Search results for "Regeneration"
showing 10 items of 889 documents
Bone Healing with or without Platelet-Rich Plasma around Four Different Dental Implant Surfaces in Beagle Dogs
2013
Purpose Surface development is one of the major aims in dental implant engineering. Additive application of substances could possibly improve the new bone formation around dental implants. The present study evaluated the bone reaction on four different implant surfaces with or without platelet-rich plasma (PRP). Materials and Methods Four self-tapping titanium screw implants (Branemark MK III [Nobel Biocare, Goteborg, Sweden], Osseotite [3i, Miami, FL, USA], Xive [Densply Friadent, Mannheim, Germany], and Compress [IGfZ eG, Diez, Germany]) with different surfaces were inserted in each hemimandible of 12 female beagle dogs; the implant positions and the application of PRP were randomized. Af…
In vitro plant regeneration of caper (Capparis spinosa L.) from floral explants and genetic stability of regenerants
2011
A new technique to regenerate caper plants (Capparis spinosa L. subsp. rupestris) starting from flower explant is reported. In vitro plant regeneration was attempted using stigma, anthers and unfertilized ovules of unopened flowers collected in the field. Plant regeneration was achieved from unfertilized ovules on MS medium supplemented with 88 mM sucrose and 13 lM 6-benzyladenine (BA). New individuals obtained from unfertilized ovules were used as source material for micropropagation and multiple shoots were obtained on MS medium sup- plemented with the adeninic cytokinin BA and the auxin indole-3-butyric acid (IBA). Explants obtained in micro- propagation step were used for rooting step u…
Inactivation and Regeneration Kinetics of Horseradish Peroxidase Heated at High Temperatures.
1997
The inactivation kinetics of horseradish peroxidase (HRP) heated in capillary tubes in the range 110 to 135°C was studied. Its regeneration kinetics when stored at 4 and 25°C was also considered. As the severity of the treatment increased, the absolute value of the regeneration decreased. The storage temperature of the enzyme did not affect the percentage of maximum activity regenerable, although when this temperature was raised from 4 to 25°C the speed of regeneration increased. Kinetics of HRP inactivation determined after heating and after regeneration were compared. Both forms of the enzyme showed similar behavior with first-order inactivation kinetics, with Ea = 19.5 ± 1.0 kcal/mol and…
In situ forming hydrogels of new amino hyaluronic acid/benzoyl-cysteine derivatives as potential scaffolds for cartilage regeneration
2012
A new chemical strategy is described to link ethylenediamino (EDA) groups to primary hydroxyl groups of hyaluronic acid (HA) and the obtained derivatives have been characterized by 1H-NMR and 13C-NMR analyses. Such HA–EDA derivatives have been exploited to control the functionalization degree in benzoyl-cysteine (BC) groups, chosen as moieties able to allow both self-assembling in aqueous media and an oxidative crosslinking. In particular, the kinetics of oxidation of thiol groups in HA–EDA–BC derivatives has been studied in Dulbecco's Phosphate Buffer Solution (DPBS) pH 7.4 by colorimetric assays and rheological measurements. Mechanical properties of chemical hydrogels obtained after oxida…
p38 MAPK: A dual role in hepatocyte proliferation through reactive oxygen species
2013
p38 MAPKs are important mediators of signal transduction that respond to a wide range of extracellular stressors such as UV radiation, osmotic shock, hypoxia, pro-inflammatory cytokines, and oxidative stress. The most abundant family member is p38α, which helps to couple cell proliferation and growth in response to certain damaging stimuli. In fact, increased proliferation and impaired differentiation are hallmarks of p38α-deficient cells. It has been reported that reactive oxygen species (ROS) play a critical role in cytokine-induced p38α activation. Under physiological conditions, p38α can function as a mediator of ROS signaling and either activate or suppress cell cycle progression depen…
Mechanical Characterization of Polysaccharide/polyaminoacid Hydrogels as Potential Scaffolds for Tissue Regeneration
2011
The mechanical properties of hydrogel scaffolds based on hyaluronic acid (HA) that were chemically crosslinked with α,β-poly(N-2-hydroxyethyl)(2-aminoethylcarbamate)-D,L-aspartamide (PHEA-EDA) were investigated. Variation of these properties as a function of three different PHEA-EDA amounts used to crosslink HA has been related to the reaction efficiency evaluated using a colorimetric assay. Moreover, the amount of unreacted amino groups that was still present in the hydrogels was related to the attachment behavior of human dermal fibroblasts to the hydrogel surface. The mechanical data and biological results suggest the suitability of the investigated hydrogels as scaffolds for the regener…
Biological evaluation of PLLA membranes, with different pore diameters, to stimulate cell adhesion and growth in vitro
2015
Polymeric membranes prepared via DIPS (Diffusion Induced Phase Separation) are widely studied and utilized as scaffolds for the regeneration of tissue. In this work, poly (L)-lactide membrane are prepared through a DIPS protocol starting from a ternary solution made of polymer, dioxane (solvent) and water (non-solvent). A three-dimensional, porous and mechanically stable membrane is desirable for ingrowth of human bronchial epithelial cells. Polymeric membranes prepared via DIPS (Diffusion Induced Phase Separation) are widely studied and utilized as scaffolds for the regeneration of tissue. In this work, poly (L)-lactide membrane are prepared through a DIPS protocol starting from a ternary …
Bio-inspired Resorbable Calcium Phosphate-Polymer Nanocomposites for Bone Healing Devices with Controlled Drug Release
2011
In orthopedic research, increasing attention is being paid to bioresorbable composite materials as an attractive alternative to permanent metal bone healing devices. Typical composites consist of a biodegradable polyester matrix loaded with bioactive calcium phosphate ceramic particles (tricalcium phosphate, TCP or hydroxyapatite, HA) added to improve the biological response and mechanical properties of the neat polymer. The mechanical behavior of such particle-reinforced composites, however, falls far short of the expected performance in high-load bearing situations. Replicating some features of nacre—a strong and tough natural nanocomposite with a very high content of brittle inorganic ph…
Potential use of new diphenylurea derivatives in micropropagation of Capparis spinosa L.
2011
A protocol for in vitro multiplication of caper (Capparis spinosa L. subsp. rupestris) from nodal segments collected from mature plants was developed. For shoot multiplication, one auxin (indol-3-butyric acid, IBA) and cytokinins of two different classes were used: the N6-substituted adenine derivatives 6-benzylamino purine (BAP), and the two synthetic phenylurea derivatives N-phenyl-N′-benzothiazol-6-ylurea (PBU) and N-phenyl-N′-(1,2,3-thidiazol-5-yl) urea (thidiazuron, TDZ). Maximum shoot production was achieved from explants cultured with the adeninic cytokinin BAP (4 μM) and the auxin IBA (0.5 μM). New shoots longer than 1 cm were used for rooting. To induce root formation, three auxins…
Modulation of Fatty Acid Patterns During Protoplast Isolation
1983
Protoplast isolation and regeneration is known from numerous plant species (Binding et al. 1). But there are plant species which show very unconstant regeneration or no reaction at all, even if the isolation showed high viability of the protoplasts. Does this lacking response only depend on medium composition and effectors or are there other unknown conditions? The procedure of protoplast isolation and the use of strong hypertonic media is a dramatic disturbance of cell metabolism and might be a stress situation, which cannot be overcome by the cell. Fleck et al. (2) reported “osmotic-stress proteins” in Nicotiana sylvestris protoplasts and Kaiser et al. (3) showed a remarkable influence of…