffraction. All of the reflection seen in vivo can be preserved in vitro provided that the proper ionic conditions are maintained. Our results show clearly that the 30-40-nm maximum is a packing reflection. The packing we observe in vivo is directly correlated to the side-by-side arrangement of 20- 30-nm fibers observed in thin sections of fixed and dehydrated cells and isolated chromosomes. This confirms that such packing is present in living cells and is not merely an artifact of electron microscopy. As expected, the packing reflection is shifted to longer spacings when the fibers are spread apart by reducing the concentration of divalent cations in vitro. Because the 18-, 11.0-, 6.0-, 3.8-, 2.7-, and 2.1-nm reflections are not affected by the decondensation caused by removal of divalent cations, these periodicities must reflect the internal structure of the chromaticn fibers.

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Carbon dots derived from Fusobacterium nucleatum for intracellular determination of Fe3+ and bioimaging both in vitro and in vivo

Analytical Methods ◽

10.1039/d1ay00020a ◽

2021 ◽

Author(s):

Lijuan Liu ◽

Shengting Zhang ◽

Xiaodan Zheng ◽

Hongmei Li ◽

Qi Chen ◽

...

Keyword(s):

Carbon Dots ◽

Fusobacterium Nucleatum ◽

Living Cells ◽

First Time ◽

Fluorescent Carbon Dots ◽

Fluorescent Carbon

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.

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SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. II

The Journal of General Physiology ◽

10.1085/jgp.16.2.233 ◽

1932 ◽

Vol 16 (2) ◽

pp. 233-242 ◽

Cited By ~ 27

Author(s):

B. G. Wilkes ◽

Elizabeth T. Palmer

Keyword(s):

Physiological Activity ◽

Outer Region ◽

Living Cells ◽

Yeast Cells ◽

Live Cells ◽

Intracellular Enzyme ◽

Relationship Of ◽

Kinetics Of

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H+) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exerts its physiological activity changes its pH freely and to the same extent as that of the suspending medium. It is suggested that this may indicate that this intracellular enzyme may perform its work somewhere in the outer region of the cell. 4. In using live cells containing maltase, no evidence of increased sucroclastic activity around pH 6.9, due to the action of Weidenhagen's α-glucosidase (maltase), was found.

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Photo-Crosslinked Polymeric Matrix with Antimicrobial Functions for Excisional Wound Healing in Mice

Nanomaterials ◽

10.3390/nano8100791 ◽

2018 ◽

Vol 8 (10) ◽

pp. 791 ◽

Cited By ~ 3

Author(s):

Ming-Hsiang Chang ◽

Yu-Ping Hsiao ◽

Chia-Yen Hsu ◽

Ping-Shan Lai

Keyword(s):

Wound Healing ◽

Wound Infection ◽

Polymer Solution ◽

Wound Dressing ◽

Glycol Diacrylate ◽

Excisional Wound ◽

Poly Ethylene ◽

Systemic Infections

Wound infection extends the duration of wound healing and also causes systemic infections such as sepsis, and, in severe cases, may lead to death. Early prevention of wound infection and its appropriate treatment are important. A photoreactive modified gelatin (GE-BTHE) was synthesized by gelatin and a conjugate formed from the 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and the 2-hydroxyethyl methacrylate (HEMA). Herein, we investigated the photocurable polymer solution (GE-BTHE mixture) containing GE-BTHE, poly(ethylene glycol) diacrylate (PEGDA), chitosan, and methylene blue (MB), with antimicrobial functions and photodynamic antimicrobial chemotherapy for wound dressing. This photocurable polymer solution was found to have fast film-forming property attributed to the photochemical reaction between GE-BTHE and PEGDA, as well as the antibacterial activity in vitro attributed to the ingredients of chitosan and MB. Our in vivo results also demonstrated that untreated wounds after 3 days had the same scab level as the GE-BTHE mixture-treated wounds after 20 s of irradiation, which indicates that the irradiated GE-BTHE mixture can be quickly transferred into artificial scabs to protect wounds from an infection that can serve as a convenient excisional wound dressing with antibacterial efficacy. Therefore, it has the potential to treat nonhealing wounds, deep burns, diabetic ulcers and a variety of mucosal wounds.

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Local Toxicity of Topically Administrated Thermoresponsive Systems: In Vitro Studies with In Vivo Correlation

Toxicologic Pathology ◽

10.1177/0192623318810199 ◽

2018 ◽

Vol 47 (3) ◽

pp. 426-432 ◽

Cited By ~ 3

Author(s):

Sivan Yogev ◽

Ayelet Shabtay-Orbach ◽

Abraham Nyska ◽

Boaz Mizrahi

Keyword(s):

Block Copolymer ◽

Ethylene Glycol ◽

Medical Devices ◽

Poly Lactic Acid ◽

Poly Ethylene Glycol ◽

Thermoresponsive Polymers ◽

Wide Range ◽

Poly Ethylene

Thermoresponsive materials have the ability to respond to a small change in temperature—a property that makes them useful in a wide range of applications and medical devices. Although very promising, there is only little conclusive data about the cytotoxicity and tissue toxicity of these materials. This work studied the biocompatibility of three Food and Drug Administration approved thermoresponsive polymers: poly( N-isopropyl acrylamide), poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) tri-block copolymer, and poly(lactic acid-co-glycolic acid) and poly(ethylene glycol) tri-block copolymer. Fibroblast NIH 3T3 and HaCaT keratinocyte cells were used for the cytotoxicity testing and a mouse model for the in vivo evaluation. In vivo results generally showed similar trends as the results seen in vitro, with all tested materials presenting a satisfactory biocompatibility in vivo. pNIPAM, however, showed the highest toxicity both in vitro and in vivo, which was explained by the release of harmful monomers and impurities. More data focusing on the biocompatibility of novel thermoresponsive biomaterials will facilitate the use of existing and future medical devices.

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In Vitro and in Vivo Imaging of Nitroxyl with Copper Fluorescent Probe in Living Cells and Zebrafish

Molecules ◽

10.3390/molecules23102551 ◽

2018 ◽

Vol 23 (10) ◽

pp. 2551 ◽

Cited By ~ 3

Author(s):

Sathyadevi Palanisamy ◽

Yu-Liang Wang ◽

Yu-Jen Chen ◽

Chiao-Yun Chen ◽

Fu-Te Tsai ◽

...

Keyword(s):

Critical Role ◽

Model Organism ◽

Living Cells ◽

Biological Species ◽

Zebrafish Model ◽

Physiological Processes ◽

Collective Data ◽

Angeli's Salt

Nitroxyl (HNO) plays a critical role in many physiological processes which includes vasorelaxation in heart failure, neuroregulation, and myocardial contractility. Powerful imaging tools are required to obtain information for understanding the mechanisms involved in these in vivo processes. In order to develop a rapid and high sensitive probe for HNO detection in living cells and the zebrafish model organism, 2-((2-(benzothiazole-2yl)benzylidene) amino)benzoic acid (AbTCA) as a ligand, and its corresponding copper(II) complex Cu(II)-AbTCA were synthesized. The reaction results of Cu(II)-AbTCA with Angeli’s salt showed that Cu(II)-AbTCA could detect HNO quantitatively in a range of 40–360 µM with a detection limit of 9.05 µM. Furthermore, Cu(II)-AbTCA is more selective towards HNO over other biological species including thiols, reactive nitrogen, and reactive oxygen species. Importantly, Cu(II)-AbTCA was successfully applied to detect HNO in living cells and zebrafish. The collective data reveals that Cu(II)-AbTCA could be used as a potential probe for HNO detection in living systems.

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Functional Organization of the Yeast SAGA Complex: Distinct Components Involved in Structural Integrity, Nucleosome Acetylation, and TATA-Binding Protein Interaction

Molecular and Cellular Biology ◽

10.1128/mcb.19.1.86 ◽

1999 ◽

Vol 19 (1) ◽

pp. 86-98 ◽

Cited By ~ 205

Author(s):

David E. Sterner ◽

Patrick A. Grant ◽

Shannon M. Roberts ◽

Laura J. Duggan ◽

Rimma Belotserkovskaya ◽

...

Keyword(s):

Histone Acetylation ◽

Structural Integrity ◽

Functional Organization ◽

Binding Protein ◽

Tata Binding Protein ◽

Saga Complex ◽

Specific Domain ◽

Nucleosomal Histone

ABSTRACT SAGA, a recently described protein complex in Saccharomyces cerevisiae, is important for transcription in vivo and possesses histone acetylation function. Here we report both biochemical and genetic analyses of members of three classes of transcription regulatory factors contained within the SAGA complex. We demonstrate a correlation between the phenotypic severity of SAGA mutants and SAGA structural integrity. Specifically, null mutations in the Gcn5/Ada2/Ada3 or Spt3/Spt8 classes cause moderate phenotypes and subtle structural alterations, while mutations in a third subgroup, Spt7/Spt20, as well as Ada1, disrupt the complex and cause severe phenotypes. Interestingly, double mutants (gcn5Δ spt3Δand gcn5Δ spt8Δ) causing loss of a member of each of the moderate classes have severe phenotypes, similar tospt7Δ, spt20Δ, or ada1Δmutants. In addition, we have investigated biochemical functions suggested by the moderate phenotypic classes and find that first, normal nucleosomal acetylation by SAGA requires a specific domain of Gcn5, termed the bromodomain. Deletion of this domain also causes specific transcriptional defects at the HIS3 promoter in vivo. Second, SAGA interacts with TBP, the TATA-binding protein, and this interaction requires Spt8 in vitro. Overall, our data demonstrate that SAGA harbors multiple, distinct transcription-related functions, including direct TBP interaction and nucleosomal histone acetylation. Loss of either of these causes slight impairment in vivo, but loss of both is highly detrimental to growth and transcription.

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TRENDS AND CHALLENGES OF CARTILAGE TISSUE ENGINEERING

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237209001209 ◽

2009 ◽

Vol 21 (03) ◽

pp. 149-155 ◽

Cited By ~ 2

Author(s):

Hsu-Wei Fang

Keyword(s):

Tissue Engineering ◽

Stem Cells ◽

Growth Factors ◽

Bone Cells ◽

Cartilage Tissue Engineering ◽

Bioactive Molecules ◽

In Vivo Studies ◽

Cartilage Tissue

Cartilage injuries may be caused by trauma, biomechanical imbalance, or degenerative changes of joint. Unfortunately, cartilage has limited capability to spontaneous repair once damaged and may lead to progressive damage and degeneration. Cartilage tissue-engineering techniques have emerged as the potential clinical strategies. An ideal tissue-engineering approach to cartilage repair should offer good integration into both the host cartilage and the subchondral bone. Cells, scaffolds, and growth factors make up the tissue engineering triad. One of the major challenges for cartilage tissue engineering is cell source and cell numbers. Due to the limitations of proliferation for mature chondrocytes, current studies have alternated to use stem cells as a potential source. In the recent years, a lot of novel biomaterials has been continuously developed and investigated in various in vitro and in vivo studies for cartilage tissue engineering. Moreover, stimulatory factors such as bioactive molecules have been explored to induce or enhance cartilage formation. Growth factors and other additives could be added into culture media in vitro, transferred into cells, or incorporated into scaffolds for in vivo delivery to promote cellular differentiation and tissue regeneration.Based on the current development of cartilage tissue engineering, there exist challenges to overcome. How to manipulate the interactions between cells, scaffold, and signals to achieve the moderation of implanted composite differentiate into moderate stem cells to differentiate into hyaline cartilage to perform the optimum physiological and biomechanical functions without negative side effects remains the target to pursue.

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