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Emulsion electrospinning – method to introduce proteins for biomedical applications

Kurpanik Roksana, Rapacz-Kmita Alicja, Ścisłowska-Czarnecka Anna, Stodolak-Zych Ewa

Engineering of Biomaterials

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2021

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Vol. 24, no. 162

20--25

EN

The aim of this work was to obtain polymer fibers by the emulsion electrospinning. For this purpose, polycaprolactone (PCL) was used, which was modified before the electrospinning stage with micelles obtained by the oil-in-water (O/W) emulsion method. Micelles were obtained by combining the non-ionic surfactant Tween 80 or Triton X-100 used at different concentrations with the amino acid alanine. The obtained fibrous substrates had a typical unimodal fiber size distribution and their average size was in the range of 590-800 nm. The effectiveness of the emulsion electrospinning process was confirmed by Fourier Transform Infrared Spectroscopy - Attenuated Total Reflectance (FTIR-ATR) showing the presence of surfactants. The addition of micelles to the polymer solution significantly reduces the contact angle of nonwoven fabrics: from 120° (for PCL) to ~20-30° for surfactant-loaded nonwovens, and the micellar form allows tracking the release of alanine into the solution (UV-Vis). The combination of the core-shell- -morphology of the emulsion electrospun fibers allows comparable amino acid release times. There were no significant differences in both the amount of alanine released and the rate of its release between PCL/ Tween80/alanine and PCL/Triton X-100/alanine fibers, which were characterized by a similar fiber size.

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Application of alanine dosimetry in dose assessment for ocular melanoma patients undergoing proton radiotherapy : preliminary results

Mierzwińska G., Kłodowska M., Michalec B., Pędracka A., Rydygier M., Swakoń J., Waligórski M. P. R.

Nukleonika

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2015

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Vol. 60, No. 3, part 2

609--613

EN

Basing on alanine solid state/electron paramagnetic resonance (EPR) dosimetry, a supplementary method of cumulatively recording the therapeutic dose received by ocular cancer patients undergoing fractionated proton radiotherapy is proposed. By applying alanine dosimetry during the delivery of consecutive fractions, the dose received within each fraction can be read out by EPR spectrometry and a fi nal permanent cumulative record of the total dose delivered obtained. The dose response of the alanine detector was found to be practically independent on its position within the extended proton Bragg peak region. Dose measurements based on entrance dose recorded in proton beams individually formed for each patient are presented. The described method will be applied as a complementary Quality Assurance procedure for patients undergoing proton radiotherapy at the Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland (IFJ PAN).

3

Taurine-EVA copolymer-paraffin rods dosimeters for EPR high-dose radiation dosimetr

Maghraby A. M., Mansour A., Abdel-Fattah A. A.

Nukleonika

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2014

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Vol. 59, No. 1

9--13

EN

Taurine/EPR rods (3 × 10 mm) have been prepared by a simple technique in the laboratory where taurine powder was mixed with a molten mixture of paraffin wax and an ethylene vinyl acetate (EVA) copolymer. The binding mixture EVA/Paraffin does not present interference or noise in the EPR signal before or after irradiation. The rods show good mechanical properties for safe and multi-use handling. An EPR investigation of radiation induced radicals in taurine rods revealed that there are two types of radicals produced after exposure to gamma radiation (60Co). EPR spectra were recorded and analyzed – also the microwave power saturation and modulation amplitude were studied and optimized. Response of taurine to different radiation doses (1.5–100 kGy) was studied and found to follow a linear relationship up to 100 kGy. Radiation induced radicals in taurine persists and showed a noticeable stability over 94 days following irradiation. Uncertainities associated with the evaluation of radiation doses using taurine dosimeters were discussed and tabulated. It was found that taurine possesses good dosimetric properties using EPR spectroscopy in high doses in addition to its simple spectrum.

4

Theoretical Inversion of Amino Acids (Alanine and Aspartic Acid) by Semi-empirical Methods

Mohamed M. E.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 7, iss. 1

37--44

EN

The inversion reaction coordinate of free amino acids (alanine, aspartic acid) have been computationally calculated by semi-empirical methods AM1. A transition state for free alanine and aspartic acid were obtained as a three membered ring in which the α-C-H and α-C-CH3 are slightly elongated, 1.2 and 2.17 Å respectively in the alanine transition state. The activation energy of alanine is 77.52 kcal/mol in the gas phase and 76.66 kcal/mol in aqueous phase, and for aspartic acid is 54.87 kcal/mol in the gas phase and 50.86 kcal/mol in aqueous phase.

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Alanine dosimetry of 60 MeV proton beam - preliminary results

Michalec B., Mierzwińska G., Sowa U., Ptaszkiewicz M., Nowak T., Swakoń J.

Nukleonika

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2012

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Vol. 57, No. 4

503-506

EN

Electron paramagnetic resonance (EPR) spectrometry (X-band) was used to determine the dose absorbed in alanine detectors, of different shapes and different alanine content, irradiated with Co-60 gamma rays and in a 60 MeV proton beam. The goal of our study was to confirm applicability of alanine as a passive detector in therapeutic proton beam. In the paper dose response characteristic and relative efficiency of alanine are shown. The study confirmed that alanine detectors with a high alanine content (ca. 95%) may be a useful and convenient tool for dose measurements in proton beams, used for eye cancer treatment.

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Aminoalkylphosphines, theWater-Soluble Chiral Phosphines

Smoleński P., Pruchnik F. P.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 10

1771-1771

EN

Chiral water-soluble heterocyclic phosphines 2,2',2''-[1,3,5-diazaphosphinane-1,3,5- triyltris(methyleneimino)]tripropanoic acid (1), 2,2',2''-[1,3,5-diazaphosphinane- 1,3,5-triyltris(methyleneimino)]tris(3-phenylpropanoic) acid (2) and 2,2',2''-[1,3,5-diazaphosphinane- 1,3,5-triyltris(methyleneimino)]tris(4-methylpentanoic) acid (3) were obtained in reactions of tris(hydroxymethyl)phosphine with chiral amino acids: alanine, phenylalanine and leucine. Course of reaction of amino acids depends on the acidity of solution, at pH 6mainly heterocyclic compounds were obtained, however in basic solutions products of Mannich-type condensation 2,2',2''-[phosphinetriyltris(methyleneimino)] tripropanoic acid (4), 2,2',2''-[phosphinetriyltris(methyleneimino)]tris(3-phenylpropanoic) acid (5) and 2,2',2''-[phosphinetriyltris(methyleneimino)]tris(4-methylpentanoic) acid (6) are formed. The prepared compounds were characterized using spectroscopic methods.

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Własności dielektryczne kryształów LATGS. Część I

Jasiński T.

Zeszyty Naukowe Politechniki Rzeszowskiej. Fizyka

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1998

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z. 7 [164]

35-45

PL

W pracy przedstawiono wyniki badań własności dielektrycznych kryształów siarczanu trójglicyny z domieszką L-α-alaniny w dwu piramidach wzrostu: (001) i (110). Stwierdzono, że domieszka L-α-alaniny wbudowuje się nierównomiernie do kryształu LATGS. Więcej domieszki znajduje się w piramidzie wzrostu (001) niż w piramidzie (110). Ponadto domieszka L-α-alaniny powoduje obniżenie wartości przenikalności elektrycznej ε, przesuniecie temperatury Curie Tc w stronę wyższych wartości temperatury oraz przesunięcie pętli histerezy dielektrycznej o wartości Eb.

EN

The results of research on dieleetric properties of triglycine sulphate crystals with L-α-alanine admixture in two growth piramids: (001) and (110) have been shown in this article. It has been proved that the L-α-alanine admixture builds uequally into the LATGS crystal. There is more admixture in the growth piramid (001) than in the piramid (110). Moreover, L-α-alanine admixture causes the decrease m permitivity ε, the shift of the Curie point towards higher temperatures, as well as the move of the dieleetric hysteresis loop o f Eb value.