Differential scanning calorimetry applied to the storage at ultra low temperatures of olive and hop in vitro grown shoot-tips

2000 ◽  
Vol 349 (1-2) ◽  
pp. 147-151 ◽  
Author(s):  
David Martı́nez ◽  
M Ángeles Revilla ◽  
Aránzazu Espina ◽  
José R Garcı́a
Keyword(s):  
Differential Scanning Calorimetry ◽  
Low Temperatures ◽  
Shoot Tips ◽  
Scanning Calorimetry

scholarly journals CRYOPRESERVATION OF PAPAYA SHOOT TIPS BY VITRIFICATION

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1066b-1066
Author(s):  
Leigh E. Towill
Keyword(s):  
Differential Scanning Calorimetry ◽  
Ethylene Glycol ◽  
Plant Cells ◽  
External Solution ◽  
Final Concentration ◽  
Shoot Tips ◽  
Scanning Calorimetry ◽  
Simple Method ◽  
Peg 8000

Papaya shoot tips, obtained either from seedlings or from in vitro plants, survived liquid nitrogen (-196°C) exposure using a vitrification procedure. Vitrification is a technically simple method but requires large concentrations of cryoprotectants. These were added in two steps, first slow addition of dimethylsulfoxide (DMSO) and PEG-8000, and subsequent fast addition of ethylene glycol (PG). The final concentration before cooling was 40% EG, 7.8% DMSO, and 10% PEG-8000. Both rapid cooling and rapid warming rates were required. Differential scanning calorimetry (DSC) was used to determine that the external solution vitrified upon cooling. It could not be demonstrated by DSC that cells within the shoot-tip vitrified, but since both DMSO and EG rapidly permeate plant cells, vitrification within the cells seems a likely explanation for retention of viability.

The preparation, characterization, structure and dissolution analysis of apremilast solvatomorphs

2017 ◽  
Vol 73 (4) ◽  
pp. 305-313 ◽  
Author(s):  
Yun-Deng Wu ◽  
Xiao-Lei Zhang ◽  
Xiao-Hong Liu ◽  
Jian Xu ◽  
Mei Zhang ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Hydrogen Bonding ◽  
Psoriatic Arthritis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Dissolution Rates ◽  
X Ray ◽  
Similarity Factor ◽  
Hydrogen Bonding Interactions

Apremilast (AP) {systematic name: (S)-2-[1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethyl]-4-acetamidoisoindoline-1,3-dione} is an inhibitor of phosphodieasterase-4 (PDE4) and is indicated for the treatment of adult patients with active psoriatic arthritis. The ability of AP to form solvates has been investigated and three solvatomorphs of AP, namely, the AP ethyl acetate hemisolvate, C22H24N2O7S·0.5C4H8O2, the AP toluene hemisolvate, C22H24N2O7S·0.5C7H8, and the AP dichloromethane monosolvate, C22H24N2O7S·CH2Cl2, were obtained. The three AP solvatomorphs were characterized by X-ray powder diffraction, thermogravimetric analysis and differential scanning calorimetry. Single-crystal X-ray diffraction was used to analyze the structures, crystal symmetry, packing modes, stoichiometry and hydrogen-bonding interactions of the solvatomorphs. In addition, dissolution analyses were performed to study the dissolution rates of different AP solvatomorph tablets in vitro and to make comparisons with commercial apremilast tablets (produced by Celgene); all three solvatomorphs showed similar dissolution rates and similar values of the similarity factor f2 in a comparison of their dissolution profiles.

The Crystal Structures at 10 K of the Trigonal Salts KMIII(NH3)6(ClO4)2Cl2, MIII = Os and Cr, and the Possibility of Phase Transitions

1999 ◽  
Vol 52 (3) ◽  
pp. 219 ◽  
Author(s):  
Philip A. Reynolds ◽  
Brian N. Figgis ◽  
Alexander N. Sobolev
Keyword(s):  
Differential Scanning Calorimetry ◽  
Transition Temperature ◽  
Crystal Structures ◽  
Low Temperatures ◽  
Simple Structure ◽  
Alkali Metal Cations ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Threefold Axis ◽  
X Ray

The crystal structures of KOs(NH3)3(ClO4)2Cl2 and KCr(NH3)6(ClO4)2Cl2 were determined at 10 K by X-ray diffraction, and for the osmium salt also at 293 K. At 293 K the osmium salt is trigonal, space group R 3m, with the same simple structure as others of this class of double salt. At 10 K, in agreement with previous radius ratio predictions, both crystals are best described as remaining R 3m. All previously studied members, with larger alkali metal cations, are twinned R 3 at low temperatures, with small, symmetry-breaking rotations of the hexaamminemetal(III) and perchlorate ions about the threefold axis. Differential scanning calorimetry on CsRu(NH3)6(ClO4)2Cl2 suggests that the R 3m to R 3 change is very extended in temperature with only a small discontinuity at the transition temperature.

Differential scanning calorimetry of human blood serum exposed in vitro to X-ray radiation

2019 ◽  
Vol 680 ◽  
pp. 178358 ◽  
Author(s):  
Agnieszka Kiełboń ◽  
Anna Michnik ◽  
Kinga Polaczek Grelik ◽  
Klaudia Duch ◽  
Ewa Sadowska-Krępa
Keyword(s):  
Differential Scanning Calorimetry ◽  
Blood Serum ◽  
Human Blood ◽  
Human Blood Serum ◽  
Scanning Calorimetry ◽  
X Ray

scholarly journals Stepwise Glucoheptoamidation of Poly(Amidoamine) Dendrimer G3 to Tune Physicochemical Properties of the Potential Drug Carrier: In Vitro Tests for Cytisine Conjugates

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 473 ◽  
Author(s):  
Anna Czerniecka-Kubicka ◽  
Piotr Tutka ◽  
Marek Pyda ◽  
Małgorzata Walczak ◽  
Łukasz Uram ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Physicochemical Properties ◽  
Drug Carrier ◽  
Human Fibroblasts ◽  
Pamam Dendrimer ◽  
In Vitro Tests ◽  
Scanning Calorimetry ◽  
Ζ Potential ◽  
Cell Accumulation

Third-generation poly(amidoamine) dendrimer (PAMAM) was modified by stepwise primary amine group amidation with d-glucoheptono-1,4-lactone. The physicochemical properties of the conjugates—size, ζ potential in lysosomal pH 5 and in neutral aqueous solutions, as well as intramolecular dynamics by differential scanning calorimetry—were determined. Internalization and toxicity of the conjugates against normal human fibroblasts BJ were monitored in vitro in order to select an appropriate carrier for a drug delivery system. It was found that initial glucoheptoamidation (up to 1/3 of amine groups of neat dendrimers available) resulted in increase of conjugate size and ζ potential. Native or low substituted dendrimer conjugates accumulated efficiently in fibroblast cells at nontoxic 1 µM concentration. Further substitution of dendrimer caused consistent decrease of size and ζ potential, cell accumulation, and toxicity. All dendrimers are amorphous at 36.6 °C as determined by differential scanning calorimetry (DSC). The optimized dendrimer, half-filled with glucoheptoamide substituents, was applied as carrier bearing two covalently attached cytisine molecules: a rigid and hydrophobic alkaloid. The conjugate with 2 cytisine and 16 glucoheptoamide substituents showed fast accumulation and no toxicity up to 200 µM concentration. The half-glucoheptoamidated PAMAM dendrimer was selected as a promising anticancer drug carrier for further applications.

scholarly journals In Vitro Corrosion Behavior of Lingual Orthodontic Archwires

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Carlos Suárez ◽  
Teresa Vilar ◽  
Pablo Sevilla ◽  
Javier Gil
Keyword(s):  
Differential Scanning Calorimetry ◽  
Stainless Steel ◽  
Rhombohedral Phase ◽  
Nickel Titanium ◽  
Scanning Calorimetry ◽  
Lingual Orthodontics ◽  
Phase Transition Temperatures ◽  
Different Types ◽  
Orthodontic Archwires

Objectives. To investigate the in vitro electrochemical corrosive behavior of archwires used in lingual orthodontics and the effects on the phase transition temperatures.Materials and Methods. Six different types of archwires of stainless steel, titanium-molybdenum, nickel-titanium and nickel-titanium-copper were used. Corrosion tests were performed following ISO-standard 10993-15:2000. Differential scanning calorimetry and scanning electron microscopy were used.Results. The stainless steel archwires showed anEpitaround −600 mV, and those of titanium alloys showedEpitvalues around 1000 mV. Differential scanning calorimetry detected a rhombohedral phase in nickel-titanium archwires, while it was not detected in nickel-titanium-copper wires. A difference of 2°C to 3.5°C from the manufacturer's claim was found in the as-received and polarized samples, respectively.Conclusions. The 0.016 stainless steel archwires were found to be the less resistant to corrosion. A rhombohedral phase was detected on the nickel-titanium archwires. No major differences were observed among groups concerning phase transformation temperatures.

scholarly journals Preparation and characterization of baicalein loaded phytosomes: Assessment of in vitro parameters

2020 ◽  
Vol 12 (4) ◽  
pp. 22-29
Author(s):  
KanchanV Zade ◽  
Alok Pal Jain
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Herbal Extracts ◽  
Scanning Calorimetry ◽  
Reverse Phase ◽  
Tem Analysis ◽  
Transmission Electron

Phytosome is a complex between natural active ingredient and a phospholipid. Further, phytosomes been applied to many popular herbal extracts or active molecules for augmenting oral dissolution. Therefore, in present investigation, orally administered Baicalein, atype of flavanoids, is poorly absorbed, and shows suboptimal dissolution. The phytosomes encapsulating baicalein (1:1 Mm) were prepared by reverse phase evaporation method followed by lyophilization. Transmission electron microscopy (TEM) analysis revealed that phytosomes were almost spherical in shape with particle size below 100 nm. The Powder ex-ray diffraction (PXRD) and differential scanning calorimetry (DSC) demonstrated that Baicalein loaded phytosomes were amorphous in nature. Amorphization of therapeutic moiety leads to improvement in dissolution. In conclusion, epigallocatechin loaded phytosomes exhibited promising results and warrant further in vitro andin vivo investigations under a set of stringent parameters for transforming in to a clinically viable products.

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